A method for predicting battery output and a battery system providing the method.

Abstract

The present invention relates to a method for predicting the charging output and discharging output of a battery and a battery system providing such a method, and the battery system of the present invention includes a battery including a plurality of battery modules each including a plurality of battery cells, and a main control circuit that determines a representative temperature corresponding to the temperature of the battery based on a plurality of module temperatures which are the temperatures of each of the plurality of battery modules, a coolant temperature which is the temperature of coolant flowing between the plurality of battery modules, and the atmospheric temperature, and predicts an output value of the battery based on the determined representative temperature and a state of charge (SOC) of the battery determined according to a predetermined criterion.

Description

Technical Field

[0001] [Cross - reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2022 - 0183568, filed on December 23, 2022, and all the contents disclosed in the document of the Korean patent application are incorporated herein by reference in their entirety.

[0002] The present invention relates to a method for predicting the charging output and discharging output of a battery and a battery system providing the method.

Background Art

[0003] One of the core technologies in battery development is the output of the battery during charging or discharging. In particular, when formulating an operation plan for a system in which a battery is mounted, the output of the battery is a very important factor.

[0004] The magnitude of the battery output is closely related to the temperature of the battery. For example, when the external atmospheric temperature is high, the maximum cell temperature having the maximum value among the cell temperatures is extracted for each of the plurality of battery cells, and the maximum output of the battery can be predicted based on the extracted maximum cell temperature. As another example, when the external atmospheric temperature is low, the minimum cell temperature having the minimum value among the cell temperatures is extracted for each of the plurality of battery cells, and the maximum output of the battery can be predicted based on the extracted minimum cell temperature.

[0005] However, in such a conventional method for predicting the battery output, in order to measure the cell temperature, a device such as a temperature sensor must be mounted on each of the plurality of battery cells. Also, in the conventional method, the process of determining the cell temperature representative of the battery temperature based on the measured plurality of cell temperatures is complicated. That is, the conventional method has the burden of cost generation due to the purchase of a plurality of temperature sensors and the need for a separate process for determining the battery temperature.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention provides a battery system and a battery output prediction method that precisely predict the output of a battery based on the cell temperature of some of the battery cells that make up a plurality of battery cells constituting a battery. [Means for solving the problem]

[0007] A battery system according to one feature of the present invention includes a battery comprising a plurality of battery modules, each containing a plurality of battery cells, and a main control circuit that determines a representative temperature corresponding to the temperature of the battery based on a plurality of module temperatures, which are the temperatures of each of the plurality of battery modules, a cooling water temperature, which is the temperature of the cooling water flowing between the plurality of battery modules, and the ambient temperature, and predicts the output value of the battery based on the determined representative temperature and the battery's charge state (SOC, State of Charge) determined by a predetermined standard.

[0008] The main control circuit can determine the maximum value among the multiple module temperatures as the representative temperature if the multiple module temperatures fall within an average temperature range corresponding to an average temperature range exceeding a predetermined first reference temperature and below a predetermined second reference temperature.

[0009] The main control circuit can determine the maximum value among the multiple module temperatures as the representative temperature if the temperatures of the multiple modules exceed the average temperature range and the ambient temperature is equal to or greater than the cooling water temperature.

[0010] The main control circuit can determine the minimum of the multiple module temperatures as the representative temperature if the temperatures of the multiple modules exceed the average temperature range and the ambient temperature is lower than the cooling water temperature.

[0011] The main control circuit can correct the predicted output value by reducing it according to a predetermined standard if the representative temperature falls within an extreme temperature range corresponding to a minimum reference temperature that is lower than the first reference temperature and an excess of the maximum reference temperature that is higher than the second reference temperature.

[0012] Each of the plurality of battery modules includes a reference cell, which is a battery cell located within a predetermined range from the outlet of the cooling water plate through which the cooling water flows, and the module temperature of each of the plurality of battery modules can correspond to the cell temperature of the reference cell.

[0013] Each of the plurality of battery cells is configured in a columnar shape, including a lower surface located in close proximity to the cooling water, an upper surface facing the lower surface at a predetermined distance, and a side surface connecting the lower surface and the upper surface. When the lower surface is cooled, the temperature of the upper surface reaches its maximum value, and when the lower surface is heated, the temperature of the upper surface reaches its minimum value.

[0014] The cell temperature of the reference cell can correspond to the temperature measured on the upper surface of the reference cell.

[0015] A battery output prediction method according to another feature of the present invention is a method for predicting the output of a battery comprising a plurality of battery modules, each comprising a plurality of battery cells, and includes the steps of: receiving a plurality of module temperatures, which are the temperatures of each of the plurality of battery modules; determining a representative temperature corresponding to the temperature of the battery based on the plurality of module temperatures, the temperature of the cooling water flowing between the plurality of battery modules, and the ambient temperature; and predicting the output value of the battery based on the determined representative temperature and the charge state (SOC) of the battery determined by a predetermined criterion.

