CN108761343B

CN108761343B - SOH correction method and device

Info

Publication number: CN108761343B
Application number: CN201810570779.9A
Authority: CN
Inventors: 李盼盼; 周夏荣; 劳力; 王扬; 周鹏
Original assignee: Sinoev Hefei Technologies Co Ltd
Current assignee: Sinoev Hefei Technologies Co Ltd
Priority date: 2018-06-05
Filing date: 2018-06-05
Publication date: 2020-10-16
Anticipated expiration: 2038-06-05
Also published as: CN108761343A

Abstract

The embodiment of the invention provides a method and a device for correcting SOH. The method comprises the following steps: obtaining SOC-OCV curves corresponding to different SOHs; dividing each SOC-OCV curve in the plurality of SOC-OCV curves into two parts according to a preset division strategy, calculating according to the first electric quantity and a first SOC corresponding to the first electric quantity in the first part to obtain a first SOH, and calculating according to the second electric quantity and a second SOC corresponding to the second electric quantity in the second part to obtain a second SOH, wherein the first electric quantity and the second electric quantity are related to the current state of the battery; and correcting the current SOH of the battery according to the first SOH and the second SOH of each SOC-OCV curve. The SOH corrected in this way has a high accuracy throughout the life cycle of the battery.

Description

SOH correction method and device

Technical Field

The invention relates to the technical field of electric automobiles, in particular to a method and a device for correcting SOH.

Background

The power of the electric automobile comes from the battery, and the battery can age, increase the internal resistance, attenuate the capacity and the like in the using process. The SOH (section Of health) represents an aging state Of the Battery, and the aging state Of the Battery affects safety and reliability Of the electric vehicle, so the SOH is an important parameter for BMS (Battery Management System) monitoring, and the quick and accurate monitoring Of the SOH Of the Battery is significant to long-term safe and effective operation Of the Battery.

Disclosure of Invention

In order to overcome the above disadvantages in the prior art, embodiments of the present invention provide a method and an apparatus for correcting SOH, which can correct the current SOH of a battery to a more accurate value, so that a driver can accurately grasp the health status of the battery.

The embodiment of the invention provides an SOH correction method, which comprises the following steps:

obtaining SOC-OCV curves corresponding to different SOHs;

dividing each SOC-OCV curve in a plurality of SOC-OCV curves into two parts according to a preset division strategy, calculating according to a first electric quantity and a first SOC corresponding to the first electric quantity in the first part to obtain a first SOH, and calculating according to a second electric quantity and a second SOC corresponding to the second electric quantity in the second part to obtain a second SOH, wherein the first electric quantity and the second electric quantity are related to the current state of the battery;

and correcting the current SOH of the battery according to the first SOH and the second SOH of each SOC-OCV curve.

Optionally, in an embodiment of the present invention, the correcting the current SOH of the battery according to the first SOH and the second SOH of each SOC-OCV curve includes:

calculating the difference value of the first SOH and the second SOH of the same SOC-OCV curve respectively;

comparing a plurality of difference values corresponding to the plurality of SOC-OCV curves to obtain a minimum difference value of the plurality of difference values;

and correcting the current SOH of the battery according to the first SOH and the second SOH of the SOC-OCV curve corresponding to the minimum difference value.

Optionally, in an embodiment of the present invention, the correcting the current SOH of the battery according to the first SOH and the second SOH of the SOC-OCV curve corresponding to the minimum difference includes:

calculating an average of the first SOH and the second SOH of the SOC-OCV curve corresponding to the minimum difference;

and correcting the current SOH of the battery according to the average value.

Optionally, in an embodiment of the present invention, the dividing each SOC-OCV curve of the plurality of SOC-OCV curves into two parts according to a preset dividing strategy includes:

acquiring intersection points of a plurality of SOC-OCV curves;

and dividing each SOC-OCV curve into two parts according to the intersection point.

