Apparatus and method for calculating battery energy

Abstract

To provide an apparatus and a method for calculating battery energy that can eliminate test complexity, time-consumption, and test data dependency associated with a conventional approach for calculating battery energy.SOLUTION: An apparatus for calculating battery energy includes: a memory for storing relation information between a step-classified SOC of a battery device and a plurality of pieces of battery characteristic information corresponding to each step-classified SOC; and a processor for calculating a plurality of target SOCs with respect to a plurality of preset nodes, calculating a plurality of pieces of target battery characteristic information, each defined for the plurality of nodes based on the relation information stored in the memory and the plurality of calculated target SOCs, calculating a plurality of target powers, each defined for the plurality of nodes from the plurality of pieces of calculated target battery characteristic information, and calculating energy of the battery device using a weighted sum method with respect to the plurality of calculated target powers.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a battery energy calculation device and method.

Background Art

[0002] The energy stored in a battery (e.g., a lithium-ion battery), hereinafter referred to as battery energy, is defined as the cumulative power of the battery when the battery is discharged from a defined maximum state of charge (SOC) to a defined minimum SOC. Such battery energy is one of the main indicators showing the performance of the battery. For example, battery energy has a direct relationship with the distance that an electric vehicle can travel when the battery is fully charged or partially charged, where the charge level of the battery is defined as the SOC (State Of Charge). Also, battery energy is used as a measurement of the state of health (SOH), which is the ratio between the stored energy in the current state and the energy defined for a fresh battery cell at the beginning of life (BOL), and the end-of-life (EOL) condition of the battery can be defined through the battery energy.

[0003] The discharge method applied to measure battery energy is embodied through standard profiles such as WLTP (Worldwide Harmonized Light Vehicles Test Procedure) or UDDSS (Urban Dynamometer Driving Schedule), or through specific profiles such as constant power or constant current. Battery energy is calculated as the integrated value of the power extracted from the battery when the battery is discharged by the above-described discharge method within a specific temperature and specific SOC range. A common approach to calculating battery energy is to create a look-up table of test results or find an appropriate fitting function after conducting discharge tests at various SOHs of the battery. However, such an approach is complex, requires a significant amount of time, and depends on specific test data. Also, when changing test conditions, there is the inconvenience that all necessary tests have to be conducted again. Therefore, there is a need to improve the conventional approach to calculating battery energy.

[0004] The above information disclosed in the technology that becomes the background of such an invention is only for improving the understanding of the background of the present invention, and may include information that does not constitute the prior art.

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to provide a battery energy calculation device and method that can eliminate the test complexity, time consumption, and test data dependence that occurred when calculating conventional battery energy.

[0006] However, the technical problems to be solved by the present invention are not limited to the above-described problems, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

Means for Solving the Problems

[0007] A battery energy calculation device and method according to an embodiment of the present invention for solving the above technical problem calculates target power based on a target SOC, a target OCV, and a target resistance value defined for a plurality of nodes, and then calculates battery energy using a weighted sum method for the calculated target power.

Advantages of the Invention

[0008] According to the present invention, by calculating battery energy based on a simple and improved model, it is possible to eliminate the test complexity, time consumption, and test data dependence that occurred when calculating conventional battery energy.

[0009] However, the technical problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0010] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described later, serve to further understand the technical idea of the present invention. Therefore, the present invention should not be construed as being limited only to the matters described in such drawings.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 4

Embodiments for Carrying Out the Invention

[0012] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in this specification and the claims should not be construed as being limited to their ordinary or dictionary meanings. The inventor should be based on the principle that he can appropriately define the concept of the terms in order to explain his invention in the best way, and should be construed as meanings and concepts that conform to the technical idea of the present invention. Therefore, the embodiments described in this specification and the configurations shown in the drawings are only some of the most preferred embodiments of the present invention, and do not represent all of the technical ideas of the present invention. It should be understood that there may be various equivalents and modifications that can replace them at the time of this application. Also, the "comprise, include" and / or "comprising, including" used in this specification are used to identify the presence of the recited shape, number, step, operation, member, element and / or group thereof, and do not exclude the presence or addition of one or more other shapes, numbers, operations, members, elements and / or groups. Also, when describing each embodiment of the present invention, "~ may be" can include "one or more embodiments of the present invention".

[0013] In addition, to facilitate the understanding of the invention, the accompanying drawings may not illustrate components at their actual scales and may exaggerate the dimensions of some components. Also, in different embodiments, the same reference numerals may be assigned to the same components.

[0014] References to two comparison objects being "identical" mean "substantially identical". Thus, "substantially identical" can include cases with deviations considered to be at a low level in the art, for example, deviations within 5%. Also, the uniformity of any parameter in a given region may mean being uniform from an average perspective.

[0015] Terms such as "first", "second", etc. are used to describe various components, but it is natural that these components are not limited by these terms. These terms are merely used to distinguish one component from another, and it is natural that, unless otherwise stated, the first component may be the second component.