[0016] The step of determining the representative temperature may include a step of determining whether the plurality of module temperatures belong to an average temperature range corresponding to a temperature exceeding a predetermined first reference temperature and a temperature below a predetermined second reference temperature, and a first temperature determination step of determining the maximum value among the plurality of module temperatures as the representative temperature if, as a result of the determination, the plurality of module temperatures belong to the average temperature range.

[0017] The step of determining the representative temperature further includes, if, as a result of the determination, none of the multiple module temperatures fall within the average temperature range, a step of determining whether the ambient temperature is less than the cooling water temperature, and, if, as a result of the determination, the ambient temperature is less than the cooling water temperature, a second temperature determination step of determining the minimum value among the multiple module temperatures as the representative temperature, and if, as a result of the determination, the ambient temperature is equal to or greater than the cooling water temperature, the first temperature determination step can be performed.

[0018] The output prediction method may further include, after the step of predicting the output value of the battery, the step of determining whether the representative temperature falls within an extreme temperature range corresponding to a minimum reference temperature that is lower than a predetermined temperature below the first reference temperature and an extreme temperature that is higher than a predetermined temperature above the second reference temperature; if, as a result of the determination, the representative temperature falls within the extreme temperature range, the step of reducing and correcting the predicted output value according to a predetermined standard; and if, as a result of the determination, the representative temperature does not fall within the extreme temperature range, the step of confirming the predicted output value as the output of the battery. [Effects of the Invention]

[0019] This invention can reduce manufacturing costs by decreasing the number of temperature sensors required to measure the battery temperature.

[0020] This invention allows for a highly reliable prediction of the battery output by using a battery temperature determination process that takes into account the ambient temperature and coolant temperature, even when predicting the overall battery output based on the cell temperature of some battery cells. [Brief explanation of the drawing]

[0021] [Figure 1] This is a diagram for explaining a battery system according to an embodiment. [Figure 2] This is an exemplary diagram for explaining one type of battery cell that constitutes the battery of FIG. 1. [Figure 3] This is an exemplary diagram for explaining another type of battery cell that constitutes the battery of FIG. 1. [Figure 4] This is a diagram for explaining the characteristics of the cylindrical battery cell of FIG. 2. [Figure 5] This is a diagram for explaining the characteristics of the cylindrical battery cell of FIG. 2. [Figure 6] This is an exemplary diagram for explaining the structure of the battery of FIG. 1. [Figure 7] This is a diagram for explaining the cross-section of the battery of FIG. 6. [Figure 8] This is a diagram for explaining an example where two battery modules that constitute the battery of FIG. 6 are located on the upper and lower surfaces of a single cooling plate CP. [Figure 9] This is a diagram for explaining the structure of the cooling plate shown in FIGS. 6 to 8. [Figure 10] This is a diagram for explaining the temperature of the cooling water flowing through the cooling plate, the atmospheric temperature, and the temperature of the battery cell according to the position of the cooling plate. [Figure 11] This is a diagram for explaining the temperature of the cooling water flowing through the cooling plate, the atmospheric temperature, and the temperature of the battery cell according to the position of the cooling plate. [Figure 12] This is a diagram for explaining the position of the reference cell in the first battery module M1 of FIG. 7. [Figure 13] This is a diagram for explaining the position of the reference cell in the second battery module M2 of FIG. 7. [Figure 14] This is a diagram for explaining the position of the reference cell in the third battery module M₃ of FIG. 7. [Figure 15] This is a diagram for explaining the position of the reference cell in the fourth battery module M4 of FIG. 7. [Figure 16]This is a flowchart illustrating a method for predicting battery output according to one embodiment. [Figure 17] Figure 16 is an illustrative diagram illustrating the concepts of maximum and minimum temperature. [Modes for carrying out the invention]

[0022] The embodiments disclosed herein will be described in detail below with reference to the attached drawings, with identical or similar components numbered by the same or similar drawing numbers, and redundant descriptions thereof will be omitted. The suffixes “module” and / or “part” used for components in the following description are added or mixed for the sake of ease of specification preparation and do not have any distinguishing meaning or role in themselves. Furthermore, in describing the embodiments disclosed herein, if it is determined that a specific description of such known technology may obscure the gist of the embodiments disclosed herein, such detailed description will be omitted. Moreover, the attached drawings are merely for the purpose of facilitating the understanding of the embodiments disclosed herein, and it should be understood that the attached drawings do not limit the technical ideas disclosed herein and include all modifications, equivalents or substitutes that fall within the concept and technical scope of the present invention.

[0023] Terms including ordinal numbers, such as "first," "second," etc., can be used to describe a variety of components, but the components are not limited by such terms. These terms are used solely for the purpose of distinguishing one component from another.

[0024] When it is mentioned that one component is “linked” or “connected” to another component, it should be understood that this may mean that the other component is directly linked or connected to it, but that other components may be in between. Conversely, when it is mentioned that one component is “directly linked” or “directly connected” to another component, it should be understood that there are no other components in between.

