Method for predicting output power of battery and battery system providing same

Abstract

Provided are a method for predicting an output power of a battery and a battery system providing the same, the system including: a battery including a plurality of battery modules, each battery module including a plurality of battery cells; and a main control circuit that determines a representative temperature corresponding to the battery temperature based on a plurality of module temperatures, which are respective temperatures of the plurality of battery modules, a cooling water temperature, which is a temperature of cooling water flowing between the plurality of battery modules, and an air temperature, and predicting an output power value of the battery based on a state of charge (SOC) of the battery, the SOC being determined based on the determined representative temperature and a predetermined reference.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2022-0183568 filed in the Korean Intellectual Property Office on December 23, 2022, the entire contents of which are incorporated herein by reference.

[0003] The present disclosure relates to a method for predicting the output power of a battery and a battery system providing the method. Background Art

[0004] One of the key technologies in battery development may be related to output power when the battery is charged or discharged. In particular, when planning the operation of a system equipped with a battery, the output power of the battery may be a very important factor.

[0005] The magnitude of the battery output power may be closely related to the battery temperature. For example, when the external air temperature is high, the maximum cell temperature with the maximum value may be extracted from the corresponding cell temperatures of multiple battery cells, and the maximum output power of the battery may be predicted based on the extracted maximum cell temperature. For another example, when the external air temperature is low, the minimum cell temperature with the minimum value may be extracted from the corresponding cell temperatures of multiple battery cells, and the maximum output power of the battery may be predicted based on the extracted minimum cell temperature.

[0006] However, the existing method of predicting the output power of the battery as described above may require installing a device such as a temperature sensor on each of the plurality of battery cells to measure the cell temperature. In addition, the existing method may require a complicated process of determining the cell temperature representing the battery temperature based on the plurality of measured cell temperatures. That is, the existing method may have the burden of cost caused by purchasing a plurality of temperature sensors and requires a separate process to determine the battery temperature. Summary of the invention

[0007] Technical issues

[0008] The present disclosure seeks to provide a battery system and a method for predicting the output power of a battery, which can accurately predict the output power of a battery based on cell temperatures of some battery cells among a plurality of battery cells included in the battery.

[0009] Technical methods

[0010] According to one embodiment, a battery system is provided, which includes: a battery including a plurality of battery modules, each battery module including a plurality of battery cells; and a main control circuit, which determines a representative temperature corresponding to the battery temperature based on a plurality of module temperatures which are corresponding temperatures of the plurality of battery modules, a cooling water temperature which is the temperature of cooling water flowing between the plurality of battery modules, and an air temperature, and predicts an output power value of the battery based on a state of charge SOC of the battery, which is determined based on the determined representative temperature and a predetermined reference.

[0011] When the plurality of module temperatures fall within an average temperature range corresponding to temperatures higher than a predetermined first reference temperature and lower than a predetermined second reference temperature, the main control circuit may determine a maximum value among the plurality of module temperatures as a representative temperature.

[0012] When the plurality of module temperatures are outside the average temperature range and the air temperature is the cooling water temperature or higher, the main control circuit may determine a maximum value among the plurality of module temperatures as the representative temperature.

[0013] When the plurality of module temperatures are outside the average temperature range and the air temperature is lower than the cooling water temperature, the main control circuit may determine a minimum value among the plurality of module temperatures as the representative temperature.

[0014] When the representative temperature falls within an extreme temperature range corresponding to a temperature lower than a minimum reference temperature that is a predetermined temperature lower than a first reference temperature or a temperature higher than a maximum reference temperature that is a predetermined temperature higher than a second reference temperature, the main control circuit may correct the predicted output power value by reducing the predicted output power value based on a predetermined benchmark.

[0015] Each of the plurality of battery modules may include a reference cell which is a battery cell disposed within a predetermined range from an outlet of a cooling water plate through which cooling water flows among the plurality of battery cells, and a module temperature of each of the plurality of battery modules may correspond to a cell temperature of the reference cell.

[0016] Each of the plurality of battery cells may be formed in a cylindrical shape having a bottom disposed close to cooling water, a top opposite to the bottom while being spaced a predetermined distance from the bottom, and a side connecting the bottom with the top, and when the bottom is cooled, the temperature of the top may have a maximum value, and when the bottom is heated, the temperature of the top may have a minimum value.

[0017] The cell temperature of the reference cell may correspond to the temperature of the reference cell measured at the top thereof.

[0018] According to another embodiment, a method for predicting the output power of a battery is provided, the method being a method for predicting the output power of a battery comprising a plurality of battery modules, each battery module comprising a plurality of battery cells, the method comprising: receiving a plurality of module temperatures as corresponding temperatures of the plurality of battery modules; determining a representative temperature corresponding to the battery temperature based on the plurality of module temperatures, a cooling water temperature as the temperature of cooling water flowing between the plurality of battery modules, and an air temperature; and predicting the output power value of the battery based on a state of charge SOC of the battery, the state of charge SOC being determined based on the determined representative temperature and a predetermined reference.

