CN113866656A

CN113866656A - DCR calculation method, apparatus, device, and medium

Info

Publication number: CN113866656A
Application number: CN202010615264.3A
Authority: CN
Inventors: 杜明树; 阮见; 李世超; 卢艳华; 张伟
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2020-06-30
Filing date: 2020-06-30
Publication date: 2021-12-31

Abstract

The application discloses a DCR calculation method, a DCR calculation device, DCR calculation equipment and a DCR calculation medium, and relates to the field of battery power. The DCR calculation method comprises the following steps: acquiring a first state parameter of the power battery, wherein the first state parameter comprises at least one of the following parameters: the charging method comprises the steps that a first voltage parameter, a first current parameter and a first time parameter of a quasi-static stage are obtained, and the time length of the charging current of a power battery in the quasi-static stage, which is smaller than a current threshold, reaches a preset time threshold; acquiring a quasi-static open-circuit voltage (OCV) of the power battery based on the first state parameter; acquiring second state parameters of the power battery, wherein the second state parameters comprise a second voltage parameter, a second current parameter, a first charge state SOC and a first battery temperature in a charging stage; based on the quasi-static OCV, the second voltage parameter, and the second current parameter, a charging DCR at the first SOC and the first battery temperature is calculated. According to the circuit fault detection method and the sampling detection circuit provided by the embodiment of the application, the DCR of the battery can be calculated in the use process of the battery.

Description

DCR calculation method, apparatus, device, and medium

Technical Field

The present application relates to the field of battery power, and in particular, to a DCR calculation method, apparatus, device, and medium.

Background

With the development of new energy, new energy is adopted as power in more and more fields. Due to the advantages of high energy density, cyclic charging, safety, environmental protection and the like, the battery cell is widely applied to the fields of new energy automobiles, consumer electronics, energy storage systems and the like.

The existing Direct Current Resistance (DCR) calculation method needs to perform offline calculation on the DCR of the battery cell in a test environment, and can only calculate the DCR of the battery cell under a standing condition.

Disclosure of Invention

The circuit fault detection method and the sampling detection circuit provided by the embodiment of the application can be used for calculating the DCR of the battery in the use process of the battery.

In a first aspect, a method for calculating a dc resistance DCR is provided, including: acquiring a first state parameter of the power battery, wherein the first state parameter comprises at least one of the following parameters: the charging method comprises the steps that a first voltage parameter, a first current parameter and a first time parameter of a quasi-static stage are obtained, and the time length of the charging current of a power battery in the quasi-static stage, which is smaller than a current threshold, reaches a preset time threshold; acquiring a quasi-static open-circuit voltage (OCV) of the power battery based on the first state parameter; acquiring second state parameters of the power battery, wherein the second state parameters comprise a second voltage parameter, a second current parameter, a first charge state SOC and a first battery temperature in a charging stage; based on the quasi-static OCV, the second voltage parameter, and the second current parameter, a charging DCR at the first SOC and the first battery temperature is calculated.

In an optional embodiment, the method further comprises: acquiring a corresponding relation between charging DCR and battery temperature under a first SOC; and determining a first charging DCR corresponding to each of a plurality of preset battery temperature values under the first SOC by utilizing the corresponding relation.

In an optional embodiment, the method further comprises: acquiring second charging DCRs corresponding to a plurality of preset battery temperature values under the first SOC; calculating the difference value of a first charging DCR corresponding to each of the preset battery temperature values and a second charging DCR corresponding to each of the preset battery temperature values; and under the condition that the difference value is larger than the first preset threshold value, updating the difference value of the second charging DCR corresponding to each of the plurality of preset battery temperature values into the first charging DCR corresponding to each of the plurality of preset battery temperature values.

In an optional embodiment, the method further comprises: acquiring a discharging DCR at a first SOC and a first battery temperature; determining the ratio of the discharging DCR to the charging DCR; based on the ratio and the discharging DCR information, obtaining a first charging DCR corresponding to each of a plurality of preset battery temperature values, wherein the discharging DCR information comprises: the discharging DCR under the first SOC corresponds to the battery temperature, and/or the discharging DCR corresponding to each of a plurality of preset battery temperature values under the first SOC.

In an optional embodiment, the method further comprises: acquiring net accumulated charge-discharge capacity in a charging stage; and under the condition that the net accumulated charge-discharge capacity is larger than a preset capacity threshold, acquiring a third state parameter of the power battery, wherein the third state parameter comprises at least one of the following parameters: a third voltage parameter, a third current parameter and a second time parameter of a next quasi-static stage of the quasi-static stage; acquiring a quasi-static OCV of the power battery based on the third state parameter; acquiring a fourth state parameter of the power battery, wherein the fourth state parameter comprises a fourth voltage parameter, a fourth current parameter, a second state of charge (SOC) and a second battery temperature of a next charging stage of the charging stage; based on the fourth voltage parameter and the fourth current parameter, a charging DCR at a second SOC and a second battery temperature is obtained.

In an optional embodiment, the second voltage parameter includes a voltage value at the last time of a preset time period of the charging phase, and the second current parameter includes current values at a plurality of different times within the preset time period; calculating a charging DCR at a first SOC and a first battery temperature based on the quasi-static OCV, the second voltage parameter, and the second current parameter, comprising: calculating target parameters representing the current value fluctuation degrees at a plurality of different moments; calculating the current mean value of the current values at a plurality of different moments; and under the condition that the target parameter is smaller than a first preset threshold and the current mean value is smaller than a second preset threshold, calculating the charging DCR according to the quasi-static OCV, the voltage value at the last moment and the current mean value.

In a second aspect, a method for calculating a dc resistance DCR is provided, where the method includes: acquiring a first state parameter of the power battery, wherein the first state parameter comprises at least one of the following parameters: the method comprises the steps that a first voltage parameter, a first current parameter and a first time parameter of a quasi-static stage are obtained, and the duration that the charging current of a power battery is smaller than a current threshold value in the quasi-static stage reaches a preset time threshold value or the duration that the discharging current of the power battery is smaller than the current threshold value reaches a preset time threshold value; acquiring a quasi-static open-circuit voltage (OCV) of the power battery based on the first state parameter; acquiring second state parameters of the power battery, wherein the second state parameters comprise a second voltage parameter, a second current parameter, a first charge state SOC and a first battery temperature in a discharging stage; based on the quasi-static OCV, the second voltage parameter, and the second current parameter, a discharge DCR at the first SOC and the first battery temperature is calculated.

In an optional embodiment, the method further comprises: acquiring a corresponding relation between discharging DCR under a first SOC and battery temperature; and determining a first discharging DCR corresponding to each of a plurality of preset battery temperature values under the first SOC by utilizing the corresponding relation.

