Discharge allowable power control method, device, vehicle and medium for power battery

Abstract

The present invention relates to the technical field of power batteries, and in particular to a method, device, vehicle and medium for controlling discharge allowable power, which includes: obtaining the lowest cell voltage of the power battery at the current moment; if the lowest cell voltage of the power battery at the current moment is less than a preset undervoltage threshold, obtaining the actual discharge power of the power battery at the moment when the lowest cell voltage of the power battery begins to be less than the preset undervoltage threshold, and the lowest cell voltage of the power battery at the previous moment; according to the lowest cell voltage of the power battery at the current moment and the lowest cell voltage of the power battery at the previous moment, calculating the voltage change trend and voltage change amount of the lowest cell voltage of the power battery, thereby determining the target change rate of the discharge allowable power of the power battery at the current moment; controlling the discharge allowable power of the power battery according to the actual discharge power and the target change rate. Thus, the problems of power limitation caused by over-discharge of the battery in the prior art and sudden change of vehicle power are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power batteries, and in particular to a method, device, vehicle and medium for controlling the discharge allowable power of a power battery. Background Art

[0002] With the advancement of new energy vehicle technology, the cost-effectiveness of batteries has improved, but their output capacity is close to the limit. When the battery's discharge allowable power cannot meet actual needs, the risk of over-discharge increases, leading to vehicle power system failure. Currently, power is mainly controlled by SOC (State of Charge) and temperature, but the SOC estimation accuracy is limited, which may cause the battery discharge allowable power obtained by table lookup to be inaccurate, and the actual power exceeds the load capacity, triggering undervoltage protection and power limitation, and ultimately leading to power failure and safety issues.

[0003] In the related art, publication number CN115230533A proposed a power control strategy and control system for a power battery system undervoltage. This power limiting method has the risk of battery over-discharge and does not consider the recovery problem after power limiting. Publication number CN110967637A proposed a battery allowable power estimation method, device, system and storage medium. The actual current acquisition accuracy of the battery, the charge state value estimation accuracy and the accumulated charge and discharge power will affect the battery allowable power estimation result, thereby increasing the risk of battery over-discharge.

[0004] However, the pre-undervoltage power control and battery allowable power estimation in related technologies have the risk of battery over-discharge, which affects the battery's output capacity and may cause the vehicle to be unable to provide sufficient power when maximum power is required, affecting driving experience and safety. Summary of the invention

[0005] One of the purposes of the present invention is to provide a method for controlling the discharge allowable power of a power battery, so as to solve the problem in the prior art that in actual use of the power battery, if the discharge allowable power is higher than the actual capacity of the battery and is not effectively controlled, it will cause over-discharge of the battery, triggering rapid power limitation, and causing sudden change or loss of vehicle power; the second purpose is to provide a device for controlling the discharge allowable power of a power battery; the third purpose is to provide a vehicle; the fourth purpose is to provide a storage medium; the fifth purpose is to provide a program product.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A method for controlling the discharge allowable power of a power battery comprises: obtaining the lowest cell voltage of a power battery at a current moment; if the lowest cell voltage of the power battery at a current moment is less than a preset undervoltage threshold, obtaining the actual discharge power of the power battery at a moment when the lowest cell voltage of the power battery begins to be less than the preset undervoltage threshold, and the lowest cell voltage of the power battery at a previous moment; calculating the voltage change trend and the voltage change amount of the lowest cell voltage of the power battery according to the lowest cell voltage of the power battery at a current moment and the lowest cell voltage of the power battery at a previous moment, determining the target change rate of the discharge allowable power of the power battery at a current moment according to the voltage change trend and / or the voltage change amount; and controlling the discharge allowable power of the power battery according to the discharge actual power and the target change rate.

[0008] According to the above technical means, the embodiment of the present invention monitors the lowest single cell voltage of the power battery, and when the voltage is found to be lower than the preset undervoltage threshold, analyzes the voltage change trend and change amount, and adjusts the target change rate of the discharge allowable power accordingly, so that the discharge allowable power is highly matched with the actual discharge capacity of the power battery, thereby ensuring the vehicle power performance while avoiding the risk of excessive battery discharge. By accurately controlling the discharge allowable power of the power battery, it is possible to ensure that the vehicle can obtain stable power output under various working conditions, which not only improves the driving comfort and smoothness, allowing the driver to enjoy the fun of driving, but also in emergency or high-load conditions, the vehicle can respond quickly and provide sufficient power output, thereby significantly enhancing the safety and reliability of the entire vehicle.

[0009] Furthermore, the target change rate includes a target decrease rate, and the allowable discharge power of the power battery is controlled according to the actual discharge power and the target change rate, including: if the target change rate is the target decrease rate, the actual discharge power of the power battery at the moment when the lowest single cell voltage of the power battery starts to be less than a preset undervoltage threshold is taken as the starting point, and the allowable discharge power of the power battery is controlled to decrease according to the target decrease rate.

[0010] According to the above technical means, in the embodiment of the present invention, when the target change rate is the target decrease rate, the actual discharge power of the power battery at the moment when the lowest single cell voltage of the power battery begins to be less than the preset undervoltage threshold is taken as the starting point, and the discharge allowable power is controlled to decrease according to the target decrease rate. This can effectively control the discharge power of the battery, avoid over-discharge of the battery, and ensure that the battery can smoothly and safely reduce the discharge power when it is close to exhaustion, thereby extending the service life of the battery.

[0011] Further, the target change rate of the discharge allowable power of the power battery at the current moment is determined according to the voltage change trend and / or the voltage change amount, including: identifying whether the voltage change trend is a downward trend; if the voltage change trend is a downward trend, calculating the target decrease rate of the discharge allowable power of the power battery at the current moment according to the voltage change amount.

[0012] According to the above technical means, the embodiment of the present invention realizes fine control of the target change rate of the power battery discharge allowable power by identifying the voltage change trend. If the voltage change trend is a downward trend, the target decrease rate is calculated based on the voltage change amount, so that the discharge allowable power can be adjusted in time to slow down the discharge speed of the battery, ensuring that the battery maintains a stable and safe power output during the discharge process.

[0013] Further, the target decrease rate of the discharge allowable power of the power battery at the current moment is calculated according to the voltage change, including: obtaining a decrease rate correction coefficient of the discharge allowable power of the power battery; and calculating the target decrease rate according to the voltage change and the decrease rate correction coefficient.

