CN113851757B

CN113851757B - Power battery thermal management method and device

Info

Publication number: CN113851757B
Application number: CN202111121840.XA
Authority: CN
Inventors: 任庆鑫
Original assignee: Jingwei Hengrun Tianjin Research And Development Co ltd
Current assignee: Jingwei Hengrun Tianjin Research And Development Co ltd
Priority date: 2021-09-24
Filing date: 2021-09-24
Publication date: 2023-08-08
Anticipated expiration: 2041-09-24
Also published as: CN113851757A

Abstract

The invention provides a power battery thermal management method and a device, which are applied to the technical field of automobiles, wherein the method takes obtained reference running data as target running data, then determines the running time length and a first mapping relation of a vehicle according to the target running data, determines a second mapping relation based on a power battery thermal balance equation and the first mapping relation, completes the prediction of the working temperature of the power battery at each running time in the running time length through the first mapping relation and the second mapping relation, then obtains the highest working temperature recorded in the second mapping relation and the target running time corresponding to the highest working temperature, and starts a forced cooling device before the target running time if the obtained highest working temperature is greater than or equal to a preset temperature threshold. By starting the forced cooling device before the target running time, the forced cooling device cools the power battery in advance, so that the performance requirement on the forced cooling device can be effectively reduced, and the overall cost control of the vehicle is facilitated.

Description

Power battery thermal management method and device

Technical Field

The invention belongs to the technical field of automobiles, and particularly relates to a power battery thermal management method and device.

Background

In recent years, power batteries used in new energy automobiles are continuously developed towards high energy density, and the high energy density power batteries are inevitably accompanied with high heat generation in operation, so that in order to ensure that the power batteries are in a proper working temperature range in the working process, the new energy automobiles have to adopt corresponding heat management methods to control the heat generation process, particularly the heat dissipation process of the new energy automobiles.

The existing power battery thermal management method generally monitors and obtains the highest temperature Tmax of the power battery according to a battery management system, and determines which management measures to take according to the magnitude relation between the highest temperature Tmax and a preset temperature threshold. For example, if the highest temperature Tmax of the power battery is greater than or equal to a preset temperature threshold T1, starting a forced cooling device to forcedly cool the power battery; if the highest temperature Tmax of the power battery is greater than or equal to a preset temperature threshold T2 which is higher than T1, the output power of the power battery is forcedly limited to prevent the battery from generating a great amount of heat further in order to ensure the safety of the power battery and the vehicle.

The existing thermal management method is realized based on the actual temperature of the power battery, when the actual temperature of the power battery reaches a preset temperature threshold T1, the power battery is in a higher temperature state in fact, more importantly, the power battery still continuously generates heat to be subjected to forced cooling at the moment, the forced cooling device is required to have enough cooling capacity to rapidly reduce the temperature of the power battery in a short time, the performance requirement on the forced cooling device is higher, and the overall cost control of a vehicle is not facilitated.

Further, if the cooling capacity of the forced cooling device is insufficient, the battery temperature is greater than or equal to a preset temperature threshold T2 to trigger a power limiting measure, so that the vehicle cannot effectively respond to the driving requirement, and the driving experience of the user is affected.

Disclosure of Invention

In view of the above, the present invention aims to provide a thermal management method and a thermal management device for a power battery, which predict the temperature of the power battery and start a forced cooling device before the power battery reaches the highest temperature, so that the power battery has enough time to cool down, and further solve the problems in the prior art, and the specific scheme is as follows:

in a first aspect, the present invention provides a power cell thermal management method, comprising:

acquiring reference running data of a vehicle, and taking the reference running data as target running data;

determining the driving time length of the vehicle and a first mapping relation according to the target driving data; the first mapping relation records the corresponding relation between the output current and the running time of the power battery of the vehicle in the running time;

determining a second mapping relation based on a power battery heat balance equation and the first mapping relation;

The second mapping relation records the corresponding relation between the working temperature of the power battery and the running time under the condition that the power battery is controlled to work according to the first mapping relation and a natural cooling mode is adopted;

acquiring the highest working temperature recorded in the second mapping relation and a target running time corresponding to the highest working temperature;

and if the highest working temperature is greater than or equal to a preset temperature threshold value, starting the forced cooling device before the target running time.

Optionally, the turning on the forced cooling device before the target driving moment includes:

acquiring preset starting time of the forced cooling device;

determining a target strong cooling starting moment in the candidate duration;

the candidate duration is a duration from the starting time of the running duration to the target running time, and the candidate duration does not include the target running time;

the target forced cooling starting time is a driving time corresponding to the working temperature of the power battery in the driving time period being smaller than the preset temperature threshold;

and controlling the forced cooling device to be started at the target forced cooling starting moment and continuously running the preset starting time.

Optionally, the determining the target strong cooling start time in the candidate duration includes:

selecting at least one driving time in the candidate duration as a first candidate strong cooling start time;

based on a power battery heat balance equation and the first mapping relation, respectively determining a third mapping relation corresponding to each first candidate strong cold starting moment;

the third mapping relation records a corresponding relation between the working temperature of the power battery and the running time under the condition that the power battery is controlled to work according to the first mapping relation and the forced cooling device is controlled to be started at the first candidate forced cooling starting time and continuously runs for the preset starting time;

if at least one third mapping relation exists and meets a first preset screening condition, determining a target strong-cold starting moment in first candidate strong-cold starting moments corresponding to each third mapping relation meeting the first preset screening condition;

wherein, the first preset screening condition includes: and any working temperature of the power battery recorded in the third mapping relation is smaller than the preset temperature threshold.

Optionally, determining the target strong-cold start time in the first candidate strong-cold start time corresponding to each third mapping relation satisfying the first preset screening condition includes:

Taking the third mapping relation meeting the first preset screening condition as a target third mapping relation;

respectively calculating the average value of the working temperatures recorded in the third mapping relation of each target to obtain a corresponding temperature average value;

and taking the first candidate strong cooling start time corresponding to the target third mapping relation with the smallest temperature mean value as the target strong cooling start time.

screening a second candidate strong cooling starting moment in the candidate duration based on a power battery heat balance equation and a dichotomy, and recording a fourth mapping relation;

the fourth mapping relation records a corresponding relation between the working temperature of the power battery and the running time under the condition that the power battery is controlled to work according to the first mapping relation and the forced cooling device is controlled to be started at the second candidate forced cooling starting time and continuously run for the preset starting time, and any working temperature of the power battery recorded in the fourth mapping relation is smaller than the preset temperature threshold;

and determining the target strong cooling starting moment in the second candidate strong cooling starting moment.