[0025] In this application, terms such as “includes” or “having” are intended to specify the presence of features, figures, stages, actions, components, parts, or combinations thereof as described in the specification, and should be understood not to preemptively exclude the possibility of the presence or addition of one or more other features, figures, stages, actions, components, parts, or combinations thereof.

[0026] Figure 1 is a diagram illustrating a battery system according to one embodiment.

[0027] Referring to Figure 1, the battery system 1 includes a battery 10, a relay 20, and a battery management system (hereinafter referred to as BMS, Battery Management System) 30.

[0028] In Figure 1, the higher-level system 2 may be a system on which the battery system 1 is installed and which is operated by power supplied by the battery 10. For example, the higher-level system 2 may include an automobile system, an energy storage system (ESS), etc.

[0029] The battery 10 is connected between the two output terminals OUT1 and OUT2 of the battery system 1, a relay 20 is connected between the positive terminal of the battery system 1 and the first output terminal OUT1, and a current sensor (not shown) can be connected between the negative terminal of the battery system 1 and the second output terminal OUT2. The configuration and the connections between the configurations shown in Figure 1 are examples and the invention is not limited thereto.

[0030] The battery 10 may include multiple battery modules M, each containing multiple battery cells Cell1-Celln electrically connected in series and parallel. In one embodiment, the battery cells may be rechargeable secondary batteries. A predetermined number of battery cells can be connected in series and / or parallel to form a battery module, and a predetermined number of battery modules can be connected in series and / or parallel to form the battery 10.

[0031] Relay 20 controls the electrical connection between the battery system 1 and the external device. When relay 20 is turned on, the battery system 1 and the external device are electrically connected for charging or discharging, and when relay 20 is turned off, the battery system 1 and the external device are electrically disconnected. At this time, the external device may be a charger in a charging cycle where power is supplied to charge the battery 10, or a load (e.g., a motor) in a discharge cycle where the battery 10 discharges power to the external device.

[0032] The BMS30 includes a monitoring unit 31 and a main control circuit 33.

[0033] The monitoring unit 31 can collect multiple module temperatures, which are the temperatures of each of the multiple battery modules M1-Mn, and transmit the collected multiple module temperatures to the main control circuit 33.

[0034] Module temperature (MT) is the temperature of the battery module. In this embodiment, the module temperature MT can correspond to the cell temperature (CT) of a battery cell (hereinafter referred to as the reference cell) among the multiple battery cells Cell1-Celln that constitute the battery module M, which is determined according to a predetermined criterion. The method for determining the reference cell is explained in detail in Figures 2 to 14.

[0035] The main control circuit 33 can determine a representative temperature corresponding to the temperature of the battery 10 based on the temperatures of multiple modules, the temperature of the cooling water flowing between multiple battery modules M1-Mn, and the ambient temperature. Furthermore, the main control circuit 33 can predict the output of the battery 10 based on the representative temperature and the charge state (SOC) of the battery 10. In this case, the output of the battery 10 may be either a charging output or a discharging output, and is expressed as a numerical value.

[0036] Referring to Figure 1, for example, the main control circuit 33 can communicate with the higher-level system 2, which houses the battery system 1, to receive information regarding the coolant temperature and ambient temperature. As another example, the main control circuit 33 can directly receive information regarding the coolant temperature and ambient temperature from various temperature sensors (not shown) mounted on the higher-level system 2. However, it is not limited to this, and the main control circuit 33 can collect information regarding the coolant temperature and ambient temperature in a variety of ways.

[0037] Table 1 below is an example of a look-up table that includes the charge output power (COP) of battery 10 based on battery temperature and state of charge (SOC).

[0038] [Table 1]

[0039] The main control circuit 33 can predict the charging output of the battery 10 by matching the battery temperature and state of charge (SOC) with Table 1. In this embodiment, the battery temperature disclosed in Table 1 can correspond to a representative temperature calculated based on multiple module temperatures, cooling water temperature, and ambient temperature.

[0040] Table 2 below is an example of a lookup table that includes the discharge output power (DOP) of battery 10 based on its temperature and state of charge (SOC).

[0041] [Table 2]

[0042] The main control circuit 33 can predict the discharge output of the battery 10 by matching the temperature and state of charge (SOC) of the battery 10 with Table 2. In this embodiment, the battery temperature disclosed in Table 2 can correspond to a representative temperature calculated based on multiple module temperatures, cooling water temperature, and ambient temperature.

[0043] Conventionally, to collect the temperature of the battery 10, a temperature sensor corresponding to the total number of battery cells constituting the battery 10 was required. Furthermore, conventional BMS 30 performed a complex process to determine the temperature of the battery 10 based on the measured cell temperatures of all battery cells.

[0044] In this embodiment, the monitoring unit 31 measures only the cell temperature CT of a reference cell representative of the battery module M and determines the measured cell temperature CT as the module temperature MT. The main control circuit 33 also performs a simple process of determining one of the module temperatures MT of each of the multiple battery modules constituting the battery 10 as the representative temperature of the battery 10. Thus, the temperature of the battery 10 can be determined using only the number of temperature sensors corresponding to the number of battery modules M.