[0014] According to the above technical means, the embodiment of the present invention introduces a descent rate correction coefficient, which can make a more refined adjustment to the target descent rate. The target descent rate is obtained according to the voltage change and the descent rate correction coefficient, and the change of the battery state is accurately responded to, thereby ensuring that the battery is discharged in the optimal manner and improving the energy utilization efficiency of the battery.

[0015] Furthermore, the descent rate correction coefficient is a linear equation, and the proportional coefficient and the offset in the linear equation are preset values.

[0016] According to the above technical means, the descent rate correction coefficient in the embodiment of the present invention is a linear equation used to dynamically adjust the rate of weight update, the proportional coefficient is a preset value, which is usually used to adjust the amplitude of power change, and the offset is a constant term used to adjust the output of the control algorithm. The embodiment of the present invention can achieve precise control of the discharge power of the power battery by reasonably setting the descent rate correction coefficient, proportional coefficient and offset, thereby ensuring the performance and safety of the battery under various working conditions.

[0017] Furthermore, the allowable discharge power of the power battery is controlled according to the actual discharge power and the target change rate, including: if the target change rate is the target rising rate, the allowable discharge power of the power battery at the moment when the lowest single cell voltage of the power battery starts to rise is taken as the starting point, and the allowable discharge power of the power battery is controlled to rise according to the target rising rate.

[0018] According to the above technical means, in an embodiment of the present invention, when the target change rate is the target rising rate, the discharge allowable power of the power battery at the moment when the lowest single cell voltage of the power battery starts to rise is taken as the starting point, and the discharge allowable power of the power battery is controlled to rise according to the target rising rate, so as to respond to the change of the battery state in time, quickly restore the discharge capacity of the battery, and improve the use efficiency of the battery.

[0019] Further, the target change rate of the discharge allowable power of the power battery at the current moment is determined according to the voltage change trend and / or the voltage change amount, including: identifying whether the voltage change trend is an upward trend; if the voltage change trend is an upward trend, the target increase rate of the discharge allowable power of the power battery at the current moment is a preset rate.

[0020] According to the above technical means, the embodiment of the present invention realizes fine control of the target change rate of the allowable discharge power of the power battery by identifying the voltage change trend. If the voltage change trend is an upward trend, the target increase rate of the allowable discharge power of the power battery at the current moment is a preset rate. By maintaining a certain allowable discharge power change rate, it can be ensured that the battery can stably return to a normal working state, while avoiding the risks that may be caused by sudden voltage changes.

[0021] Furthermore, before controlling the allowable discharge power of the power battery according to the actual discharge power and the target change rate, it also includes: identifying whether the lowest single cell voltage of the power battery at the current moment is less than the discharge cut-off voltage of the power battery, wherein the discharge cut-off voltage is less than a preset undervoltage threshold; if it is identified that the lowest single cell voltage of the power battery at the current moment is less than the discharge cut-off voltage of the power battery, discharging of the power battery is prohibited, otherwise, controlling the allowable discharge power of the power battery according to the actual discharge power and the target change rate.

[0022] According to the above technical means, the embodiment of the present invention can protect the safe discharge of the battery by identifying whether the lowest single cell voltage of the power battery at the current moment is less than the discharge cut-off voltage of the power battery. If it is identified that the lowest single cell voltage of the power battery at the current moment is lower than the discharge cut-off voltage, the power battery will be immediately prohibited from continuing to discharge for safety reasons, effectively protecting the battery, extending its service life, and ensuring the safety of the entire vehicle; otherwise, the discharge allowable power of the power battery is controlled according to the actual discharge power and the target change rate, ensuring that the battery maintains stable performance during the discharge process, avoiding an excessively fast discharge rate, and thus extending the battery life.

[0023] Furthermore, it also includes: if the lowest single cell voltage of the power battery at the current moment is greater than or equal to a preset undervoltage threshold, obtaining the maximum temperature and the minimum temperature of the power battery; and determining the discharge allowable power of the power battery according to the maximum temperature and the minimum temperature.

[0024] According to the above technical means, in the embodiment of the present invention, when the lowest single cell voltage of the power battery at the current moment is greater than or equal to the preset undervoltage threshold, the maximum temperature and the minimum temperature of the power battery are obtained to monitor the temperature distribution in real time, thereby reflecting the working state and health of the battery; the allowable discharge power of the power battery is determined according to the maximum temperature and the minimum temperature, so as to achieve precise control of the battery discharge process, balance the load between the single cells, and avoid over-discharge or under-discharge.

[0025] A device for controlling the discharge allowable power of a power battery comprises: a first acquisition module for acquiring the lowest cell voltage of a power battery at a current moment; a second acquisition module for acquiring, if the lowest cell voltage of the power battery at a current moment is less than a preset undervoltage threshold, the actual discharge power of the power battery at the moment when the lowest cell voltage of the power battery starts to be less than the preset undervoltage threshold, and the lowest cell voltage of the power battery at a previous moment; a first determination module for calculating the voltage change trend and the voltage change amount of the lowest cell voltage of the power battery according to the lowest cell voltage of the power battery at a current moment and the lowest cell voltage of the power battery at a previous moment, and determining the target change rate of the discharge allowable power of the power battery at a current moment according to the voltage change trend and / or the voltage change amount; and a control module for controlling the discharge allowable power of the power battery according to the discharge actual power and the target change rate.

[0026] Furthermore, the target change rate includes a target decrease rate, and the control module is also used to: if the target change rate is a target decrease rate, then taking the actual discharge power of the power battery at the moment when the lowest single cell voltage of the power battery starts to be less than a preset undervoltage threshold as the starting point, the discharge allowable power of the power battery is controlled to decrease according to the target decrease rate.

[0027] Furthermore, the first determination module is further used to: identify whether the voltage change trend is a downward trend; if the voltage change trend is a downward trend, calculate the target decrease rate of the discharge allowable power of the power battery at the current moment according to the voltage change amount.

[0028] Furthermore, the first determination module is further used to: obtain a decrease rate correction coefficient of the discharge allowable power of the power battery; and calculate a target decrease rate according to the voltage change and the decrease rate correction coefficient.

[0029] Furthermore, the descent rate correction coefficient is a linear equation, and the proportional coefficient and the offset in the linear equation are preset values.

[0030] Furthermore, the control module is also used for: if the target change rate is a target rising rate, taking the discharge allowable power of the power battery at the moment when the lowest cell voltage of the power battery starts to rise as a starting point, controlling the discharge allowable power of the power battery to rise according to the target rising rate.

