CN117962690A - Power battery discharge allowable power control method, device, vehicle and medium - Google Patents
Power battery discharge allowable power control method, device, vehicle and medium Download PDFInfo
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Abstract
The invention relates to the technical field of power batteries, in particular to a discharge allowable power control method, a device, a vehicle and a medium, wherein the method comprises the following steps: acquiring the lowest single voltage of the power battery at the current moment; if the lowest single voltage of the power battery at the current moment is smaller than the preset undervoltage threshold, acquiring the discharging actual power of the power battery at the moment when the lowest single voltage of the power battery starts to be smaller than the preset undervoltage threshold and the lowest single voltage of the power battery at the last moment; according to the lowest single voltage of the power battery at the current moment and the lowest single voltage of the power battery at the last moment, calculating the voltage change trend and the voltage change quantity of the lowest single voltage of the power battery, and accordingly determining the target change rate of the discharge allowable power of the power battery at the current moment; the discharge allowable power of the power battery is controlled according to the discharge actual power and the target change rate. Therefore, the problems of power limitation caused by overdischarge of the battery, abrupt change of vehicle power and the like in the prior art are solved.
Description
Technical Field
The invention relates to the technical field of power batteries, in particular to a discharge allowable power control method and device of a power battery, a vehicle and a medium.
Background
With the progress of new energy automobile technology, the cost performance of the battery is improved, but the output capacity of the battery is near the limit. When the allowable power for discharging the battery cannot meet the actual demand, the over-discharge risk increases, and the power system of the vehicle is failed. At present, power is mainly controlled through State of Charge (SOC) and temperature, but SOC estimation accuracy is limited, which may cause inaccuracy of battery discharge allowable power obtained by table lookup, actual power exceeds load capacity, under-voltage protection and power limitation are caused, and finally power failure and safety problems are caused.
In the related art, publication number CN115230533a proposes a power battery system pre-under-voltage power control strategy and control system, and the power limiting method has a risk of battery over-discharge, and does not consider the problem of recovery after power limitation. The method, the device, the system and the storage medium for estimating the allowable power of the battery, which are provided by the publication No. CN110967637A, influence the estimation result of the allowable power of the battery through the actual current acquisition precision, the estimation precision of the state of charge value and the accumulated charge and discharge electric quantity of the battery, so that the risk of overdischarge of the battery is increased.
However, in the related art, the pre-under-voltage power control and the battery allowable power estimation have the risk of overdischarge of the battery, which affects the output capability of the battery, and may cause that the vehicle cannot provide enough power when the maximum power is required, which affects the driving experience and safety.
Disclosure of Invention
One of the purposes of the present invention is to provide a method for controlling the allowable power of a power battery in order to solve the problems of the prior art that if the allowable power of the power battery is higher than the actual capacity of the battery and is not effectively controlled, the battery is overdischarged, the rapid limitation of the power is caused, and the power of the vehicle is suddenly changed or lost; the second purpose is to provide a discharging allowable power control device of the power battery; a third object is to provide a vehicle; a fourth object is to provide a storage medium; it is a fifth object to provide a program product.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
a discharge allowable power control method of a power battery, comprising: acquiring the lowest single voltage of the power battery at the current moment; if the lowest single voltage of the power battery at the current moment is smaller than the preset undervoltage threshold, acquiring the discharging actual power of the power battery at the moment when the lowest single voltage of the power battery starts to be smaller than the preset undervoltage threshold and the lowest single voltage of the power battery at the last moment; calculating the voltage change trend and the voltage change quantity of the lowest single voltage of the power battery according to the lowest single voltage of the power battery at the current moment and the lowest single voltage of the power battery at the last moment, and determining the 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 quantity; the discharge allowable power of the power battery is controlled according to the discharge actual power and the target change rate.
According to the technical means, the embodiment of the invention analyzes the voltage change trend and the change amount by monitoring the lowest single voltage of the power battery, and adjusts the target change rate of the discharge allowable power according to the voltage change trend and the change amount when the voltage is lower than the preset undervoltage threshold value, so that the discharge allowable power is highly matched with the actual discharge capacity of the power battery, and the risk of overdischarge of the battery is avoided while the vehicle power performance is ensured. By accurately controlling the discharge allowable power of the power battery, the vehicle can be ensured to obtain stable power output under various working conditions, so that not only the driving comfort and fluency are improved, the driver can enjoy the driving fun as much as possible, but also the vehicle can rapidly respond under the working conditions of emergency or high load to provide sufficient power output, and the safety and reliability of the whole vehicle are obviously enhanced.
Further, the target rate of change includes a target rate of decrease, and controlling the discharge allowable power of the power cell based on the discharge actual power and the target rate of change includes: and if the target change rate is the target descent rate, controlling the allowable power descent of the discharge of the power battery according to the target descent rate by taking the actual discharge power of the power battery as a starting point at the moment when the lowest single voltage of the power battery starts to be smaller than the preset undervoltage threshold value.
According to the technical means, when the target change rate is the target falling rate, the embodiment of the invention takes the actual discharge power of the power battery at the moment when the lowest single voltage of the power battery starts to be smaller than the preset undervoltage threshold value as the starting point, and controls the discharge allowable power to fall according to the target falling rate, so that the discharge power of the battery can be effectively controlled, the over-discharge of the battery is avoided, and the discharge power can be stably and safely reduced when the battery is close to the exhaustion, thereby prolonging the service life of the battery.
Further, 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 comprises the following steps: identifying whether the voltage change trend is a falling trend; and if the voltage change trend is a descending trend, calculating the target descending rate of the allowable discharging power of the power battery at the current moment according to the voltage change quantity.
According to the technical means, the embodiment of the invention realizes the fine control of the target change rate of the allowable power for discharging the power battery by identifying the voltage change trend, and if the voltage change trend is a descending trend, the target descending rate is obtained according to the voltage change amount, so that the allowable power for discharging can be timely adjusted, the discharging speed of the battery is slowed down, and the stable and safe power output of the battery in the discharging process is ensured.
Further, calculating a target rate of decrease of the discharge allowable power of the power cell at the present time from the voltage variation amount, including: acquiring a reduction rate correction coefficient of discharge allowable power of the power battery; and calculating the target falling rate according to the voltage change amount and the falling rate correction coefficient.
