Vehicle battery discharge allowable power limiting method and device, vehicle-mounted terminal and vehicle

Abstract

The invention provides a vehicle battery discharge allowable power limiting method and device, a vehicle-mounted terminal and a vehicle, and the method comprises the steps: obtaining the health state and aging state of a vehicle battery, and achieving the comprehensive monitoring of the performance of the battery, guaranteeing the safety of the battery, prolonging the service life of the battery, and optimizing the use basis of the battery; by calculating the working parameters of the battery and the voltage critical value of the battery cell, especially the predicted value under the condition of full-power use of the whole vehicle, compared with a traditional power implementation mode, the voltage of the battery cell can be prevented from being suddenly lowered to an undervoltage state, sudden failure of the battery is prevented, and therefore the reliability and safety of the vehicle are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle battery management, and in particular to a method and device for limiting the permissible discharge power of a vehicle battery, a vehicle-mounted terminal and a vehicle. Background Art

[0002] The estimation of the power battery discharge power SOP (state of power) is a key core algorithm of the battery management system. The correct use of discharge power affects the battery life. Improper use will cause the battery to over-discharge, affecting the vehicle's power and economy, etc.

[0003] Many SOP methods and algorithms have been published in the industry, but few are actually used in the whole vehicle. When the actual battery management system uses the strategy algorithm from the initial power value to the power target value, there are many considerations, such as: 1. Whether the battery has a fault that requires limiting the discharge power. If so, multiply the initial power value by the corresponding power limit coefficient to get the power target value; 2. Combined with the battery health state SOH, multiply the initial power value by the corresponding power limit coefficient to get the power target value, but the strategy algorithm from the initial power value to the power target value has the following problems: 1. When the whole vehicle uses the power target value, sudden acceleration may cause a sudden increase in discharge power, resulting in overvoltage of the battery cell; 2. Due to battery aging problems, the polarization internal resistance of the battery increases, and the SOH (state of health) and SOP estimation are inaccurate, resulting in battery undervoltage; 3. Considering the comfort of the whole vehicle, the rate of power reduction is too small, and the actual discharge power is large, resulting in the battery voltage being continuously pulled down; Summary of the invention

[0004] The present application provides a method, device and vehicle-mounted terminal for limiting the allowable discharge power of a vehicle battery to solve the above-mentioned technical problems.

[0005] A method for limiting the allowable discharge power of a vehicle battery provided in an embodiment of the present application includes: obtaining a vehicle battery status, wherein the vehicle battery status includes a battery health status and / or a battery aging status; detecting battery operating parameters corresponding to the vehicle battery status, and calculating a vehicle battery cell voltage critical value through the battery operating parameters, wherein the vehicle battery cell voltage critical value includes a battery cell voltage prediction value when the entire vehicle is used at full power; if the vehicle battery cell voltage critical value is less than a vehicle battery cell undervoltage threshold, increasing the rate of decrease of the vehicle battery voltage and reducing the allowable discharge power to limit the allowable discharge power of the vehicle battery.

[0006] In one embodiment of the present application, the battery operating parameters corresponding to the respective battery states of the vehicle are detected, and the critical value of the vehicle battery cell voltage is calculated through the battery operating parameters, including: in the battery health state, the battery operating parameters in the battery health state are detected, the battery operating parameters in the battery health state include the battery health operating current, the battery health battery internal resistance and the current battery voltage in the battery health state, and the critical value of the healthy battery cell voltage is calculated based on the battery health operating current, the battery health battery internal resistance and the current battery voltage in the battery health state; in the battery aging state, the battery operating parameters in the battery aging state are detected, the battery operating parameters in the battery aging state include the battery aging operating current, the current available power in the battery aging state and the current battery voltage in the battery aging state, and the critical value of the battery aging cell voltage is calculated based on the battery aging operating current, the current available power in the battery aging state and the current battery voltage in the battery aging state.