[0031] Furthermore, the first determination module is further used to: identify whether the voltage change trend is an upward trend; if the voltage change trend is an upward trend, the target increase rate of the discharge allowable power of the power battery at the current moment is a preset rate.

[0032] Furthermore, it also includes: an identification module, which is used to identify whether the lowest single cell voltage of the power battery at the current moment is less than the discharge cut-off voltage of the power battery before controlling the discharge allowable power of the power battery according to the discharge actual power and the target change rate, wherein the discharge cut-off voltage is less than a preset undervoltage threshold; a control module, which is also used to prohibit the power battery from discharging if it is identified that the lowest single cell voltage of the power battery at the current moment is less than the discharge cut-off voltage of the power battery, otherwise, control the discharge allowable power of the power battery according to the discharge actual power and the target change rate.

[0033] Furthermore, it also includes: a second determination module, which is used to obtain the maximum temperature and the minimum temperature of the power battery if the lowest single cell voltage of the power battery at the current moment is greater than or equal to the preset undervoltage threshold; and determine the discharge allowable power of the power battery according to the maximum temperature and the minimum temperature.

[0034] A vehicle comprises: a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement a method for controlling the discharge allowable power of a power battery.

[0035] A computer-readable storage medium stores a computer program, which is executed by a processor to implement a method for controlling the discharge allowable power of a power battery.

[0036] A computer program is used to implement a method for controlling the discharge allowable power of a power battery when the computer program is executed.

[0037] The beneficial effects of the present invention include:

[0038] (1) The embodiment of the present invention monitors the lowest cell voltage of the power battery. When the voltage is found to be lower than the preset undervoltage threshold, the voltage change trend and change amount are analyzed, and the target change rate of the discharge allowable power is adjusted accordingly, so that the discharge allowable power is highly matched with the actual discharge capacity of the power battery, thereby ensuring the vehicle's power performance while avoiding the risk of excessive battery discharge. By accurately controlling the discharge allowable power of the power battery, it is possible to ensure that the vehicle can obtain stable power output under various working conditions, which not only improves the driving comfort and smoothness, allowing the driver to fully enjoy the fun of driving, but also allows the vehicle to respond quickly under emergency or high-load conditions and provide sufficient power output, thereby significantly enhancing the safety and reliability of the entire vehicle;

[0039] (2) In the embodiment of the present invention, when the target change rate is the target decrease rate, the actual discharge power of the power battery at the moment when the lowest cell voltage of the power battery begins to be less than the preset undervoltage threshold is taken as the starting point, and the discharge allowable power is controlled to decrease according to the target decrease rate. This can effectively control the discharge power of the battery, avoid over-discharge of the battery, and ensure that the discharge power of the battery can be smoothly and safely reduced when the battery is close to exhaustion, thereby extending the service life of the battery.

[0040] (3) The embodiment of the present invention realizes fine control of the target change rate of the power battery discharge allowable power by identifying the voltage change trend. If the voltage change trend is a downward trend, the target decrease rate is calculated according to the voltage change amount, so that the discharge allowable power can be adjusted in time to slow down the discharge speed of the battery, ensuring that the battery maintains a stable and safe power output during the discharge process;

[0041] (4) The embodiment of the present invention introduces a descent rate correction coefficient, which can make a more refined adjustment to the target descent rate. The target descent rate is obtained according to the voltage change and the descent rate correction coefficient, and the change of the battery state is accurately responded to, thereby ensuring that the battery is discharged in an optimal manner and improving the energy utilization efficiency of the battery.

[0042] (5) In the embodiment of the present invention, the descent rate correction coefficient is a linear equation used to dynamically adjust the rate of weight update, the proportional coefficient is a preset value, which is usually used to adjust the amplitude of power change, and the offset is a constant term used to adjust the output of the control algorithm. By reasonably setting the descent rate correction coefficient, the proportional coefficient and the offset, the embodiment of the present invention can achieve precise control of the power battery discharge power, thereby ensuring the performance and safety of the battery under various working conditions;

[0043] (6) In the embodiment of the present invention, when the target change rate is the target rising rate, the discharge allowable power of the power battery at the moment when the lowest cell voltage of the power battery starts to rise is taken as the starting point, and the discharge allowable power of the power battery is controlled to rise according to the target rising rate, so as to respond to the change of the battery state in a timely manner, quickly restore the discharge capacity of the battery, and improve the use efficiency of the battery;

[0044] (7) The embodiment of the present invention realizes fine control of the target change rate of the power battery discharge allowable power by identifying the voltage change trend. If the voltage change trend is an upward trend, the target increase rate of the power battery discharge allowable power at the current moment is a preset rate. By maintaining a certain discharge allowable power change rate, it can ensure that the battery can stably return to a normal working state, while avoiding the risks that may be caused by voltage mutation.

[0045] (8) The embodiment of the present invention can protect the safe discharge of the battery by identifying whether the lowest single cell voltage of the power battery at the current moment is less than the discharge cut-off voltage of the power battery. If it is identified that the lowest single cell voltage of the power battery at the current moment is lower than the discharge cut-off voltage, the power battery will be immediately prohibited from continuing to discharge for safety reasons, effectively protecting the battery, extending its service life, and ensuring the safety of the entire vehicle; otherwise, the discharge allowable power of the power battery is controlled according to the actual discharge power and the target change rate, ensuring that the battery maintains stable performance during the discharge process, avoiding an excessively fast discharge rate, and thus extending the battery life;

[0046] (9) When the lowest cell voltage of the power battery at the current moment is greater than or equal to the preset undervoltage threshold, the embodiment of the present invention can monitor the temperature distribution in real time by obtaining the maximum temperature and the minimum temperature of the power battery, thereby reflecting the working state and health of the battery; the allowable discharge power of the power battery is determined according to the maximum temperature and the minimum temperature, so as to achieve precise control of the battery discharge process, balance the load between the single cells, and avoid over-discharge or under-discharge.

[0047] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 A flow chart of a method for controlling discharge allowable power of a power battery provided by an embodiment of the present invention;

[0049] Figure 2 A schematic diagram of the discharge allowable power control principle of a power battery provided by an embodiment of the present invention;

[0050] Figure 3 A flow chart of a method for controlling discharge allowable power of a power battery provided by one embodiment of the present invention;

[0051] Figure 4 A block diagram of a discharge allowable power control device for a power battery provided by an embodiment of the present invention;

[0052] Figure 5 A schematic structural diagram of a vehicle provided in an embodiment of the present invention.