According to the technical means, the embodiment of the invention introduces the descending speed correction coefficient, can more finely adjust the target descending speed, obtains the target descending speed according to the voltage variation and the descending speed correction coefficient, and accurately responds to the change of the battery state, thereby ensuring that the battery discharges in an optimal way and improving the energy utilization efficiency of the battery.
Further, the decreasing rate correction coefficient is a linear equation, and the proportionality coefficient and the offset in the linear equation are preset values.
According to the above technical means, in the embodiment of the present invention, the decreasing rate correction coefficient is a linear equation, which is used to dynamically adjust the rate of weight update, the proportionality coefficient is a preset value, which is usually used to adjust the amplitude of power change, and the offset is a constant term, which is used to adjust the output of the control algorithm. According to the embodiment of the invention, the accurate control of the discharging power of the power battery can be realized by reasonably setting the descending rate correction coefficient, the proportional coefficient and the offset, so that the performance and the safety of the battery under various working conditions are ensured.
Further, controlling the discharge allowable power of the power cell according to the discharge actual power and the target rate of change, comprising: if the target rate of change is the target rate of rise, the power cell is controlled to rise in the allowable power for discharge in accordance with the target rate of rise, starting from the allowable power for discharge of the power cell at the time when the lowest cell voltage of the power cell starts to rise.
According to the technical means, when the target change rate is the target rising rate, the embodiment of the invention takes the discharge allowable power of the power battery at the moment when the lowest single voltage of the power battery starts to rise as the starting point, controls the discharge allowable power of the power battery to rise according to the target rising rate, can timely respond to the change of the battery state, quickly recovers the discharge capacity of the battery, and improves the service efficiency of the battery.
Further, 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 comprises the following steps: identifying whether the voltage change trend is an ascending trend; if the voltage change trend is an ascending trend, the target ascending rate of the discharge allowable power of the power battery at the current moment is a preset rate.
According to the technical means, the embodiment of the invention realizes the fine control of the target change rate of the allowable power for discharging the power battery by identifying the voltage change trend, if the voltage change trend is an ascending trend, the target ascending rate of the allowable power for discharging the power battery at the current moment is a preset rate, and the battery can be ensured to be stably restored to the normal working state by keeping a certain allowable power change rate, so that the risk possibly caused by voltage abrupt change is avoided.
Further, before controlling the discharge allowable power of the power cell according to the discharge actual power and the target rate of change, it further includes: identifying whether the lowest single voltage of the power battery at the current moment is smaller than the discharge cut-off voltage of the power battery, wherein the discharge cut-off voltage is smaller than a preset undervoltage threshold; and if the lowest single voltage of the power battery at the current moment is identified to be smaller than the discharge cut-off voltage of the power battery, the power battery is forbidden to discharge, otherwise, the discharge allowable power of the power battery is controlled according to the discharge actual power and the target change rate.
According to the technical means, the embodiment of the invention can protect the safe discharge of the battery by identifying whether the lowest single voltage of the power battery at the current moment is smaller than the discharge cut-off voltage of the power battery, and if the lowest single voltage of the power battery at the current moment is smaller than the discharge cut-off voltage, the power battery is immediately forbidden to continue to discharge due to safety consideration, so that the battery is effectively protected, the service life of the battery is prolonged, and the safety of the whole vehicle is ensured; otherwise, the discharge allowable power of the power battery is controlled according to the discharge actual power and the target change rate, so that the stable performance of the battery in the discharge process is ensured, the excessively fast discharge rate is avoided, and the service life of the battery is prolonged.
Further, the method further comprises the following steps: if the lowest single voltage of the power battery at the current moment is greater than or equal to a preset undervoltage threshold value, acquiring the highest temperature and the lowest temperature of the power battery; the discharge allowable power of the power battery is determined according to the highest temperature and the lowest temperature.
According to the technical means, when the lowest single voltage of the power battery at the current moment is larger than or equal to the preset undervoltage threshold, the temperature distribution condition can be monitored in real time by acquiring the highest temperature and the lowest temperature of the power battery, so that the working state and the health condition of the battery are reflected; the discharge allowable power of the power battery is determined according to the highest temperature and the lowest temperature, so that the accurate control of the battery discharge process can be realized, the load among the single batteries is balanced, and the overdischarge or the underdischarge is avoided.
A discharge allowable power control device of a power battery, comprising: the first acquisition module is used for acquiring the lowest single voltage of the power battery at the current moment; the second acquisition module is used for acquiring the discharging actual power of the power battery at the moment when the lowest single voltage of the power battery starts to be smaller than the preset undervoltage threshold value and the lowest single voltage of the power battery at the last moment if the lowest single voltage of the power battery at the current moment is smaller than the preset undervoltage threshold value; the first determining module is used for calculating the voltage variation trend and the voltage variation of the lowest single voltage of the power battery according to the lowest single voltage of the power battery at the current moment and the lowest single voltage of the power battery at the last moment, and determining the target variation rate of the discharge allowable power of the power battery at the current moment according to the voltage variation trend and/or the voltage variation; and the control module is used for controlling the discharge allowable power of the power battery according to the discharge actual power and the target change rate.
Further, the target rate of change includes a target rate of descent, and the control module is further configured to: and if the target change rate is the target descent rate, controlling the allowable power descent of the discharge of the power battery according to the target descent rate by taking the actual discharge power of the power battery as a starting point at the moment when the lowest single voltage of the power battery starts to be smaller than the preset undervoltage threshold value.
Further, the first determining module is further configured to: identifying whether the voltage change trend is a falling trend; and if the voltage change trend is a descending trend, calculating the target descending rate of the allowable discharging power of the power battery at the current moment according to the voltage change quantity.
Further, the first determining module is further configured to: acquiring a reduction rate correction coefficient of discharge allowable power of the power battery; and calculating the target falling rate according to the voltage change amount and the falling rate correction coefficient.
Further, the decreasing rate correction coefficient is a linear equation, and the proportionality coefficient and the offset in the linear equation are preset values.