[0045] The following describes in detail how to determine a representative reference cell for battery module M based on the structural and positional characteristics of the battery cell.

[0046] Figure 2 is an illustrative diagram illustrating one type of battery cell that makes up the battery in Figure 1, Figure 3 is an illustrative diagram illustrating another type of battery cell that makes up the battery in Figure 1, and Figures 4 and 5 are diagrams illustrating the characteristics of the cylindrical battery cell in Figure 2.

[0047] Referring to Figure 2, one example is that a battery cell is small and cylindrical in size. For example, the specifications for a cylindrical battery cell used in an electric vehicle are that the diameter of the top and bottom surfaces is 21 mm and the height is 70 mm. Referring to Figure 3, another example is that a battery cell may be large and pouch-shaped. For example, the specifications for a pouch-shaped battery cell used in an electric vehicle are that the width is 590 mm and the height is 100 mm.

[0048] Referring to Figures 2 and 3, compared to pouch-shaped battery cells, cylindrical battery cells have a much smaller cross-section that is heated or cooled, resulting in a nearly identical temperature distribution within the cross-section. Furthermore, cylindrical battery cells exhibit a constant temperature change with respect to height.

[0049] Referring to Figure 4, for example, when the bottom surface Cell_BOT of the cylindrical battery cell in Figure 2 is cooled, the temperature of the top surface Cell_TOP is the highest among all the surfaces constituting the battery cell (CellT_MAX). Referring to Figure 5, as another example, when the bottom surface Cell_BOT of the cylindrical battery cell in Figure 2 is heated, the temperature of the top surface Cell_TOP is the lowest among all the surfaces constituting the battery cell (CellT_MIN).

[0050] In this embodiment, the battery cells constituting the battery 10 and battery module may be cylindrical battery cells as described in Figures 2, 4, and 5. In this embodiment, the battery cell is configured in a columnar shape including a lower surface Cell_BOT located in close proximity to the cooling water, an upper surface Cell_TOP facing the lower surface Cell_BOT at a predetermined distance, and a side surface Cell_SIDE connecting the lower surface Cell_BOT and the upper surface Cell_TOP. However, it is not limited to this, and the battery 10 can be configured regardless of its shape as long as the temperature of the upper surface Cell_TOP is highest when the lower surface Cell_BOT is cooled, and the temperature of the upper surface Cell_TOP is lowest when the lower surface Cell_BOT is heated.

[0051] The structure of battery 10, which includes multiple battery modules, each containing multiple battery cells, will be described in detail below.

[0052] Figure 6 is an illustrative diagram illustrating the structure of the battery in Figure 1, Figure 7 is a diagram illustrating a cross-section of the battery in Figure 6, and Figure 8 is a diagram illustrating an example in which the two battery modules constituting the battery in Figure 6 are located on the upper and lower surfaces of a single cooling plate CP.

[0053] Battery 10 may include at least one battery pack, each containing multiple battery modules M, each containing multiple battery cells Cell1_Celln. For example, battery 10 may include at least one battery pack as shown in Figure 6. Hereafter, battery 10 will be described as containing one battery pack, but it is not limited to this, and may contain multiple battery packs as shown in Figure 6. In this case, the number of module temperatures required in the method for calculating the representative temperature described below may increase, but the basic calculation method remains the same.

[0054] Referring to Figures 6 and 7, for example, the battery 10 has four battery modules M1, M2, M3, and M4 located on the upper and lower surfaces of two cooling plates CP_T and CP_B, respectively, and each of the four battery modules M1, M2, M3, and M4 can contain multiple battery cells Cell1_Celln connected in parallel.

[0055] The cooling plate CP may be a plate over which cooling water, a liquid that cools the heat of the battery cells, flows. In this embodiment, the battery 10 may include two cooling plates CP, which can be distinguished as an upper cooling plate CP_T and a lower cooling plate CP_B depending on their position. Referring to Figures 6 and 7, the first battery module M1 may be located at the upper part TT of the upper cooling plate CP_T, and the second battery module M2 may be located at the lower part TB of the upper cooling plate CP_T. In this case, the lower surfaces Cell_BOT of the multiple battery cells contained in the first battery module M1 and the second battery module M2 may all be positioned to be close to or in contact with the upper cooling plate CP_T. Also, the third battery module M3 may be located at the upper part BT of the lower cooling plate CP_B, and the fourth battery module M4 may be located at the lower part BB of the lower cooling plate CP_B. In this case, the lower surfaces Cell_BOT of the multiple battery cells contained in the third battery module M3 and the fourth battery module M4 may all be positioned to be close to or in contact with the lower cooling plate CP_B. Referring to Figure 8, the upper cooling plate CP_T and the lower cooling plate CP_B can each accommodate battery modules positioned above and below the cooling plate CP, respectively.

