Remaining charging time estimation method, system, vehicle and storage medium

Abstract

The present invention discloses a method, system, vehicle and storage medium for estimating remaining charging time, wherein the range of the SOC lower limit to the fully charged SOC of the battery is divided into N charging intervals in sequence, each charging interval is divided into M current ranges according to the current value, and each current range under each charging interval is configured with a corresponding storage location for storing historical charging time values; the method specifically comprises the following steps: Step 1. Calculate the initial value of the remaining charging time: Step 2. Calculate the remaining charging time. The present invention can accurately calculate the remaining charging time.

Description

Technical Field

[0001] The present invention belongs to the field of charging technology, and specifically relates to a remaining charging time estimation method, system, vehicle and storage medium. Background Art

[0002] As the global climate deteriorates, urban air pollution intensifies, and oil resources are over-consumed, more and more people in the automotive field are turning their attention to electric vehicles. Power batteries are an important part of electric vehicles, and the battery charging time and remaining charging time estimation during the battery charging process are very important to the user experience.

[0003] Estimating the remaining charging time accurately can provide users with appropriate guidance on vehicle use. Users can reasonably arrange vehicle use according to their own circumstances based on the remaining charging time estimated by this method, reduce unnecessary waiting, and improve user experience. In addition, estimating the remaining charging time accurately can also provide support for the vehicle reservation charging function. The reservation charging can more accurately control the vehicle to charge during the period with lower electricity prices, saving users' charging expenses and improving user experience.

[0004] With the increasing popularity of new energy vehicles, how to improve the user experience of new energy vehicles has gradually become a focus of increasing attention for major automobile manufacturers. New energy vehicle charging technology has always been a technical difficulty and focus that users are very concerned about; estimating the accurate remaining charging time can provide users with accurate vehicle use plans, but how to accurately calculate the remaining charging time is a difficulty in the automotive industry; because battery temperature, ambient temperature, charging current, etc. will affect the calculation of the remaining charging time.

[0005] For example, the battery remaining charging time estimation method, device and equipment disclosed in patent document CN201810434096.0 is based on a multi-stage constant current charging method, and the charging time of a charging stage is obtained according to SOC difference*calibrated charging capacity / average current. Since there are errors in battery temperature changes, SOC estimation value, charging capacity, SOC calibration value, etc. during the charging process, this estimation method is not accurate and cannot meet the precision requirements.

[0006] Another example is a method for estimating the remaining charging time of a battery pack disclosed in patent document CN201810133081.0. This method estimates the remaining charging time according to three stages: heating time, constant current charging time, and constant voltage charging time. This method has clear stages, but insufficient accuracy and cannot adapt to the complex constant current charging logic of current vehicle manufacturers.

[0007] Therefore, it is necessary to develop a new remaining charging time estimation method, system, vehicle and storage medium. Summary of the invention

[0008] The present invention provides a remaining charging time estimation method, system, vehicle and storage medium, which can accurately calculate the remaining charging time.

[0009] A remaining charging time estimation method disclosed in the present invention divides the SOC range from the lower limit of the battery to the fully charged SOC into N charging intervals in sequence, divides each charging interval into M current ranges according to the current value, and configures a corresponding storage location for storing historical charging time values ​​for each current range under each charging interval; the method comprises the following steps:

[0010] Step 1. Calculate the initial value of the remaining charging time:

[0011] (a) Calculate the initial value of the remaining charging time T during the charging process including the heating process Pred The method is as follows:

[0012] T Pred = T Heat + T Chrg1 ;

[0013] Among them, T Heat For heating time only;

[0014] T Chrg1 is the first charging process time;

[0015] Charging process time T Chrg1 The calculation method is as follows: determine the charging path according to the current value corresponding to the heating exit temperature, determine the charging interval n according to the SOC1 when entering the charging, and calculate the charging process time according to the charging interval n where the SOC1 is and the charging path;