[0007] In one embodiment of the present application, a battery aging cell voltage critical value is calculated according to the battery aging working current, the current available power under the battery aging state, and the current battery voltage under the battery aging state, including: performing a lookup operation in an allowable current table generated in advance or in real time according to the battery aging state to obtain an allowable current, performing a lookup operation in a cell ohmic impedance table generated in advance or in real time according to the battery aging state to obtain a cell ohmic impedance; obtaining a vehicle battery aging voltage according to the allowable current, the battery aging working current, and the cell ohmic impedance; obtaining the battery aging cell voltage critical value according to the vehicle battery aging voltage, the current battery voltage under the battery aging state, and the current available power under the battery aging state.

[0008] In one embodiment of the present application, the battery aging cell voltage critical value is obtained according to the vehicle battery aging voltage, the current battery voltage in the battery aging state and the current available power in the battery aging state, including: calculating the predicted voltage drop of the current available power in the battery aging state within a preset time; subtracting the aging voltage from the current battery voltage in the battery aging state, and then subtracting the predicted voltage drop to obtain the battery aging cell voltage critical value.

[0009] In one embodiment of the present application, obtaining the vehicle battery aging voltage according to the allowable current, the battery aging working current and the battery cell ohmic impedance includes:

[0010] V 老化 =(I 许用 -I 实际 )×DCR

[0011] Among them, I许用 is the allowable current of the battery under aging condition, I 实际 is the battery aging working current, DCR: battery cell ohmic resistance.

[0012] In one embodiment of the present application, a healthy battery cell voltage critical value is calculated based on the battery healthy operating current, the battery healthy battery internal resistance and the current battery voltage in the battery healthy state, including: determining the product of the battery healthy operating current and the battery healthy battery internal resistance as a typical voltage drop; subtracting the typical voltage drop from the current battery voltage in the battery healthy state to obtain the healthy battery cell voltage critical value.

[0013] In one embodiment of the present application, after the critical value of the vehicle battery cell voltage is less than the vehicle battery cell undervoltage threshold, it also includes: sending a pre-start signal to the range extender control system; after the range extender control system receives the signal, starting the range extender for cooling to replenish energy for subsequent high-power demand of the vehicle.

[0014] The vehicle battery discharge allowable power limiting device provided in an embodiment of the present application comprises: a vehicle battery status acquisition module, used to acquire the vehicle battery status, wherein the vehicle battery status comprises a battery health status and / or a battery aging status; a battery operating parameter detection module, used to detect the battery operating parameters respectively corresponding to the vehicle battery status, and calculate the vehicle battery cell voltage critical value through the battery operating parameters, wherein the vehicle battery cell voltage critical value comprises a battery cell voltage prediction value when the whole vehicle is used at full power; an undervoltage detection module, used to increase the vehicle battery voltage drop rate and reduce the discharge allowable power if the vehicle battery cell voltage critical value is less than the vehicle battery cell undervoltage threshold value, so as to limit the vehicle battery discharge allowable power.

[0015] An embodiment of the present application provides a vehicle-mounted terminal, including a processor, a memory and a communication bus; the communication bus is used to connect the processor and the memory; the processor is used to execute a computer program stored in the memory to implement the above-mentioned vehicle battery discharge allowable power limitation method.

[0016] The beneficial effects of the present application are as follows: by obtaining the health status and aging status of the vehicle battery, the battery performance can be fully monitored to ensure battery safety, extend battery life and optimize the basis for battery use; by calculating the battery operating parameters and the critical value of the battery cell voltage, especially the predicted value when the vehicle is used at full power, compared with the traditional power realization method, it can prevent the battery cell voltage from being suddenly pulled down to an undervoltage state, prevent the battery from suddenly failing, thereby improving the reliability and safety of the vehicle.

[0017] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0019] Figure 1 is a flow chart of a method for limiting the discharge allowable power of a vehicle battery shown in an exemplary embodiment of the present application;

[0020] Figure 2 is a block diagram of a vehicle battery discharge allowable power limiting device shown in an exemplary embodiment of the present application;

[0021] Figure 3 It is a structural schematic diagram of a vehicle-mounted terminal shown in an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0022] The following will describe the implementation methods of the present application with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for illustrating the present application, not for limiting the scope of protection of the present application.