In an optional embodiment, the method further comprises: acquiring second discharging DCRs corresponding to a plurality of preset battery temperature values under the first SOC; calculating the difference value of a first discharging DCR corresponding to each of the preset battery temperature values and a second discharging DCR corresponding to each of the preset battery temperature values; and under the condition that the difference value is larger than the first preset threshold value, updating the difference value of the second discharging DCR corresponding to each of the plurality of preset battery temperature values into the first discharging DCR corresponding to each of the plurality of preset battery temperature values.

In an optional embodiment, the method further comprises: acquiring a charging DCR at a first SOC and a first battery temperature; determining the ratio of the discharging DCR to the charging DCR; based on the ratio and the charging DCR information, obtaining first discharging DCRs corresponding to a plurality of preset battery temperature values respectively, wherein the charging DCR information comprises: the charging DCR under the first SOC corresponds to the battery temperature, and/or the charging DCR corresponds to each of a plurality of preset battery temperature values under the first SOC.

In an optional embodiment, the method further comprises: acquiring net accumulated charge-discharge capacity in a discharge stage; and under the condition that the net accumulated charge-discharge capacity is larger than a preset capacity threshold, acquiring a third state parameter of the power battery, wherein the third state parameter comprises at least one of the following parameters: a third voltage parameter, a third current parameter and a second time parameter of a next quasi-static stage of the quasi-static stage; acquiring a quasi-static OCV of the power battery based on the third state parameter; acquiring fourth state parameters of the power battery, wherein the fourth state parameters comprise a fourth voltage parameter, a fourth current parameter, a second charge state SOC and a second battery temperature of a next discharging stage of the discharging stage; based on the fourth voltage parameter and the fourth current parameter, a discharge DCR at a second SOC and a second battery temperature is obtained.

In an optional embodiment, the second voltage parameter includes a voltage value at the last moment of a preset time period of the discharge phase, and the second current parameter includes current values at a plurality of different moments within the preset time period; calculating a discharge DCR at a first SOC and a first battery temperature based on the quasi-static OCV, the second voltage parameter, and the second current parameter, comprising: calculating target parameters representing the current value fluctuation degrees at a plurality of different moments; calculating the current mean value of the current values at a plurality of different moments; and under the condition that the target parameter is smaller than a first preset threshold and the current mean value is smaller than a second preset threshold, calculating the discharging DCR according to the quasi-static OCV, the voltage value at the last moment and the current mean value.

In a third aspect, a dc resistance DCR calculation apparatus is provided, including: the first parameter acquisition module is used for acquiring a first state parameter of the power battery, wherein the first state parameter comprises at least one of the following parameters: the charging method comprises the steps that a first voltage parameter, a first current parameter and a first time parameter of a quasi-static stage are obtained, and the time length of the charging current of a power battery in the quasi-static stage, which is smaller than a current threshold, reaches a preset time threshold; the open-circuit voltage acquisition module is used for acquiring the quasi-static open-circuit voltage OCV of the power battery based on the first state parameter; the second parameter acquisition module is used for acquiring second state parameters of the power battery, wherein the second state parameters comprise a second voltage parameter, a second current parameter, a first charge state SOC and a first battery temperature in a charging stage; and the direct current resistance calculation module is used for calculating the charging DCR under the first SOC and the first battery temperature based on the quasi-static OCV, the second voltage parameter and the second current parameter.

In a fourth aspect, there is provided a dc resistance DCR calculation apparatus including: the first parameter acquisition module is used for acquiring a first state parameter of the power battery, wherein the first state parameter comprises at least one of the following parameters: the method comprises the steps that a first voltage parameter, a first current parameter and a first time parameter of a quasi-static stage are obtained, and the duration that the charging current of a power battery is smaller than a current threshold value in the quasi-static stage reaches a preset time threshold value or the duration that the discharging current of the power battery is smaller than the current threshold value reaches a preset time threshold value; the open-circuit voltage acquisition module is used for acquiring the quasi-static open-circuit voltage OCV of the power battery based on the first state parameter; the second parameter acquisition module is used for acquiring second state parameters of the power battery, wherein the second state parameters comprise a second voltage parameter, a second current parameter, a first charge state SOC and a first battery temperature in a discharging stage; and the direct-current resistance calculation module is used for calculating the discharge DCR under the first SOC and the first battery temperature based on the quasi-static OCV, the second voltage parameter and the second current parameter.

In a fifth aspect, a DCR computing device is provided, comprising: a memory for storing a program;

a processor, configured to execute a program stored in the memory, to perform the DCR calculation method provided in the first aspect or any optional implementation manner of the first aspect, or to perform the DCR calculation method provided in the second aspect or any optional implementation manner of the second aspect.

In a sixth aspect, a computer storage medium is provided, on which computer program instructions are stored, and the computer program instructions, when executed by a processor, implement the DCR calculation method provided in the first aspect or any optional implementation manner of the first aspect, or when executed by the processor, implement the DCR calculation method provided in the second aspect or any optional implementation manner of the second aspect.

According to the DCR calculation method, the device, the equipment and the medium in the embodiment of the application, the quasi-static OCV of the power battery can be calculated according to the first state parameter of the power battery in the quasi-static stage. The charging DCR is then calculated using the quasi-static OCV, the second state parameter of the charging phase. Because the quasi-static OCV which is closer to the actual OCV of the battery can be calculated by utilizing the state parameters in the quasi-static stage, and the charging DCR can be calculated by utilizing the static OCV and the second state parameters in the charging stage, the DCR of the battery is calculated in the using process of the battery.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly described below, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic flowchart of a DCR calculation method provided in an embodiment of the present application;

FIG. 2 is a schematic flow chart diagram of an exemplary DCR calculation method provided in an embodiment of the present application;

FIG. 3 is a schematic flow chart diagram of another exemplary DCR calculation method provided by an embodiment of the present application;

FIG. 4 is a schematic flow chart diagram of yet another exemplary DCR calculation method provided by an embodiment of the present application;

FIG. 5 is a schematic flow chart diagram of yet another exemplary DCR calculation method provided by an embodiment of the present application;

fig. 6 is a schematic diagram of a calculation logic of the charging DCR in the parameter calculation mode according to the embodiment of the present application;

FIG. 7 is a schematic flow chart diagram of another DCR calculation method provided in the embodiments of the present application;

FIG. 8 is a schematic structural diagram of a DCR computing device according to an embodiment of the present application;

FIG. 9 is a schematic structural diagram of another DCR computing device provided in the embodiments of the present application;

FIG. 10 is a block diagram of an exemplary hardware architecture of a DCR computing device in an embodiment of the present application.

Detailed Description

Features and exemplary embodiments of various aspects of the present application will be described in detail below, and in order to make objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail below with reference to the accompanying drawings and the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application. It will be apparent to one skilled in the art that the present application may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present application by illustrating examples thereof.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The embodiment of the application provides a DCR calculation method, a DCR calculation device and a DCR calculation medium, which can be applied to a scene of calculating charging DCR and discharging DCR of a power battery. The method can be applied to a specific scene of calculating the charging DCR and the discharging DCR of the power battery in a vehicle in a charging process, a discharging process and a driving process. For example, the charging DCR may refer to a DCR of the power battery during charging. The discharge DCR may refer to the DCR of the power cell during discharge. The charging DCR and the discharging DCR may have other definitions under different scenes and different standards, and specific physical definitions thereof are not particularly limited.