[0053] Among them, 1-minimum single cell voltage, 2-actual discharge power, 3-allowed discharge power, 4-power drop turning point a, 5-power increase turning point b, 6-battery minimum single cell voltage recovery point c, 7-preset undervoltage threshold d. DETAILED DESCRIPTION

[0054] The following will describe the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, 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 invention. It should be understood that the preferred embodiments are only for illustrating the present invention, not for limiting the scope of protection of the present invention.

[0055] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention 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 arbitrarily, and the component layout may also be more complicated.

[0056] As the cost-effectiveness of new energy vehicle power batteries continues to improve, their output capacity has gradually approached its limit. In this case, if the battery discharge allowable power is lower than the actual output capacity, it is very likely to cause excessive discharge of the battery, thereby causing power failure.

[0057] At present, the industry mainly sets the allowable power based on the current battery SOC (state of charge) and temperature by looking up the power MAP table. However, there is an obvious problem with this method: the accuracy of SOC estimation usually fluctuates within the range of 5% to 8%, and sometimes the deviation is even greater. Such estimation accuracy may cause the battery discharge allowable power obtained by looking up the table to be higher than the actual value. When this high allowable power exceeds the actual load capacity of the battery, the battery voltage may drop rapidly, triggering the undervoltage protection mechanism, which in turn greatly limits the battery power, causing vehicle power failure or even complete power loss, posing a serious threat to the safety of the vehicle.

[0058] In related technology 1, temperature, SOC value and cell voltage are taken into consideration, and the allowed discharge power is adjusted according to these parameters. When it is detected that the lowest cell voltage is lower than the preset pre-undervoltage threshold and the duration reaches the preset undervoltage protection time, the allowed discharge power will be reduced. However, if the actual power is much lower than the allowable power of the current battery, even if the pre-undervoltage threshold is triggered, the allowed power after limitation may still be higher than the actual power, thus posing a risk of over-discharging the battery. In addition, this strategy does not address the issue of recovery after power limitation.

[0059] In related technology 2, the battery's state of charge, temperature, operating data and hysteresis coefficient are taken into account. However, this method relies on the battery open circuit voltage estimation model, battery internal resistance, battery current state of charge and temperature, and cumulative charge and discharge capacity for estimation. Due to the influence of battery current acquisition accuracy, the accuracy of charge and discharge capacity may be affected. At the same time, the estimation accuracy of the state of charge value may also affect the query results of the battery internal resistance and allowable power, resulting in estimation deviation of the battery allowable power and increasing the risk of battery over-discharge.

[0060] Specifically, Figure 1 A schematic flow chart of a method for controlling discharge allowable power of a power battery provided in an embodiment of the present invention.

[0061] like Figure 1 As shown, the discharge allowable power control method of the power battery includes the following steps:

[0062] In step S101, the lowest cell voltage of the power battery at the current moment is obtained.

[0063] The lowest single cell voltage may be the single cell with the lowest voltage value at the current moment.

[0064] It can be understood that the embodiment of the present invention can understand the performance status of the battery in real time by monitoring the lowest single cell voltage of the power battery at the current moment, and promptly discover possible safety hazards of the battery, such as over-discharge of single cells, internal short circuit, etc., to prevent the battery from being damaged due to undervoltage and ensure the safety of the battery.

[0065] In step S102, if the lowest cell voltage of the power battery at the current moment is less than the preset undervoltage threshold, the actual discharge power of the power battery at the moment when the lowest cell voltage of the power battery starts to be less than the preset undervoltage threshold and the lowest cell voltage of the power battery at the previous moment are obtained.

[0066] The preset undervoltage threshold may be a minimum voltage limit value preset in order to protect the safety of the battery, and the actual discharge power may be the power actually output by the power battery.

[0067] It can be understood that in the embodiment of the present invention, when the lowest single cell voltage of the power battery at the current moment is less than the preset under-voltage threshold, by comparing the actual discharge power of the power battery at the moment when the lowest single cell voltage starts to be less than the preset under-voltage threshold, the rate of decline of battery performance can be determined, thereby detecting whether the battery has potential faults and avoiding battery damage due to over-discharge.

[0068] In an embodiment of the present invention, the method of the embodiment of the present invention also includes: if the lowest single cell voltage of the power battery at the current moment is greater than or equal to a preset undervoltage threshold, obtaining the maximum temperature and the minimum temperature of the power battery; determining the allowable discharge power of the power battery according to the maximum temperature and the minimum temperature.

[0069] It can be understood that, in the embodiment of the present invention, when the lowest single cell voltage of the power battery at the current moment is greater than or equal to the preset undervoltage threshold, the maximum temperature and the minimum temperature of the power battery are obtained to monitor the temperature distribution in real time, thereby reflecting the working state and health condition of the battery; the allowable discharge power of the power battery is determined according to the maximum temperature and the minimum temperature, so as to achieve precise control of the battery discharge process, balance the load between the single cells, and avoid over-discharge or under-discharge.

[0070] In step S103, the voltage change trend and voltage change amount of the lowest single cell voltage of the power battery are calculated according to the lowest single cell voltage of the power battery at the current moment and the lowest single cell voltage of the power battery at the previous moment, and the target change rate of the discharge allowable power of the power battery at the current moment is determined according to the voltage change trend and voltage change amount.

[0071] Among them, the voltage change trend can be the change direction of the lowest single cell voltage of the power battery over time, including a downward trend and an upward trend. The downward trend can be a process in which the voltage value is gradually decreasing, and the upward trend can be a process in which the voltage value is gradually increasing; the voltage change amount can be the difference between the lowest single cell voltage of the power battery between two adjacent moments; the target change rate of the allowable discharge power can be the maximum change speed allowed for the discharge power of the power battery.

[0072] It can be understood that the embodiments of the present invention can more accurately control the discharge process of the battery and realize adaptive discharge control by calculating the voltage change trend and voltage change amount of the lowest single cell voltage of the power battery and determining the target change rate of the discharge allowable power according to these parameters, thereby adapting to different usage scenarios and user needs, maximizing the use of battery energy, improving battery efficiency, and extending battery life.