[0016] (b) Calculate the initial value of the remaining charging time T during the charging process without the heating process Pred The method is as follows:

[0017] T Pred = T Chrg2 ;

[0018] Among them, T Chrg2 is the second charging process time;

[0019] Charging process time T Chrg2 The calculation method is as follows: determine the charging path according to the actual charging current during charging, determine the charging interval n according to the SOC2 when entering the charging, and calculate the charging process time according to the charging interval n where the SOC2 is and the charging path;

[0020] Step 2. Calculate the remaining charging time:

[0021] T Pred(t+1) = TPred(t) -(SOC t+1 -SOC t )*Kn;

[0022] Kn=T n / (SOC n -SOC n-1 );

[0023] Wherein, t is the charging time;

[0024] T Pred (t) is the remaining charging time at time t. When the charging process includes the heating process only, T Pred (t) The initial value is T Pred(0)= T Heat + T Chrg1 ; When the charging process does not include the heating process, T Pred (t) The initial value is T Pred(0) =T Chrg2 ;

[0025] T Pred (t+1) is the remaining charging time at time t+1;

[0026] SOC t+1 is the SOC value at time t+1;

[0027] SOC t is the SOC value at time t;

[0028] SOC n is the SOC upper limit corresponding to the charging interval n;

[0029] SOC n-1 is the SOC lower limit corresponding to the charging interval n;

[0030] Kn is the rate of change of the remaining charging time in the nth charging interval.

[0031] Optionally, in step 1, the T Chrg1 The calculation method is as follows:

[0032] T Chrg1 =T n *(SOC n -SOC1) / (SOC n -SOC n-1 )+T n+1 +…+T N ;

[0033] Among them, T n It is the historical charging time value of the nth charging interval.

[0034] Optionally, in step 1, the TChrg2 The calculation method is as follows:

[0035] T Chrg2 =T n *(SOC n -SOC2) / (SOC n -SOC n-1 )+T n+1 +…+T N ;

[0036] Among them, T n It is the historical charging time value of the nth charging interval.

[0037] Optionally, in step 2, during the charging process, the actual charging time of each charging interval is stored, specifically:

[0038] During the charging process, the battery SOC and current value are checked in real time, and the charging interval and current range are determined based on the SOC and current value. The actual charging time in the charging interval and current range is stored in the corresponding storage location, and the storage data is based on the first-in-first-out principle.

[0039] Optionally, step 2 further includes: filtering the remaining charging time, and updating and displaying the remaining charging time after filtering at a preset time interval.

[0040] Optionally, the SOC of each charging interval is 1 / N of (SOCmax-SOCmin), where SOCmin is the lower limit of the SOC of the battery, and SOCmax is the SOC value when the battery is fully charged.

[0041] Optionally, the heating time T Heat The calculation method is as follows:

[0042] T Heat =(T Tar -T Min )*T Rate ;

[0043] Among them, T Tar For heating only exit temperature, T Min is the minimum battery temperature, T Rate The battery heating rate.

[0044] In a second aspect, the remaining charging time estimation system described in the present invention includes a memory and a controller, wherein the memory stores a computer-readable program, and when the computer-readable program is called by the controller, it can execute the steps of the remaining charging time estimation method described in the present invention.

[0045] In a third aspect, an electric vehicle described in the present invention adopts the remaining charging time estimation system described in the present invention.

[0046] In a fourth aspect, a storage medium according to the present invention stores a computer-readable program therein, and when the computer-readable program is called, it can execute the steps of the remaining charging time estimation method according to the present invention.

[0047] The present invention has the following advantages:

[0048] (1) The initial value of the remaining charging time for full charge obtained by the present invention based on historical data can be closer to the initial value of the remaining charging time actually charged by customers recently, and the remaining charging time finally calculated is more accurate;

[0049] (2) Applicable to AC charging and DC charging; Applicable to charging process without heating and charging process with heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a schematic diagram of the process of this embodiment;

[0051] Figure 2 The figure is a schematic diagram of the charging path of a charging process. DETAILED DESCRIPTION

[0052] The present invention will be further described below in conjunction with the accompanying drawings.