Optionally, the power battery thermal management method provided in the first aspect of the present invention further includes:

in the process of screening the second candidate strong-cold starting time in the candidate duration based on the dichotomy, if the second candidate strong-cold starting time meeting the second preset screening condition exists, determining the second candidate strong-cold starting time corresponding to the second preset screening condition as the target strong-cold starting time, and stopping screening;

the second preset screening condition comprises: and under the condition that the power battery is controlled to work according to the first mapping relation, and the forced cooling device is controlled to be started at the second candidate forced cooling starting moment and continuously operates for the preset starting duration, the average value of the working temperature of the power battery is smaller than a service life temperature threshold value, and the service life temperature threshold value is smaller than the preset temperature threshold value.

in the process of screening the second candidate strong cold starting moment in the candidate duration based on the dichotomy, if the condition is metStopping temperature screening; wherein Δt is a preset duration, n is a set value, Y is a candidate duration, and p is the number of times of executed screening.

Optionally, if the target strong cold start time is not determined in the candidate time length, the preset start time length is increased, and the step of determining the target strong cold start time in the candidate time length is performed again.

calculating the average value of the actual output current of the power battery in the target duration to obtain the average value of the actual measured current;

calculating the average value of the output current of the power battery under the condition of controlling the power battery to work according to the first mapping relation in the target time length to obtain a predicted current average value;

if the difference value between the actually measured current average value and the predicted current average value exceeds a preset current range, taking the actual running data of the vehicle as the target running data;

and returning to the step of executing the first mapping relation and determining the running duration of the vehicle according to the target running data.

In a second aspect, the present invention provides a power battery thermal management device, comprising:

a first acquisition unit configured to acquire reference running data of a vehicle, and take the reference running data as target running data;

A first determining unit, configured to determine a driving duration of the vehicle and a first mapping relationship according to the target driving data;

the first mapping relation records the corresponding relation between the output current and the running time of the power battery of the vehicle in the running time;

the second determining unit is used for determining a second mapping relation based on a power battery heat balance equation and the first mapping relation;

a second obtaining unit, configured to obtain a highest operating temperature recorded in the second mapping relationship and a target driving time corresponding to the highest operating temperature;

and the control unit is used for starting the forced cooling device before the target running time if the highest working temperature is greater than or equal to a preset temperature threshold value.

The method and the device for thermal management of the power battery provided by the invention are characterized in that after the reference running data of the vehicle is obtained and the obtained reference running data is used as target running data, the running time length of the vehicle and a first mapping relation are determined according to the target running data, and a second mapping relation is further determined based on a power battery thermal balance equation and the first mapping relation, wherein the first mapping relation records the corresponding relation between the output current and the running time when the power battery of the vehicle runs; and the second mapping relation records the corresponding relation between the working temperature of the power battery and the running time under the condition that the power battery is controlled to work according to the first mapping relation and a natural cooling mode is adopted, namely, the working temperature of the power battery at each running time in a running time period is predicted through the first mapping relation and the second mapping relation, then the highest working temperature recorded in the second mapping relation and the target running time corresponding to the highest working temperature are obtained, and if the obtained highest working temperature is greater than or equal to a preset temperature threshold value, the forced cooling device is started before the target running time.

According to the thermal management method and the thermal management device, the working temperature of the power battery is predicted based on the reference driving data, if the highest working temperature in the predicted result is greater than or equal to the preset temperature threshold, the forced cooling device is started before the target driving time corresponding to the highest working temperature, so that the forced cooling device cools the power battery in advance.

Further, as the power battery is cooled in advance, the temperature of the power battery cannot be further increased, and further protection measures for limiting power output cannot be triggered, so that the vehicle is ensured to effectively respond to driving requirements, and the driving experience of a user is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a flow chart of a method for thermal management of a power cell according to an embodiment of the present invention;

FIG. 2 is a flow chart of another method of thermal management of a power cell provided by an embodiment of the present invention;

FIG. 3 is a flow chart of yet another method for thermal management of a power cell according to an embodiment of the present invention;

fig. 4 is a block diagram of a power battery thermal management device according to an embodiment of the present invention;

fig. 5 is a block diagram of another power battery thermal management device according to an embodiment of the present invention.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The power battery thermal management method provided by the embodiments of the invention can be applied to a controller of a battery management system in a whole vehicle, can also be applied to other controllers which can acquire various driving data, execute a preset control program and control the output of a power battery in the whole vehicle, and can be applied to a server on a network side in certain cases.

Referring to fig. 1, fig. 1 is a flowchart of a power battery thermal management method according to an embodiment of the present invention, as shown in fig. 1, the flowchart may include:

s100, acquiring reference driving data of the vehicle, and taking the reference driving data as target driving data.

In the power battery thermal management method provided in this embodiment, the reference running data mainly refers to parameters that can be used to determine the running duration of the vehicle and the change of the output current of the power battery during the running duration, especially during a certain driving cycle. Since the parameters acquired in S100 are prepared for determining the driving duration and the first mapping relationship in S110, the specific parameters acquired in this step are related to the specific method for determining the driving duration and the first mapping relationship in S110.

In practical applications, the reference driving data may include a departure place, a destination, a current SOC (State of Charge) value, a current SOE (State of Energy) value, historical data of power battery output current, road condition information from the departure place to the destination, road network change information, traffic light setting conditions, and the like of the vehicle, which are not listed here one by one.

It should be noted that, in most cases, the method provided by the embodiment of the present invention is performed immediately after the vehicle is started, that is, most of the reference running data is obtained directly or predicted based on the history data and the current state of the vehicle, so in this step, the reference running data is first used as the target running data for the subsequent control process, if in the actual driving process, the deviation between the control based on the reference running data and the actual situation is found to be larger, the method provided by the present invention can instead perform the subsequent management process based on the actual running data of the vehicle, that is, the actual running data is used as the target running data, and further, the better management effect is achieved.