[0073] In an embodiment of the present invention, the target change rate includes a target decrease rate and a target increase rate. The target change rate of the discharge allowable power of the power battery at the current moment is determined according to the voltage change trend and the voltage change amount, including: identifying whether the voltage change trend is a decrease trend or an increase trend; if the voltage change trend is a decrease trend, then calculating the target decrease rate of the discharge allowable power of the power battery at the current moment according to the voltage change amount; if the voltage change trend is an increase trend, then the target increase rate of the discharge allowable power of the power battery at the current moment is a preset rate.

[0074] Among them, the preset rate can be calibrated according to the actual vehicle conditions.

[0075] It is understandable that the embodiment of the present invention realizes fine control of the target change rate of the power battery discharge allowable power by identifying the voltage change trend. If the voltage change trend is a downward trend, the target decrease rate is calculated according to the voltage change amount, and the discharge allowable power can be adjusted in time to slow down the discharge speed of the battery, ensuring that the battery maintains a stable and safe power output during the discharge process. If the voltage change trend is an upward trend, the target increase rate of the power battery discharge allowable power at the current moment is a preset rate. By maintaining a certain discharge allowable power change rate, it can be ensured that the battery can stably return to a normal working state, while avoiding the risks that may be caused by voltage mutations.

[0076] In an embodiment of the present invention, the target decrease rate of the discharge allowable power of the power battery at the current moment is calculated according to the voltage change, including: obtaining a decrease rate correction coefficient of the discharge allowable power of the power battery; and calculating the target decrease rate according to the voltage change and the decrease rate correction coefficient.

[0077] Among them, the descent rate correction coefficient can be a linear equation, and the target descent rate r=A*dU+R, wherein dU can be the absolute value of the difference between the current single cell maximum voltage and the single cell maximum voltage at the previous moment, A can be the battery discharge power descent rate proportional coefficient, and R is the deviation. A and R can be specifically calibrated according to the actual vehicle.

[0078] It can be understood that the embodiment of the present invention introduces a descent rate correction coefficient, which can make a more refined adjustment to the target descent rate. The target descent rate is obtained according to the voltage change and the descent rate correction coefficient, and the change of the battery state is accurately responded to, thereby ensuring that the battery is discharged in an optimal manner and improving the energy utilization efficiency of the battery.

[0079] It should be noted that the setting of the descent rate correction coefficient is based on the proportional coefficient and the offset. By reasonably setting the descent rate correction coefficient, the proportional coefficient and the offset, precise control of the power battery discharge power can be achieved, thereby ensuring the performance and safety of the battery under various working conditions.

[0080] In step S104 , the discharge allowable power of the power battery is controlled according to the actual discharge power and the target change rate.

[0081] It can be understood that the embodiment of the present invention controls the allowable discharge power of the power battery by comparing the actual discharge power with the target change rate. By accurately controlling the allowable discharge power of the power battery, it can ensure that the vehicle can obtain stable power output under various working conditions, which not only improves the driving comfort and smoothness, allowing the driver to fully enjoy the fun of driving, but also in emergency or high-load conditions, the vehicle can respond quickly and provide sufficient power output, thereby significantly enhancing the safety and reliability of the entire vehicle.

[0082] In an embodiment of the present invention, the discharge allowable power of the power battery is controlled according to the actual discharge power and the target change rate, including: if the target change rate is a target decrease rate, the actual discharge power of the power battery at the moment when the lowest single cell voltage of the power battery begins to be less than a preset undervoltage threshold is taken as the starting point, and the discharge allowable power of the power battery is controlled to decrease according to the target decrease rate.

[0083] The target decrease rate may be a speed at which the current discharge allowable power of the power battery needs to decrease.

[0084] It can be understood that, in the embodiment of the present invention, when the target change rate is the target decrease rate, the actual discharge power of the power battery at the moment when the lowest single cell voltage of the power battery begins to be less than the preset undervoltage threshold is taken as the starting point, and the discharge allowable power is controlled to decrease according to the target decrease rate. This can effectively control the discharge power of the battery, avoid over-discharge of the battery, and ensure that the battery can smoothly and safely reduce the discharge power when it is close to exhaustion, thereby extending the service life of the battery.

[0085] In the embodiment of the present invention, if the target change rate is the target drop rate, the calculation formula of the discharge allowable power is:

[0086] P2=Pr*t,

[0087] Wherein, P is the actual discharge power of the power battery at the moment when the lowest single cell voltage of the power battery begins to be less than the preset undervoltage threshold, r is the target decrease rate, and t is the cycle processing period of the battery management system.

[0088] In an embodiment of the present invention, the discharge allowable power of the power battery is controlled according to the actual discharge power and the target change rate, including: if the target change rate is the target rising rate, the discharge allowable power of the power battery is taken as the starting point when the lowest single cell voltage of the power battery starts to rise, and the discharge allowable power of the power battery is controlled to rise according to the target rising rate.

[0089] The target rising rate may be a rate at which the current discharge of the power battery allows the power to increase from a lower level to a higher level.

[0090] It can be understood that, in the embodiment of the present invention, when the target change rate is the target rising rate, the discharge allowable power of the power battery at the moment when the lowest single cell voltage of the power battery starts to rise is taken as the starting point, and the discharge allowable power of the power battery is controlled to rise according to the target rising rate, so as to respond to the change of the battery state in time, quickly restore the discharge capacity of the battery, and improve the battery utilization efficiency.

[0091] In the embodiment of the present invention, if the target change rate is the target rising rate, the calculation formula of the discharge allowable power is:

[0092] P2=P'2+B*t,

[0093] Wherein, P'2 is the discharge allowable power of the power battery at the moment when the lowest cell voltage of the power battery starts to rise, B is the target rising rate, and P'2 is calculated according to the formula P2=Pr*t.

[0094] It can be understood that the embodiment of the present invention calculates the allowable discharge power of the power battery through the above formula, which can ensure that the battery always remains within a safe range during the discharge process, which not only ensures the safety and stability of the battery itself, but also provides continuous and reliable power support for the vehicle.

[0095] In an embodiment of the present invention, before controlling the discharge allowable power of the power battery according to the actual discharge power and the target change rate, it also includes: identifying whether the lowest single cell voltage of the power battery at the current moment is less than the discharge cut-off voltage of the power battery, wherein the discharge cut-off voltage is less than a preset undervoltage threshold; if it is identified that the lowest single cell voltage of the power battery at the current moment is less than the discharge cut-off voltage of the power battery, discharging of the power battery is prohibited, otherwise, controlling the discharge allowable power of the power battery according to the actual discharge power and the target change rate.