[0019] Determination of the representative temperature may include: determining whether multiple module temperatures fall within an average temperature range corresponding to temperatures that are higher than a predetermined first reference temperature and lower than a predetermined second reference temperature; and when as a result of the determination, the multiple module temperatures fall within the average temperature range, determining a first temperature, that is, determining a maximum value among the multiple module temperatures as the representative temperature.

[0020] The determination of the representative temperature may also include: when as a result of the determination, the multiple module temperatures do not fall within the average temperature range, determining whether the air temperature is lower than the cooling water temperature; and when as a result of the determination, the air temperature is lower than the cooling water temperature, determining a second temperature, that is, determining the minimum value among the multiple module temperatures as the representative temperature, and when as a result of the determination, the air temperature is the cooling water temperature or higher, performing the determination of the first temperature.

[0021] The method may also include: after predicting the output power value of the battery, determining whether the representative temperature falls within an extreme temperature range corresponding to a temperature lower than a minimum reference temperature that is a predetermined temperature lower than a first reference temperature or a temperature higher than a maximum reference temperature that is a predetermined temperature higher than a second reference temperature; when as a result of the determination the representative temperature falls within the extreme temperature range, correcting the predicted output power value by lowering the predicted output power value; and when as a result of the determination the representative temperature does not fall within the extreme temperature range, confirming the predicted output power value as the output power of the battery.

[0022] Beneficial Effects

[0023] As explained above, the present disclosure may reduce manufacturing costs by reducing the number of temperature sensors required to measure battery temperature.

[0024] Even when the output power of the entire battery is predicted based on the cell temperatures of some battery cells, the present disclosure can predict the output power of the battery with higher reliability by using a battery temperature determination process performed in consideration of the outside air temperature and the cooling water temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a view showing a battery system according to one embodiment.

[0026] Figure 2 It is shown that the Figure 1 An example view of one type of battery cell in a battery.

[0027] Figure 3 It is shown that the Figure 1 An example view of another type of battery cell in a battery.

[0028] Figure 4 and Figure 5 is the explanation Figure 2 A view of the features of a cylindrical battery cell.

[0029] Figure 6 is the explanation Figure 1 An example view of the structure of a battery.

[0030] Figure 7 It is shown Figure 6 A view of a cross section of a battery.

[0031] Figure 8 It is shown that the Figure 6 FIG. 1 is a view of an example in which two battery modules of a battery are arranged on the top and bottom of a cooling plate CP.

[0032] Fig. 9 is the explanation Figures 6 to 8 A view of the structure of the cooling plate is shown in FIG.

[0033] Fig.10 and Fig.11 It is a view explaining the temperature of cooling water flowing in the cooling plate, the air temperature, and the temperature of the battery cells based on the positions of the cooling plates.

[0034] Figures 12 to 15 It is shown Figure 7 FIG. 1 is a view of a position of a reference cell in each of the first to fourth battery modules M1, M2, M3, and M4.

[0035] Fig.16 is a flowchart explaining a method for predicting output power of a battery according to another embodiment.

[0036] Fig.17 is the explanation Fig.16 Example view of the maximum and minimum temperature concepts. DETAILED DESCRIPTION

[0037] Hereinafter, the embodiments disclosed in the specification are described in detail with reference to the accompanying drawings, and the components identical or similar to each other are represented by the same or similar reference numerals, and their repeated description is omitted. The terms "module" and / or "unit" of the components described in the following description are only used to make the specification easy to understand. Therefore, these terms do not have meanings or functions that are distinguished from each other by themselves. In addition, when it is determined that the detailed description of the known technology related to the present disclosure may obscure the main points of the present disclosure, the detailed description will be omitted. In addition, it should be understood that the drawings are provided only to allow the embodiments of the present disclosure to be easy to understand, and the spirit of the present disclosure is not limited by the drawings, and includes all modifications, equivalents and substitutes included in the spirit and scope of the present disclosure.

[0038] Terms including ordinal numbers such as "first", "second", etc. may be used to describe various components. However, these components are not limited by these terms. These terms are only used to distinguish one component from another component.

[0039] It should be understood that when a component is referred to as being “connected to” or “coupled to” another component, the component may be directly connected to or directly coupled to the other component, or may be connected to or coupled to the other component with a third component interposed therebetween. On the other hand, it should be understood that when referred to as being “directly connected to” or “directly coupled to” another element, the element may be connected to or coupled to the other element without a third element interposed therebetween.

[0040] It should be understood that the terms "including", "having", etc. used in the present application specify the existence of the features, numbers, steps, operations, components, parts or their combinations mentioned in the specification, and do not exclude the existence or possible addition of one or more other features, numbers, steps, operations, components, parts or their combinations.

[0041] Figure 1 is a view showing a battery system according to one embodiment.

[0042] refer to Figure 1 , the battery system 1 may include a battery 10 , a relay 20 , and a battery management system (BMS) 30 .