[0056] The following describes in detail how to determine a representative reference cell for battery module M based on the positional characteristics of the battery cells.

[0057] Figure 9 is a diagram illustrating the structure of the cooling plate shown in Figures 6 to 8, and Figures 10 and 11 are diagrams illustrating the temperature of the cooling water flowing through the cooling plate, the ambient temperature, and the temperature of the battery cells according to the position of the cooling plate.

[0058] Referring to Figure 9, the cooling plate CP can include an inlet for the cooling water (CW) to flow in and an outlet for the cooling water to flow out. Furthermore, a flow path is formed within the cooling plate CP by multiple partition walls. The cooling water CW flows along the flow path and exchanges heat with the multiple battery cells in contact with the cooling plate CP. In other words, the cooling water CW can absorb heat from the multiple battery cells, thereby lowering their temperatures. Therefore, as the cooling water CW flows along the flow path, its temperature gradually increases. In summary, the temperature of the cooling water CW is lowest at position A, near the inlet, and highest at position B, near the outlet. Hereafter, the temperature of the cooling water CW will be referred to as the cooling water temperature.

[0059] Referring to Figure 10, let's assume, for example, that the air temperature is 25°C, the coolant temperature is 10°C, and the battery cell temperature corresponds to the air temperature. In this environment, referring to Figures 6 and 8, the coolant CW is heated by the atmosphere as it flows along the flow path. That is, the temperature of the coolant CW gradually increases as the travel time and / or distance of the coolant CW increases. For example, when the coolant temperature at the inlet is 10°C, the coolant temperature at the outlet will be 12°C, 13°C, 14°C, etc. In Figure 10, let's assume the coolant temperature near the outlet is 12°C.

[0060] In Figure 10, the temperature of the battery cell is higher than the coolant temperature, so the lower surface of the battery cell is cooled by the coolant CW. Also, since the lower surface of the battery cell is in contact with (or close to) the cooling plate CP, the temperature of the lower surface of the battery cell becomes the same as the coolant temperature within a predetermined error range. For example, the lower surface of battery cell Cell_A, located at position A near the inlet, is cooled by the coolant, and consequently, the temperature of the lower surface of battery cell Cell_A is the same as the coolant temperature (10°C), which is 10°C. The lower surface of battery cell Cell_B, located at position B near the outlet, is cooled by the coolant, and consequently, the temperature of the lower surface of battery cell Cell_B is the same as the coolant temperature (12°C), which is 12°C. As explained earlier in Figure 4, when the lower surface is cooled, the temperature of the upper surface is higher than the temperature of the lower surface. For example, assuming that the temperature difference between the top and bottom surfaces of a battery cell is approximately 1°C due to its characteristics, the temperature of the top surface of battery cell Cell_A is approximately 11°C, and the temperature of the top surface of battery cell Cell_B is approximately 13°C.

[0061] To summarize the case shown in Figure 10, when the ambient temperature is higher than the cooling water temperature, the temperature of battery cell Cell_B, which is located near the outlet among the multiple battery cells in contact with (or close to) the cooling plate CP, is the highest. In particular, the temperature of the upper surface of battery cell Cell_B is the highest.

[0062] Referring to Figure 11, let's assume, for example, that the air temperature is 5°C, the coolant temperature is 10°C, and the battery cell temperature corresponds to the air temperature. In this environment, referring to Figures 6 and 8, the coolant CW is cooled by the atmosphere as it flows along the flow path. That is, the temperature of the coolant CW gradually decreases as the travel time and / or distance of the coolant CW increases. For example, when the coolant temperature at the inlet is 10°C, the coolant temperature at the outlet will be 8°C, 7°C, 6°C, etc. In Figure 11, let's assume the coolant temperature near the outlet is 8°C.

[0063] In Figure 11, the temperature of the battery cell is lower than the coolant temperature, so the lower surface of the battery cell is heated by the coolant CW. Also, since the lower surface of the battery cell is in contact with (or close to) the cooling plate CP, the temperature of the lower surface of the battery cell becomes the same as the coolant temperature within a predetermined error range. For example, the temperature of the lower surface of battery cell Cell_A, located at position A near the inlet, is 10°C, the same as the coolant temperature (10°C). The temperature of the lower surface of battery cell Cell_B, located at position B near the outlet, is 8°C, the same as the coolant temperature (8°C). As explained earlier in Figure 5, when the lower surface is heated, the temperature of the upper surface becomes lower than the temperature of the lower surface. For example, assuming that the temperature difference between the upper and lower surfaces is about 1°C due to the characteristics of the battery cell, the temperature of the upper surface of battery cell Cell_A is about 9°C, and the temperature of the upper surface of battery cell Cell_B is about 7°C.

[0064] To summarize the case shown in Figure 11, when the ambient temperature is lower than the cooling water temperature, the temperature of battery cell Cell_B, which is located closest to the outlet, is the lowest among the multiple battery cells in contact with (or near) the cooling plate CP. In particular, the temperature of the upper surface of battery cell Cell_B is the lowest.