[0096] The discharge cut-off voltage may be a preset safety threshold. When the voltage of a single battery is lower than this value, the battery should stop discharging to avoid damage to the battery due to excessive discharge.

[0097] It can be understood that the embodiment of the present invention can protect the safe discharge of the battery by identifying whether the lowest single cell voltage of the power battery at the current moment is less than the discharge cut-off voltage of the power battery. If it is identified that the lowest single cell voltage of the power battery at the current moment is lower than the discharge cut-off voltage, the power battery will be immediately prohibited from continuing to discharge for safety reasons, thereby effectively protecting the battery, extending its service life, and ensuring the safety of the entire vehicle; otherwise, the discharge allowable power of the power battery is controlled according to the actual discharge power and the target change rate, ensuring that the battery maintains stable performance during the discharge process, avoiding an excessively fast discharge rate, and thus extending the battery life.

[0098] According to the method for controlling the discharge allowable power of a power battery proposed in an embodiment of the present invention, by monitoring the lowest cell voltage of the power battery, when it is found that the voltage is lower than the preset undervoltage threshold, the voltage change trend and change amount are analyzed, and the target change rate of the discharge allowable power is adjusted accordingly, so that the discharge allowable power is highly matched with the actual discharge capacity of the power battery, thereby ensuring the vehicle power performance while avoiding the risk of excessive discharge of the battery. By accurately controlling the discharge allowable power of the power battery, it is possible to ensure that the vehicle can obtain stable power output under various working conditions, which not only improves the driving comfort and smoothness, allowing the driver to enjoy the driving pleasure, but also in emergency or high-load conditions, the vehicle can respond quickly and provide sufficient power output, thereby significantly enhancing the safety and reliability of the whole vehicle, thereby solving the problem in the prior art that if the discharge allowable power of the power battery is higher than the actual capacity of the battery and is not effectively controlled in actual use, the battery will be over-discharged, causing rapid power limitation, resulting in sudden change or loss of vehicle power, and other problems.

[0099] The following is a specific example to illustrate the method for controlling the discharge allowable power of a power battery according to an embodiment of the present invention. Before the method for controlling the discharge allowable power of a power battery is specifically described, the principle of controlling the discharge allowable power of a power battery is first introduced. The contents are as follows:

[0100] like Figure 2 As shown, when the power battery is working at the actual discharge power 2, the minimum cell voltage 1 will gradually decrease over time. Once this minimum cell voltage 1 is lower than the preset undervoltage threshold 7, the power battery's discharge allowable power 3 is quickly reduced based on the power drop turning point 4 corresponding to the preset undervoltage threshold 7. As the power battery continues to discharge, the minimum cell voltage 1 continues to decrease, and the power battery's discharge allowable power 3 will also continue to decrease accordingly. In this process, due to the continuous reduction in power, the rate of decrease of the minimum cell voltage 1 will gradually slow down. When it is observed that the minimum cell voltage 1 begins to rise, that is, it reaches the battery's minimum cell voltage recovery point 6, then based on the power increase turning point 5 corresponding to the recovery point 6, the power battery's discharge allowable power 3 is increased to restore the normal working performance of the battery.

[0101] The embodiment of the present invention determines the lowest cell voltage of the battery in real time, calculates the battery discharge allowable power according to the current output power of the power battery and the lowest cell voltage, and when the lowest cell voltage reaches a preset undervoltage threshold, controls the power reduction rate according to the voltage change. When the voltage change is large, the discharge allowable power decreases quickly; when the voltage change is small, the discharge allowable power decreases slowly. When the lowest cell voltage rises back, the discharge allowable power rises back at a certain rate, thereby realizing adaptive control of the discharge allowable power, avoiding excessive dependence on the battery SOC, and the power battery performs power regulation and protection according to its own discharge capability, solving problems such as power mutation and power loss.

[0102] based on Figure 2 The principle shown in the figure is as follows: the method for controlling the discharge allowable power of the power battery is described as follows: Figure 3 As shown, the following steps are included:

[0103] S1: First, the current battery SOC, battery temperature and battery cell voltage are acquired through the battery management system.

[0104] S2: By comparing the temperature data of each battery cell, the highest temperature and the lowest temperature are obtained, and by comparing the voltage of each battery cell, the lowest battery cell voltage U is obtained. min According to the current battery SOC and battery cell temperature, the battery discharge power mapping table is queried to obtain the power values ​​corresponding to the highest temperature and the lowest temperature, and the minimum value is taken as the reference discharge allowable power P0.

[0105] S3: Compare the lowest battery cell voltage U min With the preset battery undervoltage threshold U1, when the battery minimum single cell voltage U min When it is less than U1, the current actual output power P and the table reference discharge allowable power P0 are recorded.

[0106] S4: Determine the current minimum cell voltage change trend. When the minimum cell voltage U min When it shows a downward trend, enter S5, otherwise enter S9.

[0107] S5: Calculate the power change rate r, r = parameter A*dU+R, dU is the current U min With the previous moment U min A can be the battery discharge power decrease rate correction coefficient, and R can be the basic rate. A and R are calibrated according to the actual vehicle.

[0108] S6: If the battery discharge allows the power to be immediately reduced, the specific calculation method is: allowed power P2 = Pr*t, where t is the cycle processing period of the battery management system.

[0109] S7: When the battery has the lowest single cell voltage Umin If the voltage is less than U2, where U2 is the discharge cut-off voltage, the battery needs to stop discharging and execute S8, otherwise execute S1.

[0110] S8: The power P2 is allowed to be immediately set to 0 and discharging is prohibited.

[0111] S9: If the current discharge allowable power is increased, the calculation method is: allowable power P2 = P'2 + parameter B*t, where B is the battery discharge power increase rate, which can be calibrated according to the actual vehicle.

[0112] In summary, the embodiment of the present invention can achieve smooth adjustment of the battery output power, significantly improve the power smoothness of the whole vehicle, and effectively avoid the discomfort caused by sudden changes in power. At the same time, the embodiment of the present invention adopts a single discharge power mapping table to realize the control of the discharge allowable power, avoiding the power fluctuation problem that may occur during the switching of multiple tables, and improving the stability and reliability of the system. On the basis of the discharge power mapping table, by optimizing the control strategy, the battery power can be increased by more than 20%, further enhancing the power performance of the whole vehicle. In addition, the embodiment of the present invention can also effectively overcome the impact of SOC deviation. Even when the SOC deviation reaches more than 20%, it can ensure that the battery will not have an over-discharge problem, thereby extending the service life of the battery and improving the safety of the whole vehicle.