[0016] Throughout the specification, unless otherwise stated, each component may be singular or plural.

[0017] The placement of any configuration "above (or below)" a component or "on (or under)" a component means not only that the any configuration is placed in contact with the upper surface (or lower surface) of the component, but also that other configurations may be interposed between the component and any configuration placed above (or below) the component.

[0018] Also, when it is described that one component is "connected", "coupled", or "joined" to another component, it should be understood that the respective components may be directly connected or joined to each other, but there may also be cases where other components "intervene" between the components, or where the components are "connected", "coupled", or "joined" via other components. Further, when one part is said to be electrically coupled to another part, this includes not only the case where they are directly connected, but also the case where other elements are interposed therebetween and they are connected.

[0019] Throughout the specification, when it is stated as "A and / or B", this means A, B, or A and B, unless otherwise specified. That is, "and / or" includes all combinations or any combination of the plurality of listed items. When it is stated as "C to D", this means C or more and D or less, unless otherwise specified.

[0020] First, for a clear understanding of the present embodiment, assume as follows. The battery device described in the present embodiment means a single battery cell, and the battery energy means the cumulative power of the battery device (i.e., the integrated value of the power discharged from the battery) when the battery device (i.e., the battery cell) is discharged within a specific temperature and a specific SOC range (i.e., it means the remaining energy of the battery device), and the above-mentioned specific temperature and specific SOC range are set by a user input to the input module 100 described later.

[0021] Rather than calculating battery energy through a physical discharge test on the battery device, this embodiment focuses on the process of calculating battery energy using experimental data pre-secured through a discharge test on the battery device and battery parameters (described later) set by the user. The energy derived through a conventional discharge test according to the Worldwide Harmonized Light Vehicles Test Procedure (WLTP) profile or a constant current profile is utilized as a criterion for judging the reliability of the battery energy calculated by the processor 400 of this embodiment.

[0022] The "target" described below is adopted as a term to clearly express that it corresponds to a parameter directly considered when calculating battery energy, and the "step" is adopted as a term to clearly express that it corresponds to a parameter utilized when deriving the "target" parameter.

[0023] Based on the above content, hereinafter, the operation of the battery energy calculation device of this embodiment will be specifically described with reference to the drawings.

[0024] FIG. 1 is a block configuration diagram of a battery energy calculation device according to an embodiment of the present invention, FIG. 2 is an exemplary diagram for explaining battery characteristic information in a battery energy calculation device according to an embodiment of the present invention, and FIGS. 3A to 3D are exemplary diagrams for explaining the error rate of battery energy calculated through a battery energy calculation device according to an embodiment of the present invention.

[0025] Referring to FIG. 1, the battery energy calculation device according to this embodiment can include an input module 100, an output module 200, a memory 300, and a processor 400.

[0026] The input module 100 can receive parameters (hereinafter referred to as battery parameters for the sake of clear distinction of terms) that are utilized when the processor 400 described later calculates battery energy from the user. The input module 100 may be implemented by a computing device (e.g., a PC or a mobile device) that provides a UI (User Interface) for receiving battery parameters. The battery parameters input through the input module 100 may be transmitted to the processor 400 via wired communication such as UART, CAN, Ethernet LAN, SPI, or I2C, or wireless communication such as WI-FI or Bluetooth (registered trademark).

[0027] The battery parameters input through the input module 100 may include: i) the first SOC (maximum SOC), ii) the second SOC (minimum SOC), iii) the current parameter applied for the change from the first SOC to the second SOC, iv) the temperature at which the battery energy is calculated, v) the capacity degradation parameter indicating the degree of capacity degradation of the battery device, vi) the resistance degradation parameter indicating the degree of resistance degradation of the battery device, vii) the number of battery devices connected in series, and viii) the number of battery devices connected in parallel.

[0028] In this embodiment, the battery energy is calculated in a manner that mimics the process of the SOC of the device changing, and the above-described first SOC (SOC MAX ) and the second SOC (SOC MIN ) define the maximum value and the minimum value of the range in which the SOC changes, respectively. The first SOC has a value greater than the second SOC.

[0029] The current parameter (I D ) is the discharge current drawn from the battery for the change from the first SOC (SOC MAX ) to the second SOC (SOC MIN ) and has an average value over time.

[0030] The temperature (Temp) means the temperature of the environment in which the battery energy is calculated (i.e., energy is extracted from the battery).

[0031] The capacity degradation parameter (facQ) is a parameter that indicates the SOH of the capacity of the battery device, and is the capacity (Q bol ) at the BOL (Beginning Of Life) of the battery device and the current capacity (Q cur ), and is defined as the ratio between them (i.e., facQ = Q cur / Q bol *100).

