KR102066223B1 - Method, apparatus and program for maintaining battery lifetime - Google Patents

Abstract

Disclosed is a method for managing the battery life performed by a computer. The method comprises the steps of: selecting a depth of discharge (DOD) of a battery; calculating a state of charge (SOC) of the battery; calculating and accumulating the amount of battery power; calculating the battery life expectancy based on the selected DOD; determining battery target life; comparing the calculated battery life expectancy with the battery target life expectancy; and, if the battery life expectancy is shorter than the battery target life, reducing the DOD.

Description

Battery life management methods, devices and programs {METHOD, APPARATUS AND PROGRAM FOR MAINTAINING BATTERY LIFETIME}

The present invention relates to a battery life management method, apparatus and program.

An ESS (Energy Saving System) is a device that stores power and transmits it where it is needed when power is needed. Generally, power is stored and supplied from a power plant, but recently, research is being actively conducted to combine with renewable energy such as wind and solar power.

In addition, in recent years, the improvement of the stability of the system using the ESS and the effective operation of energy such as auxiliary power is proposed and the module has been mass produced. In order for the ESS system to be reliable, it is necessary to study and manage the battery life. In particular, estimating the remaining life of the battery is very important in view of the reliability, maintenance and stability of the operation of the ESS module.

Publication No. 10-2012-0134415, published 12/12/2012

The problem to be solved by the present invention is to provide a battery life management method, apparatus and program.

Problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

Battery life management method according to an aspect of the present invention for solving the above problems, the step of selecting a depth of discharge (DOD) of the battery, calculating a state of charge (SOC) of the battery, use of the battery Calculating and accumulating power, calculating a battery life expectancy based on the selected DOD, determining a battery life expectancy, comparing the calculated battery life expectancy with the battery target life, and the battery prediction If the life is shorter than the battery target life, reducing the DOD.

In addition, the calculating of the SOC may include estimating the SOC of the battery using a Shepherd Battery Model.

The calculating of the SOC may include estimating the SOC of the battery through a coulomb counting method.

The calculating of the SOC may include calculating an open circuit voltage (OCV) of the battery and estimating the SOC of the battery based on the calculated OCV.

The calculating of the SOC may include charging the battery at a light load time of the battery and calculating the SOC of the battery in the charging step.

Battery life management apparatus according to an aspect of the present invention for solving the above problems includes a memory for storing one or more instructions and a processor for executing the one or more instructions stored in the memory, the processor is one or more Selecting the DOD of the battery, calculating the SOC of the battery, calculating and accumulating the amount of power used by the battery, calculating a battery life expectancy based on the selected DOD, and a battery target by executing an instruction. Determining a lifespan, comparing the calculated battery life expectancy with the battery target lifespan, and reducing the DOD when the battery life expectancy is shorter than the battery target lifespan.

In accordance with an aspect of the present invention for solving the above problems, there is provided a computer program stored in a computer-readable recording medium to perform the battery life management method according to the disclosed embodiment is a computer.
In addition, the present invention provides a battery life management method performed by a computer, comprising the steps of: selecting a depth of discharge (DOD) of the battery; Calculating a state of charge (SOC) of the battery; Calculating and accumulating the amount of power used by the battery; Calculating a battery life expectancy based on the selected DOD; Determining a battery target life; Comparing the calculated battery life expectancy with the battery target life; And reducing the DOD if the battery life expectancy is shorter than the battery target life. The calculating of the SOC of the battery includes: initiating battery charge / discharge for SOC estimation; Estimating the SOC using the current integration method; If an error occurs by checking whether an error occurs according to the current integration method, the SOC of the battery is measured, the open circuit voltage (OCV) is measured based on the Shepherd model, and the accumulated error is reset. Returning to estimating the SOC using the current integration method; If the error does not occur, the step of charging and discharging the battery is terminated when the SOC is 0, and if the SOC is non-zero returning to the step of estimating the SOC using the current integration method, the German Shepherd model circuit Provided is a battery life management method comprising a parallel RC circuit.

Other specific details of the invention are included in the detailed description and drawings.

According to the disclosed embodiment, it is possible to improve the reliability of the entire system of the ESS system by managing the life of the battery, there is an advantage that the maintenance and repair of the system is easy.

Effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a diagram illustrating a system according to an exemplary embodiment.
2 is a flowchart illustrating a battery life management method according to an exemplary embodiment.
3 is a flowchart illustrating a method of estimating an SOC in detail according to an exemplary embodiment.
4 is a diagram illustrating an improved German Shepherd model circuit, according to an exemplary embodiment.
5 is a block diagram of an apparatus according to an embodiment.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be embodied in various different forms, and the present embodiments only make the disclosure of the present invention complete, and those of ordinary skill in the art that It is provided to fully inform the skilled worker of the scope of the invention, which is defined only by the scope of the claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, "comprises" and / or "comprising" does not exclude the presence or addition of one or more other components in addition to the mentioned components. Like reference numerals refer to like elements throughout, and "and / or" includes each and all combinations of one or more of the mentioned components. Although "first", "second", etc. are used to describe various components, these components are of course not limited by these terms. These terms are only used to distinguish one component from another. Therefore, of course, the first component mentioned below may be a second component within the technical spirit of the present invention.

Unless otherwise defined, all terms used in the present specification (including technical and scientific terms) may be used in a sense that can be commonly understood by those skilled in the art. In addition, terms that are defined in a commonly used dictionary are not ideally or excessively interpreted unless they are specifically defined clearly.

As used herein, the term "part" or "module" refers to a hardware component such as software, FPGA, or ASIC, and the "part" or "module" plays certain roles. However, "part" or "module" is not meant to be limited to software or hardware. The “unit” or “module” may be configured to be in an addressable storage medium or may be configured to play one or more processors. Thus, as an example, a "part" or "module" may include components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, Procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Functions provided within components and "parts" or "modules" may be combined into smaller numbers of components and "parts" or "modules" or into additional components and "parts" or "modules". Can be further separated.

In the present specification, the computer refers to any kind of hardware device including at least one processor, and according to an embodiment, it may be understood as a meaning encompassing a software configuration that operates on the hardware device. For example, a computer may be understood as including, but not limited to, a smartphone, a tablet PC, a desktop, a notebook, and a user client and an application running on each device.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Each step described herein is described as being performed by a computer, but the subject of each step is not limited thereto, and at least some of the steps may be performed by different devices according to embodiments.

In the present specification, the battery may mean a lithium ion (Li-ion) battery, but is not limited thereto.

1 is a diagram illustrating a system according to an exemplary embodiment.

Referring to FIG. 1, an ESS 10 and a computer 100 are shown.

In one embodiment, the computer 100 manages battery life of the ESS 10 based on information collected from the ESS 10. The computer 100 may be a system embedded in the ESS 10 or may be a management computer or server located in the same region as the ESS 10.

In addition, the computer 100 may be provided at a remote location with the ESS 10 to manage the battery life of the ESS 10 based on information collected from the ESS 10 by performing network communication with the ESS 10. . According to an embodiment, the computer 100 may manage battery life of the plurality of ESSs 10.

The network may be a wired network such as a local area network (LAN), a wide area network (WAN), or a value added network (VAN), or a mobile radio communication network or a satellite communication network. It can be implemented in any kind of wireless network.

According to an embodiment, the computer 100 may mean a cloud server. In this case, the ESS 10 includes a local computer, transmits and receives information through a network communication between the local computer and the computer 100, and based on the analysis result of the computer 100, the local computer receives the battery of the ESS 10. You can also manage the lifetime.

The life of a battery is indicated by battery cycles, and the remaining cycles of a battery generally increase with less battery's depth of discharge (DOD). Setting up the battery The DOD and hence battery cycles allow you to approximate the total amount of power available for the entire life of the battery.

With this premise, charging and discharging can be performed in one day according to the set DOD to obtain the remaining life of the battery. Since the total amount of power available depends on the DOD setting, the proper DOD setting is essential for the application of the ESS. The life expectancy of the battery can be approximated by the power used compared to the battery power according to the set DOD. In this case, the life expectancy of the battery can be expressed as shown in Equation 1 below.

2 is a flowchart illustrating a battery life management method according to an exemplary embodiment.