[0113] Next, the discharge allowable power control device of a power battery according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0114] Figure 4 It is a block diagram of a discharge allowable power control device for a power battery according to an embodiment of the present invention.

[0115] like Figure 4 As shown, the discharge permission power control device 10 of the power battery includes: a first acquisition module 100 , a second acquisition module 200 , a first determination module 300 and a control module 400 .

[0116] Among them, the first acquisition module 100 is used to obtain the lowest single cell voltage of the power battery at the current moment; the second acquisition module 200 is used to obtain the actual discharge power of the power battery at the moment when the lowest single cell voltage of the power battery starts to be less than the preset undervoltage threshold, and the lowest single cell voltage of the power battery at the previous moment if the lowest single cell voltage of the power battery at the current moment is less than the preset undervoltage threshold; the first determination module 300 is used to calculate the voltage change trend and voltage change amount of the lowest single cell voltage of the power battery according to the lowest single cell voltage of the power battery at the current moment and the lowest single cell voltage of the power battery at the previous moment, and determine the target change rate of the discharge allowable power of the power battery at the current moment according to the voltage change trend and the voltage change amount; the control module 400 is used to control the discharge allowable power of the power battery according to the actual discharge power and the target change rate.

[0117] In an embodiment of the present invention, the target change rate includes a target decrease rate, and the control module 400 is further used to: if the target change rate is a target decrease rate, then taking the actual discharge power of the power battery at the moment when the lowest single cell voltage of the power battery begins to be less than a preset undervoltage threshold as the starting point, control the discharge allowable power of the power battery to decrease according to the target decrease rate.

[0118] Furthermore, the first determination module 300 is also used to: identify whether the voltage change trend is a downward trend; if the voltage change trend is a downward trend, calculate the target decrease rate of the discharge allowable power of the power battery at the current moment according to the voltage change amount.

[0119] Furthermore, the first determination module 300 is further configured to: obtain a decrease rate correction coefficient of the discharge allowable power of the power battery; and calculate a target decrease rate according to the voltage variation and the decrease rate correction coefficient.

[0120] Furthermore, the descent rate correction coefficient is a linear equation, and the proportional coefficient and the offset in the linear equation are preset values.

[0121] Furthermore, the control module 400 is also used for: if the target change rate is a target rising rate, taking the discharge allowable power of the power battery at the moment when the lowest cell voltage of the power battery starts to rise as the starting point, controlling the discharge allowable power of the power battery to rise according to the target rising rate.

[0122] Furthermore, the first determination module 300 is further used to: identify whether the voltage change trend is an upward trend; if the voltage change trend is an upward trend, the target increase rate of the discharge allowable power of the power battery at the current moment is a preset rate.

[0123] Furthermore, it also includes: an identification module, which is used to identify whether the lowest single cell voltage of the power battery at the current moment is less than the discharge cut-off voltage of the power battery before controlling the discharge allowable power of the power battery according to the actual discharge power and the target change rate, wherein the discharge cut-off voltage is less than a preset undervoltage threshold; the control module 400 is also used to prohibit the power battery from discharging if it is identified that the lowest single cell voltage of the power battery at the current moment is less than the discharge cut-off voltage of the power battery, otherwise, control the discharge allowable power of the power battery according to the actual discharge power and the target change rate.

[0124] In an embodiment of the present invention, it also includes: a second determination module, which is used to obtain the maximum temperature and the minimum temperature of the power battery if the lowest single cell voltage of the power battery at the current moment is greater than or equal to the preset undervoltage threshold; and determine the allowable discharge power of the power battery according to the maximum temperature and the minimum temperature.

[0125] It should be noted that the above explanation of the embodiment of the method for controlling the discharge allowable power of a power battery is also applicable to the device for controlling the discharge allowable power of a power battery of this embodiment, and will not be repeated here.

[0126] According to the discharge allowable power control device of the power battery proposed in the embodiment of the present invention, by monitoring the lowest single cell voltage of the power battery, when it is found that the voltage is lower than the preset undervoltage threshold, the voltage change trend and change amount are analyzed, and the target change rate of the discharge allowable power is adjusted accordingly, so that the discharge allowable power is highly matched with the actual discharge capacity of the power battery, thereby ensuring the vehicle power performance while avoiding the risk of excessive discharge of the battery. By accurately controlling the discharge allowable power of the power battery, it is possible to ensure that the vehicle can obtain stable power output under various working conditions, which not only improves the driving comfort and smoothness, allowing the driver to enjoy the driving pleasure, but also in emergency or high-load conditions, the vehicle can respond quickly and provide sufficient power output, thereby significantly enhancing the safety and reliability of the whole vehicle, thereby solving the problem in the prior art that if the discharge allowable power of the power battery is higher than the actual capacity of the battery and is not effectively controlled in actual use, the battery will be over-discharged, causing rapid power limitation, resulting in sudden change or loss of vehicle power, and so on.

[0127] Figure 5 A schematic diagram of the structure of a vehicle provided in an embodiment of the present invention. The vehicle may include:

[0128] A memory 501 , a processor 502 , and a computer program stored in the memory 501 and executable on the processor 502 .

[0129] When the processor 502 executes the program, the method for controlling the discharge allowable power of the power battery provided in the above embodiment is implemented.

[0130] Furthermore, the vehicle also includes:

[0131] The communication interface 503 is used for communication between the memory 501 and the processor 502 .

[0132] The memory 501 is used to store computer programs that can be executed on the processor 502 .

[0133] The memory 501 may include a high-speed RAM (Random Access Memory) memory, and may also include a non-volatile memory, such as at least one disk memory.

[0134] If the memory 501, the processor 502 and the communication interface 503 are implemented independently, the communication interface 503, the memory 501 and the processor 502 can be connected to each other through a bus and communicate with each other. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 5 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0135] Optionally, in a specific implementation, if the memory 501, the processor 502 and the communication interface 503 are integrated on a chip, the memory 501, the processor 502 and the communication interface 503 can communicate with each other through an internal interface.

[0136] The processor 502 may be a CPU (Central Processing Unit), or an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present invention.

[0137] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, and when the program is executed by a processor, the method for controlling the discharge allowable power of a power battery as described above is implemented.