As to how to determine whether or not the switching of the target travel data is necessary, details will be described later, and will not be described in detail here.

S110, determining the driving time length of the vehicle and a first mapping relation according to the target driving data.

First, it is conceivable that in the present embodiment, the running time of the vehicle refers to the running time in the current driving cycle, that is, if the vehicle does not flameout on the way from the departure point to the destination, the whole process is one driving cycle, and if the vehicle is stopped by flameout several times on the way from the departure point to the destination, it is theoretically possible to divide into a plurality of driving cycles, and this case is required to execute the management method provided by the present invention in each driving cycle.

Further, in the first mapping relationship described in the embodiment of the present invention, a correspondence relationship between the output current and the driving time of the power battery of the vehicle in the foregoing driving duration, that is, a time-dependent change relationship of the output current of the power battery in the driving cycle, is mainly recorded.

The specific embodiment of the first mapping relation can be a functional relation between the output current of the power battery and the running time, namely, the functional relation is expressed by a specific functional formula, a curve of the change of the output current along with the running time, or a group of data pairs, wherein each data pair records one running time and the output current corresponding to the running time.

For the specific determination process of the first mapping relationship, the method may be implemented in combination with the prior art, for example:

1. and the first mapping relation is estimated by combining a vehicle-mounted or mobile phone navigation system. For example, the destination is input in the vehicle-mounted or mobile navigation, the arrival time, i.e. the driving duration, can be directly predicted by calculation, the prediction of the arrival time is comprehensively calculated according to a scientific data model system and a navigation system tested by a large number of users for years, and factors such as big data accumulation, real-time road condition research and judgment, road network condition evolution trend estimation, road historical operation data comparison and the like, and even the number of traffic lights and waiting time in the route can be predicted, so that the change condition of the output current of the power battery in the driving duration can be obtained.

2. Based on historical driving data of a user recorded by a vehicle BMS (Battery Management System, a battery management system), and the SOC or SOE calculated by the BMS, the change condition of the output current of the power battery is estimated when the vehicle runs within a driving time period corresponding to the SOC or SOE of 0.

3. And taking the NEDC (New European Driving Cycle ) working condition as the estimation of the running current working condition, and combining the SOC or SOE calculated by the BMS to estimate the change condition of the output current of the power battery when the NEDC working condition runs within the running time corresponding to the SOC or SOE of 0.

Of course, in practical application, other methods may be adopted to obtain the estimated running duration, and the change situation of the output current of the power battery is not listed here.

S120, determining a second mapping relation based on the power battery heat balance equation and the first mapping relation.

The power battery heat balance equation designed in the embodiment of the invention and the subsequent embodiments is as follows:

Q _p，n -Q _n，n -Q _c，n ＝C _b m _b (T _n+1 -T _n )

wherein Q is _p，n The heat generated by the power battery in the running time period corresponding to the running time n to the running time n+1; q (Q) _n，n The heat dissipated by the power battery in a natural cooling mode in the running time period corresponding to the running time n to the running time n+1; q (Q) _c，n In order to dissipate heat of the power battery in a forced cooling mode in a driving time period corresponding to the driving time n to the driving time n+1, Q is as follows when a natural cooling mode is adopted _c，n ＝0；C _b Specific heat capacity of the power battery; m is m _b Is the mass of the power battery; t (T) _n+1 The temperature of the power battery corresponding to the driving time n+1; t (T) _n The temperature of the power battery corresponding to the traveling time n.

The method for obtaining the respective parameter items involved in the above-mentioned heat balance equation is described below.

For Q _p，n In the prior art, the embodiment of the invention is realized by adopting a Bernedi heat generation model, and the expression of the model is as follows:

wherein, the liquid crystal display device comprises a liquid crystal display device,at t _n The heat generation power of the power cell at the moment, it is conceivable that t is assumed _n+1 -t _n For a smaller period of time, it can be considered that +.>Remain unchanged; i is the estimated working current of the power battery based on the first mapping relation; OCV is the open-circuit voltage of the power battery, and is related to the SOC value and the battery temperature T of the power battery; u is the actual working voltage of the power battery; f is the temperature of the power battery, and it should be noted that the parameter T is the measured temperature of the power battery at the initial time of the driving cycle, and is the predicted temperature in the subsequent application.

I (OCV-U) is calculated to obtain polarized heat comprising Joule heat caused by internal resistance of the battery and polarized heat caused by mass transfer loss;and calculating to obtain the reaction heat of the anode and the cathode of the power battery.

Wherein, when the power battery leaves the factory, the battery manufacturer has measured the OCV in detail, and can obtain the corresponding OCV and the corresponding OCV for the actual productInformation.

For Q _n，n Can be realized based on Newton's law of cooling, which has the following relation:

wherein T is _e，n The ambient temperature outside the power battery pack (i.e., the power battery) at time n; r is R _n Is the convective heat transfer resistance between the power battery pack and the external environment.

In practical application, R _n The value of (2) is influenced by the relative speed Ve between the power cell pack and the surrounding air, so that the value can be determined as follows:

and placing the power battery pack to be tested in a wind tunnel or an incubator, adjusting the temperature of the wind tunnel or the incubator to be the maximum temperature Tmax allowed by the power battery pack, and standing until the temperature of all battery monomers in the battery pack is Tmax+/-1 ℃. Starting the test, adjusting the temperature of the wind tunnel or the incubator to Te (Te < Tmax is the possible ambient temperature of the vehicle, for example, the temperature range is-30-50 ℃, the temperature can be selected by taking 10 ℃ as the gradient, the smaller the gradient is, and R is obtained through measurement _n More accurate) and controlling the wind speed in the incubator to be Ve (for example, the possible speed interval of the vehicle is 0-120 km/h, then the gradient can be selected by taking 10km/h as the gradient, the smaller the gradient is, R is obtained through measurement _n More accurate) until all the cell temperatures in the battery pack stabilize to te±1 ℃, the test is stopped. During the test, the battery temperature was recorded at different times. R can be obtained according to the test procedure _n The following are provided:

wherein R is _n Is at ambient temperature T _e Convective heat transfer resistance, T, at time n under conditions of relative velocity Ve between the power battery pack and ambient air _m And T _m+1 The temperature of the power battery pack to be tested during the test is shown. According to the above test, the battery temperature T can be obtained _b Ambient temperature T _e R related to the relative velocity Ve between the battery pack and the ambient air _n Can be used for calculating Q _n，n And (3) using.