Optionally, in this embodiment of the present invention, the calculating a first SOH according to the first electric quantity and a first SOC corresponding to the first electric quantity in the first portion and calculating a second SOH according to the second electric quantity and a second SOC corresponding to the second electric quantity in the second portion includes:

acquiring a first voltage corresponding to the first electric quantity, and acquiring the first SOC corresponding to the first voltage in the first part according to the first voltage;

acquiring a second voltage corresponding to the second electric quantity, and acquiring a second SOC corresponding to the second voltage in the second part according to the second voltage;

calculating according to the first electric quantity and the first SOC to obtain a first capacity, and calculating according to the second electric quantity and a second SOC to obtain a second capacity;

and calculating to obtain the first SOH according to the initial capacity of the battery and the first capacity, and calculating to obtain the second SOH according to the initial capacity of the battery and the second capacity.

The embodiment of the invention also provides an SOH correction device, which comprises:

the acquisition module is used for acquiring SOC-OCV curves corresponding to different SOHs;

the calculation module is used for dividing each SOC-OCV curve in the plurality of SOC-OCV curves into two parts according to a preset division strategy, calculating according to a first electric quantity and a first SOC corresponding to the first electric quantity in the first part to obtain a first SOH, and calculating according to a second electric quantity and a second SOC corresponding to the second electric quantity in the second part to obtain a second SOH, wherein the first electric quantity and the second electric quantity are related to the current state of the battery;

and the correction module is used for correcting the current SOH of the battery according to the first SOH and the second SOH of each SOC-OCV curve.

Optionally, in an embodiment of the present invention, the correction module includes:

the first correction submodule is used for respectively calculating the difference value of the first SOH and the second SOH of the same SOC-OCV curve;

the second correcting submodule is used for comparing a plurality of difference values corresponding to the plurality of SOC-OCV curves to obtain the minimum difference value in the plurality of difference values;

and the third correction submodule is used for correcting the current SOH of the battery according to the first SOH and the second SOH of the SOC-OCV curve corresponding to the minimum difference.

Optionally, in an embodiment of the present invention, a manner that the third correction submodule corrects the current SOH of the battery according to the first SOH and the second SOH of the SOC-OCV curve corresponding to the minimum difference includes:

and correcting the current SOH of the battery according to the average value.

Optionally, in an embodiment of the present invention, a manner in which the calculation module divides each of the plurality of SOC-OCV curves into two parts according to a preset division strategy includes:

acquiring intersection points of a plurality of SOC-OCV curves;

Optionally, in this embodiment of the present invention, a manner that the calculating module calculates a first SOH according to the first electric quantity and a first SOC corresponding to the first electric quantity in the first portion, and calculates a second SOH according to the second electric quantity and a second SOC corresponding to the second electric quantity in the second portion includes:

and calculating to obtain the first SOH according to the initial capacity of the battery and the first capacity, and calculating to obtain the second SOH according to the initial capacity of the battery and the second capacity. Compared with the prior art, the invention has the following beneficial effects:

the embodiment of the invention provides a method and a device for correcting SOH. Firstly, a plurality of SOC-OCV curves of a battery under different SOHs are obtained, and then each SOC-OCV curve in the plurality of SOC-OCV curves is divided into two parts according to a preset division strategy. And then, calculating to obtain a first SOH according to a preset first electric quantity and a first SOC (state of charge) corresponding to the first electric quantity in the first part, and calculating to obtain a second SOH according to a preset second electric quantity and a second SOC corresponding to the second electric quantity in the second part. Wherein the first and second amounts of power are associated with a current state of a battery. And finally, correcting the current SOH of the battery according to the first SOH and the second SOH of each SOC-OCV curve. The SOH is corrected in the mode, the corrected SOH has higher accuracy in the whole life cycle of the battery, and a driver can conveniently and accurately master the health state of the battery.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a block diagram of a computing device provided by embodiments of the present invention.

Fig. 2 is a schematic flow chart of an SOH correction method according to an embodiment of the present invention.

Fig. 3 is one of the flow diagrams of the sub-steps included in step S120 in fig. 2.

Fig. 4 is a second schematic flowchart of the sub-steps included in step S120 in fig. 2.

Fig. 5 is a flowchart illustrating sub-steps included in step S130 in fig. 2.

Fig. 6 is a flowchart illustrating sub-steps included in sub-step S133 in fig. 5.

FIG. 7 is a schematic diagram of a plurality of SOC-OCV curves provided by an embodiment of the present invention.