[0032] The resistance degradation parameter is a parameter that indicates the SOH of the DCIR (Direct Current Internal Resistance, hereinafter referred to as the resistance value) of the battery device, and is the resistance value (R bol ) at the BOL (Beginning Of Life) of the battery device and the current resistance value (R cur ), and is defined as the ratio between them (i.e., facR = R cur / R bol *100).

[0033] The number (nS) of battery devices connected in series and the number (nP) of battery devices connected in parallel mean parameters that are utilized when calculating the total energy of the battery system. That is, when all the values of nS and nP are 1, the energy of a single battery cell is calculated, and when the value of nS or nP is 2 or more, the energy of a battery module or a battery pack is calculated. Thus, nS and nP function as parameters for determining whether the battery energy calculation target is a battery cell, a battery module, or a battery pack.

[0034] The symbols and units of the battery parameters as described above follow Table 1 below, and the symbols and units in Table 1 are consistently applied in this specification.

[0035]

Table 1

[0036] Next, the output module 200 can display the battery energy calculated by the processor 400, and may be implemented in a computing device (e.g., a PC or a mobile device) that provides a UI for displaying the battery energy. The battery energy calculated by the processor 400 may be transmitted to the output module 200 via wired communication such as UART, CAN, Ethernet LAN, SPI, or I2C, or wireless communication such as WI-FI or Bluetooth for display.

[0037] The memory 300 may store data and applications (programs or applets) related to the battery energy calculation operation by the processor 400, and the operation system for driving the processor 400. Each piece of information stored in the memory 300 may be selectively retrieved by the processor 400 as needed. The memory 300 may be implemented by a non-volatile storage device (e.g., NVM, Non-Volatile Memory), SSD / HDD storage, SD card, magnetic storage media, or flash storage media, and may be connected to the processor 400 via wired communication such as UART, CAN, Ethernet LAN, SPI, or I2C, or wireless communication such as WI-FI or Bluetooth.

[0038] To calculate the battery energy, the memory 300 may store relationship information between the step-by-step SOC (State Of Charge) of the battery device (e.g., a plurality of SOCs having a 1% step) and a plurality of battery characteristic information corresponding to each step-by-step SOC. The battery characteristic information may include a step-by-step OCV (Open Circuit Voltage) and a step-by-step resistance value corresponding to each step-by-step SOC. Accordingly, the relationship information means information defining the relationship among each step-by-step SOC, each step-by-step OCV, and each step-by-step resistance value.

[0039] The relationship information can be based on experimental data obtained from a discharge test on the battery device. As the discharge test, a well-known GITT (Galvanostatic Intermittent Titration Technique) test shown in FIG. 2 (a method in which the battery device arranged in the temperature chamber is charged to 100% SOC and discharged to 0% SOC in a state where its temperature is stabilized at a specific temperature) may be adopted. Through the GITT test, a data sheet of the battery device (i.e., the battery cell) may be secured in advance. The data sheet may define a function (hereinafter, the first function) for calculating the OCV corresponding to a specific SOC and the capacity (Capacity, Q (Ah)) of the battery cell. Through such a data sheet, the SOC, OCV, and resistance value (R) of the battery device can be calculated. Expressing this in a mathematical formula is as shown in the following Mathematical Formula 1.

[0040]

Number

[0041] In Mathematical Formula 1, t has a unit of [seconds] (this is uniformly applied to all the following mathematical formulas), Ic has a unit of [A] as the discharge current, Q has a unit of [Ah] as the capacity of the cell, and a has a value of 36 as a unit conversion constant. F OCV() is a first function for calculating the OCV corresponding to a specific SOC. CCV is the Closed Circuit Voltage, Ucell is the cell voltage, and Udrop indicates the voltage drop of the cell.

[0042] Based on the above formula 1, the SOC for each step, the corresponding OCV for each step, and the resistance value for each step may be calculated, and a lookup table of relationship information may be created. The multiple SOCs reflected in the lookup table can have a 1% step grid, whereby the matching relationship between the SOC for each 1% step, the OCV corresponding to each step SOC, and the resistance value can be defined in the lookup table.

[0043] When a lookup table is provided, a function (hereinafter referred to as the second function) for calculating the resistance value corresponding to a specific SOC may be defined. As will be specifically described below, in this embodiment, the SOC, OCV, and resistance value utilized when calculating the battery energy correspond to target values defined for a plurality of preset nodes, rather than the step-by-step values on the lookup table. The target OCV corresponding to a specific target SOC may be derived through the above-described first function. Since a function (i.e., the second function) for converting a specific SOC to a specific resistance value is required to obtain the target resistance value from a specific target SOC, such a second function may be derived by the designer based on the lookup table and predefined in the memory 300. As an analysis method applied when deriving the second function from the lookup table, well-known regression analysis methods such as linear regression analysis or polynomial regression analysis may be applied.