[0043] exist Figure 1 , the upper system 2 may be installed together with the battery system 1, and operate by receiving power from the battery 10. For example, the upper system 2 may include an automobile system, an energy storage system (ESS), and the like.

[0044] The battery 10 may be connected between two output terminals OUT1 and OUT2 of the battery system 1 , the relay 20 may be connected between the positive electrode of the battery system 1 and the first output terminal OUT1 , and a current sensor (not shown) may be connected between the negative electrode of the battery system 1 and the second output terminal OUT2 . Figure 1 The components shown in and the connection relationships between the components are examples, and the present disclosure is not limited thereto.

[0045] The battery 10 may include a plurality of battery modules M, each of which includes a plurality of battery cells Cell1 to Celln electrically connected in series and in parallel to each other. In some examples, the battery cells may be rechargeable secondary batteries. A predetermined number of battery cells may be connected in series and / or in parallel to each other to form a battery module, and a predetermined number of battery modules may be connected in series and / or in parallel to each other to form the battery 10.

[0046] The relay 20 may control the electrical connection between the battery system 1 and the external device. When the relay 20 is turned on, the battery system 1 and the external device may be electrically connected to each other to thereby perform charging or discharging of the battery, and when the relay 20 is turned off, the battery system 1 and the external device may be electrically disconnected from each other. Here, the external device may be a charger in a charging cycle in which the battery 10 receives power to thereby be charged, and may be a load (e.g., a motor) in a discharging cycle in which the battery 10 discharges power to the external device.

[0047] The BMS 30 may include a monitoring unit 31 and a main control circuit 33 .

[0048] The monitoring unit 31 may collect a plurality of module temperatures that are the temperature of each of the plurality of battery modules M1 to Mn and transmit the collected module temperatures to the main control circuit 33 .

[0049] The module temperature MT may be the temperature of the battery module. In some examples, the module temperature MT may correspond to a cell temperature CT of a battery cell (hereinafter referred to as a reference cell) determined based on a predetermined reference among a plurality of battery cells Cell1 to Celln included in the battery module M. Here, reference may be made to Figures 2 to 14 The method for determining the reference monomer is described in detail.

[0050] The main control circuit 33 may determine a representative temperature corresponding to the temperature of the battery 10 based on a plurality of module temperatures, a cooling water temperature (which is the temperature of cooling water flowing between the plurality of battery modules M1 to Mn), and an air temperature. In addition, the main control circuit 33 may predict the output power of the battery 10 based on the representative temperature and the state of charge SOC of the battery 10. Here, the output power of the battery 10 may be a charging output power or a discharging output power, and may be expressed by a numerical value.

[0051] refer to Figure 1 For example, the main control circuit 33 may receive information about the cooling water temperature and the air temperature by communicating with the upper system 2 installed together with the battery system 1. For another example, the main control circuit 33 may directly receive information about the cooling water temperature and the air temperature from various temperature sensors (not shown) installed on the upper system 2. However, the present disclosure is not limited thereto, and the main control circuit 33 may collect information about the cooling water temperature and the air temperature in various ways.

[0052] Table 1 below shows an example of a lookup table including the charging output power COP of the battery 10 according to the temperature and the state of charge SOC of the battery.

[0053] Table 1

[0054]

[0055] The main control circuit 33 can predict the charging output power of the battery 10 by matching the battery temperature with the battery's state of charge SOC in the above Table 1. In some examples, the battery temperature disclosed in Table 1 may correspond to a representative temperature calculated based on a plurality of module temperatures, cooling water temperature, and air temperature.

[0056] Table 2 below is an example of a lookup table including the discharge output power DOP of the battery 10 based on the temperature and the state of charge SOC of the battery 10 .

[0057] Table 2

[0058]

[0059] The main control circuit 33 can predict the discharge output power of the battery 10 by matching the temperature of the battery 10 with its state of charge SOC in Table 2. In some examples, the battery temperature disclosed in Table 2 above may correspond to a representative temperature calculated based on multiple module temperatures, cooling water temperature, and air temperature.

[0060] In the prior art, the number of temperature sensors corresponding to the total number of battery cells included in the battery 10 is required in order to collect the temperature of the battery 10. In addition, the existing BMS 30 may perform a complicated process of determining the temperature of the battery 10 based on the measured cell temperatures of all battery cells.

[0061] In some examples, the monitoring unit 31 may measure only the cell temperature CT of the reference cell representing the battery module M, and determine the measured cell temperature CT as the module temperature MT. In addition, the main control circuit 33 may perform a simple process of determining one of the corresponding module temperatures MT of the plurality of battery modules included in the battery 10 as a representative temperature, which is the temperature of the battery 10. Then, the main control circuit 33 may determine the temperature of the battery 10 by using only the number of temperature sensors corresponding to the number of the battery modules M.

[0062] Hereinafter, the specification describes in detail a method for determining a reference cell representing a battery module M based on structural and positional characteristics of the battery cells.