Further, the control module is further configured to: if the target rate of change is the target rate of rise, the power cell is controlled to rise in the allowable power for discharge in accordance with the target rate of rise, starting from the allowable power for discharge of the power cell at the time when the lowest cell voltage of the power cell starts to rise.
Further, the first determining module is further configured to: identifying whether the voltage change trend is an ascending trend; if the voltage change trend is an ascending trend, the target ascending rate of the discharge allowable power of the power battery at the current moment is a preset rate.
Further, the method further comprises the following steps: the identification module is used for identifying whether the lowest single voltage of the power battery at the current moment is smaller than the discharge cut-off voltage of the power battery or not before the discharge allowable power of the power battery is controlled according to the discharge actual power and the target change rate, wherein the discharge cut-off voltage is smaller than a preset undervoltage threshold; and the control module is also used for prohibiting the power battery from discharging if the lowest single voltage of the power battery at the current moment is identified to be smaller than the discharge cut-off voltage of the power battery, otherwise, controlling the discharge allowable power of the power battery according to the discharge actual power and the target change rate.
Further, the method further comprises the following steps: the second determining module is used for acquiring the highest temperature and the lowest temperature of the power battery if the lowest single voltage of the power battery at the current moment is greater than or equal to a preset undervoltage threshold value; the discharge allowable power of the power battery is determined according to the highest temperature and the lowest temperature.
A vehicle, comprising: the system comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, wherein the processor executes the program to realize the discharge permission power control method of the power battery.
A computer-readable storage medium having stored thereon a computer program for execution by a processor for implementing a power control method for discharging a power battery.
A computer program which, when executed, enables a power control method for effecting discharge of a power cell.
The beneficial effects of the invention include:
(1) According to the embodiment of the invention, by monitoring the lowest single voltage of the power battery, when the voltage is found to be lower than the preset undervoltage threshold, the voltage change trend and the change quantity 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, and the risk of overdischarge of the battery is avoided while the vehicle power performance is ensured. By accurately controlling the discharge allowable power of the power battery, the vehicle can be ensured to obtain stable power output under various working conditions, so that not only the driving comfort and fluency are improved, the driver can enjoy the driving fun as much as possible, but also the vehicle can respond rapidly under the working conditions of emergency or high load to provide sufficient power output, and the safety and reliability of the whole vehicle are obviously enhanced;
(2) When the target change rate is the target falling rate, the embodiment of the invention takes the actual discharge power of the power battery at the moment when the lowest single voltage of the power battery starts to be smaller than the preset undervoltage threshold value as the starting point, controls the discharge allowable power to fall according to the target falling rate, can effectively control the discharge power of the battery, avoids over-discharge of the battery, ensures that the discharge power can be stably and safely reduced when the battery is close to exhaustion, and prolongs the service life of the battery.
(3) According to the embodiment of the invention, the voltage change trend is identified to realize the fine control of the target change rate of the allowable power of the power battery during discharge, if the voltage change trend is a descending trend, the target descending rate is obtained according to the voltage change amount, the allowable power during discharge can be timely adjusted, the discharge speed of the battery is slowed down, and the stable and safe power output of the battery during discharge is ensured;
(4) According to the embodiment of the invention, the descending speed correction coefficient is introduced, so that the target descending speed can be more finely adjusted, the target descending speed is obtained according to the voltage variation and the descending speed correction coefficient, and the change of the battery state is accurately responded, thereby ensuring that the battery discharges in an optimal mode and improving the energy utilization efficiency of the battery;
(5) In the embodiment of the invention, the descending rate correction coefficient is a linear equation and is used for dynamically adjusting the rate of weight updating, the proportionality coefficient is a preset value and is usually used for adjusting the amplitude of power change, and the offset is a constant term and is used for adjusting the output of a control algorithm. According to the embodiment of the invention, the accurate control of the discharging power of the power battery can be realized by reasonably setting the descending rate correction coefficient, the proportional coefficient and the offset, so that the performance and the safety of the battery under various working conditions are ensured;
(6) When the target change rate is the target rising rate, the embodiment of the invention takes the discharge allowable power of the power battery at the moment when the lowest single voltage of the power battery starts to rise as the starting point, controls the discharge allowable power of the power battery to rise according to the target rising rate, can timely respond to the change of the battery state, quickly recovers the discharge capacity of the battery, and improves the service efficiency of the battery;
(7) According to the embodiment of the invention, the voltage change trend is identified to realize the fine control of the target change rate of the allowable power for discharging the power battery, if the voltage change trend is an ascending trend, the target ascending rate of the allowable power for discharging the power battery at the current moment is a preset rate, and the battery can be ensured to be stably restored to a normal working state by keeping a certain allowable power change rate, so that the risk possibly caused by voltage abrupt change is avoided;
(8) According to the embodiment of the invention, whether the lowest single voltage of the power battery at the current moment is smaller than the discharge cut-off voltage of the power battery is identified, so that the battery can be protected from being safely discharged, if the lowest single voltage of the power battery at the current moment is identified to be smaller than the discharge cut-off voltage, the power battery can be immediately forbidden from being continuously discharged due to safety consideration, the battery is effectively protected, the service life of the battery is prolonged, and the safety of the whole vehicle is ensured; otherwise, controlling the discharge allowable power of the power battery according to the discharge actual power and the target change rate, ensuring the stable performance of the battery in the discharge process, avoiding the excessively fast discharge rate and prolonging the service life of the battery;
(9) According to the embodiment of the invention, when the lowest single voltage of the power battery at the current moment is greater than or equal to the preset undervoltage threshold, the temperature distribution condition can be monitored in real time by acquiring the highest temperature and the lowest temperature of the power battery, so that the working state and the health condition of the battery are reflected; the discharge allowable power of the power battery is determined according to the highest temperature and the lowest temperature, so that the accurate control of the battery discharge process can be realized, the load among the single batteries is balanced, and the overdischarge or the underdischarge is avoided.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
Fig. 1 is a flowchart of a discharge allowable power control method of a power battery according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a discharge allowable power control principle of a power battery according to an embodiment of the present invention;
FIG. 3 is a flow chart of a method for controlling the discharge allowable power of a power battery according to an embodiment of the present invention;
fig. 4 is a block diagram of a discharging allowable power control device of a power battery according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of a vehicle according to an embodiment of the present invention.