FIG. 8 is a schematic diagram of calculation of SOH according to the embodiment of the present invention.

FIG. 9 is a schematic diagram illustrating a comparison between a true SOH and a corrected SOH according to an embodiment of the present invention.

Fig. 10 is a block diagram of an SOH correction apparatus according to an embodiment of the present invention.

Icon: 100-a computing device; 110-a memory; 120-a memory controller; 130-a processor; 200-SOH correction means; 210-an obtaining module; 220-a calculation module; 230-a correction module; 231-a first correction submodule; 232-a second syndrome module; 233-a third correction submodule.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Meanwhile, in the description of the present invention, the terms "first", "second", and the like are used only for distinguishing the description, and are not to be construed as indicating or implying relative importance.

Before the inventor of the present application proposes the technical solution in the embodiment of the present application, the SOH algorithm of the electric vehicle currently determines the state of health of the battery according to the amount of the driving mileage, however, the difference of the usage habits of the user is not considered in this way, which may result in low accuracy of the estimated SOH. Some methods predict the SOH of the battery by establishing an electrochemical model, an empirical model and the like, but the establishment of the model requires the introduction of a large number of parameters and a large number of experiments, is relatively complex and is difficult to use in practical electric vehicles.

The defects existing in the above solutions are the results obtained after the inventor has practiced and studied carefully, so the discovery process of the above problems and the solutions proposed by the following embodiments of the present application for the above problems should be the contribution of the inventor to the present application in the process of the present application.

Referring to fig. 1, fig. 1 is a block diagram of a computing device 100 according to an embodiment of the invention. The computing device 100 may be a controller on an electric vehicle, or may be a computer used in testing the SOH of the battery, or the like. The computing device 100 includes: memory 110, memory controller 120, processor 130 and SOH correction apparatus 200. By the SOH correction apparatus 200, an SOH with high accuracy can be obtained and the calculation process is not complicated.

The elements of the memory 110, the memory controller 120 and the processor 130 are electrically connected directly or indirectly to realize data transmission or interaction. For example, the components may be electrically connected to each other via one or more communication buses or signal lines. The memory 110 stores therein an SOH correction apparatus 200, and the SOH correction apparatus 200 includes at least one software functional module that can be stored in the memory 110 in the form of software or firmware (firmware). The processor 130 executes various functional applications and data processing by running software programs and modules stored in the memory 110, such as the SOH correction apparatus 200 in the embodiment of the present invention, so as to implement the SOH correction method in the embodiment of the present invention.

The Memory 110 may be, but is not limited to, a Random Access Memory (RAM), a Read Only Memory (ROM), a Programmable Read-Only Memory (PROM), an Erasable Read-Only Memory (EPROM), an electrically Erasable Read-Only Memory (EEPROM), and the like. The memory 110 is used for storing a program, and the processor 130 executes the program after receiving the execution instruction. Access to the memory 110 by the processor 130 and possibly other components may be under the control of the memory controller 120.

The processor 130 may be an integrated circuit chip having signal processing capabilities. The Processor 130 may be a general-purpose Processor including a Central Processing Unit (CPU), a Network Processor (NP), and the like. But may also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components. The various methods, steps and logic blocks disclosed in the embodiments of the present invention may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It will be appreciated that the configuration shown in FIG. 1 is merely illustrative, and that computing device 100 may also include more or fewer components than shown in FIG. 1, or have a different configuration than shown in FIG. 1. The components shown in fig. 1 may be implemented in hardware, software, or a combination thereof.

Referring to fig. 2, fig. 2 is a schematic flow chart of an SOH correction method according to an embodiment of the present invention. The method can correct the current SOH of the battery to a more accurate value. The specific flow of the SOH correction method is explained in detail below.

And step S110, obtaining SOC-OCV curves corresponding to different SOHs.

A plurality of SOC-OCV curves may be obtained by performing a charge-discharge cycle test on a battery in advance. Alternatively, in the embodiment, when the SOH corresponding to the battery of the electric vehicle is corrected, all SOC-OCV curves obtained through the preliminary test can be directly used as a basis for subsequently correcting the current SOH of the battery, so that the accuracy of the corrected SOH is higher. It is also possible to select a part of the SOC-OCV curves from all the SOC-OCV curves obtained through the preliminary test as a basis for the subsequent SOH correction, thereby reducing the amount of calculation. The SOC-OCV curve represents a relationship between SOC (State of Charge, also called a remaining battery) and OCV (Open Circuit Voltage).