[0044] Thus, a lookup table in which the matching relationship between the SOC for each step, the OCV for each step, and the resistance value for each step is created, the first function for calculating the OCV corresponding to a specific SOC, and the second function for calculating the resistance value corresponding to a specific SOC may be stored in the memory 300 as the relationship information.

[0045] On the other hand, a plurality of pieces of such relationship information (i.e., a look-up table, first and second functions) may be acquired based on the results of a plurality of tests (e.g., GITT test) performed on the battery device at a plurality of temperatures and stored in the memory 300.

[0046] The processor 400 may be embodied as a central processing unit (CPU) or a system on chip (SoC) as the main body for calculating battery energy, drive an operation system or an application, control a plurality of hardware or software components connected to the processor 400, and perform various data processing and operations. The processor 400 may be configured to execute at least one instruction stored in the memory 300 and, as a result of the execution, store data in the memory 300.

[0047] In particular, the processor 400 is embodied as a vehicle controller (e.g., BMS, Battery Management System), derives the vehicle's travelable distance based on the battery energy calculated through the process described later, and then displays it through the output module 200 so that the user can recognize the vehicle's travelable distance at the current time. For this purpose, a look-up table or a function defining the relationship between battery energy and the vehicle's travelable distance may be pre-stored in the memory 300.

[0048] To calculate the battery energy, the processor 400 can operate to: i) calculate a plurality of target SOCs respectively defined for a plurality of preset nodes, calculate a plurality of target battery characteristic information respectively defined for the plurality of nodes based on the relationship information stored in the memory 300 and the calculated plurality of target SOCs; ii) calculate a plurality of target powers respectively defined for the plurality of nodes from the calculated plurality of target battery characteristic information; and iii) calculate the energy of the battery device by using a weighted sum method for the calculated plurality of target powers.

[0049] The operation of the processor 400 as described above is based on the Gauss-Legendre Quadrature Rule. As is well known, the Gauss-Legendre Quadrature Rule is a rule for approximating the definite integral of a function in numerical analysis and can be expressed by the following Equation 2.

[0050]

Equation

[0051] In Equation 2, x i is an orthogonal node, wi is an orthogonal weight value, and n is the number of sample points.

[0052] In this embodiment, focus on the process of calculating the energy of the battery device based on the relationship information stored in the memory 300 and the Gauss-Legendre Quadrature Rule according to Equation 2. The plurality of nodes (x i ), the weight values (w i ) to be described later, and the target power (P xi ) respectively correspond to the orthogonal nodes, orthogonal weight values, and function f of the Gauss-Legendre Quadrature Rule according to Equation 2.

[0053] Based on the above content, the process of calculating battery energy will be specifically described below, focusing on the detailed operations of the processor 400.

[0054] First, the processor 400 calculates a plurality of target SOCs (SOC i ) respectively defined for a plurality of preset nodes (x xi ). Based on the relationship information stored in the memory 300 and the calculated plurality of target SOCs (SOC xi ), the processor 400 can calculate a plurality of target OCVs (OCV i ) and a plurality of target resistance values (R xi ) respectively defined for the plurality of nodes (x xi ).

[0055] As described above, the plurality of nodes (x i ) can correspond to the orthogonal nodes of the Gauss-Legendre Quadrature Rule. The number (n) of the nodes (x i ) may be predefined as a value for optimizing the energy of the battery device (i.e., for minimizing the error of the calculated battery energy) (e.g., n = 5). Also, a plurality of preset values may be assigned to each of the plurality of nodes (x i ) for optimizing the energy of the battery device. According to the Gauss-Legendre Quadrature Rule, the preset values set for each node are as shown in Table 2 below (n = 5).

[0056]

Table 2

[0057] Based on the node configuration and preset values as shown in Table 2, the processor 400 calculates the first SOC (SOC MAX ), the second SOC (SOC MIN ) and the node (x iApply a plurality of setting values to a function with (argument), and calculate a plurality of target SOCs (SOC xi ). When expressed as a mathematical formula, it is as shown in the following formula 3.

[0058]

Equation

[0059] In an example where the number (n) of nodes (x i ) is 5, the five setting values in Table 2 are respectively substituted into the right side of formula 3, and five target SOCs (SOC x1 , SOC x2 , SOC x3 , SOC x4 , SOC x5 ) can be calculated.

[0060] When a plurality of target SOCs are calculated, the processor 400 applies the plurality of target SOCs (SOC xi ) calculated through formula 3 to the first function described above (that is, the function for converting a specific SOC to a specific OCV) respectively, and can calculate a plurality of target OCVs (OCV xi ). When expressed as a mathematical formula, it is as shown in the following formula 4.

[0061]

Equation

[0062] In formula 4, F OCV () represents the first function. In an example where the number (n) of nodes (x i ) is 5, the five target SOCs (SOC x1 , SOC x2 , SOC x3 , SOC x4 , SOC x5 ) are respectively substituted into the right side of formula 3, and five target OCVs (OCV x1 , OCV x2 , OCV x3, OCV x4 , OCV x5 ) can be calculated.