Wherein, 1-lowest cell voltage, 2-discharge actual power, 3-discharge allowable power, 4-power falling turning point a, 5-power rising turning point b, 6-lowest cell voltage rising point c and 7-preset under-voltage threshold d.
Detailed Description
Further advantages and effects of the present invention will become readily apparent to those skilled in the art from the disclosure herein, by referring to the accompanying drawings and the preferred embodiments. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention. It should be understood that the preferred embodiments are presented by way of illustration only and not by way of limitation.
It should be noted that the illustrations provided in the following embodiments merely illustrate the basic concept of the present invention by way of illustration, and only the components related to the present invention are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complicated.
With the continuous improvement of the cost performance of the power battery of the new energy automobile, the output capacity of the power battery gradually approaches the limit. In this case, if the allowable power for discharging the battery is lower than the actual output capacity, there is a high possibility that the battery is overdischarged, thereby causing a power failure.
Currently, the industry mainly sets the allowable power according to the current battery SOC (state of charge) and temperature by looking up a power MAP table. However, this method has a significant problem: the accuracy of the SOC estimation typically fluctuates in the range of 5% -8%, sometimes even more. Such estimation accuracy may result in the battery discharge allowable power obtained by look-up table being higher than the actual value. When the high allowable power exceeds the actual load capacity of the battery, the battery voltage can be rapidly reduced, an under-voltage protection mechanism is triggered, the battery power is further greatly limited, the power failure of the vehicle is caused, even the power is completely lost, and serious threat is brought to the safety of the vehicle.
In related art 1, temperature, SOC value, and cell voltage are taken into consideration, and allowable discharge power is adjusted according to these parameters. When the lowest cell voltage is detected to be lower than the preset pre-undervoltage threshold value and the duration reaches the preset undervoltage protection time, the allowable discharge power is reduced. However, if the actual power is far below the current allowable power of the battery, the limited allowable power may still be higher than the actual power even if the pre-under-voltage threshold is triggered, thereby risking over-discharge of the battery. Furthermore, the strategy does not involve a problem of restoration after power limitation.
In related art 2, the state of charge, temperature, operating condition operation data, and hysteresis coefficients of the battery are considered. However, this method relies on a battery open circuit voltage estimation model, battery internal resistance, current state of charge and temperature of the battery, and accumulated charge-discharge charge to estimate. Due to the influence of the battery current collection precision, the accuracy of the charge and discharge electric quantity can be influenced, and meanwhile, the estimation precision of the state of charge value can also influence the query result of the internal resistance and the allowable power of the battery, so that the estimation deviation of the allowable power of the battery is caused, and the risk of overdischarge of the battery is increased.
Specifically, fig. 1 is a schematic flow chart of a discharge allowable power control method of a power battery according to an embodiment of the present invention.
As shown in fig. 1, the discharge allowable power control method of the power battery includes the steps of:
in step S101, the lowest cell voltage of the power battery at the present time is obtained.
The lowest cell voltage may be the one with the lowest voltage value in the current cell.
It can be understood that by monitoring the lowest single voltage of the power battery at the current moment, the embodiment of the invention can know the performance state of the battery in real time, and timely find potential safety hazards of the battery, such as over-discharge and internal short circuit of the single battery, prevent the battery from being damaged due to under-voltage, and ensure the safety of the battery.
In step S102, if the lowest cell voltage of the power battery at the current time is less than the preset under-voltage threshold, the discharging actual power of the power battery at the time when the lowest cell voltage of the power battery begins to be less than the preset under-voltage threshold and the lowest cell voltage of the power battery at the last time are obtained.
The preset undervoltage threshold value can be a preset minimum voltage limit value for protecting the safety of the battery, and the discharging actual power can be the actual output power of the power battery.
It can be understood that when the lowest single voltage of the power battery at the current moment is smaller than the preset undervoltage threshold, the embodiment of the invention can judge the reduction speed of the battery performance by comparing the discharging actual power of the power battery at the moment when the lowest single voltage starts to be smaller than the preset undervoltage threshold, thereby detecting whether the battery has potential faults and avoiding the damage of the battery caused by overdischarge.
In the embodiment of the present invention, the method of the embodiment of the present invention further includes: if the lowest single voltage of the power battery at the current moment is greater than or equal to a preset undervoltage threshold value, acquiring the highest temperature and the lowest temperature of the power battery; the discharge allowable power of the power battery is determined according to the highest temperature and the lowest temperature.
It can be understood that when the lowest single voltage of the power battery at the current moment is greater than or equal to the preset undervoltage threshold, the embodiment of the invention can monitor the temperature distribution condition in real time by acquiring the highest temperature and the lowest temperature of the power battery, thereby reflecting the working state and the health condition of the battery; the discharge allowable power of the power battery is determined according to the highest temperature and the lowest temperature, so that the accurate control of the battery discharge process can be realized, the load among the single batteries is balanced, and the overdischarge or the underdischarge is avoided.
In step S103, a voltage variation trend and a voltage variation amount of the lowest cell voltage of the power cell are calculated according to the lowest cell voltage of the power cell at the current time and the lowest cell voltage of the power cell at the previous time, and a target variation rate of the allowable discharge power of the power cell at the current time is determined according to the voltage variation trend and the voltage variation amount.
The voltage change trend can be the change direction of the lowest single voltage of the power battery along with time, and comprises a descending trend and an ascending trend, wherein the descending trend can be the process that the voltage value is gradually reduced, and the ascending trend can be the process that the voltage value is gradually increased; the voltage variation can be the difference between the lowest cell voltages of the power cells between two adjacent moments; the target rate of change of the discharge allowable power may be a maximum rate of change allowable for the power cell discharge power.
It can be understood that the embodiment of the invention can more precisely control the discharging process of the battery and realize self-adaptive discharging control by calculating the voltage change trend and the voltage change quantity of the lowest single voltage of the power battery and determining the target change rate of the discharging allowable power according to the parameters, thereby adapting to different use scenes and user requirements, maximally utilizing the energy of the battery, improving the service efficiency of the battery and prolonging the service life of the battery.