Alternatively, when a partial SOC-OCV curve is selected from all SOC-OCV curves obtained through preliminary tests, SOC-OCV curves corresponding to different SOHs may be selected. In one implementation of the present embodiment, an SOC-OCV curve may be selected that corresponds to an SOH between 80% and 100%. Further, for example, an SOC-OCV curve is selected at 5% intervals based on SOH.

Step S120, each SOC-OCV curve in the plurality of SOC-OCV curves is divided into two parts according to a preset division strategy, a first SOH is obtained through calculation according to the first electric quantity and a first SOC corresponding to the first electric quantity in the first part, and a second SOH is obtained through calculation according to the second electric quantity and a second SOC corresponding to the second electric quantity in the second part.

Referring to fig. 3, fig. 3 is a flowchart illustrating one of the sub-steps included in step S120 in fig. 2. Step S120 may include substeps S121 and substep S122.

In substep S121, intersections of a plurality of SOC-OCV curves are obtained.

And a substep S122 of dividing each SOC-OCV curve into two parts according to the intersection point.

Experiments show that as the battery ages, the OCV gradually decreases when the battery is fully charged and gradually increases when the battery is empty, so that different SOC-OCV curves have intersection points. Therefore, in the present embodiment, after obtaining a plurality of SOC-OCV curves, the intersection points of the plurality of SOC-OCV curves can be directly obtained from the plurality of SOC-OCV curves. And dividing each SOC-OCV curve in the plurality of SOC-OCV curves into two parts according to the intersection point. For example, if a curve records 10% to 100% of SOC, and the intersection point corresponds to 50% of SOC, the curve can be divided into two parts according to 50%, that is: 10% -50% of the total weight of the composition is one part, and 50% -100% of the total weight of the composition is the other part.

Referring to fig. 4, fig. 4 is a second schematic flowchart of the sub-steps included in step S120 in fig. 2. Step S120 may also include substep S124, substep S125, substep S126, and substep S127.

Substep S124, obtaining a first voltage corresponding to the first electric quantity, and obtaining the first SOC corresponding to the first voltage in the first portion according to the first voltage.

And a substep S125 of obtaining a second voltage corresponding to the second amount of power, and obtaining the second SOC corresponding to the second voltage in the second portion according to the second voltage.

The electric vehicle displays the current SOC and the current electric quantity of the battery, wherein the displayed current SOC of the battery has deviation from the real SOC of the battery, and therefore the SOC directly used in the subsequent calculation process is the SOC obtained from an SOC-OCV curve. In this embodiment, before the calculation, the first electric quantity may be set according to the SOC range of the first portion, the SOC displayed by the electric vehicle during charging and discharging for the preset number of times closest to the present, and the present electric quantity. And setting the second amount of power in the same manner. Therefore, the first electric quantity and the second electric quantity related to the current state of the battery are obtained, and the first SOC corresponding to the first electric quantity is ensured to be in the first part, and the second SOC corresponding to the second electric quantity is ensured to be in the second part. Alternatively, the preset number of times may be one time, that is, the first electric quantity and the second electric quantity are set by a charging process or a discharging process which is the closest to the current time, that is, the first electric quantity and the second electric quantity are set according to the current charging process or the current discharging process.

And after the battery is kept still for a preset time, obtaining the voltage when the electric quantity of the battery is the first electric quantity to be used as the first voltage. And a second voltage is obtained in the same manner. Since the SOC-OCV curves are curves about SOC and OCV, a plurality of first SOCs corresponding to the first voltage may be obtained on a first portion of the plurality of SOC-OCV curves according to the first voltage, and a plurality of second SOCs corresponding to the second voltage may be obtained on a second portion of the plurality of SOC-OCV curves according to the second voltage.

And a substep S126, calculating to obtain a first capacity according to the first electric quantity and the first SOC, and calculating to obtain a second capacity according to the second electric quantity and the second SOC.