[0063] Further, the processor 400 applies the resistance degradation parameters in Table 1 to the results obtained by applying a plurality of target SOCs (SOC xi ) to the above-described second function (i.e., the function for converting a specific SOC to a specific resistance value), respectively, so as to calculate a plurality of target resistance values (R xi ). The second function corresponds to the theoretical function defined based on the above-described Equation 1 and the look-up table in the memory 300, and since the resistance degradation degree of the actual battery device is not reflected in the second function, the processor 400 reflects the resistance degradation of the actual battery device and, in order to calculate a more accurate target resistance value, applies the resistance degradation parameter (facR) to the result value obtained by applying a plurality of target SOCs (SOC xi ) to the second function, so as to calculate a plurality of target resistance values (R xi ). The plurality of target resistance values (R xi ) can be calculated by the following Equation 5.

[0064]

Equation

[0065] In Equation 5, R() represents the second function, and b has a value of 100 as a unit conversion constant. In the example where the number (n) of nodes (x i ) is 5, five target SOCs (SOC x1 , SOC x2 , SOC x3 , SOC x4 , SOC x5 ) are respectively substituted into the right side of Equation 5, and five target resistance values (R x1 , R x2 , R x3 , R x4 , R x5 ) can be calculated.

[0066] Through Equations 4 and 5, when a plurality of target OCVs (OCV xi ) and a plurality of target resistance values (R xi ) are calculated, the processor 400 can calculate a plurality of target powers (P xi ) respectively defined for a plurality of nodes from the calculated plurality of target OCVs (OCV xi ) and the plurality of target resistance values (R xi ). At this time, the processor 400 can calculate a plurality of target powers (P xi ) respectively defined for a plurality of nodes (x xi ) based on the plurality of target OCVs (OCV D ), the plurality of target resistance values (R i ), and the current parameters (I xi ) in Table 1. Expressing this in an equation, it is as shown in Equation 6 below.

[0067]

Equation

[0068] When a plurality of target powers (P xi ) are calculated through Equation 6, the processor 400 can calculate the energy of the battery device using a weighted sum method for the calculated plurality of target powers (P xi ). The said weighted sum follows the Gauss-Legendre Quadrature Rule of Equation 2.

[0069] On the other hand, since the weighted sum target in this embodiment is the target power (P xi ) and the calculation target is the battery energy, a time interval parameter is required to calculate the battery energy. From the time point when the SOC of the battery is the first SOC (i.e., the maximum SOC), that is, the time point when discharge starts, to the time point when discharge reaches a specific SOC xi until the time (T xi) can be expressed by the following Equation 7 based on the relational expressions of current, time, capacity, and SOC (in Equation 7, the capacity of the battery device is corrected by the capacity degradation parameter (facQ)).

[0070]

Equation

[0071] In Equation 7, a and b have values of 36 and 100 respectively as unit conversion constants. From Equation 7, the time (T END ) from the point in time when the SOC of the battery is the first SOC (i.e., the maximum SOC), that is, the point in time when discharge starts, to the point in time when discharge reaches the second SOC (i.e., the minimum SOC), that is, the point in time when discharge ends, can be expressed by the following Equation 8.

[0072]

Equation

[0073] On the other hand, the process of calculating the battery energy (E) by applying the Gauss-Legendre Quadrature Rule to a plurality of target powers (P xi ) calculated through Equation 6 can be expressed by the following Equation 9.

[0074]

Equation

[0075] In Equation 9, c and d have values of 3600 and 1000 respectively as unit conversion constants. According to Equation 9, the time interval parameter required to calculate the battery energy (E) corresponds to T END / 2. Therefore, from Equation 8, the time interval parameter (T SCALE ) can be expressed as shown in the following Equation 10.

[0076]

Equation

[0077] As a result, the time interval parameter (T SCALE ) applied to the weighted sum method is based on the capacity (Q) of the battery device, the current parameter (I D ) in Table 1 and the capacity degradation parameter (facQ), and the first and second SOC (SOC MAX , SOC MIN ) and can be calculated.

[0078] Finally, the processor 400 can apply the time interval parameter (T xi ) to the result value obtained by applying the weighted sum method to a plurality of target powers (P SCALE ) to calculate the energy (E) of the battery device. Expressed as a mathematical formula, it is as shown in the following Mathematical Formula 11.

[0079]

Equation

[0080] The weighting value (w i ) according to Mathematical Formula 11 has a correlation with the node setting value (x i ) based on the Gauss-Legendre Quadrature Rule. The correlation means that the node setting value (x i ) and the weighting value (w i ) for the sample point (i) have a one-to-one correspondence with each other. The correlation follows Table 3 below.