Further, for Q _c，n And can also be realized according to newton's law of cooling:

wherein T is _c，m The cooling temperature of the forced cooling mode at m time is the cooling liquid temperature if the cooling mode is liquid cooling, and is the refrigerant evaporation temperature if the cooling mode is direct cooling; r is R _c，n Heat transfer resistance for the power battery pack and the forced cooling device.

Wherein R is _c，n The values of (2) may be determined as follows:

And placing the power battery pack in a wind tunnel or an incubator, adjusting the temperature of the wind tunnel or the incubator to be the maximum temperature Tmax allowed by the power battery pack, and standing until the temperature of all battery monomers in the power battery pack is Tmax+/-1 ℃. Beginning test, adjusting the temperature of the wind tunnel or the incubator to be T _c，m Forced cooling is started until the temperature of all battery monomers in the battery pack is stabilized to T _c，m Stop the test at + -1deg.C. During the test, the battery temperature was recorded at different times. R can be obtained according to the test procedure _c，n The following are provided:

it is conceivable that the above-described process of obtaining the relevant parameters is performed between actual applications of the power battery to the whole vehicle, and after obtaining the corresponding parameters, the relevant parameters can be directly applied to the use process of the power battery, without repeatedly measuring the above-described parameters during the use process of the vehicle. Based on the above, combine with Q _p，n -Q _n，n -Q _c，n ＝C _b m _b (T _n+1 -T _n ) And the corresponding relation between the output current of the power battery and the running time recorded in the first mapping relation can obtain the change relation of the working temperature of the power battery along with the running time.

In this step, the corresponding relationship between the operating temperature of the power battery under the self-cooling condition and the driving time is obtained, so that the Q in the heat balance equation of the power battery is needed _c，n And taking zero, the corresponding relation between the working temperature of the power battery and the running time, namely the second mapping relation, can be obtained under the condition that the power battery is controlled to work according to the first mapping relation and a natural cooling mode is adopted. Correspondingly, forced cooling is started in the control process to obtain corresponding Q _c，n The pair between the working temperature and the running time of the power battery can be obtained under the forced cooling modeThe correspondence.

S130, acquiring the highest operating temperature recorded in the second mapping relation and the target running time corresponding to the highest operating temperature.

As described above, the second mapping relationship records the operating temperatures of the power battery at each driving time in the driving time period of the vehicle, so that the operating temperature corresponding to any driving time can be obtained by querying the second mapping relationship. Based on this, by traversing the second map, the highest operating temperature recorded therein and the target travel time corresponding to the highest operating temperature can be obtained.

S140, judging whether the highest working temperature is greater than or equal to a preset temperature threshold, and if so, executing S150.

The preset temperature threshold value in the embodiment of the invention can be set based on the allowable highest temperature of the power battery in practical application, and the specific value of the preset temperature threshold value is not limited, and can be flexibly selected according to practical control and protection requirements.

After the highest working temperature is obtained, judging the magnitude relation between the obtained highest working temperature and a preset temperature threshold, wherein the highest working temperature is obtained under the self-cooling condition, so that if the highest working temperature is smaller than the preset temperature threshold, the working temperature of the power battery does not exceed the preset temperature threshold in the natural cooling mode in the whole running time of the vehicle, and further, the situation that a forced cooling device is not required to be started in the current driving cycle can be judged, and the current management process can be temporarily exited; correspondingly, if the obtained maximum working temperature is greater than or equal to the preset temperature threshold, the forced cooling device needs to be started in the current driving cycle, and then the step S150 is continued.

S150, starting the forced cooling device before the target driving moment.

In a specific application, the time and the duration of turning on the forced cooling device should be determined according to a preset temperature threshold, and the forced cooling device should be turned on so that the highest working temperature of the power battery is smaller than the preset temperature threshold.

In order to reduce the performance requirement on the forced cooling device and provide a better running environment for the power battery, the management method provided by the embodiment of the invention starts the forced cooling device when the running time reaches the target running time after determining the target running time when the highest working temperature is required to occur, and reduces the temperature of the power battery in advance.

In summary, according to the thermal management method provided by the embodiment of the invention, the working temperature of the power battery is predicted based on the reference driving data, if the highest working temperature in the predicted result is greater than or equal to the preset temperature threshold, it is indicated that forced cooling is necessary, the forced cooling device is started before the target driving time corresponding to the highest working temperature, so that the forced cooling device cools the power battery in advance.

Based on the foregoing, it is conceivable that the key to achieving the above-mentioned management objective is how to determine at which time before the target driving time the forced cooling apparatus is turned on, and for this reason, the embodiment of the present invention provides a more specific embodiment, and the implementation manner of S150 in the foregoing embodiment is expanded.

Optionally, referring to fig. 2, fig. 2 is a flowchart of another power battery thermal management method according to an embodiment of the present invention, and on the basis of the description shown in fig. 1, a specific flow of turning on the forced cooling device before the target driving time may include:

s200, acquiring preset starting time of the forced cooling device.

In practical application, the preset opening time period may be set based on the minimum opening time period of the forced cooling device, and in general cases, the preset opening time period may be set to be the minimum opening time period of the forced cooling device, and of course, other time periods longer than the minimum opening time period may also be selected, and the specific value of the preset opening time period is not specifically limited in the present invention.

S210, determining the target strong cooling start time in the candidate time length.

Specifically, the candidate duration mentioned in the embodiment of the present invention is a duration between the start time of the foregoing travel duration and the target travel time, and it is conceivable that the candidate duration does not include the target travel time since the forced cooling device is to be turned on before the target travel time. Correspondingly, the target forced cooling start time is the driving time corresponding to the working temperature of the power battery in the driving time period being smaller than the preset temperature threshold, namely if the forced cooling device starts at the target forced cooling start time and keeps the operation of the forced cooling device for the preset start time period, the working temperature of the power battery in the current driving cycle can be ensured not to be higher than the preset temperature threshold any more.