In the embodiment of the invention, the target change rate comprises a target falling rate and a target rising rate, 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 the voltage change quantity, and comprises the following steps: identifying whether the voltage change trend is a descending trend or an ascending trend; if the voltage change trend is a descending trend, calculating the target descending rate of the discharge allowable power of the power battery at the current moment according to the voltage change quantity; if the voltage change trend is an ascending trend, the target ascending rate of the discharge allowable power of the power battery at the current moment is a preset rate.
The preset speed can be calibrated according to actual vehicle conditions.
It can be understood that the embodiment of the invention realizes the fine control of the target change rate of the allowable power for discharging the power battery by identifying the voltage change trend, and if the voltage change trend is a descending trend, the target descending rate is obtained according to the voltage change amount, the allowable power for discharging can be timely adjusted, the discharging speed of the battery is slowed down, and the stable and safe power output of the battery in the discharging process is ensured. If the voltage change trend is an ascending trend, the target ascending rate of the discharge allowable power of the power battery at the current moment is a preset rate, and the battery can be ensured to be stably restored to a normal working state by keeping a certain discharge allowable power change rate, so that the risk possibly caused by voltage abrupt change is avoided.
In the embodiment of the invention, the target rate of decline of the discharge allowable power of the power battery at the current moment is calculated according to the voltage variation, and the method comprises the following steps: acquiring a reduction rate correction coefficient of discharge allowable power of the power battery; and calculating the target falling rate according to the voltage change amount and the falling rate correction coefficient.
The drop rate correction coefficient may be a linear equation, the target drop rate r=a×du+r, where dU may be an absolute value of a difference between the current highest voltage of the single body and the previous highest voltage of the single body, a may be a proportional coefficient of the drop rate of the battery discharge power, R may be a deviation amount, and a and R may be specifically calibrated according to an actual vehicle.
It can be understood that the embodiment of the invention introduces the descending speed correction coefficient, can more finely adjust the target descending speed, obtains the target descending speed according to the voltage variation and the descending speed correction coefficient, and accurately responds to the change of the battery state, thereby ensuring the battery to discharge in an optimal way and improving the energy utilization efficiency of the battery.
It should be noted that, setting the dropping rate correction coefficient is based on the scaling factor and the offset, and by reasonably setting the dropping rate correction coefficient, the scaling factor and the offset, accurate control of the discharging power of the power battery can be achieved, so as to ensure the performance and the safety of the battery under various working conditions.
In step S104, the discharge allowable power of the power cell is controlled according to the discharge actual power and the target rate of change.
It can be understood that the embodiment of the invention controls the discharge allowable power of the power battery by discharging the actual power and the target change rate, and can ensure that the vehicle can obtain stable power output under various working conditions by accurately controlling the discharge allowable power of the power battery, thereby not only improving the comfort and fluency of driving, enabling a driver to enjoy the pleasure of driving, but also enabling the vehicle to rapidly respond and provide sufficient power output under the working conditions of emergency or high load, and further obviously enhancing the safety and reliability of the whole vehicle.
In an embodiment of the present invention, controlling a discharge allowable power of a power battery according to a discharge actual power and a target rate of change includes: and if the target change rate is the target descent rate, controlling the allowable power descent of the discharge of the power battery according to the target descent rate by taking the actual discharge power of the power battery as a starting point at the moment when the lowest single voltage of the power battery starts to be smaller than the preset undervoltage threshold value.
Wherein the target rate of decrease may be a rate at which the current discharge of the power cell allows the power to be reduced.
It can be understood that when the target change rate is the target falling rate, the embodiment of the invention takes the actual discharge power of the power battery at the moment when the lowest single voltage of the power battery starts to be smaller than the preset undervoltage threshold value as the starting point, and controls the discharge allowable power to fall according to the target falling rate, so that the discharge power of the battery can be effectively controlled, the over-discharge of the battery is avoided, and the discharge power can be stably and safely reduced when the battery is close to the exhaustion, thereby prolonging the service life of the battery.
In the embodiment of the present invention, if the target change rate is the target decrease rate, the calculation formula of the discharge allowable power is:
P2＝P-r*t，
Wherein P is the actual discharge power of the power battery at the moment when the lowest single voltage of the power battery starts to be smaller than the preset undervoltage threshold value, r is the target falling rate, and t is the cycle processing period of the battery management system.
In an embodiment of the present invention, controlling a discharge allowable power of a power battery according to a discharge actual power and a target rate of change includes: if the target rate of change is the target rate of rise, the power cell is controlled to rise in the allowable power for discharge in accordance with the target rate of rise, starting from the allowable power for discharge of the power cell at the time when the lowest cell voltage of the power cell starts to rise.
Wherein the target rate of rise may be a rate at which the current discharge of the power cell allows the power to increase from a lower level to a higher level.
It can be understood that when the target change rate is the target rising rate, the embodiment of the invention takes the discharge allowable power of the power battery at the moment when the lowest single voltage of the power battery starts to rise as the starting point, controls the discharge allowable power of the power battery to rise according to the target rising rate, can timely respond to the change of the battery state, quickly recovers the discharge capacity of the battery, and improves the service efficiency of the battery.
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:
P2＝P'2+B*t，
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 formula P 2 =p-r×t.
It can be understood that the embodiment of the invention calculates the discharge allowable power of the power battery through the formula, can ensure that the battery is always kept in a safe range in the discharge process, not only ensures the safety and stability of the battery, but also provides continuous and reliable power support for the vehicle.
In the embodiment of the invention, before controlling the discharge allowable power of the power battery according to the discharge actual power and the target change rate, the method further comprises the following steps: identifying whether the lowest single voltage of the power battery at the current moment is smaller than the discharge cut-off voltage of the power battery, wherein the discharge cut-off voltage is smaller than a preset undervoltage threshold; and if the lowest single voltage of the power battery at the current moment is identified to be smaller than the discharge cut-off voltage of the power battery, the power battery is forbidden to discharge, otherwise, the discharge allowable power of the power battery is controlled according to the discharge actual power and the target change rate.
The discharge cut-off voltage may be a preset safety threshold, and when the voltage of the single battery is lower than the preset safety threshold, the battery should stop discharging to avoid damage caused by overdischarge of the battery.