For better understanding of the present application, a DCR calculation method, an apparatus, a device and a medium according to embodiments of the present application will be described in detail below with reference to the accompanying drawings, and it should be noted that these embodiments are not intended to limit the scope of the present disclosure.

Fig. 1 is a schematic flowchart of a DCR calculation method provided in an embodiment of the present application. As shown in fig. 1, the DCR calculation method 100 in the present embodiment may include the following S101-S104.

S101, acquiring a first state parameter of the power battery.

First, for a first state parameter.

The first state parameter includes at least one of: a first voltage parameter, a first current parameter, and a first time parameter of the quasi-static phase.

The first voltage parameter, the first current parameter, and the first time parameter may each be one value or a plurality of values. If multiple values are included, the multiple values may be represented as a sequence in the order of acquisition. In particular, it can be represented as a current sequence I _ RestList, a time sequence T _ RestList and a voltage sequence U _ RestList. Taking the current sequence I _ RestList as an example, if the current I is collected in the quasi-static stage₁-i_nThen the current sequence I _ RestList ═ I₁,…,i_n]Wherein n is an integer.

The specific data of the first state parameter is related to the calculation manner of the quasi-static OCV, and for convenience of description, the first state parameter will be described in detail when describing a specific embodiment of the quasi-static OCV, and will not be described first.

Second, for the quasi-stationary phase.

In the quasi-static phase, the time length for which the charging current of the power battery is smaller than the current threshold needs to reach the preset time threshold dT. That is, in the quasi-static stage, the power battery needs to be charged with a small-rate current or the charging current is 0.

Wherein, for the preset time threshold dT, the preset time threshold dT may be inversely related to the temperature. If the preset time threshold value dT is set to be a fixed value, the temperature of the power battery is not larger than the preset temperature threshold value in the quasi-standing stage.

And S102, acquiring the quasi-static open-circuit voltage OCV of the power battery based on the first state parameter.

In some embodiments, the first calculation method of the quasi-static OCV may include steps a1 and a 2.

Step a1, determining a steady state battery model for characterizing the change of the open circuit voltage OCV with time during the steady state based on the first state parameter.

In step a2, the steady-state time threshold Tt is substituted into the steady-state battery model to obtain the quasi-static OCV.

Accordingly, the first state parameter may comprise a current sequence I _ RestList, a time sequence T _ RestList, a voltage sequence U _ RestList and a steady-state time threshold Tt.

In some embodiments, the second calculation method of the quasi-static OCV may include step a 3.

In step a3, the voltage at the end of the quasi-stationary phase is taken as the quasi-static OCV.

Accordingly, the first state parameter may comprise a voltage or a sequence of voltages U _ RestList at the end of the quasi-stationary phase. Exemplarily, if the voltage sequence U _ RestList ═ V₁,V₂,…,Vn]Then Vn can be taken as the quasi-static OCV.

In some embodiments, a third method of calculating a quasi-static OCV may include step a 4.

And a4, inputting multiple groups of corresponding voltage values and current values into a preset equivalent circuit model, and identifying to obtain the quasi-static OCV.

At this time, the first state parameter may include a current sequence I _ RestList and a voltage sequence U _ RestList.

And S103, acquiring a second state parameter of the power battery.

Wherein the second State parameters include a second voltage parameter, a second current parameter, a first State Of Charge (SOC), and a first battery temperature during the charging phase.

For example, the second current parameter may comprise a current value i at a plurality of different instants in time within a preset time period of the charging phase₁,…,i_mAnd m is an integer. The second current parameter may be represented as I _ List ═ I₁,…,i_m]. Illustratively, if the duration of the charging phase is t₁Then may precede t₂Second acquisition i₁,…,i_m，t₁Greater than t₂。

For example, the second voltage parameter may comprise a specific value, for example, the voltage value U at the last moment of the preset time period of the charging phase₀. Still alternatively, the voltage values U at a plurality of different times within the preset time period of the charging phase may be₁,…,U_mThe second voltage parameter may be expressed as U _ List ═ U₁,…,U_m]. Illustratively, may be U_mThe voltage value U as the last moment of the preset time period₀

In addition, for the charging phase and the quasi-static phase. The power battery can enter the charging phase after the quasi-static phase is finished. That is, the end time of the quasi-static phase is earlier than the start time of the charging phase. If the operation mode of the power battery comprises a DCR calculation mode, the calculation module sequentially comprises a first quasi-static stage, a first charging stage, a second quasi-static stage, a second charging stage, …, a Kth quasi-static stage and a Kth charging stage, wherein K is an integer.

Optionally, a charging DCR may be calculated in each quasi-static stage, and the net accumulated charge-discharge capacity in each charging stage needs to be greater than the preset capacity threshold dQ.

And S104, calculating the charging DCR at the first SOC and the first battery temperature based on the quasi-static OCV, the second voltage parameter and the second current parameter.

In some embodiments, the second voltage parameter comprises a voltage value U at the last instant of the preset time period of the charging phase₀The second current parameter comprises a plurality of variables within a preset time periodCurrent value i at the same time₁,…,i_m。

Accordingly, the calculation manner of the charging DCR may be embodied as steps b1-b 4.

And b1, calculating target parameters representing the current value fluctuation degrees at a plurality of different moments. Illustratively, the target parameter may be m current values i₁,…,i_mVariance, range, standard deviation, coefficient of variation, etc.

Step b2, calculating the current average value of the current values at a plurality of different time points

Step b3, when the target parameter is less than the first preset threshold and the current mean value

And under the condition that the voltage value is smaller than a second preset threshold value, calculating the charging DCR according to the quasi-static OCV, the voltage value at the last moment and the current average value.

First, for the first preset threshold and the second preset threshold, they may be set according to specific scenarios and actual requirements.

Next, for the embodiment of step b 3. For example, the voltage value U at the last moment of the preset time period of the charging phase may be calculated first₀The difference value with the quasi-static OCV is calculated, and the difference value and the current mean value are calculated

And the ratio is taken as the charging DCR.

According to the DCR calculation method, the quasi-static OCV of the power battery can be calculated according to the first state parameter of the power battery in the quasi-static stage. The charging DCR is then calculated using the quasi-static OCV, the second state parameter of the charging phase. Because the quasi-static OCV which is closer to the actual OCV of the battery can be calculated by utilizing the state parameters in the quasi-static stage, and the charging DCR can be calculated by utilizing the static OCV and the second state parameters in the charging stage, the DCR of the battery is calculated in the using process of the battery.