[0081]

Table 3

[0082] On the one hand, the battery energy calculated by Equation 11 is for a single battery cell. When a battery structure in which nS battery cells are connected in series or nP battery cells are connected in parallel is defined as a battery system (battery module or battery pack), one or more of the values of nS and nP are applied to Equation 11, and the total energy of the battery system can be calculated. Expressing this in an equation is as follows: Equation 12 below.

[0083]

Number

[0084] Also, as described above, a plurality of pieces of relationship information (i.e., look-up tables, first and second functions) may be acquired based on the results of a plurality of tests (e.g., GITT tests) on the battery device at a plurality of temperatures and stored in the memory 300. Thus, the processor 400 may be configured to read from the memory 300 the relationship information corresponding to the currently input (set) temperature through the input module 100 and calculate the energy of the battery device.

[0085] FIG. 3 is an exemplary diagram showing the process of calculating battery energy through a conventional WLTP profile. FIG. 3A shows the change in SOC, FIG. 3B shows the change in discharge current, FIG. 3C shows the voltage change of the battery device, and FIG. 3D shows the energy change. In FIG. 3, two vertical lines corresponding to the time coordinates 33.39 and 123.6 are the vertical lines that coincide in FIGS. 3A to 3D and indicate the SOC change range. The battery parameters applied to FIG. 3 follow Table 4 below, and the battery energy was derived to be 11.14 kWh.

[0086]

Table 4

[0087] When the battery parameters in Table 4 applied to the battery energy calculation process through the WLTP profile are applied identically to Equation 12 adopted in this embodiment, the battery energy is calculated to be 11.24 kWh.

[0088] Error rate (ε ENERGY ) is defined as in Equation 13 below, compared to the battery energy calculation result (E EXPER ) through the WLTP profile, the error rate of the battery energy calculation result (E eq12 ) through Equation 12 adopted in this embodiment appears as 0.89%, and it can be confirmed that the reliability of the battery energy calculation method adopted in this embodiment can be guaranteed.

[0089]

Number

[0090] Figure 4 is a flowchart of a battery energy calculation method according to an embodiment of the present invention. As described above, in this embodiment, the processor 400 operates to simulate the process in which the SOC of the battery device changes from the first SOC to the second SOC and calculate the energy of the battery device. Hereinafter, the battery energy calculation method according to this embodiment will be described with reference to Figure 4. Specific descriptions of configurations overlapping with the above-described content will be omitted, and the description will focus on the chronological configuration.

[0091] First, the processor 400 calculates a plurality of target SOCs respectively defined for a plurality of preset nodes, and calculates a plurality of target battery characteristic information respectively defined for the plurality of nodes based on the relationship information stored in the memory 300 (that is, the relationship information between the step-by-step SOC of the battery device and the plurality of battery characteristic information corresponding to each step-by-step SOC) and the calculated plurality of target SOCs (S100). Here, the battery characteristic information can include the step-by-step OCV and the step-by-step resistance value corresponding to each step-by-step SOC, and the relationship information means information defining the relationship between each step-by-step SOC, each step-by-step OCV, and each step-by-step resistance value. On the other hand, a plurality of set values defined in advance may be assigned to each of the plurality of nodes in order to optimize the energy of the battery device calculated by the weighted sum method.

[0092] In the S100 stage, the processor 400 applies a plurality of set values to a function with the first SOC, the second SOC, and the node as factors to calculate a plurality of target SOCs. After that, the calculated plurality of target SOCs are applied to the relationship information to calculate a plurality of target OCVs respectively defined for the plurality of nodes and a plurality of target resistance values respectively defined for the plurality of nodes. When calculating the plurality of target resistance values, the processor 400 calculates the target resistance value based on the relationship information and a resistance degradation parameter indicating the resistance degradation degree of the battery device.

[0093] Subsequently, the processor 400 calculates a plurality of target powers respectively defined for the plurality of nodes from the plurality of target battery characteristic information calculated in the S100 stage (S200). At this time, the processor 400 calculates a plurality of target powers respectively defined for the plurality of nodes based on the plurality of target OCVs, the plurality of target resistance values, and a current parameter applied for the change from the first SOC to the second SOC.

[0094] Subsequently, the processor 400 calculates the capacity of the battery device, the current parameter applied for the change from the first SOC to the second SOC, the capacity degradation parameter indicating the degree of capacity degradation of the battery device, and the time interval parameter applied to the weighted sum method based on the first and second SOCs (S300). The S200 stage and the S300 stage may have their chronological execution order changed.

[0095] Subsequently, the processor 400 calculates the energy of the battery device using a weighted sum method for the plurality of target powers calculated in the S200 stage (S400). Specifically, the time interval parameter calculated in the S300 stage is applied to the result value obtained by applying the weighted sum method to the plurality of target powers to calculate the energy of the battery device. The weighting value applied to the weighted sum method can have an associated relationship based on the set value assigned to the node and a predefined rule (e.g., Gauss-Legendre Quadrature Rule). On the other hand, when the battery device is embodied by a single battery cell and a battery structure in which nS of the battery cells are connected in series or nP are connected in parallel is defined as the battery system (nS and nP are natural numbers of 2 or more), in the S400 stage, the processor 400 can also calculate the total energy of the battery system by applying one or more of the values of nS and nP to the energy of the battery device.