Optionally, referring to fig. 3, fig. 3 is a flowchart of still another power battery management method according to an embodiment of the present invention, where the embodiment focuses on a method for determining a target strong cold start time, specifically,

s300, selecting at least one driving time in the candidate duration as a first candidate strong cooling start time.

Firstly, selecting the number of the first candidate strong-cold starting moments, namely selecting a plurality of first candidate strong-cold starting moments simultaneously in a candidate duration, and respectively executing subsequent steps aiming at each first candidate strong-cold starting moment, wherein the processing mode is thought to require a processor to have enough strong operation capacity and high requirements on equipment hardware; correspondingly, only one first candidate strong-cold start time can be selected at a time, and subsequent operation steps are executed for the first candidate strong-cold start time, so that the hardware performance requirement on the processor can be remarkably reduced.

Secondly, for the specific selection of the candidate strong cooling starting time, any time in the candidate duration can be used as the first candidate strong cooling starting time in a traversing mode.

S310, based on a power battery heat balance equation and the first mapping relation, determining a third mapping relation corresponding to each first candidate strong cold starting moment respectively.

As described above, in the case of natural cooling of the power battery, Q in the power battery thermal equilibrium equation can be calculated _c，n Taking zero, correspondingly, starting forced cooling in the control process to obtain corresponding Q _c，n And obtaining the corresponding relation between the working temperature of the power battery and the running time under the forced cooling mode of the power battery. The main purpose of this step is to obtain the relevant data of the power battery under the forced cooling condition, so in the power battery heat balance equation described in this step, Q _c，n It is necessary to participate in a specific calculation process.

Based on the definition of the second mapping relationship, the third mapping relationship mentioned in the embodiment refers to a corresponding relationship between the working temperature of the power battery and the driving time when the power battery is controlled to work according to the first mapping relationship and the forced cooling device is controlled to be started at the first candidate forced cooling start time and continuously run for a preset start time.

That is, through the foregoing steps, the correspondence between the power battery output current and the running time, that is, the first map, and the first candidate forced cooling start time and the preset start time period of the forced cooling apparatus have been obtained, and in this step, it is necessary to further obtain the correspondence between the operating temperature of the power battery and the running time period in the case where the power battery output current is controlled in accordance with the first map, and the forced cooling apparatus is controlled to be started at the first candidate forced cooling start time and to continue to run for the preset start time period.

It should be noted that, for each first candidate strong-cold start time, a corresponding third mapping relationship needs to be obtained, that is, one first candidate strong-cold start time corresponds to one third mapping relationship, and for each third mapping relationship obtaining process, the obtaining process of the second mapping relationship may be implemented by referring to the obtaining process of the first mapping relationship, which is not described herein again.

S320, judging whether at least one third mapping relation meets the first preset screening condition, and if so, executing S330.

Optionally, the first preset screening condition is: and any working temperature of the power battery recorded in the third mapping relation is smaller than a preset temperature threshold.

If at least one third mapping relationship exists to meet the first preset screening condition, it is indicated that at least one management process exists, so that the working temperature of the power battery in the whole driving duration is smaller than the preset temperature threshold, and the expected control target can be achieved, and in this case, S330 is continuously executed.

If any third mapping relation does not exist to meet the first preset screening condition, the fact that the current preset opening time length of forced cooling is difficult to meet the cooling requirement is indicated, the preset opening time length needs to be further increased, and the control flow provided by the embodiment shown in fig. 2 is re-executed until at least one third mapping relation meeting the first preset screening condition is determined. The specific content for increasing the preset opening time period will be expanded later, and will not be described in detail here.

S330, determining a target strong cooling start time in the first candidate strong cooling start time corresponding to each third mapping relation meeting the first preset screening condition.

Specifically, if only one third mapping relation satisfying the first preset screening condition is satisfied, the first candidate strong-cold start time corresponding to the third mapping relation is taken as the target strong-cold start time, and if a plurality of third mapping relations satisfying the first preset screening condition are included, one of a plurality of third mapping relations satisfying the first preset screening condition is required to be selected.

Optionally, when the third mapping relationship meeting the first preset screening condition includes a plurality of third mapping relationships, the third mapping relationship meeting the first preset screening condition may be used as a target third mapping relationship, average values of working temperatures recorded in the target third mapping relationships are calculated respectively to obtain corresponding temperature average values, and then a first candidate strong-cold start time corresponding to the target third mapping relationship with the smallest obtained temperature average value is used as the target strong-cold start time.

It is conceivable that the target third mapping relationship determined according to the above process can make the working temperature of the power battery lowest, which is more beneficial to prolonging the service life of the power battery.

Alternatively, in practical applications, the foregoing driving duration may be very long, which results in a relatively large range of candidate durations, and the entire process of determining the target strong cooling start time may take a long time, which may be a significant challenge for the computing capability and computing time of the processor.

In order to determine the target strong-cold start time in a shorter time, it may be further determined whether at least one third mapping relationship satisfies the second preset screening condition, and the target strong-cold start time is determined in the first candidate strong-cold start time corresponding to each third mapping relationship satisfying the second preset screening condition.

The second preset screening conditions in this embodiment are as follows: the average value of the working temperatures of the power batteries recorded in the third mapping relation is smaller than a service life temperature threshold value, and the service life temperature threshold value is smaller than a preset temperature threshold value.

Specifically, the lifetime temperature threshold mentioned in this embodiment refers to an average temperature of the power battery allowed by the service life of the power battery, and if the average temperature of the power battery in the whole working process is not greater than the average temperature, it is indicated that the current driving cycle does not damage the service life of the power battery, in this case, the target third mapping relationship may be determined in at least one third mapping relationship satisfying the second preset screening condition, and the first candidate strong-cold start time corresponding to the target third mapping relationship may be used as the target strong-cold start time.