[0065] In summary, if the ambient temperature is higher than the coolant temperature, the temperature of battery cell Cell_B, located near the outlet of the cooling plate CP, will be the highest among the multiple battery cells that make up the battery module. Conversely, if the ambient temperature is lower than the coolant temperature, the temperature of battery cell Cell_B, located near the outlet of the cooling plate CP, will be the lowest among the multiple battery cells that make up the battery module. In other words, knowing the ambient temperature and coolant temperature, the maximum or minimum temperature within the battery module can be predicted using only the temperature of battery cell Cell_B located near the outlet of the cooling plate CP. This method for predicting the maximum or minimum temperature within the battery module is identically applicable to the multiple battery modules M1, M2, M3, and M4 that make up the battery pack.

[0066] Figures 12 to 15 illustrate the positions of the reference cells in the first to fourth battery modules M1, M2, M3, and M4, respectively, as shown in Figure 7.

[0067] As explained earlier in Figures 4 to 11, the maximum or minimum temperature inside the battery module can be predicted solely by the temperature of battery cell Cell_B located near the outlet of the cooling plate CP.

[0068] In this embodiment, in each of the multiple battery modules M1, M2, M3, and M4, a battery cell Cell_B located close to the outlet of the cooling plate CP is defined as a reference cell representing the battery module. In other words, the reference cell may be one of the multiple battery cells constituting the battery module that is located within a predetermined distance from the outlet of the cooling plate CP.

[0069] Referring to Figures 6, 7, and 12, the reference cell TT_Cell_B of the first battery module M1 can be located close to the outlet of the cooling plate CP, from the upper TT of the upper cooling plate CP_T. Referring to Figures 6, 7, and 13, the reference cell TB_Cell_B of the second battery module M2 can be located close to the outlet of the cooling plate CP, from the lower TB of the upper cooling plate CP_T. Referring to Figures 6, 7, and 14, the reference cell BT_Cell_B of the third battery module M3 can be located close to the outlet of the cooling plate CP, from the upper BT of the lower cooling plate CP_B. Referring to Figures 6, 7, and 15, the reference cell BB_Cell_B of the fourth battery module M4 can be located close to the outlet of the cooling plate CP, from the lower BB of the lower cooling plate CP_B.

[0070] In one embodiment, the module temperature of each of the multiple battery modules M1, M2, M3, and M4 can correspond to the temperature of their respective reference cells. In another embodiment, the module temperature of each of the multiple battery modules M1, M2, M3, and M4 can correspond to the temperature measured on the upper surface of their respective reference cells.

[0071] Figure 16 is a flowchart illustrating a method for predicting battery output according to one embodiment, and Figure 17 is an illustrative diagram illustrating the concepts of maximum and minimum temperature in Figure 16.

[0072] A method for predicting battery output and a battery system providing this method will be described with reference to Figures 1 to 17.

[0073] Referring to Figure 16, first, the main control circuit 33 receives information regarding the temperatures of multiple modules, which are the temperatures of each of the multiple battery modules M1, M2, M3, and M4, from the monitoring unit 31 (S100).

[0074] The monitoring unit 31 can collect the temperatures of multiple modules and transmit the collected information about the multiple module temperatures to the main control circuit 33. The module temperature MT is the temperature of the battery module. In this embodiment, the module temperature MT can correspond to the cell temperature CT of a reference cell among the multiple battery cells Cell1-Celln that make up the battery module M.

[0075] Next, the main control circuit 33 determines whether multiple module temperatures fall within the average temperature range (S200).

[0076] The average temperature range is the temperature range in which the battery 10 can operate normally within a predicted range according to a pre-set process. In this embodiment, the average temperature range can be defined as the temperature range that exceeds a predetermined first reference temperature and falls below a predetermined second reference temperature. Referring to Figure 17, for example, the first reference temperature T2 is 10°C and the second reference temperature T3 is 35°C. However, it is not limited to this, and the first reference temperature T2 and the second reference temperature T3 can be determined by considering various circumstances such as the structure of the battery 10.

[0077] Next, if the determination shows that multiple module temperatures fall within the average temperature range (S200, YES), the main control circuit 33 determines the maximum temperature among the multiple module temperatures as the representative temperature (first representative temperature determination step) (S300).

[0078] If multiple module temperatures fall within the average temperature range, the main control circuit 33 determines the highest temperature among the multiple module temperatures as the representative temperature. If even one of the multiple module temperatures does not fall within the average temperature range, the main control circuit 33 executes step S400.

[0079] Next, if the determination shows that at least one module temperature does not fall within the average temperature range (S200, NO), the main control circuit 33 determines whether the ambient temperature is equal to or greater than the cooling water temperature (S400).

[0080] For example, the main control circuit 33 can communicate with the higher-level system 2, which houses the battery system 1, to receive information regarding coolant temperature and ambient temperature. Alternatively, the main control circuit 33 can directly receive information regarding coolant temperature and ambient temperature from various temperature sensors (not shown) mounted on the higher-level system 2. However, it is not limited to these methods, and the main control circuit 33 can collect information regarding coolant temperature and ambient temperature in a variety of ways.