[0063] Figure 2 It is shown that the Figure 1 An example view of a type of battery cell in a battery; Figure 3 It is shown that the Figure 1 An example view of another type of battery cell in a battery of; and Figure 4 and Figure 5 is the explanation Figure 2 A view of the features of a cylindrical battery cell.

[0064] refer to Figure 2 As an example, the battery cell may have a small cylindrical shape. For example, the specification of a cylindrical battery cell for an electric vehicle may adopt 21 mm as its top and bottom diameters and 70 mm as its height. Figure 3 As another example, the battery cell may have a large pouch shape. For example, the specification of a pouch-type battery cell for an electric vehicle may adopt a horizontal length of 590 mm and a vertical length of 100 mm.

[0065] refer to Figure 2 and Figure 3 , compared with the pouch-type battery cell, the cross-section of the heated or cooled cylindrical battery cell can be very small, and the temperature distribution in the cross-section can therefore be almost the same. In addition, the cylindrical battery cell can have a constant temperature change based on its height.

[0066] refer to Figure 4 , for example, when Figure 2When the bottom Cell_BOT of a cylindrical battery cell is cooled, the temperature of the top Cell_TOP thereof may be the highest Cell_MAX among all surfaces included in the battery cell. Figure 5 , for another example, when Figure 2 When the bottom Cell_BOT of the cylindrical battery cell is heated, the temperature of the top Cell_TOP may be the lowest Cell_MIN among all surfaces included in the battery cell.

[0067] In some examples, the battery cells included in the battery 10 and the battery module may be reference Figure 2 , Figure 4 and Figure 5 The cylindrical battery cell described. In some examples, the battery cell may be formed into a cylindrical shape having a bottom Cell_BOT disposed close to cooling water, a top Cell_TOP opposite to the bottom Cell_BOT while being spaced a predetermined distance from the bottom, and a side Cell_SIDE connecting the bottom Cell_BOT and the top Cell_TOP. However, the present disclosure is not limited thereto, and when the temperature of the top Cell_TOP of the battery cell is the highest when the bottom Cell_BOT is cooled and the temperature of the top Cell_TOP is the lowest when the bottom Cell_BOT is heated, the battery cell may form the battery 10 regardless of its shape.

[0068] Hereinafter, the specification describes in detail the structure of the battery 10 including a plurality of battery modules including a plurality of battery cells.

[0069] Figure 6 is the explanation Figure 1 An example view of the structure of a battery; Figure 7 It is shown Figure 6 a cross-sectional view of a battery; and Figure 8 It is shown that the Figure 6 FIG. 1 is a view of an example in which two battery modules of a battery are arranged on the top and bottom of a cooling plate CP.

[0070] The battery 10 may include at least one battery pack including a plurality of battery modules M, each of which includes a plurality of battery cells Cell1 to Celln. Figure 6 At least one battery pack shown in FIG. 1 . Hereinafter, the battery 10 is described as including one battery pack, but the present disclosure is not limited thereto, and the battery 10 may include Figure 6 In this case, the number of module temperatures required for the method of calculating the representative temperature described below can be increased. However, the basic calculation method can also be applied thereto.

[0071] refer to Figure 6 and Figure 7 For example, the battery 10 may include four battery modules M1, M2, M3, and M4 disposed on the top and bottom of each of the two cooling plates CP_T and CP_B, and each of the four battery modules M1, M2, M3, and M4 may include a plurality of battery cells Cell1 to Celln connected in parallel to each other.

[0072] The cooling plate CP may be a plate through which cooling water flows as a liquid to cool the heat of the battery cells. In some examples, the battery 10 may include two cooling plates CP, and may be distinguished into an upper cooling plate CP_T and a lower cooling plate CP_B based on their positions. Figure 6 and Figure 7 , the first battery module M1 may be disposed on the top TT of the upper cooling plate CP_T, and the second battery module M2 may be disposed on the bottom TB of the upper cooling plate CP_T. Here, the bottom Cell_BOT of each of the multiple battery cells included in each of the first battery module M1 and the second battery module M2 may all be disposed close to or in contact with the upper cooling plate CP_T. In addition, the third battery module M3 may be disposed on the top BT of the lower cooling plate CP_B, and the fourth battery module M4 may be disposed on the bottom BB of the lower cooling plate CP_B. Here, the bottom Cell_BOT of each of the multiple battery cells included in each of the third battery module M3 and the fourth battery module M4 may all be disposed close to or in contact with the lower cooling plate CP_B. Reference Figure 8 , the upper cooling plate CP_T and the lower cooling plate CP_B may have battery modules disposed on the top and bottom of the cooling plate CP, respectively.

[0073] Hereinafter, the specification describes in detail a method for determining a reference cell representing a battery module M based on positional characteristics of battery cells.

[0074] Fig. 9 is the explanation Figures 6 to 8 A view of the structure of the cooling plate shown in FIG. Fig.10 and Fig.11 It is a view explaining the temperature of cooling water flowing in the cooling plate, the air temperature, and the temperature of the battery cells based on the positions of the cooling plates.