[0023] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application, and thus the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0024] In the following description, a large number of details are discussed to provide a more thorough explanation of the embodiments of the present application. However, it is obvious to those skilled in the art that the embodiments of the present application can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present application difficult to understand.

[0025] The embodiments of the present application respectively propose a method for limiting the allowable discharge power of a vehicle battery, a device for limiting the allowable discharge power of a vehicle battery, a vehicle-mounted terminal, and a vehicle. These embodiments will be described in detail below.

[0026] See also Figure 1 , Figure 1 FIG. 1 is a flow chart of a method for limiting the discharge allowable power of a vehicle battery according to an embodiment of the present application. Figure 1 As shown, the method at least includes steps S110 to S130, which are described in detail as follows:

[0027] Step S110, obtaining the vehicle battery status, where the vehicle battery status includes the battery health status and / or the battery aging status.

[0028] In one embodiment of the present application, the battery health state refers to the ratio of the maximum storage capacity of the battery to that of a new battery, usually expressed as a percentage, reflecting the actual current performance state of the battery, and the battery aging state refers to the phenomenon that the performance of the battery gradually decreases during use due to internal chemical reactions and external environmental factors.

[0029] Step S120, detecting the battery operating parameters corresponding to the vehicle battery state, and calculating the vehicle battery cell voltage critical value through the battery operating parameters, wherein the vehicle battery cell voltage critical value includes the battery cell voltage prediction value when the vehicle is used at full power.

[0030] Step S130 , if the critical value of the vehicle battery cell voltage is less than the vehicle battery cell undervoltage threshold, the rate of decrease of the vehicle battery voltage is increased, and the discharge allowable power is reduced to limit the discharge allowable power of the vehicle battery.

[0031] As an example, when the critical value of the battery aging cell voltage is lower than the set vehicle battery cell undervoltage threshold, the BMS (battery management system) controls the discharge SOP to start limiting in advance, reducing the limited power to 80% (calibrated value) of the original SOP. After limiting the power, the undervoltage problem will be greatly reduced even during sudden acceleration.

[0032] In one embodiment of the present application, when the calculated critical value of the battery cell voltage is lower than the preset undervoltage threshold, it indicates that the battery may not be able to withstand the current discharge rate or power requirement. At this time, the battery discharge strategy is dynamically adjusted by increasing the battery voltage drop rate and reducing the discharge allowable power. This adjustment can protect the battery from damage caused by excessive discharge while ensuring that the vehicle can still operate within a safe power range.

[0033] exist Figure 1In the technical solution shown, by obtaining the health status and aging status of the vehicle battery, the battery performance can be fully monitored to ensure battery safety, extend battery life and optimize the basis for battery use. By calculating the battery operating parameters and the critical value of the battery cell voltage, especially the predicted value when the whole vehicle is used at full power, compared with the traditional power implementation method, it can prevent the battery cell voltage from being suddenly pulled down to an undervoltage state, prevent the battery from suddenly failing, thereby improving the reliability and safety of the vehicle.

[0034] In one embodiment of the present application, the battery operating parameters corresponding to the vehicle battery state are detected, and the critical value of the battery cell voltage of the vehicle battery is calculated through the battery operating parameters, including: in the battery health state, the battery operating parameters in the battery health state are detected, the battery operating parameters in the battery health state include the battery health working current, the battery health battery internal resistance and the current battery voltage in the battery health state, and the critical value of the healthy battery cell voltage is calculated according to the battery health working current, the battery health battery internal resistance and the current battery voltage in the battery health state; in the battery aging state, the battery operating parameters in the battery aging state are detected, the battery operating parameters in the battery aging state include the battery aging working current, the current available power in the battery aging state and the current battery voltage in the battery aging state, and the critical value of the battery aging cell voltage is calculated according to the battery aging working current, the current available power in the battery aging state and the current battery voltage in the battery aging state. By obtaining the health state and aging state of the vehicle battery, comprehensive monitoring of battery performance is achieved. This is the basis for ensuring battery safety, extending battery life and optimizing battery use.