[0096] Finally, after deriving the travelable distance of the vehicle based on the battery energy calculated in the S400 stage, the processor 400 can display it through the output module 200 so that the user can recognize the travelable distance of the vehicle at the current time (S500).

[0097] Furthermore, the relationship information between the step-by-step SOC of the battery device and the plurality of battery characteristic information corresponding to each step-by-step SOC may be stored in the memory 300 in a plurality of numbers by performing a plurality of tests at a plurality of temperatures. Thus, the processor 400 can also read the relationship information corresponding to the currently set temperature from the memory 300 and operate to perform the above-described steps S100 to S500.

[0098] On the other hand, the battery energy calculation method according to the present embodiment may be created by a computer program for causing hardware to execute the above-described steps S100 to S500, stored in a computer-readable recording medium, and implemented by a general-purpose digital computer that operates the computer program. The computer-readable recording medium may correspond to a hardware device specially configured to store each program instruction word, such as ROM, RAM, a hard disk, a floppy disk, a magnetic medium such as a magnetic tape, an optical medium such as a CD-ROM or a DVD, a magneto-optical medium such as a floptical disk, or a flash memory.

[0099] As described above, according to the present invention, by calculating battery energy based on a simple and improved model, it is possible to eliminate the test complexity, time consumption, and test data dependency that occurred when calculating conventional battery energy.

[0100] As used herein, the term "module" can include a unit embodied in hardware, software, or firmware, and may be used interchangeably with terms such as, for example, logic, logic block, component, or circuit. A "module" may be an integrated component, or may be the smallest unit or a part thereof that performs one or more functions. For example, according to one embodiment, a "module" may be embodied in the form of an ASIC (Application-Specific Integrated Circuit). Also, the embodiments described herein may be embodied, for example, in a method or process, an apparatus, a software program, a data stream, or a signal. Even if discussed only in the context of a single form of embodiment (for example, only discussed as a method), the embodiment of the discussed feature may also be embodied in other forms (for example, an apparatus or a program). The apparatus may be embodied with appropriate hardware, software, and firmware, etc. The method may be embodied with an apparatus such as a processor, which generally refers to a processing device including, for example, a computer, a microprocessor, an integrated circuit, or a programmable logic device. Also, the processor includes communication devices such as a computer, a mobile phone, a portable / personal information terminal (personal digital assistant: "PDA"), and other devices that facilitate the communication of information between the apparatus and the end user.

[0101] As described above, the present invention has been described with reference to limited embodiments and drawings, but is not limited thereby. It is natural that various modifications and variations are possible within the equivalent scope of the technical idea of the present invention and the claims described below by those having ordinary knowledge in the technical field to which the present invention pertains.

Description of Reference Numerals

[0102] 100 Input module 200 Output module 300 Memory 400 Processor

Claims

1. A memory storing relationship information between step SOCs (State Of Charge) of a battery device and a plurality of pieces of battery characteristic information corresponding to each step SOC; and a processor operatively coupled to the memory, Calculating a plurality of target SOCs defined for a plurality of preset nodes, respectively, and calculating a plurality of target battery characteristic information defined for the plurality of nodes based on the relationship information stored in the memory and the calculated plurality of target SOCs; Calculating a plurality of target powers defined for the plurality of nodes from the calculated plurality of target battery characteristic information; A processor that calculates the energy of the battery device using a weighted sum scheme for the calculated target powers; A battery energy calculation device comprising:

2. The battery characteristic information includes step-by-step OCVs (Open Circuit Voltages) and step-by-step resistance values ​​corresponding to the step-by-step SOCs, The battery energy calculation apparatus of claim 1 , wherein the relationship information defines a relationship between each step of SOC, each step of OCV, and each step of resistance value.

3. The battery energy calculation device according to claim 2 , wherein the processor replicates a process in which the SOC of the battery device changes from a first SOC to a second SOC, and calculates the energy of the battery device.

4. The battery energy calculation device of claim 3, wherein each of the plurality of nodes is assigned a plurality of predefined setting values ​​to optimize the energy of the battery device calculated by the weighted sum method.

5. The processor, applying the plurality of setting values ​​to a function having factors of the first SOC, the second SOC, and the node to calculate the plurality of target SOCs; 5. The battery energy calculation device of claim 4, further comprising: applying the calculated target SOCs to the relationship information to calculate a plurality of target OCVs defined for the plurality of nodes, and a plurality of target resistance values ​​defined for the plurality of nodes, respectively.

6. The battery energy calculation device according to claim 5 , wherein the processor calculates the target resistance value based on the relationship information and a resistance deterioration parameter indicating a resistance deterioration degree of the battery device.