[0081] Next, if the result of the determination is that the ambient temperature is higher than or equal to the cooling water temperature (S400, YES), the main control circuit 33 determines the maximum temperature, which is the highest value among the multiple module temperatures, as the representative temperature (S300).

[0082] In the embodiment, the representative temperature may be the temperature corresponding to the temperature of the battery 10. Conventionally, the cell temperature of each battery cell constituting the battery 10 was collected, and the maximum or minimum temperature among them was determined as the temperature of the battery 10. However, in the embodiment, only the module temperatures of the multiple battery modules constituting the battery 10 can be collected, and the temperature of one of these modules can be determined as the temperature of the battery 10. Therefore, the battery system and battery output prediction method according to the embodiment can significantly reduce the number of temperature sensors compared to conventional methods.

[0083] Next, if the result of the determination is that the ambient temperature is lower than the cooling water temperature (S400, NO), the main control circuit 33 determines the minimum temperature, which is the lowest value among the multiple module temperatures, as the representative temperature (second representative temperature determination stage) (S500).

[0084] Next, the main control circuit 33 predicts the output of the battery 10 based on the typical temperature and the charge state (SOC) of the battery 10 (S600).

[0085] The main control circuit 33 can predict the output of the battery 10 using various conventionally known algorithms based on the typical temperature and the state of charge (SOC) of the battery 10. For example, the main control circuit 33 can predict the output of the battery 10 by matching the typical temperature and the state of charge (SOC) of the battery 10 to a lookup table.

[0086] Referring to Table 1, the main control circuit 33 can predict the charging output of the battery 10 by matching the typical temperature and the state of charge (SOC) of the battery 10 to a lookup table. For example, let's assume the typical 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 of the battery 10 to be 162,942W.

[0087] Referring to Table 2, the main control circuit 33 can predict the discharge output of battery 10 by matching the typical temperature and the state of charge (SOC) of battery 10 to a lookup table. For example, let's assume the typical temperature is 25°C and the state of charge (SOC) of battery 10 is 60%. Then, the main control circuit 33 can predict the charge output of battery 10 to be 218,423W.

[0088] Next, the main control circuit 33 determines whether the representative temperature falls within the extreme temperature range (S700).

[0089] The extreme temperature range is a temperature range in which the battery 10 is unable to operate normally beyond a predetermined range according to a set process. In one embodiment, the extreme temperature range may be a temperature range corresponding to a minimum reference temperature T1 which is lower than a predetermined temperature below the first reference temperature T2. In another embodiment, the extreme temperature range may be a temperature range corresponding to a maximum reference temperature T4 which is higher than a predetermined temperature above the second reference temperature T3. Referring to Figure 17, for example, the minimum reference temperature T1 is -30°C and the maximum reference temperature T4 is 50°C. However, it is not limited to this, and the minimum reference temperature T1 and the maximum reference temperature T4 can be determined by considering various circumstances such as the structure of the battery 10.

[0090] Next, if the determination shows that the representative temperature falls within the extreme temperature range (S700, YES), the main control circuit 33 corrects the output of the battery 10 predicted in the S600 stage (S800).

[0091] In this embodiment, the main control circuit 33 can perform a correction to reduce the predicted output of the battery 10 at the S600 stage. The main control circuit 33 can correct the output of the battery 10 by multiplying the predicted output of the battery 10 by a correction ratio (α) defined as an integer less than 1.

[0092] Referring to Table 1, let's assume, for example, that the typical temperature is -45°C and the state of charge (SOC) of battery 10 is 60%. Then, the main control circuit 33 can predict the charging output of battery 10 to be 51,728W. Let's also assume that the typical temperature (-45°C) falls within the extreme temperature range (below -30°C, above 50°C) and that the correction ratio (α) is 0.5. Then, the main control circuit 33 can perform a correction to reduce the output of battery 10 by multiplying the predicted charging output (51,728W) by the correction ratio (0.5). At this time, the main control circuit 33 can determine the corrected output of battery 10 (51,728 * 0.5 = 25,864W) as the final output of battery 10.

[0093] Referring to Table 2, let's assume, for example, that the typical temperature is 55°C and the state of charge (SOC) of battery 10 is 60%. Then, the main control circuit 33 can predict the charging output of battery 10 to be 110,348W. Let's also assume that the typical temperature (55°C) falls within the extreme temperature range (below -30°C, above 50°C) and that the correction ratio (α) is 0.5. Then, the main control circuit 33 can perform a correction to reduce the output of battery 10 by multiplying the predicted charging output (110,348W) by the correction ratio (0.5). At this time, the main control circuit 33 can determine the corrected output of battery 10 (110,348 × 0.5 = 55,174W) as the final output of battery 10.