[0075] refer to Fig. 9, the cooling plate CP may include an inlet through which the cooling water CW is introduced and an outlet through which the cooling water is discharged. In addition, a flow path may be formed in the cooling plate CP by a plurality of partition walls. The cooling water CW may flow along the flow path and exchange heat with a plurality of battery cells in contact with the cooling plate CP. That is, the cooling water CW may absorb heat from a plurality of battery cells to lower the temperature of the plurality of battery cells. Therefore, as the cooling water CW flows along the flow path, the temperature of the cooling water CW may gradually increase. In short, the temperature of the cooling water CW may be lowest at position A near the inlet and highest at position B near the outlet. Hereinafter, the temperature of the cooling water CW is described as the cooling water temperature.

[0076] refer to Fig.10 For example, assuming that the air temperature is 25°C, the cooling water temperature is 10°C, and the temperature of the battery cell corresponds to the air temperature. Figure 6 and Figure 8 , while the cooling water CW flows along the flow path, the cooling water CW may be heated by the atmosphere. That is, the temperature of the cooling water CW may gradually increase as the moving time and / or moving distance of the cooling water CW increases. For example, when the cooling water temperature at the inlet is 10°C, the cooling water temperature at the outlet may be 12°C, 13°C, 14°C, etc. Fig.10 As shown in , it is assumed that the cooling water temperature at a position close to the outlet is 12°C.

[0077] like Fig.10 As shown in , the temperature of the battery cell can be higher than the cooling water temperature, so the bottom of the battery cell can be cooled by the cooling water CW. In addition, the bottom of the battery cell can be set to be in contact with (or close to) the cooling plate CP, and the temperature of the bottom of the battery cell can be the same as the cooling water temperature within a predetermined error range. For example, the bottom of the battery cell Cell_A at position A close to the inlet can be cooled by cooling water, and eventually the temperature of the bottom of the battery cell Cell_A can be 10°C, which is the same as the cooling water temperature of 10°C. The bottom of the battery cell Cell_B at position B close to the outlet can be cooled by cooling water, and eventually the temperature of the bottom of the battery cell Cell_B can be 12°C, which is the same as the cooling water temperature of 12°C. As mentioned above with reference to Figure 4 As described, when the bottom is cooled, the temperature of the top may be higher than that of the bottom. For example, based on the characteristics of the battery cells, assuming that the temperature difference between the top and the bottom is about 1°C, the temperature of the top of the battery cell Cell_A may be about 11°C, and the temperature of the top of the battery cell Cell_B may be about 13°C.

[0078] Summarize Fig.10In the case where the air temperature is higher than the cooling water temperature, the temperature of the battery cell Cell_B disposed near the outlet may be the highest among the plurality of battery cells in contact with (or close to) the cooling plate CP. In particular, the temperature of the top of the battery cell Cell_B may be the highest.

[0079] refer to Fig.11 For example, assume that the air temperature is 5°C, the cooling water temperature is 10°C, and the temperature of the battery cell corresponds to the air temperature. Figure 6 and Figure 8 , while the cooling water CW flows along the flow path, the cooling water CW may be cooled by the atmosphere. That is, the temperature of the cooling water CW may gradually decrease as the moving time and / or moving distance of the cooling water CW increases. For example, when the cooling water temperature at the inlet is 10°C, the cooling water temperature at the inlet may be 8°C, 7°C, 6°C, etc. Fig.11 As shown in , it is assumed that the cooling water temperature at a position close to the outlet is 8°C.

[0080] like Fig.11 As shown in , the temperature of the battery cell can be lower than the cooling water temperature, so the bottom of the battery cell can be heated by the cooling water CW. In addition, the bottom of the battery cell can be arranged to be in contact with (or close to) the cooling plate CP, and the temperature of the bottom of the battery cell can be the same as the cooling water temperature within a predetermined error range. For example, the temperature of the bottom of the battery cell Cell_A at position A near the inlet can be 10°C, which is the same as the cooling water temperature of 10°C. The temperature of the bottom of the battery cell Cell_B at position B near the outlet can be 8°C, which is the same as the cooling water temperature of 8°C. As described above with reference to Figure 5 As described, when the bottom is heated, the temperature of the top may be lower than that of the bottom. For example, based on the characteristics of the battery cells, assuming that the temperature difference between the top and the bottom is about 1°C, the temperature of the top of the battery cell Cell_A may be about 9°C, and the temperature of the top of the battery cell Cell_B may be about 7°C.

[0081] Summarize Fig.11 In the case where the air temperature is lower than the cooling water temperature, the temperature of the battery cell Cell_B disposed near the outlet may be the lowest among the plurality of battery cells in contact with (or close to) the cooling plate CP. In particular, the temperature of the top of the battery cell Cell_B may be the lowest.