[0053] like Figure 1 As shown, in this embodiment, a method for estimating the remaining charging time is provided, wherein the range of the SOC lower limit to the fully charged SOC of the battery is sequentially divided into N charging intervals, each charging interval is divided into M current ranges according to the current value, and each current range under each charging interval is configured with a corresponding storage location for storing historical charging time values; the method comprises the following steps:

[0054] 1. Calculate the initial value of the remaining charging time

[0055] The specific calculation method is described separately according to the charging process including the heating process and the charging process excluding the heating process:

[0056] 1. Charging process including heating process only:

[0057] The charging process with heating only can be simply divided into heating only process and charging process. The charging process will be entered immediately after the heating only process is exited, so the initial value of the remaining charging time is T Pred For heating time only T Heat and the first charging process time T Chrg1 (i.e. only the charging time corresponding to the heating exit temperature).

[0058] TPred =T Heat + T Chrg1 ;

[0059] T Heat =(T Tar -T Min )*T Rate ;

[0060] Among them, T Tar For heating only exit temperature, T Min is the minimum battery temperature, T Rate is the battery heating rate (calibration amount);

[0061] In this embodiment, the first charging process time T Chrg1 (i.e. the charging time corresponding to the heating exit temperature only) is calculated as follows:

[0062] First, the charging path is determined according to the current value corresponding to the heating exit temperature. Since the heating process only heats the battery, the battery SOC will not change. The charging interval n is determined according to the SOC1 when entering the charging. For example, the charging starting SOC is SOC1, and the SOC interval where SOC1 is located is the nth interval. The charging process time is calculated based on the charging interval n where SOC1 is located and the charging path.

[0063] In this embodiment, the T Chrg The calculation method is as follows:

[0064] T Chrg1 =Tn*(SOC n -SOC1) / (SOC n -SOC n-1 )+T n+1 +…+T N ;

[0065] Among them, SOC n is the upper limit of SOC corresponding to charging interval n, SOC n-1 is the SOC lower limit corresponding to charging interval n, SOC1 is the SOC value when entering charging, Tn is the historical charging time value of the nth charging interval, and N means there are N charging intervals in total.

[0066] , Charging process excluding heating process:

[0067] Remaining charging time initial value T Pred The calculation method is:

[0068] T Pred = T Chrg2 ;

[0069] Among them, T Chrg2is the second charging process time, T Chrg2 The charging process path is obtained according to the actual charging current during charging, the charging interval n is determined according to the SOC2 when entering charging, and the charging process time is calculated according to the charging interval n and the charging path of SOC2. The specific calculation formula is as follows:

[0070] T Chrg =Tn*(SOC n -SOC2) / (SOC n -SOC n-1 )+T n+1 +…+T N ;

[0071] Among them, SOC n is the upper limit of SOC corresponding to charging interval n, SOC n-1 is the SOC lower limit corresponding to charging interval n, SOC2 is the SOC value when entering charging, Tn is the historical charging time value of the nth charging interval, and N means there are N charging intervals in total.

[0072] 2. Calculate the remaining charging time

[0073] According to the calculated initial value of the remaining charging time; determine the charging interval of the battery according to the SOC, such as the nth charging interval, and then calculate the charging time T corresponding to the charging interval corresponding to the SOC interval. n , calculate the remaining charging time change rate Kn corresponding to the SOC change; the change rate of each charging interval needs to be calculated for the remaining charging time value calculation of each charging interval.