In some embodiments, fig. 2 is a schematic flow chart of an exemplary DCR calculation method provided in an embodiment of the present application. As shown in fig. 2, the DCR calculation method 100 may further include S105 and S106.

And S105, acquiring the corresponding relation between the charging DCR under the first SOC and the battery temperature.

First, for the correspondence relationship between the charging DCR and the battery temperature, different SOCs may correspond to different correspondence relationships.

For example, the correspondence relationship between the charging DCR and the battery temperature may be expressed as formula (1):

DCR＝a*exp(b/Temp) (1)

wherein a and b are relational coefficients, DCR represents charging DCR, and Temp represents temperature.

In some embodiments, a and b in equation (1) may be known, such as may be calibrated offline.

In some embodiments, a and b in the formula (1) may be unknown or may need to be adjusted, and at this time, the corresponding relationship between the charging DCR and the battery temperature in the first SOC may be corrected by using the charging DCR and the first battery temperature, so that the charging DCR and the first battery temperature satisfy the corrected corresponding relationship. Specifically, the charging DCR and the first battery temperature may be substituted into equation (1) to obtain a and b.

And S106, determining first charging DCRs corresponding to the preset battery temperature values under the first SOC by using the corresponding relation. The preset battery temperature value may be set according to a specific scenario and a specific requirement, which is not particularly limited.

For example, a plurality of temperature values T1, T2, …, TL may be preset, and the plurality of temperature values T1, T2, …, TL are substituted into formula (1), so as to obtain corresponding charging DCRs, i.e., DCR1, DCR2, …, DCRL, where L is a positive integer.

Optionally, the obtained DCR11, DCR12, …, and DCR1L may be represented as a charging DCR sequence at the first SOC, which may be specifically represented as: chrgDCR _ listnew (sock) ═ DCR11, DCR12, …, DCR 1L.

In this example, the first charging DCR determined to correspond to each of the plurality of preset battery temperature values at the first SOC, acquired at S106, may be stored, for example, as a data table. In the actual use process of the battery, if the actual SOC is equal to the first SOC, the data table can be directly consulted according to the real-time temperature, the real-time charging DCR can be determined, the calculation efficiency of determining the DCR in the subsequent process is reduced, and the calculation rate is improved.

In some embodiments, fig. 3 is a schematic flow chart of another exemplary DCR calculation method provided in the embodiments of the present application. The DCR calculation method 100 may further include:

s107, second charging DCRs corresponding to the preset battery temperature values under the first SOC are obtained.

The second charging DCR corresponding to each of the preset battery temperature values may be pre-stored in the computing device, so as to quickly query the corresponding charging DCR according to the temperature.

For example, the second charging DCR corresponding to each of the plurality of preset battery temperature values may be represented as a DCR sequence, such as chrgDCR _ list (sock) ═ DCR01, DCR02, …, and DCR 0L.

And S108, calculating a difference value delta DCR between a first charging DCR corresponding to each of the preset battery temperature values and a second charging DCR corresponding to each of the preset battery temperature values.

Wherein, the difference between the two can be the mean square error, the standard deviation, the data range, etc.

For example, if the difference Δ DCR is data very poor, the difference Δ DCR may be expressed as formula (2), taking the second charging DCRs as DCR sequences chrgDCR _ list (sock) ═ DCR01, DCR02, …, and DCR0L, and the first charging DCRs as chrgDCR _ listnew (sock) ═ DCR11, DCR12, …, and DCR 1L:

ΔDCR＝max(ΔDCR₁,…,ΔDCR_L) (2)

wherein, Δ DCR_iEqual to DCR0i-DCR1i, i is any value between 1 and L.

And S109, under the condition that the difference value delta DCR is larger than the first preset threshold value, updating the difference value of the second charging DCR corresponding to each of the plurality of preset battery temperature values into the first charging DCR corresponding to each of the plurality of preset battery temperature values.

The first preset threshold may be set according to a specific scene and an actual requirement, which is not limited herein.

For S109, for example, if Δ DCR is greater than the first preset threshold, then the new chrgDCR _ list (sock) ═ DCR11, DCR12, …, DCR 1L.

In some embodiments, in addition to obtaining the first DCR corresponding to each of the plurality of preset battery temperature values according to the corresponding relationship, the calculation may be performed according to the relevant information of the discharging DCR. Fig. 4 is a schematic flowchart of another exemplary DCR calculation method provided in an embodiment of the present application. As shown in fig. 4, the DCR calculation method 100 may further include:

s110, a discharging DCR under the first SOC and the first battery temperature is obtained. The calculation method of the discharging DCR is similar to that of the charging DCR, and is not described herein again.

And S111, determining the ratio B of the discharging DCR to the charging DCR.

Specifically, the ratio B is charging DCR/discharging DCR.

And S112, obtaining first charging DCRs corresponding to the preset battery temperature values respectively based on the ratio B and the discharging DCR information.

Optionally, if the discharging DCR information includes a corresponding relationship between the discharging DCR at the first SOC and the battery temperature. Then a specific implementation of S112 includes step c1 and step c 2.

And c1, determining a calculation formula of the charging DCR according to the ratio B and the corresponding relation between the discharging DCR and the battery temperature.

For example, if the correspondence relationship between the discharge DCR and the battery temperature at the first SOC can also be expressed as formula (1), the calculation formula of the charge DCR can be expressed as formula (3):

DCR＝B*a*exp(b/Temp) (3)

and c2, substituting the preset battery temperature values into a calculation formula of the charging DCR to obtain the corresponding first charging DCR.

Optionally, if the discharging DCR information includes discharging DCRs corresponding to a plurality of preset battery temperature values under the first SOC, for example, DCR21, DCR22, …, and DCR 2L. Then a particular implementation of S112 includes step c 3.

And step c3, taking the product of the ratio B and each discharging DCR as a charging DCR. That is, if the predetermined temperature Ti corresponds to DCR2i, then B × DCR2i is the charging DCR corresponding to the predetermined temperature Ti.

In some embodiments, fig. 5 is a schematic flow chart of another exemplary DCR calculation method provided in the embodiments of the present application. As shown in FIG. 5, the DCR calculation method 100 may further include S113-S117.

And S113, acquiring the net accumulated charging and discharging capacity in the charging stage.

S114, acquiring a third state parameter of the power battery under the condition that the net accumulated charge-discharge capacity is larger than a preset capacity threshold, wherein the third state parameter comprises at least one of the following parameters: a third voltage parameter, a third current parameter, and a second time parameter of a next quasi-static phase of the quasi-static phase.

And S115, acquiring the quasi-static OCV of the power battery based on the third state parameter.

And S116, acquiring fourth state parameters of the power battery, wherein the fourth state parameters comprise a fourth voltage parameter, a fourth current parameter, a second state of charge (SOC) and a second battery temperature of a next charging stage of the charging stage.