Of course, if there are multiple third mapping relationships that satisfy the second preset screening condition, the target third mapping relationship may also be selected according to the temperature average value of the power battery corresponding to each third mapping relationship, which is not described herein again.

S220, controlling the forced cooling device to be started at the target forced cooling starting moment and continuously running for a preset starting time.

After the target forced cooling start time is determined, the forced cooling device can be controlled to start at the target forced cooling start time and continuously run for a preset start time, and in this case, the working temperature of the power battery in the whole driving cycle cannot exceed a preset temperature threshold, so that the normal use of the power battery is ensured.

Alternatively, if the method provided in the embodiment shown in fig. 3 fails to determine the target strong cooling start time within the candidate duration, which indicates that the on duration of the forced cooling apparatus is not long enough, and it is difficult to effectively reduce the temperature of the power battery, in this case, the preset on duration needs to be increased, that is, the time for controlling the start of the forced cooling apparatus is longer, and then the method provided in the embodiment shown in fig. 3 is performed again, which, of course, may be understood that step S210 in the embodiment shown in fig. 2 is performed again until the target strong cooling start time is obtained.

Optionally, there are various specific ways of increasing the preset opening duration, for example, the preset opening duration may be increased by multiple times according to a preset multiple, or the preset opening duration may be increased according to a preset amplification proportion, which are all preferable, and the method also belongs to the protection scope of the present invention under the premise of not exceeding the scope of the core idea of the present invention.

In summary, the present embodiment provides a method for determining when to start the forced cooling device, which according to the method provided in the present embodiment, not only can the forced cooling device be started in advance, and reduce the hardware requirement for the forced cooling device, but also can ensure that the working temperature of the power battery in the whole driving cycle does not exceed the preset temperature threshold, thereby being beneficial to prolonging the service life of the power battery.

Based on the method for determining the target strong-cold start time provided by the embodiment shown in fig. 3, if the number of first candidate strong-cold start times is numerous, the preset start time is most likely to be required to be continuously adjusted, and the process of determining the target strong-cold start time consumes a long time, so that a great deal of hardware resources are occupied, the thermal management effect of the power battery is also affected, and even the service life of the power battery is affected. Therefore, the embodiment of the invention also provides a method for determining the target strong cold starting moment based on the dichotomy and the power battery heat balance equation.

Specifically, when the target strong-cold starting time is determined in the candidate duration, the second candidate strong-cold starting time is screened in the candidate duration based on a power battery heat balance equation and a dichotomy, and a fourth mapping relation is recorded. The fourth mapping relationship in this embodiment is recorded in the case that the power battery is controlled to work according to the first mapping relationship, and the forced cooling device is controlled to be started at the second candidate forced cooling start time and continuously run for a preset start time, where the corresponding relationship between the working temperature of the power battery and the running time is recorded, and any working temperature of the power battery recorded in the fourth mapping relationship is less than a preset temperature threshold. Then, in each second candidate strong cold start time, a target strong cold start time is determined.

The implementation process of the above embodiment is specifically described below in conjunction with a specific dichotomy:

assuming that the highest working temperature occurs at the moment Y in the candidate duration, the driving duration is Z, and the preset opening duration of the forced cooling device is deltat, the following steps are provided:

the 1 st temperature estimation is carried out on the target strong cooling starting moment in the time period of 0-Z by a dichotomy, and the process is as follows:

in the period of 0-Y/2, T is calculated according to the following formula _n+1 ：

T is calculated according to the following formula in the time period of Y/2-Y/2+delta T _n+1 ：

In the period of Y/2+Deltat-Z, the following formula is adoptedCalculate T _n+1 ：

Judging whether the fourth mapping relation obtained by the secondary temperature estimation meets a preset screening condition, and if so, recording the secondary fourth mapping relation as T (T) 1. Wherein, preset screening conditions include: and under the condition that the power battery is controlled to work according to the first mapping relation, and the forced cooling device is controlled to continuously run for a preset starting time according to the starting time determined by the dichotomy, any working temperature of the power battery is smaller than a preset temperature threshold value.

According to the preset opening time length delta T, performing 2 nd temperature estimation on the target forced cooling opening time within the time periods of 0-Y/2 and Y/2-Y respectively by a dichotomy, namely sequentially opening the forced cooling device within the time periods of Y/4-Y/4+delta T and 3Y/4-3Y/4+delta T, and temporarily recording the obtained fourth mapping relations as T (T) 11 and T (T) 12 respectively, and judging whether the corresponding fourth mapping relations meet preset screening conditions or not:

if the T (T) 11 meets the preset screening condition and the T (T) 12 does not meet the preset screening condition, marking the T (T) 11 as T (T) 2 when the fourth mapping relation obtained by the 1 st temperature estimation meets the preset screening condition, marking the T (T) 11 as T (T) 1 when the fourth mapping relation obtained by the 1 st temperature estimation does not meet the preset screening condition, and omitting a cooling start section of a forced cooling start time estimation scheme for obtaining the T (T) 12 in the subsequent dichotomy temperature estimation, namely, continuing to estimate the forced cooling start time within a Y/2-Y time period;

If the T (T) 12 meets the preset screening condition and the T (T) 11 does not meet the preset screening condition, marking the T (T) 12 as T (T) 2 when the fourth mapping relation obtained by the 1 st temperature estimation meets the first preset screening condition, marking the T (T) 12 as T (T) 1 when the fourth mapping relation obtained by the 1 st temperature estimation does not meet the preset screening condition, and omitting a cooling start section of a forced cooling start time estimation scheme for obtaining the T (T) 11 in the subsequent dichotomy temperature estimation, namely, continuing to estimate the forced cooling start time within a time period of not 0-Y/2;

if both T (T) 11 and T (T) 12 meet the preset screening conditions, comparing the temperature average values of T (T) 11 and T (T) 12, marking the smaller one of the T (T) 11 and T (T) 12 as T (T) 2 when the fourth mapping relation obtained by the 1 st temperature estimation meets the preset screening conditions, marking the smaller one of the T (T) 11 and T (T) 12 as T (T) 1 when the fourth mapping relation obtained by the 1 st temperature estimation does not meet the preset screening conditions, and omitting the larger one of the temperature average values obtained by the T (T) 11 and T (T) 12 in the subsequent binary temperature estimation, and continuing to forcedly cool and start-stop time estimation in the corresponding time period;

if neither T (T) 11 nor T (T) 12 satisfies the preset screening condition, the fourth mapping relation is not recorded, and the cooling start interval of the cooling forced cooling start time estimation scheme of T (T) 11 and T (T) 12 is reserved, namely the forced cooling start time estimation is continued in the corresponding time period.