[0094] Next, if the determination shows that the representative temperature does not fall within the extreme temperature range (S700, NO), the main control circuit 33 finalizes the output of the battery 10 predicted in step S600 as the final output of the battery 10 (S900).

[0095] Although embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modified and improved forms by persons with ordinary skill in the art to which the present invention belongs also fall within the scope of the present invention.

Claims

1. A battery having multiple battery modules, each containing multiple battery cells, A representative temperature corresponding to the battery temperature is determined based on the temperatures of each of the multiple battery modules (multiple module temperatures), the temperature of the cooling water flowing between the multiple battery modules (cooling water temperature), and the ambient temperature. A battery system comprising a main control circuit that predicts the output value of the battery based on the determined representative temperature and the charge state of the battery determined by a predetermined standard.

2. The main control circuit described above is The battery system according to claim 1, wherein if the temperatures of the plurality of modules fall within an average temperature range corresponding to a temperature range that exceeds a predetermined first reference temperature and is less than a predetermined second reference temperature, the maximum value among the plurality of module temperatures is determined as the representative temperature.

3. The main control circuit described above is If the temperatures of the multiple modules exceed the average temperature range, and the ambient temperature is equal to or greater than the cooling water temperature, The battery system according to claim 2, wherein the maximum value among the plurality of module temperatures is determined as the representative temperature.

4. The main control circuit described above is If the temperatures of the multiple modules exceed the average temperature range, and the ambient temperature is lower than the cooling water temperature, The battery system according to claim 2, wherein the minimum value among the plurality of module temperatures is determined as the representative temperature.

5. The main control circuit described above is When the representative temperature falls within an extreme temperature range corresponding to a temperature range below a minimum reference temperature where the predetermined temperature is lower than the first reference temperature, and a temperature range above a maximum reference temperature where the predetermined temperature is higher than the second reference temperature, The battery system according to claim 2, wherein the predicted output value is reduced and corrected according to a predetermined standard.

6. Each of the aforementioned plurality of battery modules is The plurality of battery cells includes a reference cell which is a battery cell located within a predetermined range with respect to the outlet of the cooling water plate through which the cooling water flows, The module temperature of each of the aforementioned plurality of battery modules is A battery system according to any one of claims 1 to 5, corresponding to the cell temperature of the reference cell.

7. Each of the aforementioned plurality of battery cells is It is configured in a columnar shape, including a lower surface located in close proximity to the cooling water, an upper surface facing the lower surface at a predetermined distance, and a side surface connecting the lower surface and the upper surface. The battery system according to claim 6, wherein the temperature of the upper surface reaches its maximum value when the lower surface is cooled, and the temperature of the upper surface reaches its minimum value when the lower surface is heated.

8. The cell temperature of the aforementioned reference cell is The battery system according to claim 7, corresponding to the temperature measured on the upper surface of the reference cell.

9. An output prediction method for predicting the output of a battery having multiple battery modules, each containing multiple battery cells, The steps include receiving multiple module temperatures, which are the temperatures of each of the multiple battery modules, A step of determining a representative temperature corresponding to the battery temperature based on the temperatures of the plurality of modules, the cooling water temperature which is the temperature of the cooling water flowing between the plurality of battery modules, and the ambient temperature. A battery output prediction method, comprising the step of predicting the battery output value based on the determined representative temperature and the battery charge state determined by predetermined criteria.

10. The step of determining the representative temperature is: A step of determining whether the multiple module temperatures belong to an average temperature range corresponding to a temperature range that exceeds a predetermined first reference temperature and is less than a predetermined second reference temperature, A battery output prediction method according to claim 9, further comprising: a first temperature determination step in which, as a result of the determination of the multiple module temperatures, if the multiple module temperatures fall within the average temperature range, the maximum value among the multiple module temperatures is determined to be the representative temperature.

11. The step of determining the representative temperature is: If, as a result of the determination regarding the multiple module temperatures, the multiple module temperatures do not fall within the average temperature range, the step is to determine whether the ambient temperature is lower than the cooling water temperature. If, as a result of the determination regarding the ambient temperature, the ambient temperature is less than the cooling water temperature, the method further includes a second temperature determination step in which the minimum value among the plurality of module temperatures is determined as the representative temperature. The battery output prediction method according to claim 10, wherein, as a result of the determination regarding the ambient temperature, if the ambient temperature is equal to or greater than the cooling water temperature, the first temperature determination step is performed.

12. After the step of predicting the output value of the battery, A step of determining whether the representative temperature belongs to an extreme temperature range corresponding to a temperature range below a minimum reference temperature where the predetermined temperature is lower than the first reference temperature, and a temperature range above a maximum reference temperature where the predetermined temperature is higher than the second reference temperature. If, as a result of the determination regarding the representative temperature, the representative temperature falls within the extreme temperature range, the predicted output value is reduced and corrected according to a predetermined standard. The battery output prediction method according to claim 10 or 11, further comprising the step of determining, as a result of the determination relating to the representative temperature, that the representative temperature does not fall within the extreme temperature range, and confirming the predicted output value as the battery output.

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