In this embodiment, a coulomb algorithm is used to calculate a first capacity corresponding to each SOC-OCV curve according to the first SOC and the first electric quantity in the curve, and calculate a second capacity corresponding to the curve according to the second SOC and the second electric quantity in the curve. The battery capacity calculated by the coulomb algorithm is the ratio of a certain charge and discharge capacity Δ Ah to Δ SOC, that is, the battery capacity C is Δ Ah/Δ SOC.

And a substep S127 of calculating the first SOH according to the initial capacity of the battery and the first capacity and calculating the second SOH according to the initial capacity of the battery and the second capacity.

In this embodiment, after the first capacity and the second capacity corresponding to each SOC-OCV curve are calculated, the ratio of each first capacity to the initial capacity of the battery is calculated to obtain the first SOH, and the ratio of each second capacity to the initial capacity of the battery is calculated to obtain the second SOH. Here, the initial battery capacity represents a capacity when the battery is a new battery.

And S130, correcting the current SOH of the battery according to the first SOH and the second SOH of each SOC-OCV curve.

Referring to fig. 5, fig. 5 is a flowchart illustrating sub-steps included in step S130 in fig. 2. Step S130 may include substep S131, substep S132, and substep S133.

And a substep S131 of calculating the difference between the first SOH and the second SOH of the same SOC-OCV curve, respectively.

And a substep S132, comparing a plurality of difference values corresponding to the plurality of SOC-OCV curves to obtain a minimum difference value among the plurality of difference values.

And a substep S133 of correcting the current SOH of the battery according to the first SOH and the second SOH of the SOC-OCV curve corresponding to the minimum difference.

In this embodiment, the difference between the two SOHs of each SOC-OCV curve is calculated according to the first SOH and the second SOH corresponding to the SOC-OCV curve, and then the minimum difference is selected from the calculated differences, so as to select the first SOH and the second SOH that can be used for correcting the current SOH of the battery from the plurality of SOC-OCV curves.

Referring to fig. 6, fig. 6 is a flowchart illustrating sub-steps included in sub-step S133 in fig. 5. Substep S133 may include substeps S1331 and substep S1332.

A substep S1331 of calculating an average value of the first SOH and the second SOH of the SOC-OCV curve corresponding to the minimum difference value;

and a substep S1332 of correcting the current SOH of the battery according to the average value.

In this embodiment, after the minimum difference is obtained, the SOC-OCV curve corresponding to the minimum difference is determined as the target SOC-OCV curve, the average value of the first SOH and the second SOH of the target SOC-OCV curve is calculated, and the current SOH of the battery is corrected to the average value.

Since the SOC-OCV curve is constantly changed during the battery decay process, if the battery capacity is directly calculated by using the coulomb algorithm, the Δ SOC value is obtained by using the SOC-OCV curve corresponding to the new battery, or it is not known which SOC-OCV curve is used to obtain the Δ SOC value, so that the battery capacity obtained by using the coulomb algorithm has a large error, and the calculated SOH error is large. In the present embodiment, each SOC-OCV curve is divided into two parts, and the SOH corresponding to each part in different SOC-OCV curves is calculated. Then, the difference of SOH of two parts of each SOC-OCV curve is calculated, and the SOC-OCV curve with the minimum SOH difference is selected to correct the current SOH of the battery. The SOC-OCV curve selected in this manner may ensure that the corrected SOH error is minimal.

The SOH correction method is explained below by way of example.

Referring to fig. 7, fig. 7 is a schematic diagram of a plurality of SOC-OCV curves according to an embodiment of the present invention. And carrying out charge-discharge cycle test on a battery in advance to obtain a plurality of SOC-OCV curves, and selecting the SOC-OCV curves to obtain SOC-OCV curves corresponding to different SOHs. Among them, the SOC-OCV curve may be selected in such a manner that SOH is approximately 5% apart. In the embodiment of the present example, selection was made in the range of SOH from 80% to 100%, thereby obtaining 6 SOC-OCV curves. As can be seen from FIG. 7, the plurality of SOC-OCV curves have an intersection point at different SOH when the SOC is around 50%.