It can be understood that, in the embodiment of the invention, by identifying whether the lowest single voltage of the power battery at the current moment is smaller than the discharge cut-off voltage of the power battery, the battery can be protected from being safely discharged, if the lowest single voltage of the power battery at the current moment is identified to be smaller than the discharge cut-off voltage, the power battery can be immediately forbidden from being continuously discharged due to safety consideration, the battery can be effectively protected, the service life of the battery can be prolonged, and the safety of the whole vehicle can be ensured; otherwise, the discharge allowable power of the power battery is controlled according to the discharge actual power and the target change rate, so that the stable performance of the battery in the discharge process is ensured, the excessively fast discharge rate is avoided, and the service life of the battery is prolonged.
According to the method for controlling the allowable discharge power of the power battery, provided by the embodiment of the invention, by monitoring the lowest single voltage of the power battery, when the voltage is found to be lower than the preset undervoltage threshold, the voltage change trend and the change quantity are analyzed, and the target change rate of the allowable discharge power is adjusted accordingly, so that the allowable discharge power is highly matched with the actual discharge capacity of the power battery, and the risk of overdischarge of the battery is avoided while the power performance of a vehicle is ensured. By accurately controlling the discharge allowable power of the power battery, the vehicle can obtain stable power output under various working conditions, so that the comfort and fluency of driving are improved, a driver can enjoy the pleasure of driving as much as possible, the vehicle can also respond rapidly under the working conditions of emergency or high load, and sufficient power output is provided, so that the safety and reliability of the whole vehicle are obviously enhanced, and the problems that in the prior art, if the discharge allowable power is higher than the actual capacity of the battery and the power is not effectively controlled, the battery is overdischarged, the power is rapidly limited, the power of the vehicle is suddenly changed or lost and the like are solved.
The discharge allowable power control method of the power battery according to the embodiment of the invention is described by a specific embodiment, and before the discharge allowable power control method of the power battery is specifically described, the discharge allowable power control principle of the power battery is described as follows:
As shown in fig. 2, when the power cell operates at the actual discharge power 2, the minimum cell voltage 1 gradually decreases with the lapse of time. Once the lowest single voltage 1 is lower than the preset undervoltage threshold 7, the power falling turning point 4 corresponding to the preset undervoltage threshold 7 is used as a reference to reduce the allowable discharge power 3 of the power battery. As the power cell continues to discharge, the minimum cell voltage 1 continues to drop, while the discharge allowable power 3 of the power cell also continues to decrease accordingly. During this process, the rate of decrease of the lowest cell voltage 1 gradually slows down due to the continuous decrease of the power. When the lowest cell voltage 1 is observed to start rising, namely, the lowest cell voltage rising point 6 of the battery is reached, the discharge allowable power 3 of the power battery is raised based on the power rising turning point 5 corresponding to the rising point 6, and the normal working performance of the battery is restored.
According to the embodiment of the invention, the minimum single voltage of the battery is judged in real time, the allowable power for battery discharge is calculated according to the current output power of the power battery and the minimum single voltage, when the minimum single voltage reaches a preset undervoltage threshold, the power falling rate is controlled according to the voltage variation, and when the voltage variation is large, the allowable power for discharge is fast to fall; when the voltage variation is small, the allowable discharge power is slowly reduced, and when the lowest single voltage is raised, the allowable discharge power is raised at a certain speed, so that the self-adaptive control of the allowable discharge power is realized, the excessive dependence on the battery SOC is avoided, the power battery is used for power regulation and protection according to the self-discharge capacity, and the problems of power mutation, power loss and the like are solved.
Based on the principle shown in fig. 2, a description will be given below of a discharge allowable power control method of a power battery, as shown in fig. 3, including the steps of:
s1: firstly, acquiring the current battery SOC, the battery temperature and the battery cell voltage through a battery management system.
S2: the highest temperature and the lowest temperature are obtained by comparing the temperature data of each battery cell, and the lowest cell voltage U min is obtained by comparing the cell voltages of the batteries. And inquiring a battery discharge power mapping table according to the current battery SOC and the battery cell temperature, acquiring power values corresponding to the highest temperature and the lowest temperature, and taking the minimum value as reference discharge allowable power P 0.
S3: and comparing the lowest cell voltage U min with a preset under-voltage threshold U 1 of the battery, and recording the current actual output power P and the reference discharge allowable power P 0 of the lookup table when the lowest cell voltage U min of the battery is smaller than U 1.
S4: and judging the current variation trend of the lowest monomer voltage, when the lowest monomer voltage U min shows a descending trend, entering S5, otherwise entering S9.
S5: calculating a power change rate R, wherein r=a parameter a×du+r, dU is a difference between the current U min and the previous time U min, a may be a correction coefficient of a battery discharge power decrease rate, R may be a basic rate, and a and R are calibrated according to the actual vehicle.
S6: if the battery discharge allows the power to be immediately regulated down, the specific calculation method is as follows: the allowable power P 2 =p-r×t, where t is the cycle processing period of the battery management system.
S7: when the lowest cell voltage U min is less than U 2, where U 2 is the discharge cutoff voltage, the battery needs to stop discharging, and S8 is executed, otherwise S1 is executed.
S8: the allowable power P 2 is immediately set to 0, and discharge is prohibited.
S9: if the current discharge allowable power is up-regulated, the calculation method is as follows: the allowable power P 2＝P'2 + parameter B is t, wherein B is the rate of rise of the battery discharge power, and can be calibrated according to an actual vehicle.
In summary, the embodiment of the invention can realize smooth adjustment of the output power of the battery, remarkably improve the power smoothness of the whole vehicle and effectively avoid uncomfortable feeling caused by abrupt power change. Meanwhile, the embodiment of the invention can realize the control of the allowable discharge power by adopting a single discharge power mapping table, thereby avoiding the problem of power fluctuation possibly generated in the multi-table switching process and improving the stability and reliability of the system. On the basis of a discharge power mapping table, the battery power can be improved by more than 20% by optimizing a control strategy, and the power performance of the whole vehicle is further enhanced. In addition, the embodiment of the invention can also effectively overcome the influence caused by the SOC deviation, and can ensure that the battery cannot be overdischarged even if the SOC deviation reaches more than 20%, thereby prolonging the service life of the battery and improving the safety of the whole vehicle.