And S117, acquiring the charging DCR at the second SOC and the second battery temperature based on the fourth voltage parameter and the fourth current parameter.

The embodiments requiring S114 to S117 are the same as those of S101 to S104, and are not described herein again.

For convenience of explaining the present example, fig. 6 is a schematic diagram of a calculation logic of the charging DCR in the parameter calculation mode according to the embodiment of the present application. As shown in fig. 6, the embodiment of the present application provides a parameter calculation mode, and the parameter calculation mode includes a plurality of quasi-static phases and charging phases, which alternate with each other. Illustratively, the parameter calculation mode may be embodied as a battery maintenance mode.

With continued reference to fig. 6, a quasi-static phase is experienced prior to each charging phase. From the state data collected during the quasi-static phase, a quasi-static OCV value can be calculated. And collecting state parameters containing SOC in a preset time period of a charging stage. Then, the charging DCR corresponding to the SOC value is calculated. Since the parameter calculation mode includes a plurality of charging stages, a plurality of different SOCs, for example, the nth SOC and the n +1 th SOC, may be acquired. Thus, throughout the parameter calculation mode, charging DCRs at a plurality of different SOC values, or a sequence of charging DCRs at a plurality of different SOC values, may be calculated.

Based on the same application concept, the application provides a DCR calculation method for calculating the charging DCR and also provides a DCR calculation method for calculating the discharging DCR. The calculation method of the discharge DCR will be described below with reference to the drawings.

Fig. 7 is a schematic flowchart of another DCR calculation method provided in the embodiment of the present application. As shown in fig. 7, the DCR calculation method 700 in the present embodiment may include the following S701-S704.

S701, acquiring a first state parameter of the power battery.

Wherein the first state parameter comprises at least one of the following parameters: the method comprises a first voltage parameter, a first current parameter and a first time parameter of a quasi-static stage, wherein the duration that the charging current of the power battery is smaller than a current threshold value in the quasi-static stage reaches a preset time threshold value or the duration that the discharging current of the power battery is smaller than the current threshold value reaches a preset time threshold value.

For a specific implementation of S701, reference may be made to the related description of S101, which is not described herein again.

S702, acquiring the quasi-static open-circuit voltage OCV of the power battery based on the first state parameter.

For a specific implementation of S702, reference may be made to the above description of S102, which is not described herein again.

And S703, acquiring a second state parameter of the power battery.

Wherein the second state-of-charge parameters include a second voltage parameter, a second current parameter, a first state-of-charge, SOC, and a first battery temperature during a discharge phase.

For a specific implementation of S703, reference may be made to the related description of S103, which is not described herein again.

S704, calculating a discharging DCR under the first SOC and the first battery temperature based on the quasi-static OCV, the second voltage parameter and the second current parameter.

The specific implementation of S704 may refer to the above description of S104, and is not described herein again.

In some embodiments, the DCR calculation method 700 further includes:

and acquiring the corresponding relation between the discharging DCR under the first SOC and the battery temperature.

And determining a first discharging DCR corresponding to each of a plurality of preset battery temperature values under the first SOC by using the corresponding relation.

For specific implementation in this embodiment, reference may be made to the related description of the above section in conjunction with fig. 2, which is not described herein again.

In some embodiments, the DCR calculation method 700 further includes:

and acquiring second discharging DCRs corresponding to the preset battery temperature values under the first SOC.

And calculating the difference value of the first discharging DCR corresponding to the preset battery temperature values and the second discharging DCR corresponding to the preset battery temperature values.

And under the condition that the difference value is larger than a first preset threshold value, updating the difference value of the second discharging DCR corresponding to each of the plurality of preset battery temperature values into the first discharging DCR corresponding to each of the plurality of preset battery temperature values.

For specific implementation in this embodiment, reference may be made to the related description of the above section in conjunction with fig. 3, which is not described herein again.

In some embodiments, the DCR calculation method 700 further includes:

a charging DCR at the first SOC and the first battery temperature is obtained.

Determining a ratio of the discharging DCR to the charging DCR.

And obtaining first discharging DCRs corresponding to the preset battery temperature values respectively based on the ratio and the charging DCR information.

Wherein the charging DCR information includes: the charging DCR under the first SOC corresponds to the battery temperature, and/or the charging DCR corresponding to each of a plurality of preset battery temperature values under the first SOC.

For specific implementation in this embodiment, reference may be made to the related description of the above section in conjunction with fig. 4, which is not described herein again.

In some embodiments, the DCR calculation method 700 further includes:

and acquiring the net accumulated charge-discharge capacity in the discharge stage.

Acquiring a third state parameter of the power battery under the condition that the net accumulated charge-discharge capacity is larger than a preset capacity threshold, wherein the third state parameter comprises at least one of the following parameters: a third voltage parameter, a third current parameter, and a second time parameter of a next quasi-static stage of the quasi-static stage.

And acquiring the quasi-static OCV of the power battery based on the third state parameter.

And acquiring fourth state parameters of the power battery, wherein the fourth state parameters comprise a fourth voltage parameter, a fourth current parameter, a second state of charge (SOC) and a second battery temperature of a next discharging stage of the discharging stage.

Acquiring a discharge DCR at the second SOC and the second battery temperature based on the fourth voltage parameter and the fourth current parameter.

For specific implementation in this embodiment, reference may be made to the related description of the above section in conjunction with fig. 5, which is not described herein again.

In some embodiments, the second voltage parameter comprises a voltage value at a last instant of a preset time period of the discharge phase, and the second current parameter comprises a current value at a plurality of different instants within the preset time period;

s704 specifically includes:

and calculating target parameters representing the current value fluctuation degrees at the different moments.

And calculating the current average value of the current values at the plurality of different moments.

And under the condition that the target parameter is smaller than a first preset threshold and the current mean value is smaller than a second preset threshold, calculating the discharge DCR according to the quasi-static OCV, the voltage value at the last moment and the current mean value.

For specific implementation in this embodiment, reference may be made to the related description of the above section in conjunction with fig. 6, which is not described herein again.

According to the DCR calculation method in the embodiment of the application, the quasi-static OCV of the power battery can be calculated according to the first state parameter of the power battery in the quasi-static stage. The discharge DCR is then calculated using the quasi-static OCV, the second state parameter of the discharge phase. Because the quasi-static OCV which is closer to the actual OCV of the battery can be calculated by utilizing the state parameters in the quasi-static stage, and the discharging DCR can be calculated by utilizing the static OCV and the second state parameters in the discharging stage, the DCR of the battery is calculated in the using process of the battery.

Other details of the DCR calculation method according to the embodiment of the present application are similar to those of the DCR calculation method described above with reference to the examples shown in fig. 1 to 6, and can achieve corresponding technical effects, and are not described herein again for brevity.

Based on the same application concept, the embodiment of the application provides a DCR calculation device corresponding to the DCR calculation method in addition to the DCR calculation method for calculating the charging DCR. The following describes in detail an apparatus according to an embodiment of the present application with reference to the accompanying drawings.