[0074] In this embodiment, the remaining charging time is calculated as follows:

[0075] T Pred(t+1) = T Pred(t) -(SOC t+1 -SOC t )*Kn;

[0076] Kn=T n / (SOC n -SOC n-1 );

[0077] Wherein, t is the charging time;

[0078] T Pred (t) is the remaining charging time at time t. When the charging process includes the heating process only, T Pred (t) The initial value is T Pred(0)= T Heat + T Chrg1 ; When the charging process does not include the heating process, T Pred (t)The initial value is T Pred(0) = T Chrg2 ;

[0079] T Pred (t+1) is the remaining charging time at time t+1;

[0080] SOC t+1 is the SOC value at time t+1;

[0081] SOC t is the SOC value at time t;

[0082] SOC n is the SOC upper limit corresponding to the charging interval n;

[0083] SOC n-1 is the SOC lower limit corresponding to the charging interval n;

[0084] Kn is the rate of change of the remaining charging time in the nth charging interval.

[0085] If the initial value of the remaining charging time is calculated using path a in the initial stage of the charging process, if the charging to the subsequent stage conforms to path b, the remaining charging time value is corrected according to path b.

[0086] In this embodiment, the remaining charging time output value is filtered:

[0087] Update and display the remaining charging time after filtering at the preset time interval, specifically:

[0088] The remaining charging time is filtered to smooth the calculated remaining charging time; for example, it is updated every 30 seconds. At the same time, the maximum amplitude of each jump is limited, such as the maximum amplitude of each jump is 2 minutes, that is, in the update with a preset time interval of 30 seconds, the maximum reduction is only 2 minutes, and it is not allowed to reduce more than 2 minutes.

[0089] There is no filtering process in the first TBD seconds (such as 100 seconds) of charging, and the filtering strategy is applied to the remaining charging time after the TBD second (such as 100 seconds) of charging.

[0090] In this embodiment, the actual charging time of the charging process is stored as follows:

[0091] The charging process needs to divide the actual charging time and store data; the charging interval is divided into N charging intervals (see Figure 2, N=10) The SOC of each charging interval is 1 / N of (SOCmax-SOCmin), and the time required for each charging sub-interval and the average charging current are recorded in turn, and it is determined whether this time is valid (valid judgment means that the charging interval is complete data until full charge and the heating request is not for heating only). If valid, it is recorded as a charging time value. In order to make the data accurate enough, it is recommended to save at least 20 groups of data for each charging mode (charging mode includes DC fast charging and AC slow charging) (for example, if a group of charging has 10 stages of charging, then 20 groups of data need to be stored for each stage, corresponding to the time corresponding to different charging currents. Of course, the more data, the better. In this embodiment, it is limited to at least 20 groups). Each charging interval is evenly divided into m parts according to the maximum current (see Figure 2 , m=10), the maximum current interval is set according to (((the maximum value in the battery map table + 5)*(m-1)) / m, the maximum value in the battery map table + 5], the minimum current interval is set according to [0, (the maximum value in the battery map table + 5)* / m], and other current intervals are calculated in turn with reference to the maximum current interval and the minimum current interval; in addition, the storage data of each charging interval is saved in a queue, that is, according to the first-in-first-out principle, to ensure that the charging time corresponding to each charging sub-interval has only one value, which is used as Tn for the next charging.

[0092] For example, the storage location of the charging time corresponding to the first current range of the first charging interval is T0101, and the storage location of the charging time corresponding to the mth current range of the nth charging interval is Tnm. The charging time data are recorded; when developing the software, multiple groups of experiments are required to obtain the initial time values ​​of the DC charging and AC charging processes, and the calibration values ​​need to be written into the storage values ​​as the software initial values.