The life of the battery is calculated by converting it into the form of available energy of the battery, so accurate calculation and setting of DOD is essential. Therefore, in the disclosed embodiment, the Shepherd Battery Model is used to consider the life of the battery, the nonlinearity of the charge and discharge voltage, and the state of charge (SOC) in the ESS system.

First, after the DOD of the battery is selected, battery charging may be performed at light load time. Accordingly, the SOC of the battery is calculated through the current integration method, and at the same time, the power consumption of the battery is calculated and accumulated in real time. After that, discharge is performed, and after the set amount of power is used up, the battery enters the idle state. In addition, if you want to extend the life expectancy, you can increase the life expectancy by reducing the DOD.

Hereinafter, each step will be described in detail with reference to FIG. 2.

In step S102, the computer 100 starts the battery life management process.

In step S104, the computer 100 selects a depth of discharge (DOD) of the battery.

The computer 100 then calculates a state of charge (SOC) of the battery. In one embodiment, the computer 100 may calculate the SOC during the charging of the battery, but is not limited thereto.

The method of calculating the SOC of the battery by the computer 100 is not limited. For example, a method of estimating the SOC using a current integration method and a technique of estimating the SOC using an OCV (Open Circuit Voltage) may be used. It is not limited.

In one embodiment, a method of estimating SOC using a shepherd model and a current integration method may be used, which will be described later with reference to FIG. 3.

In one embodiment, the computer 100 calculates and accumulates the amount of power used by the battery.

In step S116, the computer 100 determines whether the battery is discharged based on the amount of power used by the battery. When the battery is completely discharged or consumes all the preset amount of power, the battery may be switched to the idle state (S108).

In step S118, the computer 100 calculates a battery life expectancy based on the DOD selected in step S104, and determines a battery target life.

In step S120, the computer 100 compares the calculated battery life expectancy with the battery target life.

If the battery life expectancy is shorter than the battery target life, the computer 100 may perform the step of reducing the DOD (S122).

When reducing the DOD, the set capacity of the battery can be reduced. Of course, the actual storage capacity of the battery is not reduced, so the DOD may exceed 100% if necessary.

The computer 100 may select a DOD for management of battery life, but the DOD may be adjusted according to a power production amount and a power supply and demand plan. That is, a compromised DOD may be selected in consideration of both an optimal DOD and a DOD according to an actual power supply and demand plan in battery life management.

In addition, when power supply and demand is smooth, DOD may be selected for battery life management. When power consumption is high, the DOD may need to be increased even if the battery life is somewhat damaged for smooth supply and demand.

In addition, the DOD may exceed 100%, so the DOD is optimized for battery life management, but it is also possible to set a ratio or range of power that can supply power in excess of the DOD according to the power supply plan. Do.

In the method of estimating the SOC, the computer 100 may estimate the SOC of the battery using a Shepherd Battery Model.

For example, in operation S110, the computer may perform a coulomb counting method.

The current integration method may be performed according to Equation 2 below.

The computer 100 may estimate the SOC of the battery based on the current integration method (S114).

In addition, the computer 100 may calculate an open circuit voltage (OCV) of the battery in step S112.

OCV calculation may be performed according to Equation 3 below.

The computer 100 may estimate the SOC of the battery based on the calculated OCV (S114).

Finally, the SOC of the battery can be estimated according to Equation 4 below.

The current integration method described above is the simplest technique to be implemented, but an error may accumulate through an integral part. In addition, in case of SOC estimation through OCV, it may be practically difficult to apply because a long rest time is required for accurate OCV measurement.

Therefore, the following describes the SOC estimation algorithm, which can compensate for the disadvantages of the SOC estimation algorithm through the current integration method and the OCV.

3 is a flowchart illustrating a method of estimating an SOC in detail according to an exemplary embodiment.

In step S202, the computer 100 starts battery charge / discharge for SOC estimation.

In step S204, the computer 100 performs the calculation using the current integration method. The current integration method may be performed based on Equation 2 described above.

In operation S206, the computer 100 may check whether an error has occurred according to the current integration method. If an error occurs, the computer 100 may measure the SOC of the battery in step S208.