[0082] In summary, when the air temperature is higher than the cooling water temperature, the temperature of the battery cell Cell_B disposed near the outlet of the cooling plate CP may be the highest among the multiple battery cells included in the battery module. In addition, when the air temperature is lower than the cooling water temperature, the temperature of the battery cell Cell_B disposed near the outlet of the cooling plate CP may be the lowest among the multiple battery cells included in the battery module. That is, when the air temperature and the cooling water temperature are known, the maximum or minimum temperature in the battery module can be predicted by using only the temperature of the battery cell Cell_B disposed near the outlet of the cooling plate CP. The method for predicting the maximum or minimum temperature in a battery module can be similarly applied to multiple battery modules M1, M2, M3, and M4 included in a battery pack.

[0083] Figures 12 to 15 It is shown Figure 7 FIG. 1 is a view of a position of a reference cell in each of the first to fourth battery modules M1, M2, M3, and M4.

[0084] As mentioned above Figures 4 to 11 As described, the maximum or minimum temperature in the battery module may be predicted based on only the temperature of the battery cell Cell_B disposed close to the outlet of the cooling plate CP.

[0085] In some examples, a battery cell Cell_B disposed close to an outlet of the cooling plate CP in each of the plurality of battery modules M1, M2, M3, and M4 may be defined as a reference cell representing the battery module. That is, the reference cell may be a battery cell disposed within a predetermined distance from the outlet of the cooling plate CP among a plurality of battery cells included in the battery module.

[0086] refer to Figure 6 , Figure 7 and Fig.12 , the reference cell TT_Cell_B of the first battery module M1 may be disposed close to the outlet of the cooling plate CP at the top TT of the upper cooling plate CP_T. Figure 6 , Figure 7 and Fig.13 , the reference cell TB_Cell_B of the second battery module M2 may be disposed close to the outlet of the cooling plate CP at the bottom TB of the upper cooling plate CP_T. Figure 6 , Figure 7 and Fig.14 , the reference cell BT_Cell_B of the third battery module M3 may be disposed close to the outlet of the cooling plate CP at the top BT of the lower cooling plate CP_B.

[0087] refer to Figure 6 , Figure 7 and Fig.15, the reference cell BB_Cell_B of the fourth battery module M4 may be disposed close to the outlet of the cooling plate CP at the bottom BB of the lower cooling plate CP_B.

[0088] In some examples, the module temperature of each of the plurality of battery modules M1, M2, M3, and M4 may correspond to the temperature of each reference cell. In some other examples, the module temperature of each of the plurality of battery modules M1, M2, M3, and M4 may correspond to the temperature of each reference cell measured at the top.

[0089] Fig.16 is a flow chart explaining a method for predicting output power of a battery according to another embodiment; and Fig.17 is the explanation Fig.16 Example view of the maximum and minimum temperature concepts.

[0090] refer to Figures 1 to 17 The specification describes a method for predicting the output power of a battery and a battery system providing the method.

[0091] refer to Fig.16 , the main control circuit 33 may first receive information on a plurality of module temperatures, which are respective temperatures of the plurality of battery modules M1 , M2 , M3 , and M4 , from the monitoring unit 31 ( S100 ).

[0092] The monitoring unit 31 may collect a plurality of module temperatures and transmit information about the collected plurality of module temperatures to the main control circuit 33. The module temperature MT may be the temperature of the battery module. In some examples, the module temperature MT may correspond to a cell temperature CT of a reference cell among a plurality of battery cells Cell1 to Celln included in the battery module M.

[0093] Next, the main control circuit 33 may determine whether the plurality of module temperatures fall within an average temperature range ( S200 ).

[0094] The average temperature range may be a temperature range in which the battery 10 can operate normally within a predicted range according to a predetermined process. In some examples, the average temperature range may be defined as a temperature range corresponding to a temperature higher than a predetermined first reference temperature and lower than a predetermined second reference temperature. Fig.17 , for example, the first reference temperature T2 may be 10° C., and the second reference temperature T3 may be 35° C. However, the present disclosure is not limited thereto, and the first reference temperature T2 and the second reference temperature T3 may be determined by considering various situations such as the structure of the battery 10 .

[0095] Next, as a result of the determination, when the plurality of module temperatures fall within the average temperature range (Yes in S200 ), the main control circuit 33 may determine the maximum temperature among the plurality of module temperatures as a representative temperature (ie, a step of determining a first representative temperature) ( S300 ).

[0096] When the multiple module temperatures fall within the average temperature range, the main control circuit 33 may determine the maximum temperature among the multiple module temperatures as the representative temperature. When any of the multiple module temperatures does not fall within the average temperature range, the main control circuit 33 may perform the following step S400.

[0097] Next, when at least one module temperature does not fall within the average temperature range as a result of the determination (No in S200 ), the main control circuit 33 may determine whether the air temperature is the cooling water temperature or higher ( S400 ).

[0098] For example, the main control circuit 33 may receive information about the cooling water temperature and the air temperature by communicating with the upper system 2 installed together with the battery system 1. For another example, the main control circuit 33 may directly receive information about the cooling water temperature and the air temperature from various temperature sensors (not shown) installed on the upper system 2. However, the present disclosure is not limited thereto, and the main control circuit 33 may collect information about the cooling water temperature and the air temperature in various ways.