The embodiment of the application provides a DCR calculating device. Fig. 8 is a schematic structural diagram of a DCR computing device according to an embodiment of the present application. As shown in fig. 8, the DCR calculation apparatus 800 includes: a first parameter acquisition module 810, an open circuit voltage acquisition module 820, a second parameter acquisition module 830, and a dc resistance calculation module 840.

The first parameter obtaining module 810 is configured to obtain a first state parameter of the power battery.

Wherein the first state parameter comprises at least one of the following parameters: the charging method comprises the steps that a first voltage parameter, a first current parameter and a first time parameter of a quasi-static stage are obtained, and the time length of the charging current of a power battery in the quasi-static stage, which is smaller than a current threshold, reaches a preset time threshold;

and an open-circuit voltage obtaining module 820, configured to obtain a quasi-static open-circuit voltage OCV of the power battery based on the first state parameter.

The second parameter obtaining module 830 is configured to obtain a second state parameter of the power battery, where the second state parameter includes a second voltage parameter, a second current parameter, a first state of charge SOC, and a first battery temperature in a charging phase.

A direct current resistance calculation module 840 for calculating a charging DCR at the first SOC and the first battery temperature based on the quasi-static OCV, the second voltage parameter, and the second current parameter.

In some embodiments, the DCR computing device 800 further comprises:

and the corresponding relation acquisition module is used for acquiring the corresponding relation between the charging DCR under the first SOC and the battery temperature.

And the direct current resistance determining module is used for determining a first charging DCR corresponding to each of a plurality of preset battery temperature values under the first SOC by utilizing the corresponding relation.

In some embodiments, the DCR computing device 800 further comprises:

the first direct current resistance acquisition module is used for acquiring second charging DCRs corresponding to a plurality of preset battery temperature values under the first SOC.

And the difference value calculating module is used for calculating the difference value between the first charging DCR corresponding to each of the preset battery temperature values and the second charging DCR corresponding to each of the preset battery temperature values.

And the direct current resistance updating module is used for updating the difference value of the second charging DCR corresponding to each of the plurality of preset battery temperature values into the first charging DCR corresponding to each of the plurality of preset battery temperature values under the condition that the difference value is larger than the first preset threshold value.

In some embodiments, the DCR computing device 800 further comprises:

the first direct current resistance acquisition module is used for acquiring a discharging DCR at a first SOC and a first battery temperature.

The ratio calculation module is used for determining the ratio of the discharging DCR to the charging DCR;

and the direct current resistance determining module is used for obtaining first charging DCRs corresponding to the preset battery temperature values based on the ratio and the discharging DCR information.

Wherein the discharging DCR information includes: the discharging DCR under the first SOC corresponds to the battery temperature, and/or the discharging DCR corresponding to each of a plurality of preset battery temperature values under the first SOC.

In some embodiments, the DCR computing device 800 further comprises:

and the net accumulated charge-discharge capacity acquisition module is used for acquiring the net accumulated charge-discharge capacity in the charging stage.

The third parameter obtaining module is used for obtaining a third state parameter of the power battery under the condition that the net accumulated charge-discharge capacity is larger than a preset capacity threshold, wherein the third state parameter comprises at least one of the following parameters: a third voltage parameter, a third current parameter, and a second time parameter of a next quasi-static phase of the quasi-static phase.

And the open-circuit voltage calculation module is used for acquiring the quasi-static OCV of the power battery based on the third state parameter.

The fourth parameter acquisition module is used for acquiring a fourth state parameter of the power battery, wherein the fourth state parameter comprises a fourth voltage parameter, a fourth current parameter, a second charge state SOC and a second battery temperature of a next charging stage of the charging stage;

and the direct current resistance calculation module is used for acquiring the charging DCR under the second SOC and the second battery temperature based on the fourth voltage parameter and the fourth current parameter.

In some embodiments, the second voltage parameter comprises a voltage value at a last instant of a preset time period of the charging phase, and the second current parameter comprises a current value at a plurality of different instants within the preset time period.

The dc resistance calculation module 840 specifically includes:

the first calculating unit is used for calculating target parameters representing the current value fluctuation degrees at a plurality of different moments.

The second calculation unit is used for calculating the current mean value of the current values at a plurality of different moments;

and the third calculating unit is used for calculating the charging DCR according to the quasi-static OCV, the voltage value at the last moment and the current mean value under the condition that the target parameter is smaller than the first preset threshold value and the current mean value is smaller than the second preset threshold value.

According to the DCR calculating device of the embodiment of the application, the quasi-static OCV of the power battery can be calculated according to the first state parameter of the power battery in the quasi-static stage. The charging DCR is then calculated using the quasi-static OCV, the second state parameter of the charging phase. Because the quasi-static OCV which is closer to the actual OCV of the battery can be calculated by utilizing the state parameters in the quasi-static stage, and the charging DCR can be calculated by utilizing the static OCV and the second state parameters in the charging stage, the DCR of the battery is calculated in the using process of the battery.

Other details of the DCR calculation apparatus according to the embodiment of the present application are similar to the DCR calculation method described above with reference to the examples shown in fig. 1 to fig. 6, and can achieve the corresponding technical effects, and are not repeated herein for brevity.

Based on the same application concept, the embodiment of the application provides a DCR calculating device corresponding to the DCR calculating method in addition to the DCR calculating method for calculating the discharging DCR. The following describes in detail an apparatus according to an embodiment of the present application with reference to the accompanying drawings.

The embodiment of the application provides a DCR calculating device. Fig. 9 is a schematic structural diagram of another DCR calculation apparatus according to an embodiment of the present application. As shown in fig. 9, the DCR calculation apparatus 800 includes: a first parameter obtaining module 910, an open circuit voltage obtaining module 920, a second parameter obtaining module 930, and a direct current resistance calculating module 940.

The first parameter obtaining module 910 is configured to obtain a first state parameter of the power battery, where the first state parameter includes at least one of the following parameters: the method comprises a first voltage parameter, a first current parameter and a first time parameter of a quasi-static stage, wherein the time length of the charging current of the power battery smaller than a current threshold value in the quasi-static stage reaches a preset time threshold value or the time length of the discharging current of the power battery smaller than the current threshold value reaches a preset time threshold value.

And an open-circuit voltage obtaining module 920, configured to obtain a quasi-static open-circuit voltage OCV of the power battery based on the first state parameter.

The second parameter obtaining module 930 is configured to obtain a second state parameter of the power battery, where the second state parameter includes a second voltage parameter, a second current parameter, a first state of charge SOC, and a first battery temperature during a discharging phase.

A direct current resistance calculation module 940 for calculating a discharge DCR at the first SOC and the first battery temperature based on the quasi-static OCV, the second voltage parameter, and the second current parameter.