7. 6. The battery energy calculation device of claim 5, wherein the processor calculates a plurality of target powers defined for the plurality of nodes based on the plurality of target OCVs, the plurality of target resistance values, and a current parameter applied for a change from the first SOC to the second SOC.

8. 6. The battery energy calculation device of claim 5, wherein the processor calculates a capacity of the battery device, a current parameter applied for a change from the first SOC to the second SOC, a capacity degradation parameter indicating a degree of capacity degradation of the battery device, and a time interval parameter applied to the weighted sum scheme based on the first and second SOCs.

9. The battery energy calculation device according to claim 8 , wherein the processor calculates the energy of the battery device by applying the time interval parameter to a result value obtained by applying the weighted sum method to the plurality of target powers.

10. each of the plurality of nodes is assigned a plurality of predefined setting values ​​for optimizing the energy of the battery device calculated by the weighted sum method; The battery energy calculation apparatus of claim 1 , wherein the set values ​​assigned to the nodes and the weights applied to the weighted sum method have a correlation relationship according to a predefined rule.

11. The battery device is embodied as a single battery cell, 2. The battery energy calculation device of claim 1, wherein when a battery structure in which nS battery cells are connected in series or nP battery cells are connected in parallel (nS and nP are natural numbers greater than or equal to 2) is defined as a battery system, the processor calculates the total energy of the battery system by applying one or more of the values ​​of nS and nP to the calculated energy of the battery device.

12. the relevant information is obtained based on a result of a test performed on the battery device at a specific temperature and stored in the memory, and a plurality of relevant information is stored in the memory by performing a plurality of tests at a plurality of temperatures; The battery energy calculation device according to claim 1 , wherein the processor reads related information corresponding to a currently set temperature from the memory and calculates the energy of the battery device.

13. A step of calculating a plurality of target SOCs (State Of Charge) defined for a plurality of preset nodes, respectively, by a processor, and calculating a plurality of target battery characteristic information defined for the plurality of nodes based on the calculated plurality of target SOCs and relationship information, the relationship information defining a relationship between a step-wise SOC of a battery device and a plurality of battery characteristic information corresponding to each step-wise SOC; The processor calculates a plurality of target powers defined for the plurality of nodes from the calculated plurality of target battery characteristic information; and the processor calculating the energy of the battery device using a weighted sum scheme for the calculated target powers; A battery energy calculation method comprising:

14. The battery characteristic information includes step-by-step OCVs (Open Circuit Voltages) and step-by-step resistance values ​​corresponding to the step-by-step SOCs, The method of claim 13, wherein the relationship information defines a relationship between each step of SOC, each step of OCV, and each step of resistance value.

15. The processor is operative to replicate a process in which a SOC of the battery device changes from a first SOC to a second SOC and calculate an energy of the battery device; The battery energy calculation method of claim 14, wherein each of the plurality of nodes is assigned a plurality of predefined setting values ​​to optimize the energy of the battery device calculated by the weighted sum method.

16. In the step of calculating the plurality of target SOCs and the target battery characteristic information, the processor applying the plurality of setting values ​​to a function having the first SOC, the second SOC, and the node as factors to calculate the plurality of target SOCs; 16. The battery energy calculation method of claim 15, further comprising: applying the calculated target SOCs to the relationship information to calculate a plurality of target OCVs defined for the plurality of nodes, and a plurality of target resistance values ​​defined for the plurality of nodes, respectively.

17. In the step of calculating the plurality of target powers, the processor 17. The battery energy calculation method of claim 16, further comprising: calculating a plurality of target powers defined for the plurality of nodes based on the plurality of target OCVs, the plurality of target resistance values, and a current parameter applied for a change from the first SOC to the second SOC.

18. 17. The battery energy calculation method of claim 16, further comprising: calculating a capacity of the battery device, a current parameter applied for a change from the first SOC to the second SOC, a capacity degradation parameter indicating a degree of capacity degradation of the battery device, and a time interval parameter applied to the weighted sum scheme based on the first and second SOCs.

19. In the step of calculating the energy, the processor The method of claim 18, further comprising: applying the time interval parameter to a result of applying the weighted sum method to the plurality of target powers to calculate the energy of the battery device.

20. Combined with hardware, calculating a plurality of target SOCs (State of Charge) respectively defined for a plurality of preset nodes, and calculating a plurality of target battery characteristic information respectively defined for the plurality of nodes based on the calculated plurality of target SOCs and relationship information, the relationship information defining a relationship between a step-wise SOC of a battery device and a plurality of battery characteristic information corresponding to each step-wise SOC; calculating a plurality of target powers defined for the plurality of nodes from the calculated plurality of target battery characteristic information; and Calculating the energy of the battery device using a weighted sum method for the calculated target powers; A computer program recorded on a computer-readable storage medium for executing the program.

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