[0099] Next, when the air temperature is the cooling water temperature or higher as a result of the determination (Yes in S400 ), the main control circuit 33 may determine a maximum temperature having a maximum value among the plurality of module temperatures as a representative temperature ( S300 ).

[0100] In some examples, the representative temperature may be a temperature corresponding to the temperature of the battery 10. In the prior art, the respective cell temperatures of all battery cells included in the battery 10 may be collected, and the maximum or minimum temperature among the temperatures may be determined as the temperature of the battery 10. However, in some examples, the main control circuit 33 may collect only the module temperatures of the plurality of battery modules included in the battery 10, and determine one of the module temperatures as the temperature of the battery 10. Therefore, according to the battery system and the method for predicting the output power of the battery according to the embodiment, the number of temperature sensors may be significantly reduced compared to the number of temperature sensors in the prior art.

[0101] Next, when the air temperature is lower than the cooling water temperature as a result of the determination (No in S400 ), the main control circuit 33 may determine the minimum temperature having the minimum value among the plurality of module temperatures as the representative temperature (ie, a step of determining a second representative temperature) ( S500 ).

[0102] Next, the main control circuit 33 may predict the output power of the battery 10 based on the representative temperature and the state of charge SOC of the battery 10 ( S600 ).

[0103] The main control circuit 33 can predict the output power of the battery 10 based on the representative temperature and the state of charge SOC of the battery 10 according to various known algorithms. For example, the main control circuit 33 can predict the output power of the battery 10 by matching the representative temperature with the state of charge SOC of the battery 10 in a lookup table.

[0104] Referring to Table 1, the main control circuit 33 can predict the charging output power of the battery 10 by matching the representative temperature with the state of charge SOC of the battery 10 in the lookup table. For example, assuming that the representative temperature is 25°C and the state of charge SOC of the battery 10 is 60%. Then, the main control circuit 33 can predict the charging output power of the battery 10 to be 162,942W.

[0105] Referring to Table 2, the main control circuit 33 can predict the discharge output power of the battery 10 by matching the representative temperature with the state of charge SOC of the battery 10 in the lookup table. For example, assuming that the representative temperature is 25°C and the state of charge SOC of the battery 10 is 60%. Then, the main control circuit 33 can predict that the charging output power of the battery 10 is 218,423W.

[0106] Next, the main control circuit 33 may determine whether the representative temperature falls within the extreme temperature range ( S700 ).

[0107] The extreme temperature range may be a temperature range in which it is difficult for the battery 10 to operate normally because the temperature of the battery 10 falls outside the predicted range according to the predetermined process. In some examples, the extreme temperature range may be a temperature range corresponding to a temperature lower than a minimum reference temperature T1, which is lower than the first reference temperature T2 by a predetermined temperature. In some other examples, the extreme temperature range may be a temperature range corresponding to a temperature higher than a maximum reference temperature T4, which is higher than the second reference temperature T3 by a predetermined temperature. Fig.17 , for example, the minimum reference temperature T1 may be −30° C., and the maximum reference temperature T4 may be 50° C. However, the present disclosure is not limited thereto, and the minimum reference temperature T1 and the maximum reference temperature T4 may be determined by considering various conditions such as the structure of the battery 10 .

[0108] Next, when the representative temperature falls within the extreme temperature range as a result of the determination (Yes in S700 ), the main control circuit 33 may correct the output power of the battery 10 predicted in step S600 ( S800 ).

[0109] In some examples, the main control circuit 33 may perform correction to reduce the output power of the battery 10 predicted in step S600. The main control circuit 33 may correct the output power of the battery 10 by multiplying the predicted output power of the battery 10 by a correction ratio α defined as an integer less than 1.

[0110] Referring to Table 1, it is assumed that the representative temperature is -45°C and the state of charge SOC of the battery 10 is 60%. Then, the main control circuit 33 can predict that the charging output power of the battery 10 is 51,728 W. In addition, it is assumed that the representative temperature of -45°C falls within the extreme temperature range (below -30°C and above 50°C) and the correction ratio α is 0.5. Then, the main control circuit 33 can perform a correction to reduce the output power of the battery 10 by multiplying the predicted charging output power of 51,728 W by the correction ratio of 0.5. Here, the main control circuit 33 can determine the corrected output power of the battery 10 of 51,728×0.5=25,864 W as the final output power of the battery 10.

[0111] Referring to Table 2, it is assumed that the representative temperature is 55°C and the state of charge SOC of the battery 10 is 60%. Then, the main control circuit 33 can predict that the charging output power of the battery 10 is 110,348 W. In addition, it is assumed that the representative temperature of 55°C falls within the extreme temperature range (below -30°C and above 50°C) and the correction ratio α is 0.5. Then, the main control circuit 33 can perform a correction to reduce the output power of the battery 10 by multiplying the predicted charging output power of 110,348 W by the correction ratio of 0.5. Here, the main control circuit 33 can determine the corrected output power of the battery 10 of 110,348×0.5=55,174 W as the final output power of the battery 10.