In some embodiments, the DCR computing device 900 further comprises:

and the corresponding relation acquisition module is used for acquiring the corresponding relation between the discharging DCR under the first SOC and the battery temperature.

And the direct current resistance determining module is used for determining a first discharging DCR corresponding to each of a plurality of preset battery temperature values under the first SOC by utilizing the corresponding relation.

In some embodiments, the DCR computing device 900 further comprises:

the first direct current resistance acquisition module is used for acquiring second discharging DCRs corresponding to a plurality of preset battery temperature values under the first SOC.

And the difference value calculation module is used for calculating the difference value between the first discharging DCR corresponding to each of the preset battery temperature values and the second discharging DCR corresponding to each of the preset battery temperature values.

And the direct current resistance updating module is used for updating the difference value of the second discharging DCR corresponding to each of the plurality of preset battery temperature values into the first discharging DCR corresponding to each of the plurality of preset battery temperature values under the condition that the difference value is larger than the first preset threshold value.

In some embodiments, the DCR computing device 900 further comprises:

the first direct current resistance acquisition module is used for acquiring charging DCR at a first SOC and a first battery temperature.

And the ratio calculation module is used for determining the ratio of the discharging DCR to the charging DCR.

And the direct current resistance determining module is used for obtaining first discharging DCRs corresponding to the preset battery temperature values respectively based on the ratio and the charging DCR information.

Wherein the charging DCR information includes: the charging DCR under the first SOC corresponds to the battery temperature, and/or the charging DCR corresponds to each of a plurality of preset battery temperature values under the first SOC.

In some embodiments, the DCR computing device 900 further comprises:

and the net accumulated charge-discharge capacity acquisition module is used for acquiring the net accumulated charge-discharge capacity in the discharge stage.

And the third parameter acquisition module is used for acquiring a third state parameter of the power battery under the condition that the net accumulated charge-discharge capacity is larger than a preset capacity threshold.

The third state parameter includes at least one of: a third voltage parameter, a third current parameter and a second time parameter of a next quasi-static stage of the quasi-static stage;

And the fourth parameter acquisition module is used for acquiring a fourth state parameter of the power battery, wherein the fourth state parameter comprises a fourth voltage parameter, a fourth current parameter, a second state of charge (SOC) and a second battery temperature in a next discharging stage of the discharging stage.

And the direct current resistance calculation module is used for acquiring the discharge DCR under the second SOC and the second battery temperature based on the fourth voltage parameter and the fourth current parameter.

In some embodiments, the second voltage parameter comprises a voltage value at a last instant of a preset time period of the discharge phase, and the second current parameter comprises a current value at a plurality of different instants within the preset time period.

The dc resistance calculation module 940 specifically includes:

And the second calculation unit is used for calculating the current average value of the current values at a plurality of different moments.

And the third calculating unit is used for calculating the discharging DCR according to the quasi-static OCV, the voltage value at the last moment and the current mean value under the condition that the target parameter is smaller than the first preset threshold value and the current mean value is smaller than the second preset threshold value.

According to the DCR calculation device in the embodiment of the present application, the quasi-static OCV of the power battery can be calculated according to the first state parameter of the power battery in the quasi-static phase. The discharge DCR is then calculated using the quasi-static OCV, the second state parameter of the discharge phase. Because the quasi-static OCV which is closer to the actual OCV of the battery can be calculated by utilizing the state parameters in the quasi-static stage, and the discharging DCR can be calculated by utilizing the static OCV and the second state parameters in the discharging stage, the DCR of the battery is calculated in the using process of the battery.

As shown in fig. 10, the DCR computing device 1000 includes an input device 1001, an input interface 1002, a central processor 1003, a memory 1004, an output interface 1005, and an output device 1006. The input interface 1002, the central processing unit 1003, the memory 1004, and the output interface 1005 are connected to each other through a bus 1010, and the input device 1001 and the output device 1006 are connected to the bus 1010 through the input interface 1002 and the output interface 1005, respectively, and further connected to other components of the DCR computing device 1000.

Specifically, the input device 1001 receives input information from the outside, and transmits the input information to the central processor 1003 via the input interface 1002; the central processor 1003 processes input information based on computer-executable instructions stored in the memory 1004 to generate output information, stores the output information temporarily or permanently in the memory 1004, and then transmits the output information to the output device 1006 through the output interface 1005; the output device 1006 outputs the output information to the outside of the DCR computing device 1000 for use by the user.

That is, the DCR computing device shown in fig. 10 may also be implemented to include: a memory storing computer-executable instructions; and a processor which, when executing the computer executable instructions, may implement the method of the DCR computing device described in connection with fig. 1-7.

In one embodiment, the DCR computing device 1000 shown in fig. 10 may be implemented as a device that may include: a memory for storing a program; and the processor is used for operating the program stored in the memory so as to execute the DCR calculation method of the embodiment of the application.

The embodiment of the present application further provides a computer storage medium, where computer program instructions are stored on the computer storage medium, and when the computer program instructions are executed by a processor, the DCR calculation method according to the embodiment of the present application is implemented.

It is to be understood that the present application is not limited to the particular arrangements and instrumentality described above and shown in the attached drawings. A detailed description of known methods is omitted herein for the sake of brevity. In the above embodiments, several specific steps are described and shown as examples. However, the method processes of the present application are not limited to the specific steps described and illustrated, and those skilled in the art can make various changes, modifications, and additions or change the order between the steps after comprehending the spirit of the present application.

The functional blocks shown in the above-described structural block diagrams may be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, it may be, for example, an electronic circuit, an Application Specific Integrated Circuit (ASIC), suitable firmware, plug-in, function card, or the like. When implemented in software, the elements of the present application are the programs or code segments used to perform the required tasks. The program or code segments may be stored in a machine-readable medium or transmitted by a data signal carried in a carrier wave over a transmission medium or a communication link. A "machine-readable medium" may include any medium that can store or transfer information. Examples of a machine-readable medium include electronic circuits, semiconductor memory devices, ROM, flash memory, Erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, Radio Frequency (RF) links, and so forth. The code segments may be downloaded via computer networks such as the internet, intranet, etc. In one embodiment of the present application, computer-readable storage medium refers to non-transitory readable medium.

As described above, only the specific embodiments of the present application are provided, and it can be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working processes of the system, the module and the unit described above may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

Claims

1. A method for calculating a dc resistance DCR, the method comprising:

acquiring a first state parameter of a power battery, wherein the first state parameter comprises at least one of the following parameters: a first voltage parameter, a first current parameter and a first time parameter of a quasi-static stage, wherein the time length of the charging current of the power battery in the quasi-static stage, which is smaller than a current threshold value, reaches a preset time threshold value;

acquiring a quasi-static open-circuit voltage (OCV) of the power battery based on the first state parameter;

acquiring second state parameters of the power battery, wherein the second state parameters comprise a second voltage parameter, a second current parameter, a first state of charge (SOC) and a first battery temperature in a charging stage;

calculating a charging DCR at the first SOC and the first battery temperature based on the quasi-static OCV, the second voltage parameter, and the second current parameter.