Next, a 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.
Fig. 4 is a block diagram schematically illustrating a discharge allowable power control apparatus of a power cell according to an embodiment of the present invention.
As shown in fig. 4, the discharge allowable power control device 10 of the power battery includes: the first acquisition module 100, the second acquisition module 200, the first determination module 300, and the control module 400.
The first obtaining module 100 is configured to obtain a lowest cell voltage of the power battery at the current moment; the second obtaining module 200 is configured to obtain the actual discharging power of the power battery at a time when the lowest cell voltage of the power battery starts to be smaller than the preset under-voltage threshold and the lowest cell voltage of the power battery at the previous time if the lowest cell voltage of the power battery at the current time is smaller than the preset under-voltage threshold; the first determining module 300 is configured to calculate a voltage variation trend and a voltage variation amount of the lowest cell voltage of the power battery according to the lowest cell voltage of the power battery at the current time and the lowest cell voltage of the power battery at the previous time, and determine a target variation rate of the allowable discharge power of the power battery at the current time according to the voltage variation trend and the voltage variation amount; the control module 400 is configured to control the discharge allowable power of the power cell based on the discharge actual power and the target rate of change.
In an embodiment of the present invention, the target rate of change includes a target rate of descent, and the control module 400 is further configured to: and if the target change rate is the target descent rate, controlling the allowable power descent of the discharge of the power battery according to the target descent rate by taking the actual discharge power of the power battery as a starting point at the moment when the lowest single voltage of the power battery starts to be smaller than the preset undervoltage threshold value.
Further, the first determining module 300 is further configured to: identifying whether the voltage change trend is a falling trend; and if the voltage change trend is a descending trend, calculating the target descending rate of the allowable discharging power of the power battery at the current moment according to the voltage change quantity.
Further, the first determining module 300 is further configured to: acquiring a reduction rate correction coefficient of discharge allowable power of the power battery; and calculating the target falling rate according to the voltage change amount and the falling rate correction coefficient.
Further, the decreasing rate correction coefficient is a linear equation, and the proportionality coefficient and the offset in the linear equation are preset values.
Further, the control module 400 is further configured to: if the target rate of change is the target rate of rise, the power cell is controlled to rise in the allowable power for discharge in accordance with the target rate of rise, starting from the allowable power for discharge of the power cell at the time when the lowest cell voltage of the power cell starts to rise.
Further, the first determining module 300 is further configured to: identifying whether the voltage change trend is an ascending trend; if the voltage change trend is an ascending trend, the target ascending rate of the discharge allowable power of the power battery at the current moment is a preset rate.
Further, the method further comprises the following steps: the identification module is used for identifying whether the lowest single voltage of the power battery at the current moment is smaller than the discharge cut-off voltage of the power battery or not before the discharge allowable power of the power battery is controlled according to the discharge actual power and the target change rate, wherein the discharge cut-off voltage is smaller than a preset undervoltage threshold; the control module 400 is further configured to prohibit the power battery from discharging if it is identified that the lowest cell voltage of the power battery at the current time is less than the discharge cut-off voltage of the power battery, and otherwise, control the discharge allowable power of the power battery according to the discharge actual power and the target change rate.
In an embodiment of the present invention, the method further includes: the second determining module is used for acquiring the highest temperature and the lowest temperature of the power battery if the lowest single voltage of the power battery at the current moment is greater than or equal to a preset undervoltage threshold value; the discharge allowable power of the power battery is determined according to the highest temperature and the lowest temperature.
It should be noted that the foregoing explanation of the embodiment of the method for controlling the allowable discharge power of the power battery is also applicable to the apparatus for controlling the allowable discharge power of the power battery of this embodiment, and will not be repeated here.
According to the discharging allowable power control device of the power battery, provided by the embodiment of the invention, by monitoring the lowest single voltage of the power battery, when the voltage is found to be lower than the preset undervoltage threshold, the voltage change trend and the change quantity are analyzed, and the target change rate of the discharging allowable power is adjusted accordingly, so that the discharging allowable power is highly matched with the actual discharging capacity of the power battery, and the risk of overdischarge of the battery is avoided while the vehicle power performance is ensured. By accurately controlling the discharge allowable power of the power battery, the vehicle can obtain stable power output under various working conditions, so that the comfort and fluency of driving are improved, a driver can enjoy the pleasure of driving as much as possible, the vehicle can also respond rapidly under the working conditions of emergency or high load, and sufficient power output is provided, so that the safety and reliability of the whole vehicle are obviously enhanced, and the problems that in the prior art, if the discharge allowable power is higher than the actual capacity of the battery and the power is not effectively controlled, the battery is overdischarged, the power is rapidly limited, the power of the vehicle is suddenly changed or lost and the like are solved.
Fig. 5 is a schematic structural diagram of a vehicle according to an embodiment of the present invention. The vehicle may include:
Memory 501, processor 502, and a computer program stored on memory 501 and executable on processor 502.
The processor 502 implements the discharge permission power control method of the power battery provided in the above-described embodiment when executing a program.
Further, the vehicle further includes:
a communication interface 503 for communication between the memory 501 and the processor 502.
Memory 501 for storing a computer program executable on processor 502.
The memory 501 may include high-speed RAM (Random Access Memory ) memory, and may also include non-volatile memory, such as at least one disk memory.
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 may be connected to each other via a bus and perform communication with each other. The bus may be an ISA (Industry Standard Architecture ) bus, a PCI (PERIPHERAL COMPONENT, external device interconnect) bus, or EISA (Extended Industry Standard Architecture ) bus, among others. The buses may be divided into address buses, data buses, control buses, etc. For ease of illustration, only one thick line is shown in fig. 5, but not only one bus or one type of bus.
Alternatively, 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 may perform communication with each other through internal interfaces.
The processor 502 may be a CPU (Central Processing Unit ) or an ASIC (Application SPECIFIC INTEGRATED Circuit, application specific integrated Circuit) or one or more integrated circuits configured to implement embodiments of the present invention.