And so on, recording the fourth mapping relation reserved by the ith as T (T) i, wherein i=1, 2,3 and … …; when the next temperature is estimated, estimating the continuous forced cooling start-stop time in the reserved time period, starting the forced cooling device in the corresponding time period, and respectively and temporarily marking the obtained fourth mapping relations as T (T) i1 and T (T) i2, and respectively judging whether the corresponding fourth mapping relations meet the preset screening conditions or not:

if T (T) i1 meets the preset screening condition and T (T) i2 does not meet the preset screening condition, marking T (T) i1 as T (T) i+1, and ignoring a cooling start section of a forced cooling start time prediction scheme for obtaining T (T) i2 in the subsequent dichotomy temperature prediction;

if T (T) i2 meets the preset screening condition and T (T) i1 does not meet the preset screening condition, marking T (T) i2 as T (T) i+1, and ignoring a cooling start section of a forced cooling start time prediction scheme for obtaining T (T) i1 in the subsequent dichotomy temperature prediction;

if T (T) i1 and T (T) i2 meet the preset screening conditions, comparing the temperature average values of T (T) i1 and T (T) i2, marking the smaller one of the temperature average values as T (T) i+1, and neglecting the larger one of the temperature average values of T (T) i1 and T (T) i2 in the subsequent dichotomy temperature prediction, and continuing forced cooling start-stop time prediction in the corresponding time period;

If neither T (T) i1 nor T (T) i2 meets the preset screening condition, reserving a cooling start interval for obtaining a cooling forced cooling start time estimation scheme of T (T) i1 and T (T) i2, namely continuing to estimate forced cooling start time in a corresponding time period;

optionally, in the process of screening the second candidate strong cold start time in the candidate duration based on the dichotomy, if the condition is metStopping temperature screening; wherein Δt is a preset duration, Y is a candidate duration, and q is the number of times of executed screening.

In another alternative, in the process of screening the second candidate strong cold start time in the candidate duration based on the dichotomy, if the condition is metStopping temperature screening; wherein Δt is a preset duration, n is a set value, Y is a candidate duration, and p is the number of times of executed screening. In practical applications, n can be flexibly determined according to the processing capability of the controller. The larger n is, the shorter the screening time is, but the optimal strong cold start time may be missed.

If the target strong cooling opening time is estimated with the preset opening time length of the initial forced cooling device until the fourth mapping relation meeting the preset screening condition does not appear, resetting the preset opening time length to mDeltat (m=2, 3,4 …), and repeating the steps (1) - (3) until the fourth mapping relation meeting the screening condition appears, and obtaining the target strong cooling opening time.

Optionally, on the basis of the foregoing embodiment, the present invention further provides a method for rapidly ending the screening process of the target strong-cold start time, that is, in the process of screening the second candidate strong-cold start time in the candidate duration based on the dichotomy, if there is a second candidate strong-cold start time meeting the second preset screening condition, determining the second candidate strong-cold start time corresponding to the second preset screening condition as the target strong-cold start time, and stopping screening;

wherein, the second preset screening condition comprises: and controlling the power battery to work according to the first mapping relation, and controlling the forced cooling device to be started at the second candidate forced cooling starting moment and continuously running for a preset starting time, wherein the average value of the working temperature of the power battery is smaller than a service life temperature threshold value, and of course, the service life temperature threshold value is smaller than the preset temperature threshold value.

Optionally, in any of the foregoing embodiments, the predictions of the second mapping relationship, the third mapping relationship, and the fourth mapping relationship are all derived based on the first mapping relationship, and if a significant deviation occurs between the current output situation of the vehicle in the actual driving process and the first mapping relationship, it is necessary to correct the first mapping relationship, and perform a subsequent management process based on the corrected first mapping relationship.

Specifically, calculating an average value of actual output current of the power battery in a target duration to obtain an actual measurement current average value; and controlling the average value of the output current of the power battery under the working condition of the power battery according to a first mapping relation (obtained by taking the reference driving data as the target driving data) within the target duration to obtain a predicted current average value. Then, calculating the difference value between the measured current average value and the predicted current average value, if the difference value between the measured current average value and the predicted current average value exceeds the preset current range, it can be considered that the first mapping relation obtained by taking the reference driving data as the target driving data is not accurate any more, the deviation of the angle from the actual situation of the vehicle occurs, the actual driving data of the vehicle is required to be taken as the target driving data, and the step of determining the driving duration of the vehicle and the first mapping relation according to the target driving data and the subsequent steps are executed in S110.

Specifically, the method can be calculated according to the following formula:

wherein, the liquid crystal display device comprises a liquid crystal display device,representing the measured current average value;

representing a predicted current mean;

a is a preset coefficient for adjusting the magnitude of a preset current range.

In summary, in the management method provided by the embodiment of the present invention, firstly, the situation that whether the power battery appears higher than the preset temperature threshold in the driving cycle is judged and managed according to the corresponding relation between the estimated output current and the driving time, that is, the first mapping relation, if the deviation between the actual output current and the estimated output current appears in the actual use of the vehicle is large, the second mapping relation and the third mapping relation are again confirmed based on the actual situation of the power battery, so that the timing of starting the forced cooling device is corrected, and further, the working temperature of the power battery is ensured not to be higher than the preset temperature threshold, which is helpful for prolonging the service life of the power battery.

The following describes a power battery thermal management device provided by the embodiment of the present invention, and the power battery thermal management device described below may be regarded as a functional module architecture to be set in a central device for implementing the power battery thermal management method provided by the embodiment of the present invention; the following description may be referred to with respect to the above.