Claims

1. A method for estimating remaining charging time, characterized in that: The battery SOC range from the lower limit to the fully charged SOC is divided into N charging intervals in sequence, each charging interval is divided into M current ranges according to the current value, and each current range under each charging interval is configured with a corresponding storage location for storing historical charging time values; The method comprises the following steps: Step 1. Calculate the initial value of the remaining charging time: (a) Calculate the initial value of the remaining charging time T during the charging process including the heating process Pred The method is as follows: T Pred =T Heat +T Chrg1 ; Among them, T Heat For heating time only; T Chrg1 is the first charging process time; Charging process time T Chrg1 The calculation method is as follows: determine the charging path according to the current value corresponding to the heating exit temperature, determine the charging interval n according to the SOC1 when entering the charging, and calculate the charging process time according to the charging interval n where the SOC1 is and the charging path; (b) Calculate the initial value of the remaining charging time T during the charging process without the heating process Pred The method is as follows: T Pred =T Chrg2 ; Among them, T Chrg2 is the second charging process time; Charging process time T Chrg2 The calculation method is as follows: determine the charging path according to the actual charging current during charging, determine the charging interval n according to the SOC2 when entering the charging, and calculate the charging process time according to the charging interval n where the SOC2 is and the charging path; Step 2. Calculate the remaining charging time: T Pred(t+1) = T Pred(t) -(SOC t+1 -SOC t )*Kn ; Kn=T n / (SOC n -SOC n-1 ); Wherein, t is the charging time; T Pred (t) is the remaining charging time at time t. When the charging process includes the heating process only, T Pred (t) The initial value is T Pred(0)= T Heat + T Chrg1 ; When the charging process does not include the heating process, T Pred (t) The initial value is T Pred(0) =T Chrg2 ; T Pred (t+1) is the remaining charging time at time t+1; SOC t+1 is the SOC value at time t+1; SOC t is the SOC value at time t; SOC n is the SOC upper limit corresponding to the charging interval n; SOC n-1 is the SOC lower limit corresponding to the charging interval n; Kn is the rate of change of the remaining charging time in the nth charging interval; T n It is the historical charging time value of the nth charging interval.

2. The method for estimating the remaining charging time according to claim 1, characterized in that: In step 1, the T Chrg1 The calculation method is as follows: T Chrg1 =T n *(SOC n -SOC1) / (SOC n -SOC n-1 )+T n+1 +…+T N 。 3. The method for estimating the remaining charging time according to claim 1 or 2, characterized in that: In step 1, the T Chrg2 The calculation method is as follows: T Chrg2 =T n *(SOC n -SOC2) / (SOC n -SOC n-1 )+T n+1 +…+T N 。 4. The method for estimating the remaining charging time according to claim 3, characterized in that: In step 2, during the charging process, the actual charging time of each charging interval is stored, specifically: During the charging process, the battery SOC and current value are checked in real time, and the charging interval and current range are determined based on the SOC and current value. The actual charging time in the charging interval and current range is stored in the corresponding storage location, and the storage data is based on the first-in-first-out principle.

5. The method for estimating the remaining charging time according to claim 1, 2 or 4, characterized in that: The step 2 also includes: filtering the remaining charging time, and updating and displaying the remaining charging time after filtering at a preset time interval.

6. The method for estimating the remaining charging time according to claim 5, characterized in that: The SOC of each charging interval is 1 / N of (SOCmax-SOCmin), where SOCmin is the lower limit of the battery's SOC and SOCmax is the SOC value when the battery is fully charged.

7. The remaining charging time estimation method according to claim 1, 2, 4 or 6, characterized in that: The heating time T Heat The calculation method is as follows: T Heat =(T Tar -T Min )*T Rate ; Among them, T Tar For heating only exit temperature, T Min is the minimum battery temperature, T Rate The battery heating rate.

8. A remaining charging time estimation system, characterized in that: It comprises a memory and a controller, wherein the memory stores a computer-readable program, and when the computer-readable program is called by the controller, it can execute the steps of the remaining charging time estimation method as claimed in any one of claims 1 to 7.

9. An electric vehicle, characterized in that: The remaining charging time estimation system as claimed in claim 8 is adopted.

10. A storage medium, characterized in that: A computer-readable program is stored therein, and when the computer-readable program is called, the steps of the remaining charging time estimation method as described in any one of claims 1 to 7 can be executed.

Images