2. The DCR calculation method according to claim 1, further comprising:

acquiring a corresponding relation between the charging DCR under the first SOC and the battery temperature;

and determining a first charging DCR corresponding to each of a plurality of preset battery temperature values under the first SOC by using the corresponding relation.

3. The DCR calculation method according to claim 2, further comprising:

acquiring second charging DCRs corresponding to the preset battery temperature values under the first SOC;

calculating the difference value between a first charging DCR corresponding to each of the preset battery temperature values and a second charging DCR corresponding to each of the preset battery temperature values;

and under the condition that the difference value is larger than a first preset threshold value, updating the difference value of the second charging DCR corresponding to each of the plurality of preset battery temperature values into the first charging DCR corresponding to each of the plurality of preset battery temperature values.

4. The DCR calculation method according to claim 1, further comprising:

obtaining a discharging DCR at the first SOC and the first battery temperature;

determining a ratio of the discharging DCR to the charging DCR;

obtaining first charging DCRs corresponding to the preset battery temperature values respectively based on the ratio and the discharging DCR information,

5. The DCR calculation method according to claim 1, further comprising:

acquiring the net accumulated charge-discharge capacity of the charging stage;

acquiring a third state parameter of the power battery under the condition that the net accumulated charge-discharge capacity is larger than a preset capacity threshold, wherein the third state parameter comprises at least one of the following parameters: a third voltage parameter, a third current parameter and a second time parameter of a next quasi-static stage of the quasi-static stage;

acquiring a quasi-static OCV of the power battery based on the third state parameter;

acquiring fourth state parameters of the power battery, wherein the fourth state parameters comprise a fourth voltage parameter, a fourth current parameter, a second state of charge (SOC) and a second battery temperature of a next charging stage of the charging stage;

acquiring a charging DCR at the second SOC and the second battery temperature based on the fourth voltage parameter and the fourth current parameter.

6. The DCR calculation method according to claim 1, wherein the second voltage parameter includes a voltage value at a last instant of a preset time period of the charging phase, and the second current parameter includes current values at a plurality of different instants within the preset time period;

said calculating a charging DCR at said first SOC and said first battery temperature based on said quasi-static OCV, said second voltage parameter, and said second current parameter, comprising:

calculating target parameters representing the current value fluctuation degrees at the different moments;

calculating the current average value of the current values at the different moments;

and under the condition that the target parameter is smaller than a first preset threshold and the current mean value is smaller than a second preset threshold, calculating the charging DCR according to the quasi-static OCV, the voltage value at the last moment and the current mean value.

7. A method for calculating a dc resistance DCR, the method comprising:

acquiring a first state parameter of a power battery, wherein the first state parameter comprises at least one of the following parameters: a first voltage parameter, a first current parameter and a first time parameter of a quasi-static stage, wherein the duration that the charging current of the power battery is smaller than a current threshold value in the quasi-static stage reaches a preset time threshold value or the duration that the discharging current of the power battery is smaller than the current threshold value reaches a preset time threshold value;

acquiring second state parameters of the power battery, wherein the second state parameters comprise a second voltage parameter, a second current parameter, a first state of charge (SOC) and a first battery temperature in a discharging stage;

calculating a discharge DCR at the first SOC and the first battery temperature based on the quasi-static OCV, the second voltage parameter, and the second current parameter.

8. The DCR calculation method according to claim 7, further comprising:

acquiring the corresponding relation between the discharging DCR under the first SOC and the battery temperature;

9. The DCR calculation method according to claim 8, further comprising:

acquiring second discharging DCRs corresponding to the preset battery temperature values under the first SOC;

calculating the difference value of a first discharging DCR corresponding to each of the preset battery temperature values and a second discharging DCR corresponding to each of the preset battery temperature values;

10. The DCR calculation method according to claim 7, further comprising:

acquiring a charging DCR at the first SOC and the first battery temperature;

determining a ratio of the discharging DCR to the charging DCR;

obtaining first discharging DCRs corresponding to the preset battery temperature values respectively based on the ratio and the charging DCR information,

11. The DCR calculation method according to claim 7, further comprising:

acquiring the net accumulated charge-discharge capacity of the discharge stage;

acquiring fourth state parameters of the power battery, wherein the fourth state parameters comprise a fourth voltage parameter, a fourth current parameter, a second state of charge (SOC) and a second battery temperature of a next discharging stage of the discharging stage;

12. The DCR calculation method according to claim 7, wherein the second voltage parameter includes a voltage value at a last instant of a preset time period of the discharge phase, and the second current parameter includes current values at a plurality of different instants within the preset time period;

said calculating a discharge DCR at said first SOC and said first battery temperature based on said quasi-static OCV, said second voltage parameter, and said second current parameter, comprising:

13. A dc resistance DCR calculation apparatus, comprising:

the first parameter acquisition module is used for acquiring a first state parameter of the power battery, wherein the first state parameter comprises at least one of the following parameters: a first voltage parameter, a first current parameter and a first time parameter of a quasi-static stage, wherein the time length of the charging current of the power battery in the quasi-static stage, which is smaller than a current threshold value, reaches a preset time threshold value;

the open-circuit voltage acquisition module is used for acquiring the quasi-static open-circuit voltage OCV of the power battery based on the first state parameter;

the second parameter acquisition module is used for acquiring second state parameters of the power battery, wherein the second state parameters comprise a second voltage parameter, a second current parameter, a first charge state SOC and a first battery temperature in a charging stage;

and the direct current resistance calculation module is used for calculating the charging DCR under the first SOC and the first battery temperature based on the quasi-static OCV, the second voltage parameter and the second current parameter.

14. A dc resistance DCR calculation apparatus, comprising:

the first parameter acquisition module is used for acquiring a first state parameter of the power battery, wherein the first state parameter comprises at least one of the following parameters: a first voltage parameter, a first current parameter and a first time parameter of a quasi-static stage, wherein the duration that the charging current of the power battery is smaller than a current threshold value in the quasi-static stage reaches a preset time threshold value or the duration that the discharging current of the power battery is smaller than the current threshold value reaches a preset time threshold value;

the second parameter acquisition module is used for acquiring second state parameters of the power battery, wherein the second state parameters comprise a second voltage parameter, a second current parameter, a first charge state SOC and a first battery temperature in a discharging stage;

and the direct-current resistance calculation module is used for calculating the discharging DCR under the first SOC and the first battery temperature based on the quasi-static OCV, the second voltage parameter and the second current parameter.

15. A DCR computing device, the device comprising:

a memory for storing a program;

a processor for executing the program stored in the memory to perform the DCR calculation method according to any one of claims 1 to 12.

16. A computer storage medium having computer program instructions stored thereon, which when executed by a processor, implement the DCR calculation method of any of claims 1-12.