The embodiment of the invention also provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the discharge allowable power control method of a power battery as above.
The embodiment of the invention also provides a computer program which is used for realizing the discharge allowable power control method of the power battery when being executed.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or N embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "N" means at least two, for example, two, three, etc., unless specifically defined otherwise.
Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and additional implementations are included within the scope of the preferred embodiment of the present invention in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order from that shown or discussed, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the embodiments of the present invention.
It is to be understood that portions of the present invention may be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, the N steps or methods may be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. As with the other embodiments, if implemented in hardware, may be implemented using any one or combination of the following techniques, as is well known in the art: discrete logic circuits having logic gates for implementing logic functions on data signals, application specific integrated circuits having suitable combinational logic gates, programmable gate arrays, field programmable gate arrays, and the like.
Those of ordinary skill in the art will appreciate that all or a portion of the steps carried out in the method of the above-described embodiments may be implemented by a program to instruct related hardware, where the program may be stored in a computer readable storage medium, and where the program, when executed, includes one or a combination of the steps of the method embodiments.
While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.
Claims (13)
1. A discharge allowable power control method of a power battery, comprising the steps of:
acquiring the lowest single voltage of the power battery at the current moment;
If the lowest single voltage of the power battery is smaller than a preset undervoltage threshold at the current moment, acquiring the discharging actual power of the power battery at the moment when the lowest single voltage of the power battery starts to be smaller than the preset undervoltage threshold and the lowest single voltage of the power battery at the last moment;
Calculating the voltage change trend and the voltage change quantity of the lowest single voltage of the power battery according to the lowest single voltage of the power battery at the current moment and the lowest single voltage of the power battery at the last moment, and determining the 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 quantity;
and controlling the discharge allowable power of the power battery according to the discharge actual power and the target change rate.
2. The discharge allowable power control method of a power cell according to claim 1, wherein said controlling the discharge allowable power of the power cell according to the discharge actual power and the target rate of change comprises:
And if the target change rate is the target descent rate, taking the actual discharge power of the power battery at the moment when the lowest single voltage of the power battery starts to be smaller than the preset undervoltage threshold value as a starting point, and controlling the allowable discharge power of the power battery to descend according to the target descent rate.
3. The discharge allowable power control method of a power cell according to claim 2, wherein said determining a target rate of change of the discharge allowable power of the power cell at the present time based on the voltage variation trend and/or the voltage variation amount includes:
Identifying whether the voltage variation trend is a falling trend;
and if the voltage change trend is the descending trend, calculating the target descending rate of the discharge allowable power of the power battery at the current moment according to the voltage change quantity.
4. The discharge allowable power control method of a power cell according to claim 3, wherein said calculating a target rate of decrease of the discharge allowable power of the power cell at the present time from the voltage variation amount includes:
Acquiring a reduction rate correction coefficient of the discharge allowable power of the power battery;
and calculating the target falling rate according to the voltage variation and the falling rate correction coefficient.
5. The discharge allowable power control method of a power cell according to claim 4, wherein said decrease rate correction coefficient is a linear equation in which a proportionality coefficient and an offset are preset values.
6. The discharge allowable power control method of a power cell according to claim 1, wherein said controlling the discharge allowable power of the power cell according to the discharge actual power and the target rate of change comprises:
And if the target change rate is the target rising rate, starting from the discharge allowable power of the power battery at the moment when the lowest single voltage of the power battery starts to rise, and controlling the discharge allowable power of the power battery to rise according to the target rising rate.
7. The discharge allowable power control method of a power cell according to claim 1, wherein said determining a target rate of change of the discharge allowable power of the power cell at the present time based on the voltage variation trend and/or the voltage variation amount includes:
identifying whether the voltage variation trend is an ascending trend;
And if the voltage change trend is an ascending trend, the target ascending rate of the discharge allowable power of the power battery at the current moment is a preset rate.
8. The discharge allowable power control method of a power cell according to claim 1, characterized by further comprising, before controlling the discharge allowable power of the power cell according to the discharge actual power and the target rate of change:
identifying whether the lowest single voltage of the power battery at the current moment is smaller than the discharge cut-off voltage of the power battery, wherein the discharge cut-off voltage is smaller than the preset undervoltage threshold;
And if the lowest single voltage of the power battery at the current moment is identified to be smaller than the discharge cut-off voltage of the power battery, the power battery is forbidden to discharge, otherwise, the discharge allowable power of the power battery is controlled according to the discharge actual power and the target change rate.
9. The discharge allowable power control method of a power cell according to claim 1, further comprising:
If the lowest single voltage of the power battery at the current moment is greater than or equal to the preset undervoltage threshold value, acquiring the highest temperature and the lowest temperature of the power battery;
And determining the discharge allowable power of the power battery according to the highest temperature and the lowest temperature.
10. A discharge-permitting power control device of a power battery, characterized by comprising:
The first acquisition module is used for acquiring the lowest single voltage of the power battery at the current moment;
The second acquisition module is used for acquiring the discharging actual power of the power battery at the moment when the lowest single voltage of the power battery starts to be smaller than the preset undervoltage threshold value and the lowest single voltage of the power battery at the last moment if the lowest single voltage of the power battery at the current moment is smaller than the preset undervoltage threshold value;
the first determining module is used for calculating the voltage change trend and the voltage change quantity of the lowest single voltage of the power battery according to the lowest single voltage of the power battery at the current moment and the lowest single voltage of the power battery at the last moment, and determining 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 quantity;
and the control module is used for controlling the discharge allowable power of the power battery according to the discharge actual power and the target change rate.
11. A vehicle, characterized by comprising: a memory, a processor and a computer program stored on the memory and executable on the processor, the processor executing the program to implement the discharge allowable power control method of a power cell according to any one of claims 1 to 9.
12. A computer-readable storage medium having stored thereon a computer program or instructions, characterized in that the program or instructions is executed by a processor for implementing a discharge allowable power control method of a power cell according to any one of claims 1-9.
13. A computer program product having a computer program or instructions stored thereon, which, when executed, is adapted to carry out the method of discharging allowed power control of a power cell according to any of claims 1-9.
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