Optionally, referring to fig. 4, fig. 4 is a block diagram of a power battery thermal management device according to an embodiment of the present invention, where the power battery thermal management device provided in the embodiment includes:

a first acquisition unit 10 for acquiring reference travel data of the vehicle and taking the reference travel data as target travel data;

a first determining unit 20, configured to determine a driving duration of the vehicle and a first mapping relationship according to the target driving data;

a second determining unit 30 for determining a second mapping relationship based on the power cell heat balance equation and the first mapping relationship;

A second obtaining unit 40 for obtaining the highest operating temperature recorded in the second mapping relation and a target running time corresponding to the highest operating temperature;

the control unit 50 is configured to turn on the forced cooling apparatus before the target driving time if the maximum operating temperature is equal to or higher than the preset temperature threshold.

Optionally, the control unit 50 is configured to turn on the forced cooling apparatus before the target driving time, and includes:

acquiring preset starting time of the forced cooling device;

determining a target strong cooling starting moment in the candidate duration;

the candidate duration is a duration from the starting time of the running duration to the target running time, and the candidate duration does not comprise the target running time;

the target forced cooling starting time is the running time corresponding to the working temperature of the power battery in the running time period being smaller than the preset temperature threshold value;

and controlling the forced cooling device to be started at the target forced cooling starting moment and continuously running for a preset starting time.

Optionally, the control unit 50 is configured to determine the target strong cold start time within the candidate duration, including:

based on a power battery heat balance equation and the first mapping relation, respectively determining a third mapping relation corresponding to each first candidate strong cooling starting moment;

The third mapping relation is recorded in a condition that the power battery is controlled to work according to the first mapping relation, and the forced cooling device is controlled to be started at the first candidate forced cooling starting moment and continuously operates for a preset starting time, and the corresponding relation between the working temperature of the power battery and the driving moment is formed;

if at least one third mapping relation exists and meets the first preset screening condition, determining a target strong-cold starting moment in first candidate strong-cold starting moments corresponding to the third mapping relations meeting the first preset screening condition;

wherein, the first preset screening condition includes: and any working temperature of the power battery recorded in the third mapping relation is smaller than a preset temperature threshold.

Optionally, the control unit 50 is configured to determine, in a first candidate strong-cold start time corresponding to each third mapping relationship that satisfies the first preset screening condition, a target strong-cold start time, including:

the fourth mapping relation is recorded in a corresponding relation between the working temperature of the power battery and the running time when the power battery is controlled to work according to the first mapping relation and the forced cooling device is controlled to be started at the second candidate forced cooling starting time and continuously run for a preset starting time, and any working temperature of the power battery recorded in the fourth mapping relation is smaller than a preset temperature threshold;

and determining the target strong cold start time in the second candidate strong cold start time.

Optionally, the control unit 50 is configured to increase the preset opening duration if the target strong cold opening time is not determined in the candidate duration, and return to executing the step of determining the target strong cold opening time in the candidate duration.

Optionally, the control unit 50 determines the second candidate strong-cold start time corresponding to the second preset screening condition as the target strong-cold start time if there is the second candidate strong-cold start time satisfying the second preset screening condition in the process of screening the second candidate strong-cold start time in the candidate duration based on the dichotomy, and stops screening;

The second preset screening conditions include: and under the condition that the power battery is controlled to work according to the first mapping relation, and the forced cooling device is controlled to be started at the second candidate forced cooling starting moment and continuously operates for a preset starting time, the average value of the working temperature of the power battery is smaller than a service life temperature threshold value, and the service life temperature threshold value is smaller than the preset temperature threshold value.

Optionally, the control unit 50 is configured to, during the process of screening the second candidate strong cold start time in the candidate duration based on the dichotomy, if the condition is satisfiedStopping temperature screening; wherein Δt is a preset duration, n is a set value, Y is a candidate duration, and p is the number of times of executed screening.

Optionally, referring to fig. 5, fig. 5 is a block diagram of another power battery thermal management device according to an embodiment of the present invention, and further includes, based on the embodiment shown in fig. 4:

the calculating unit 60 is configured to calculate an average value of actual output currents of the power battery within a target duration to obtain an actual measurement current average value, and calculate an average value of output currents of the power battery within the target duration under the condition that the power battery is controlled to operate according to a first mapping relationship to obtain a predicted current average value;

the updating unit 70 is configured to take the actual running data of the vehicle as the target running data and trigger the first determining unit 20 if the difference between the measured current average and the predicted current average exceeds the preset current range.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section.

Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative elements and steps are described above generally in terms of functionality in order to clearly illustrate the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software modules may be disposed in Random Access Memory (RAM), memory, read Only Memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of thermal management of a power cell, comprising:

if the highest working temperature is greater than or equal to a preset temperature threshold value, starting a forced cooling device before the target running time;

further comprises:

2. The power battery thermal management method according to claim 1, wherein the turning on the forced cooling device before the target travel time includes:

acquiring preset starting time of the forced cooling device;

determining a target strong cooling starting moment in the candidate duration;

3. The method of thermal management of a power cell of claim 2, wherein said determining a target cold start time within a candidate time period comprises:

4. The method of claim 3, wherein determining the target strong-cold start time in the first candidate strong-cold start time corresponding to each third mapping relation satisfying the first preset screening condition includes:

5. The method of thermal management of a power cell of claim 2, wherein said determining a target cold start time within a candidate time period comprises:

6. The power cell thermal management method of claim 5, further comprising:

7. The power cell thermal management method of claim 5, further comprising:

8. The method according to claim 2, wherein if the target strong cold start time is not determined within the candidate time period, the preset start time period is increased, and the step of determining the target strong cold start time period within the candidate time period is performed back.

9. A power battery thermal management device, comprising:

the control unit is used for starting the forced cooling device before the target running time if the highest working temperature is greater than or equal to a preset temperature threshold value;

further comprises:

the calculation unit is used for calculating the average value of the actual output current of the power battery in the target duration to obtain an actual measurement current average value, and calculating the average value of the output current of the power battery in the target duration under the condition of controlling the power battery to work according to the first mapping relation to obtain a predicted current average value;

and the updating unit is used for taking the actual running data of the vehicle as target running data and triggering the first determining unit if the difference value between the actually measured current average value and the predicted current average value exceeds a preset current range.