If the error does not occur, the computer 100 may check the SOC in step S216. If the SOC is 0, the charging and discharging of the battery may be terminated. If the SOC is not 0, the computer 100 may again determine the SOC. The calculation can be performed.

When the SOC is calculated in step S208, the computer 100 performs OCV measurement based on the Shepherd model in step S210.

Through steps S212 and S214, the computer 100 resets the accumulated error to compensate for the shortcomings of the current integration method.

4 is a diagram illustrating an improved German Shepherd model circuit, according to an exemplary embodiment.

While the conventional German Shepherd model circuit could not describe the transient characteristics of the battery including only the battery internal resistance R _i , the German Shepherd model circuit 200 shown in FIG. 4 includes a parallel RC circuit. The OCV of the battery can be obtained according to. Accordingly, there is an advantage that the OCV of the battery can be easily measured even in an on-line system such as an electric vehicle.

5 is a block diagram of an apparatus according to an embodiment.

The processor 102 may include a connection passage (eg, a bus, etc.) that transmits and receives signals with one or more cores (not shown) and graphics processor (not shown) and / or other components. .

Processor 102 according to one embodiment executes one or more instructions stored in memory 104 to perform the method described in connection with FIGS.

For example, the processor 102 selects a DOD of the battery by executing one or more instructions stored in the memory, calculates the SOC of the battery, calculates and accumulates the amount of power used by the battery, and based on the selected DOD. A battery life expectancy is calculated, a battery target life is determined, the calculated battery life expectancy is compared with the battery target life, and when the battery life expectancy is shorter than the battery target life, the DOD is reduced.

Meanwhile, the processor 102 may include random access memory (RAM) and read-only memory (ROM) for temporarily and / or permanently storing a signal (or data) processed in the processor 102. , Not shown) may be further included. In addition, the processor 102 may be implemented in the form of a system on chip (SoC) including at least one of a graphic processor, a RAM, and a ROM.

The memory 104 may store programs (one or more instructions) for processing and controlling the processor 102. Programs stored in the memory 104 may be divided into a plurality of modules according to functions.

The steps of a method or algorithm described in connection with an embodiment of the present invention may be implemented directly in hardware, in a software module executed by hardware, or by a combination thereof. Software modules may include random access memory (RAM), read only memory (ROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, hard disk, removable disk, CD-ROM, or It may reside in any form of computer readable recording medium well known in the art.

The components of the present invention may be implemented in a program (or an application) and stored in a medium to be executed in combination with a computer which is hardware. The components of the present invention may be implemented as software programming or software elements, and likewise, embodiments may include various algorithms implemented in combinations of data structures, processes, routines or other programming constructs, such as C, C ++. It may be implemented in a programming or scripting language such as Java, an assembler, or the like. The functional aspects may be implemented with an algorithm running on one or more processors.

In the above, embodiments of the present invention have been described with reference to the accompanying drawings, but those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features. I can understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

10: ESS
100: computer

Claims (7)

In the battery life management method performed by a computer,
Selecting a depth of discharge (DOD) of the battery;
Calculating a state of charge (SOC) of the battery;
Calculating and accumulating the amount of power used by the battery;
Calculating a battery life expectancy based on the selected DOD;
Determining a battery target life;
Comparing the calculated battery life expectancy with the battery target life; And
Reducing the DOD when the battery life expectancy is shorter than the battery target life; Including;
Calculating the SOC of the battery is:
Initiating battery charge / discharge for SOC estimation;
Estimating the SOC using the current integration method;
If an error occurs by checking whether an error occurs according to the current integration method, the SOC of the battery is measured, the open circuit voltage (OCV) is measured based on the Shepherd model, and the accumulated error is reset. Returning to estimating the SOC using the current integration method;
If the error does not occur, the step of returning to the step of estimating the SOC by using the current integration method, if the SOC is 0, the charging and discharging of the battery, and if the SOC is not 0,
Wherein the German Shepherd model circuit comprises a parallel RC circuit,
How to manage battery life. delete delete delete According to claim 1,
The step of calculating the SOC,
Charging the battery at light load time of the battery; And
Calculating SOC of the battery in the charging step; Including,
How to manage battery life. delete delete

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