[0138] An embodiment of the present invention further provides a computer program, which, when executed, implements the above method for controlling the discharge allowable power of a power battery.

[0139] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0140] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "N" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0141] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present invention belong.

[0142] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array, a field programmable gate array, etc.

[0143] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0144] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for controlling the discharge allowable power of a power battery, characterized in that: The following steps are involved: Get the lowest single cell voltage of the power battery at the current moment; If the lowest cell voltage of the power battery at the current moment is less than the preset undervoltage threshold, then obtaining the actual discharge power of the power battery at the moment when the lowest cell voltage of the power battery starts to be less than the preset undervoltage threshold, and the lowest cell voltage of the power battery at the previous moment; Calculating a voltage change trend and a voltage change amount of the lowest single cell voltage of the power battery according to the lowest single cell voltage of the power battery at the current moment and the lowest single cell voltage of the power battery at the previous moment, and determining a target change rate of the discharge allowable power of the power battery at the current moment according to the voltage change trend and / or the voltage change amount; controlling the discharge allowable power of the power battery according to the actual discharge power and the target change rate; The controlling the discharge allowable power of the power battery according to the actual discharge power and the target change rate includes: If the target change rate is a target rising rate, taking the discharge allowable power of the power battery at the moment when the lowest cell voltage of the power battery starts to rise as a starting point, the discharge allowable power of the power battery is controlled to rise according to the target rising rate; The determining, according to the voltage change trend and / or the voltage change amount, a target change rate of the discharge allowable power of the power battery at the current moment includes: Identify whether the voltage change trend is an upward trend; If the voltage change trend is an upward trend, the target increase rate of the discharge allowable power of the power battery at the current moment is a preset rate; The controlling the discharge allowable power of the power battery according to the actual discharge power and the target change rate includes: If the target change rate is a target decrease rate, taking the actual discharge power of the power battery at the moment when the lowest cell voltage of the power battery begins to be less than the preset undervoltage threshold as a starting point, the discharge allowable power of the power battery is controlled to decrease according to the target decrease rate; The determining, according to the voltage change trend and / or the voltage change amount, a target change rate of the discharge allowable power of the power battery at the current moment includes: Identify whether the voltage change trend is a downward trend; If the voltage variation trend is the downward trend, a target reduction rate of the discharge allowable power of the power battery at the current moment is calculated according to the voltage variation.

2. The method for controlling the discharge allowable power of a power battery according to claim 1, characterized in that: The calculating, according to the voltage change amount, a target decreasing rate of the discharge allowable power of the power battery at the current moment includes: Obtaining a correction coefficient of a rate of decrease of the allowable discharge power of the power battery; The target descent rate is calculated according to the voltage change amount and the descent rate correction coefficient.

3. The method for controlling the discharge allowable power of a power battery according to claim 2, characterized in that: The descent rate correction coefficient is a linear equation, and the proportional coefficient and the offset in the linear equation are preset values.

4. The method for controlling the discharge allowable power of a power battery according to claim 1, characterized in that: Before controlling the discharge allowable power of the power battery according to the actual discharge power and the target change rate, the method further includes: Identifying whether the lowest single cell voltage of the power battery at the current moment is less than a discharge cut-off voltage of the power battery, wherein the discharge cut-off voltage is less than the preset undervoltage threshold; If it is identified that the lowest single cell voltage of the power battery at the current moment is less than the discharge cut-off voltage of the power battery, the power battery is prohibited from discharging; otherwise, the discharge allowable power of the power battery is controlled according to the actual discharge power and the target change rate.

5. The method for controlling the discharge allowable power of a power battery according to claim 1, characterized in that: Also includes: If the lowest single cell voltage of the power battery at the current moment is greater than or equal to the preset undervoltage threshold, obtaining the highest temperature and the lowest temperature of the power battery; The discharge allowable power of the power battery is determined according to the maximum temperature and the minimum temperature.

6. A discharge allowable power control device for a power battery, characterized in that: include: The first acquisition module is used to obtain the lowest single cell voltage of the power battery at the current moment; A second acquisition module is used to acquire, if the lowest cell voltage of the power battery at the current moment is less than a preset undervoltage threshold, the actual discharge power of the power battery at the moment when the lowest cell voltage of the power battery starts to be less than the preset undervoltage threshold, and the lowest cell voltage of the power battery at the previous moment; a first determination module, configured to calculate a voltage change trend and a voltage change amount of the lowest single cell voltage of the power battery according to the lowest single cell voltage of the power battery at a current moment and the lowest single cell voltage of the power battery at a previous moment, and determine a target change rate of the discharge allowable power of the power battery at a current moment according to the voltage change trend and the voltage change amount; A control module, used for controlling the discharge allowable power of the power battery according to the actual discharge power and the target change rate; The controlling the discharge allowable power of the power battery according to the actual discharge power and the target change rate includes: If the target change rate is a target rising rate, taking the discharge allowable power of the power battery at the moment when the lowest cell voltage of the power battery starts to rise as a starting point, the discharge allowable power of the power battery is controlled to rise according to the target rising rate; The determining, according to the voltage change trend and the voltage change amount, a target change rate of the discharge allowable power of the power battery at the current moment includes: Identify whether the voltage change trend is an upward trend; If the voltage change trend is an upward trend, the target increase rate of the discharge allowable power of the power battery at the current moment is a preset rate; The controlling the discharge allowable power of the power battery according to the actual discharge power and the target change rate includes: If the target change rate is a target decrease rate, taking the actual discharge power of the power battery at the moment when the lowest cell voltage of the power battery begins to be less than the preset undervoltage threshold as a starting point, the discharge allowable power of the power battery is controlled to decrease according to the target decrease rate; The determining, according to the voltage change trend and / or the voltage change amount, a target change rate of the discharge allowable power of the power battery at the current moment includes: Identify whether the voltage change trend is a downward trend; If the voltage variation trend is the downward trend, a target reduction rate of the discharge allowable power of the power battery at the current moment is calculated according to the voltage variation.

7. A vehicle, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for controlling the discharge allowable power of a power battery according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program or instruction stored thereon, characterized in that: The program or instruction is executed by a processor to implement the method for controlling the discharge allowable power of a power battery as described in any one of claims 1 to 5.

9. A computer program product having a computer program or instructions stored thereon, characterized in that: When the computer program or instruction is executed, it is used to implement the method for controlling the discharge allowable power of a power battery as described in any one of claims 1 to 5.

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