[0112] Next, when the representative temperature does not fall within the extreme temperature range as a result of the determination (No in S700 ), the main control circuit 33 may finally confirm the output power of the battery 10 predicted in step S600 as the output power of the battery 10 ( S900 ).

[0113] Although the embodiments of the present disclosure have been described in detail above, the scope of the present disclosure is not limited thereto. Various modifications and improvements made by those skilled in the art to which the present disclosure relates also belong to the scope of the present disclosure.

Claims

1. A battery system comprising: A battery comprising a plurality of battery modules, each battery module comprising a plurality of battery cells; as well as a main control circuit that determines a representative temperature corresponding to a battery temperature based on a plurality of module temperatures that are respective temperatures of the plurality of battery modules, a cooling water temperature that is a temperature of cooling water flowing between the plurality of battery modules, and an air temperature, and An output power value of the battery is predicted based on a state of charge (SOC) of the battery, the state of charge (SOC) being determined based on the determined representative temperature and a predetermined reference.

2. The system according to claim 1, wherein: The main control circuit: When the plurality of module temperatures fall within an average temperature range corresponding to temperatures higher than a predetermined first reference temperature and lower than a predetermined second reference temperature, a maximum value among the plurality of module temperatures is determined as the representative temperature.

3. The system according to claim 2, wherein: The main control circuit: When the plurality of module temperatures are outside the average temperature range and the air temperature is the cooling water temperature or higher, the maximum value among the plurality of module temperatures is determined as the representative temperature.

4. The system according to claim 2, wherein: The main control circuit: When the plurality of module temperatures are outside the average temperature range and the air temperature is lower than the cooling water temperature, a minimum value among the plurality of module temperatures is determined as the representative temperature.

5. The system according to claim 2, wherein: The main control circuit: When the representative temperature falls within an extreme temperature range corresponding to a temperature lower than a minimum reference temperature that is a predetermined temperature lower than the first reference temperature or a temperature higher than a maximum reference temperature that is a predetermined temperature higher than the second reference temperature, the predicted output power value is corrected by lowering the predicted output power value based on the predetermined reference.

6. The system according to claim 1, wherein: Each of the plurality of battery modules includes a reference cell, the reference cell being a battery cell disposed within a predetermined range from an outlet of a cooling water plate through which the cooling water flows among the plurality of battery cells, and The module temperature of each of the plurality of battery modules corresponds to The cell temperature of the reference cell.

7. The system according to claim 6, wherein: Each of the plurality of battery cells is formed into a cylindrical shape having a bottom disposed close to the cooling water, a top opposed to the bottom while being spaced apart from the bottom by a predetermined distance, and a side connecting the bottom and the top, and When the bottom is cooled, the temperature of the top has a maximum value, and when the bottom is heated, the temperature of the top has a minimum value.

8. The system according to claim 7, wherein: The cell temperature of the reference cell corresponds to The temperature of the reference cell measured at the top of the reference cell.

9. A method for predicting the output power of a battery comprising a plurality of battery modules, each battery module comprising a plurality of battery cells, the method comprising: receiving a plurality of module temperatures as respective temperatures of the plurality of battery modules; determining a representative temperature corresponding to a battery temperature based on the plurality of module temperatures, a cooling water temperature that is a temperature of cooling water flowing between the plurality of battery modules, and an air temperature; as well as An output power value of the battery is predicted based on a state of charge (SOC) of the battery, the state of charge (SOC) being determined based on the determined representative temperature and a predetermined reference.

10. The method according to claim 9, wherein The determining of the representative temperature comprises: determining whether the plurality of module temperatures fall within an average temperature range corresponding to a temperature higher than a predetermined first reference temperature and lower than a predetermined second reference temperature; as well as When the plurality of module temperatures fall within the average temperature range as a result of the determination, a first temperature, that is, a maximum value among the plurality of module temperatures is determined as the representative temperature.

11. The method according to claim 10, wherein The determining of the representative temperature further comprises: When the plurality of module temperatures do not fall within the average temperature range as a result of the determination, determining whether the air temperature is lower than the cooling water temperature; as well as When the air temperature is lower than the cooling water temperature as a result of the determination, determining a second temperature, that is, determining a minimum value among the plurality of module temperatures as the representative temperature, and When the air temperature is the cooling water temperature or higher as a result of the determination, the determination of the first temperature is performed.

12. The method according to claim 10, further comprising: After said prediction of said output power value of said battery, determining whether the representative temperature falls within an extreme temperature range corresponding to a temperature lower than a minimum reference temperature lower than the first reference temperature by a predetermined temperature or a temperature higher than a maximum reference temperature higher than the second reference temperature by a predetermined temperature; When the representative temperature falls within the extreme temperature range as a result of the determination, correcting the predicted output power value by lowering the predicted output power value; as well as When the representative temperature does not fall within the extreme temperature range as a result of the determination, the predicted output power value is confirmed as the output power of the battery.

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