[0035] In one embodiment of the present application, the critical value of the battery aging cell voltage is calculated according to the battery aging working current, the current available power under the battery aging state, and the current battery voltage under the battery aging state, including: performing a search operation in a pre- or real-time generated allowable current table according to the battery aging state to obtain the allowable current, performing a search operation in a pre- or real-time generated cell ohmic impedance table according to the battery aging state to obtain the cell ohmic impedance; obtaining the vehicle battery aging voltage according to the allowable current, the battery aging working current, and the cell ohmic impedance; obtaining the critical value of the battery aging cell voltage according to the vehicle battery aging voltage, the current battery voltage under the battery aging state, and the current available power under the battery aging state. By searching in the pre- or real-time generated allowable current table according to the battery aging state, it is possible to ensure that the battery operates within a safe range and avoid safety risks such as thermal runaway and short circuit caused by overcurrent. By searching the cell ohmic impedance table, the internal resistance information of the current battery can be accurately obtained, which is crucial for accurately controlling the battery charging and discharging process and improving the energy conversion efficiency. At the same time, combined with the allowable current, the battery charging and discharging behavior can be more effectively managed to extend the battery life. By combining the allowable current, battery aging operating current and cell ohmic impedance, the voltage of the vehicle battery in the aging state can be accurately calculated, which can more accurately evaluate the actual performance of the battery and provide data support for subsequent battery management.

[0036] In one embodiment of the present application, the critical value of the battery aging cell voltage is obtained according to the aging voltage of the vehicle battery, the current battery voltage in the battery aging state, and the current available power in the battery aging state, including: calculating the predicted voltage drop of the current available power in the battery aging state within a preset time; subtracting the aging voltage from the current battery voltage in the battery aging state, and then subtracting the predicted voltage drop to obtain the critical value of the battery aging cell voltage. By calculating the predicted voltage drop of the current available power in the battery aging state within a preset time, the voltage change of the battery in the future period can be more accurately predicted, so that the battery management system can adjust the charging and discharging strategy more timely to avoid performance degradation or safety risks caused by too low or too high voltage. By subtracting the aging voltage and the predicted voltage drop from the current battery voltage in the battery aging state, the critical value of the battery aging cell voltage is obtained. When the critical value of the battery aging cell voltage is close to or lower than the undervoltage threshold, undervoltage prevention measures are triggered, such as reducing the discharge power, starting charging, etc., to optimize the battery usage strategy.

[0037] As an example, the predicted voltage drop of the current available power in the battery aging state within a preset time is calculated, including:

[0038] V 预测电压降 =ΔT×ΔV

[0039] Where: ΔT is the predicted time, which can be calibrated and adjusted; ΔV is the voltage drop within the predicted time according to the current power usage, V 预测电压降 To predict voltage drop. By calculating the predicted voltage drop of the current available power in the preset time under the battery aging state, the voltage change of the battery in the future can be more accurately predicted, so that the battery management system can adjust the charging and discharging strategy more timely to avoid performance degradation or safety risks caused by too low or too high voltage.

[0040] In one embodiment of the present application, the vehicle battery aging voltage is obtained according to the allowable current, the battery aging working current and the cell ohmic impedance, including:

[0041] V 老化 =(I 许用 -I 实际 )×DCR

[0042] Among them, I 许用 is the allowable current of the battery under aging condition, I 实际 The DCR is the ohmic resistance of the battery cell. Compared with the traditional discharge power control method, which does not combine the DCR of the battery aging, when the battery cell is aged, the battery cell voltage is rapidly pulled down when encountering high-power discharge, and the voltage cannot be effectively controlled. This solution takes the discharge DCR into consideration and predicts the maximum power. If the undervoltage risk is found, the power will be limited in advance to avoid the undervoltage risk.