Optionally, since the lowest remaining capacity of the battery is about 10% in the using process, the SOC range corresponding to the measured SOC-OCV curve is 10% to 100%, and the two measured SOC-OCV curves are divided into: 10% -50% and 50% -100%.

Referring to fig. 8, fig. 8 is a schematic diagram illustrating SOH calculation according to an embodiment of the present invention. SOH1 for SOC at 10% -50% and SOH2 for SOC at 50% -100% were calculated for each SOC-OCV curve. The difference between SOH1 and SOH2 for each SOC-OCV curve is then calculated, and the average of SOH1 and SOH2 for the SOC-OCV curve with the smallest difference is taken as the corrected SOH.

In the present embodiment, the current SOH of the battery has been previously measured to be 89.37, and the current SOH of the battery corrected in the above-described manner is 89.37, whereby it can be seen that the SOH corrected in the above-described manner is closest to the true value.

Referring to fig. 9, fig. 9 is a schematic diagram illustrating a comparison between a true SOH and a corrected SOH according to an embodiment of the present invention. As can be seen from the comparison between the actual value in fig. 9 and the corrected SOH obtained in the above manner, the error of the SOH value corrected by the present scheme is within 2%, and the SOH corrected by the present scheme has higher accuracy in the whole life cycle of the battery.

Referring to fig. 10, fig. 10 is a block diagram illustrating an SOH correction apparatus 200 according to an embodiment of the present invention. The SOH correction apparatus 200 may include a first obtaining module 210, a calculating module 220, and a correcting module 230.

The obtaining module 210 is configured to obtain SOC-OCV curves corresponding to different SOHs.

In this embodiment, the obtaining module 210 is configured to execute step S110 in fig. 2, and the detailed description about the obtaining module 210 may refer to the description of step S110 in fig. 2.

The calculation module 220 is configured to divide each SOC-OCV curve of the plurality of SOC-OCV curves into two parts according to a preset division strategy, calculate a first SOH according to a first electric quantity and a first SOC corresponding to the first electric quantity in the first part, and calculate a second SOH according to a second electric quantity and a second SOC corresponding to the second electric quantity in the second part, where the first electric quantity and the second electric quantity are related to a current state of the battery.

Optionally, the manner in which the calculation module 220 divides each SOC-OCV curve of the plurality of SOC-OCV curves into two parts according to the preset division strategy includes:

acquiring intersection points of a plurality of SOC-OCV curves;

Optionally, the manner that the calculating module 220 calculates a first SOH according to the first electric quantity and a first SOC corresponding to the first electric quantity in the first portion, and calculates a second SOH according to the second electric quantity and a second SOC corresponding to the second electric quantity in the second portion includes:

In this embodiment, the calculating module 220 is configured to execute step S120 in fig. 2, and the detailed description about the calculating module 220 may refer to the description about step S120 in fig. 2.

And the correcting module 230 is used for correcting the current SOH of the battery according to the first SOH and the second SOH of each SOC-OCV curve.

Optionally, the correction module 230 includes:

the first correction submodule 231 is configured to calculate a difference between the first SOH and the second SOH of the same SOC-OCV curve, respectively.

And a second correcting submodule 232, configured to compare a plurality of difference values corresponding to the plurality of SOC-OCV curves to obtain a minimum difference value of the plurality of difference values.

And a third correction submodule 233 for correcting the current SOH of the battery according to the first SOH and the second SOH of the SOC-OCV curve corresponding to the minimum difference.

Optionally, the manner in which the third correcting submodule 233 module corrects the current SOH of the battery according to the first SOH and the second SOH of the SOC-OCV curve corresponding to the minimum difference includes:

and correcting the current SOH of the battery according to the average value.

In the present embodiment, the correction module 230 is configured to perform step S130 in fig. 2, and the detailed description about the correction module 230 may refer to the description of step S130 in fig. 2.