[0043] In one embodiment of the present application, a healthy battery cell voltage critical value is calculated based on the battery healthy operating current, the battery healthy battery internal resistance and the current battery voltage in a healthy battery state, including: determining the product of the battery healthy operating current and the battery healthy battery internal resistance as a typical voltage drop; subtracting the typical voltage drop from the current battery voltage in a healthy battery state to obtain the healthy battery cell voltage critical value.

[0044] In one embodiment of the present application, after the critical value of the vehicle battery cell voltage is less than the vehicle battery cell undervoltage threshold, it also includes: sending a pre-start signal to the range extender control system; after the range extender control system receives the signal, starting the range extender to cool down and replenish energy for the vehicle's subsequent high power demand.

[0045] As an example, once the BMS determines that there is an undervoltage risk, it immediately sends a pre-start signal to the range extender control system. After receiving the signal, the range extender control system starts the range extender for cooling, that is, it runs the range extender without generating additional load to achieve preheating and preparation status. During the cooling process, the range extender should run at a lower speed and power to reduce energy consumption and noise. At the same time, the range extender control system should monitor the operating status of the range extender and the voltage changes of the battery cells in real time to ensure that the cooling process does not cause additional burden on the battery. When high power output is required (such as acceleration, climbing and other working conditions), the range extender should respond quickly and increase the output power to supplement the battery power. The BMS system should dynamically adjust the output power of the range extender and the discharge power of the battery according to the voltage, current and other parameters of the battery cell to ensure that the battery cell voltage is always kept within a safe range. The BMS system should monitor the power demand of the whole vehicle in real time, and reasonably allocate and manage the power of the whole vehicle according to the voltage, current, temperature and other parameters of the battery cell and the output power of the range extender. Under the premise of ensuring the safety of battery cell voltage, the power output and endurance of the vehicle should be increased as much as possible.

[0046] Figure 2 FIG. 1 is a block diagram of a vehicle battery discharge allowable power limiting device according to an exemplary embodiment of the present application. Figure 2 As shown, according to an embodiment of the present application, a vehicle battery discharge allowable power limiting device 200 includes: a vehicle battery state acquisition module 210, a battery operating parameter detection module 220 and an undervoltage detection module 230. The vehicle battery state acquisition module is used to acquire the vehicle battery state, and the vehicle battery state includes the battery health state and / or the battery aging state; the battery operating parameter detection module is used to detect the battery operating parameters corresponding to the vehicle battery state, and calculate the vehicle battery cell voltage critical value through the battery operating parameters, and the vehicle battery cell voltage critical value includes the battery cell voltage prediction value when the whole vehicle is used at full power; the undervoltage detection module is used to increase the vehicle battery voltage drop rate and reduce the discharge allowable power if the vehicle battery cell voltage critical value is less than the vehicle battery cell undervoltage threshold, so as to limit the vehicle battery discharge allowable power. By obtaining the health status and aging status of the vehicle battery, it is possible to comprehensively monitor the battery performance, ensure battery safety, extend battery life and optimize battery use. By calculating the battery operating parameters and the critical value of the battery cell voltage, especially the predicted value when the vehicle is used at full power, compared with the traditional power implementation method, it is possible to prevent the battery cell voltage from being suddenly lowered to an undervoltage state and prevent sudden battery failure, thereby improving the reliability and safety of the vehicle.

[0047] In one embodiment of the present application, the battery operating parameter detection module 220 is used to detect the battery operating parameters in the battery health state when the battery is in a healthy state, and the battery operating parameters in the battery health state include the battery health operating current, the battery health battery internal resistance and the current battery voltage in the battery health state, and calculate the healthy battery cell voltage critical value according to the battery health operating current, the battery health battery internal resistance and the current battery voltage in the battery health state; in the battery aging state, detect the battery operating parameters in the battery aging state, and the battery operating parameters in the battery aging state include the battery aging operating current, the current available power in the battery aging state and the current battery voltage in the battery aging state, and calculate the battery aging cell voltage critical value according to the battery aging operating current, the current available power in the battery aging state and the current battery voltage in the battery aging state. By obtaining the health state and aging state of the vehicle battery, comprehensive monitoring of battery performance is achieved. This is the basis for ensuring battery safety, extending battery life and optimizing battery use.

[0048] In one embodiment of the present application, the vehicle battery discharge allowable power limiting device also includes a calculation module 240, which is used to perform a search operation in a pre- or real-time generated allowable current table according to the battery aging state to obtain the allowable current, and perform a search operation in a pre- or real-time generated battery cell ohmic impedance table according to the battery aging state to obtain the battery cell ohmic impedance; obtain the vehicle battery aging voltage according to the allowable current, the battery aging working current and the battery cell ohmic impedance; obtain the battery aging battery cell voltage critical value according to the vehicle battery aging voltage, the current battery voltage under the battery aging state and the current available power under the battery aging state. By searching in the pre- or real-time generated allowable current table according to the battery aging state, it can be ensured that the battery operates within a safe range to avoid safety risks such as thermal runaway and short circuit caused by overcurrent. By searching the battery cell ohmic impedance table, the internal resistance information of the current battery can be accurately obtained, which is crucial for accurately controlling the battery charging and discharging process and improving the energy conversion efficiency. At the same time, combined with the allowable current, the battery charging and discharging behavior can be more effectively managed and the battery life can be extended. By combining the allowable current, battery aging operating current and cell ohmic impedance, the voltage of the vehicle battery in the aging state can be accurately calculated, which can more accurately evaluate the actual performance of the battery and provide data support for subsequent battery management.

[0049] In one embodiment of the present application, the calculation module is used to calculate the predicted voltage drop of the current available power in the battery aging state within a preset time; the current battery voltage in the battery aging state is subtracted from the aging voltage, and then the predicted voltage drop is subtracted to obtain the critical value of the battery aging cell voltage. By calculating the predicted voltage drop of the current available power in the battery aging state within a preset time, the voltage change of the battery in the future period can be more accurately predicted, so that the battery management system can adjust the charging and discharging strategy more timely to avoid performance degradation or safety risks caused by too low or too high voltage. By subtracting the aging voltage and the predicted voltage drop from the current battery voltage in the battery aging state, the critical value of the battery aging cell voltage is obtained. When the critical value of the battery aging cell voltage is close to or lower than the undervoltage threshold, undervoltage prevention measures are triggered, such as reducing the discharge power, starting charging, etc., to optimize the battery usage strategy.

[0050] In one embodiment of the present application, the calculation module is used to obtain the vehicle battery aging voltage according to the allowable current, the battery aging working current and the cell ohmic impedance:

[0051] V 老化 =(I 许用 -I 实际 )×DCR

[0052] Among them, I 许用 is the allowable current of the battery under aging condition, I 实际 is the working current of the battery aging, DCR: the ohmic resistance of the battery cell. By calculating the predicted voltage drop of the current available power in the preset time under the battery aging state, the voltage change of the battery in the future can be more accurately predicted, so that the battery management system can adjust the charging and discharging strategy more timely to avoid performance degradation or safety risks caused by too low or too high voltage.

[0053] In one embodiment of the present application, the calculation module is used to determine the product of the healthy working current of the battery and the healthy internal resistance of the battery as the typical voltage drop; subtract the typical voltage drop from the current battery voltage in the healthy state of the battery to obtain the critical value of the healthy battery cell voltage.

[0054] In one embodiment of the present application, the undervoltage detection module is used to send a pre-start signal to the range extender control system; after receiving the signal, the range extender control system starts the range extender to cool down and replenish energy for the subsequent high power demand of the vehicle.

[0055] As an example, once the BMS determines that there is an undervoltage risk, it immediately sends a pre-start signal to the range extender control system. After receiving the signal, the range extender control system starts the range extender for cooling, that is, it runs the range extender without generating additional load to achieve preheating and preparation status. During the cooling process, the range extender should run at a lower speed and power to reduce energy consumption and noise. At the same time, the range extender control system should monitor the operating status of the range extender and the voltage changes of the battery cells in real time to ensure that the cooling process does not cause additional burden on the battery. When high power output is required (such as acceleration, climbing and other working conditions), the range extender should respond quickly and increase the output power to supplement the battery power. The BMS system should dynamically adjust the output power of the range extender and the discharge power of the battery according to the voltage, current and other parameters of the battery cell to ensure that the battery cell voltage is always kept within a safe range. The BMS system should monitor the power demand of the whole vehicle in real time, and reasonably allocate and manage the power of the whole vehicle according to the voltage, current, temperature and other parameters of the battery cell and the output power of the range extender. Under the premise of ensuring the safety of battery cell voltage, the power output and endurance of the vehicle should be increased as much as possible.

[0056] It should be noted that the device provided in the above embodiment and the method provided in the above embodiment belong to the same concept, wherein the specific manner in which each module and unit performs the operation has been described in detail in the method embodiment, and will not be repeated here. In practical applications, the device provided in the above embodiment can distribute the above functions to different functional modules as needed, that is, divide the internal structure of the device into different functional modules to complete all or part of the functions described above, and this is not limited here.

[0057] See also Figure 3 , Figure 3 is a schematic diagram of a vehicle-mounted terminal according to an exemplary embodiment of the present application. It should be noted that: Figure 3 The vehicle-mounted terminal 300 shown is only an example and should not bring any limitation to the functions and usage area of ​​the embodiments of the present application.

[0058] like Figure 3 As shown, the vehicle terminal 300 includes a processor 301, a memory 302 and a communication bus 303; the communication bus 303 is used to connect the processor 301 and the memory 302; the processor 301 is used to execute the computer program stored in the memory 302 to implement one or more methods in the above embodiments.

[0059] The vehicle-mounted terminal provided in the present application includes a processor, a memory, a transceiver and a communication interface. The memory and the communication interface are connected to the processor and the transceiver and complete communication with each other. The memory is used to store computer programs, the communication interface is used to communicate, and the processor and the transceiver are used to run computer programs so that the electronic device executes the various steps of the above method.

[0060] In this embodiment, the memory may include a random access memory (RAM), and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0061] The above-mentioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0062] The above embodiments are merely illustrative of the principles and effects of the present application, and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A method for limiting the permissible discharge power of a vehicle battery, characterized in that: The method comprises: Acquiring a vehicle battery status, wherein the vehicle battery status includes a battery health status and / or a battery aging status; Detecting battery operating parameters corresponding to the respective battery states of the vehicle, and calculating a critical value of a battery cell voltage of the vehicle according to the battery operating parameters, wherein the critical value of a battery cell voltage of the vehicle includes a predicted value of a battery cell voltage when the vehicle is used at full power; If the critical value of the vehicle battery cell voltage is less than the vehicle battery cell undervoltage threshold, the rate of decrease of the vehicle battery voltage is increased and the discharge allowable power is reduced to limit the discharge allowable power of the vehicle battery.

2. The method for limiting the allowable discharge power of a vehicle battery according to claim 1, characterized in that: Detecting the battery operating parameters corresponding to the vehicle battery state, and calculating the critical value of the vehicle battery cell voltage according to the battery operating parameters, including: In the battery health state, detecting battery operating parameters in the battery health state, the battery operating parameters in the battery health state including battery health operating current, battery health battery internal resistance and current battery voltage in the battery health state, and calculating a healthy battery cell voltage critical value according to the battery health operating current, the battery health battery internal resistance and the current battery voltage in the battery health state; In the battery aging state, battery operating parameters in the battery aging state are detected, the battery operating parameters in the battery aging state include battery aging operating current, current available power in the battery aging state and current battery voltage in the battery aging state, and a battery aging cell voltage critical value is calculated based on the battery aging operating current, the current available power in the battery aging state and the current battery voltage in the battery aging state.

3. The method for limiting the allowable discharge power of a vehicle battery according to claim 2, characterized in that: Calculating a critical value of a battery aging cell voltage according to the battery aging working current, the current available power in the battery aging state, and the current battery voltage in the battery aging state includes: Performing a search operation in a pre- or real-time generated allowable current table according to the battery aging state to obtain the allowable current, and performing a search operation in a pre- or real-time generated battery cell ohmic impedance table according to the battery aging state to obtain the battery cell ohmic impedance; Obtaining a vehicle battery aging voltage according to the allowable current, the battery aging operating current and the battery cell ohmic impedance; The battery aging cell voltage critical value is obtained according to the vehicle battery aging voltage, the current battery voltage in the battery aging state, and the current available power in the battery aging state.

4. The method for limiting the allowable discharge power of a vehicle battery according to claim 3, characterized in that: The battery aging cell voltage critical value is obtained according to the vehicle battery aging voltage, the current battery voltage in the battery aging state, and the current available power in the battery aging state, including: Calculating a predicted voltage drop of the current available power of the battery in an aging state within a preset time; The current battery voltage in the battery aging state is subtracted from the aging voltage, and then subtracted from the predicted voltage drop to obtain the critical value of the battery aging cell voltage.

5. The method for limiting the allowable discharge power of a vehicle battery according to claim 3, characterized in that: Obtaining a vehicle battery aging voltage according to the allowable current, the battery aging working current and the battery cell ohmic impedance includes: V 老化 =(I 许用 -I 实际 )×DCR Among them, I 许用 is the allowable current of the battery under aging condition, I 实际 is the battery aging working current, DCR: battery cell ohmic resistance.

6. The method for limiting the allowable discharge power of a vehicle battery according to claim 2, characterized in that: Calculating a healthy battery cell voltage critical value according to the healthy working current of the battery, the healthy battery internal resistance of the battery, and the current battery voltage in the healthy state of the battery, including: determining a product of the healthy operating current of the battery and the healthy battery internal resistance of the battery as a typical voltage drop; The typical voltage drop is subtracted from the current battery voltage in the battery health state to obtain a healthy battery cell voltage critical value.

7. The method for limiting the allowable discharge power of a vehicle battery according to claim 1, characterized in that: After the critical value of the vehicle battery cell voltage is less than the vehicle battery cell undervoltage threshold, the method further includes: Sending a pre-start signal to the range extender control system; After receiving the signal, the range extender control system starts the range extender to cool down and replenish energy for the vehicle's subsequent high-power demand.

8. A vehicle battery discharge allowable power limiting device, characterized in that: The device comprises: A vehicle battery status acquisition module, used to acquire the vehicle battery status, wherein the vehicle battery status includes a battery health status and / or a battery aging status; A battery operating parameter detection module, used to detect the battery operating parameters corresponding to the vehicle battery state, and calculate the vehicle battery cell voltage critical value through the battery operating parameters, wherein the vehicle battery cell voltage critical value includes the battery cell voltage prediction value when the vehicle is used at full power; The undervoltage detection module is used to increase the rate of decrease of the vehicle battery voltage and reduce the discharge allowable power if the critical value of the vehicle battery cell voltage is less than the vehicle battery cell undervoltage threshold value, so as to limit the discharge allowable power of the vehicle battery.

9. A vehicle-mounted terminal, characterized in that: It comprises a processor, a memory and a communication bus; the communication bus is used to connect the processor and the memory; the processor is used to execute a computer program stored in the memory to implement the vehicle battery discharge allowable power limitation method as described in any one of claims 1 to 7.

10. A vehicle, characterized in that: It includes the vehicle battery discharge allowable power limiting device as described in claim 8 or the vehicle-mounted terminal as described in claim 9.

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