The embodiment of the invention also provides a readable storage medium, wherein the readable storage medium is stored with executable computer instructions, and the executable computer instructions are executed by a processor to realize the SOH correction method.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, apparatus, or computer program product. Accordingly, embodiments of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, embodiments of the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

Embodiments of the present invention are described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In summary, the embodiments of the present invention provide a method and an apparatus for SOH calibration. Firstly, a plurality of SOC-OCV curves of a battery under different SOHs are obtained, and then each SOC-OCV curve in the plurality of SOC-OCV curves is divided into two parts according to a preset division strategy. And then, calculating to obtain a first SOH according to a preset first electric quantity and a first SOC (state of charge) corresponding to the first electric quantity in the first part, and calculating to obtain a second SOH according to a preset second electric quantity and a second SOC corresponding to the second electric quantity in the second part. Wherein the first and second amounts of power are associated with a current state of a battery. And finally, correcting the current SOH of the battery according to the first SOH and the second SOH of each SOC-OCV curve. The SOH is corrected in the mode, the corrected SOH has higher accuracy in the whole life cycle of the battery, and a driver can conveniently and accurately master the health state of the battery.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A SOH correction method, comprising:

obtaining SOC-OCV curves corresponding to different SOHs;

dividing each SOC-OCV curve in a plurality of SOC-OCV curves into two parts according to a preset division strategy, calculating according to a first electric quantity and a first SOC corresponding to the first electric quantity in the first part to obtain a first SOH, and calculating according to a second electric quantity and a second SOC corresponding to the second electric quantity in the second part to obtain a second SOH, wherein the first electric quantity and the second electric quantity are both set on the basis of the current electric quantity of a battery and the SOC of the battery in the charging and discharging process for preset times before the current;

correcting the current SOH of the battery according to the first SOH and the second SOH of each SOC-OCV curve;

wherein, divide into two parts according to presetting every SOC-OCV curve in dividing the strategy in many SOC-OCV curves, include:

acquiring intersection points of a plurality of SOC-OCV curves;

dividing each SOC-OCV curve into two parts according to the intersection point;

the correcting the current SOH of the battery according to the first SOH and the second SOH of each SOC-OCV curve includes:

and calculating to obtain a value according to the first SOH and the second SOH of the SOC-OCV curve corresponding to the minimum difference value, and correcting the current SOH of the battery according to the value.

2. The method of claim 1, wherein calculating a value based on the first SOH and the second SOH of the SOC-OCV curve corresponding to the minimum difference and correcting the current SOH of the battery based on the value comprises:

and correcting the current SOH of the battery according to the average value.

3. The method of claim 1, wherein calculating a first SOH based on a first quantity of power and a first SOC corresponding to the first quantity of power in a first portion and calculating a second SOH based on a second quantity of power and a second SOC corresponding to the second quantity of power in a second portion comprises:

4. An SOH correction apparatus, comprising:

the calculation module is used for dividing each SOC-OCV curve in the plurality of SOC-OCV curves into two parts according to a preset division strategy, calculating according to a first electric quantity and a first SOC corresponding to the first electric quantity in the first part to obtain a first SOH, and calculating according to a second electric quantity and a second SOC corresponding to the second electric quantity in the second part to obtain a second SOH, wherein the first electric quantity and the second electric quantity are both set on the basis of the current electric quantity of the battery and the SOC of the battery in the charging and discharging process of the current preset times;

the correction module is used for correcting the current SOH of the battery according to the first SOH and the second SOH of each SOC-OCV curve;

the mode that each SOC-OCV curve in a plurality of SOC-OCV curves is divided into two parts by the calculation module according to the preset division strategy comprises the following steps:

acquiring intersection points of a plurality of SOC-OCV curves;

dividing each SOC-OCV curve into two parts according to the intersection point;

the correction module includes:

and the third correction submodule is used for calculating a value according to the first SOH and the second SOH of the SOC-OCV curve corresponding to the minimum difference value and correcting the current SOH of the battery according to the value.

5. The apparatus of claim 4 wherein the third correction submodule calculates a value based on the first SOH and the second SOH of the SOC-OCV curve corresponding to the minimum difference, and corrects the current SOH of the battery based on the value by:

and correcting the current SOH of the battery according to the average value.

6. The apparatus of claim 4, wherein the means for calculating the first SOH from the first electrical quantity and a first SOC within the first portion corresponding to the first electrical quantity and the second SOH from the second electrical quantity and a second SOC within the second portion corresponding to the second electrical quantity comprises: