Thermal circuit model generation device, state monitoring device, thermal circuit model generation method, and program

Abstract

To provide a thermal circuit model generation device, a state monitoring device, a thermal circuit model generation method, and a program capable of suppressing the number of components of a temperature measurement unit.SOLUTION: A thermal circuit model generation device according to an embodiment of the present invention is a device that generates thermal circuit information of an object that inputs and outputs a current, and includes a region generation unit and a thermal resistance generation unit. The area generation part generates at least a first calculation area and a second calculation area along a first axis of a corresponding area corresponding to the object. The thermal resistance generation unit generates, in a first calculation region, a first thermal resistance in a first axis direction according to a first heat transfer surface orthogonal to a first axis and a first heat transfer distance in the first axis direction based on a main propagation component of a heat flow propagating in a direction different from the first axis and a second axis orthogonal to the first axis.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a thermal circuit model generating device, a state monitoring device, a thermal circuit model generating method, and a program. [Background technology]

[0002] Battery modules each containing multiple battery cells and battery system devices each containing multiple battery modules are commonly known. Some battery system devices have more than 100 battery modules, and some battery system devices are large-scale, with 24 battery cells per battery module. To safely operate the battery system device, the temperature of the battery cells is monitored. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-147680 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a large-scale battery system device is constructed, the number of temperature measuring parts such as temperature sensors increases.

[0005] Therefore, the problem to be solved by the present invention is to provide a thermal circuit model generation device, a status monitoring device, a thermal circuit model generation method, and a program that can reduce the number of parts in the temperature measurement section. [Means for solving the problem]

[0006] A thermal circuit model generating device according to an embodiment of the present invention generates thermal circuit information for an object that inputs and outputs electric current, and includes a region generating unit and a thermal resistance generating unit. The region generating unit generates at least a first calculation region and a second calculation region along a first axis of a corresponding region corresponding to the object. In the first calculation region, the thermal resistance generating unit generates a first thermal conduction surface orthogonal to the first axis and a first thermal resistance in the first axial direction according to a first heat transfer distance in the first axial direction, based on a main propagation component of a heat flow propagating in a direction different from the first axis and a second axis orthogonal to the first axis. [Effects of the Invention]

[0007] According to the present invention, the number of components in the temperature measurement unit of the battery system can be reduced. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating the overall configuration of a battery system according to an embodiment of the present invention. [Figure 2] 2A and 2B are diagrams showing an example of the appearance of a battery cell included in a battery unit according to the embodiment; [Figure 3] FIG. 2 is a diagram schematically illustrating an example of the configuration of an electrode stack in a battery cell. [Figure 4] FIG. 1 is a block diagram showing an example of the configuration of a thermal circuit model generating device. [Figure 5] FIG. 1 is a diagram showing an example of a general thermal circuit. [Figure 6] 5A and 5B are diagrams illustrating examples of heat flow decomposition rules used in the present embodiment. [Figure 7] FIG. 10 is a diagram showing an example of dividing an electrode stack into calculation regions. [Figure 8] A diagram showing the XZ projection plane and YZ projection plane of the calculation domain. [Figure 9] Conceptual diagram of generating two computational domains from the region on the X side of the computational domain. [Figure 10] FIG. 10 shows the final computational domain of the computational domain. [Figure 11] A diagram showing the XZ projection plane and YZ projection plane of the calculation domain. [Figure 12] A diagram showing the XZ projection plane of the calculation domain. [Figure 13] FIG. 4 is a diagram showing an example of information about a thermal circuit generated by a thermal circuit information generating unit. [Figure 14] FIG. 2 is a block diagram showing an example of the configuration of a state monitoring device. [Figure 15] FIG. 10 is a diagram showing an example of a thermal circuit for a square can model. [Figure 16] 10 shows an example of a thermal circuit model generated by the thermal circuit model generation unit. [Figure 17] FIG. 2 is a diagram schematically illustrating the relationship between a heat generation unit, a temperature generation unit, and a state processing unit. [Figure 18] 5A and 5B are diagrams showing examples of images generated by a display processing unit. [Figure 19] 10 is a flowchart showing an example of processing by a thermal circuit model generating device. [Figure 20] 4 is a flowchart showing an example of processing by the state monitoring device. [Figure 21] FIG. 10 is a schematic block diagram of a battery unit according to a second embodiment. [Figure 22] 1A and 1B are diagrams showing examples of the arrangement of the top plate, side surfaces, and battery cells of a battery module. [Figure 23] FIG. 1 is a diagram illustrating the concept of modeling. [Figure 24] A diagram showing the heat capacity of a battery cell and other components used in the heat capacity synthesis. [Figure 25] FIG. 10 is a block diagram showing another example of the configuration of the battery unit according to the second embodiment. [Figure 26] FIG. 10 is a block diagram showing yet another example of the configuration of the battery unit. [Figure 27] 10 is a block diagram showing yet another example configuration of a battery unit. DETAILED DESCRIPTION OF THE INVENTION

[0009] A thermal circuit model generating device, a state monitoring device, a thermal circuit model generating method, and a program according to embodiments of the present invention will be described in detail below with reference to the drawings. Note that the embodiments described below are examples of embodiments of the present invention, and the present invention should not be interpreted as being limited to these embodiments. Furthermore, in the drawings referred to in this embodiment, identical parts or parts having similar functions are given the same or similar reference numerals, and repeated explanations thereof may be omitted. Furthermore, part of the configuration may be omitted from the drawings.

[0010] (First embodiment) [Overall configuration of battery system] Fig. 1 is an overall configuration diagram of a battery system 1 according to this embodiment. As shown in Fig. 1, the battery system 1 according to this embodiment is a system capable of monitoring the temperature states of battery cells, battery modules, etc., using thermal circuit models of the battery cells, battery modules, etc., and includes a thermal circuit model generation device 100, a management device 200, and a battery system device 300. Fig. 1 also shows a communication network Nw.

[0011] The thermal circuit model generation device 100 is a device that can generate a thermal circuit model of a battery cell based on, for example, the design values ​​of the battery cell. The thermal circuit model generation device 100 can also generate a thermal circuit of a battery module in which multiple battery cells are connected in series-parallel, and a thermal circuit of a battery system device 300 in which multiple battery modules are connected in series-parallel. Details of the thermal circuit model generation device 100 will be described later. In this embodiment, at least one of series, parallel, and a combination of series and parallel may be referred to as series-parallel.

[0012] The management device 200 has a CPU (Central Processing Unit) and is, for example, a computer, and has, for example, a storage unit 202, an operation unit 204, and a display unit 206. The management device 200 manages the status information transmitted from the battery system device 300 via the communication network Nw. The management device 200 can also operate the thermal circuit model generation device 100 via the communication network Nw.

[0013] The storage unit 202 is configured with, for example, an HDD (hard disk drive) or an SSD (solid state drive), etc. This storage unit 2024 stores state information transmitted from the battery system device 300 via the communication network Nw. The storage unit 202 also stores information related to the thermal circuit transmitted from the thermal circuit model generating device 100 via the communication network Nw.

[0014] The operation unit 204 is configured with input devices such as a keyboard and a mouse. The operation unit 204 inputs signals according to operations by an operator to the management device 200. The display unit 104 is, for example, a monitor. The display unit 104 displays image data supplied from a display processing unit of the management device 200.

[0015] The battery system device 300 has a state monitoring device 301 and a battery unit 302. The state monitoring device 301 is a device capable of monitoring the state of the battery unit 302 using a thermal circuit. The state monitoring device 301 is a device capable of monitoring the state of the battery cell 16, for example, using a thermal circuit model of the battery cell 16 (described later in FIG. 3). Details of the state monitoring device 301 will be described later.

[0016] The battery unit 302 is a device equipped with, for example, a lithium-ion battery, and has a plurality of battery cells 16 (see FIG. 3) connected in series or series-parallel and housed in a housing. The battery unit 302 has a voltage sensor 302a, a current sensor 302b, and a temperature sensor 302c inside the housing. The battery in the battery unit 302 is not limited to a lithium-ion battery, and may be a secondary battery containing an electrolyte, such as a lead-acid battery, a nickel-cadmium battery, or a nickel-metal hydride battery. Note that embodiments relating to a battery module in which a plurality of battery cells are connected in series-parallel and a battery system in which a plurality of battery modules are connected in series-parallel will be described later in the second embodiment.

[0017] The voltage sensor 302a detects the voltage across each battery cell 16 and the battery unit 302, and outputs the detected voltage to the state monitoring device 301. The current sensor 302b detects the charging current and discharging current of the battery unit 302. The battery unit 302 outputs the detected current to the state monitoring device 301. The temperature sensor 302c detects the ambient temperature inside the battery unit 302. The temperature sensor 302c outputs the detected temperature to the state monitoring device 301. It is to be noted that general sensors can be used for the voltage sensor 302a, the current sensor 302b, and the temperature sensor 302c.

[0018] 2 is a diagram showing an example of the appearance of a battery cell 16 included in a battery unit 302 according to this embodiment. The battery cell 16 is, for example, a rectangular cell, and houses an electrode stack 16a therein. Terminals 14 and 15 are provided on the upper surface of the electrode stack 16a. The battery cell 16 according to this embodiment is a so-called rectangular cell, but is not limited to this.

[0019] Fig. 3 is a diagram schematically illustrating an example of the configuration of an electrode laminate 16a in a battery cell 16. As shown in Fig. 3, the electrode laminate 16a is formed, for example, in a planar shape and includes a positive electrode 14, a negative electrode 15, and a separator 17. The positive electrode 14 has a positive electrode active material-containing layer supported on the surface of a positive electrode current collector foil serving as a positive electrode current collector. The positive electrode current collector foil is, for example, an aluminum foil or an aluminum alloy foil.

[0020] The negative electrode 15 has a layer containing a negative electrode active material carried on the surface of a negative electrode current collector foil serving as a negative electrode current collector. The negative electrode current collector foil is an aluminum foil, an aluminum alloy foil, or the like.

[0021] The separator 17 is made of an electrically insulating material and electrically insulates the positive electrode 14 from the negative electrode 15. The separator 17 may also be made of an organic material. The electrode stack 16a may be made of an inorganic material, or may be made of a mixture of an organic material and an inorganic material. The electrode stack 16a is integrally formed by stacking the electrodes 16a with the winding axis B as the central axis, with the winding axis B being parallel or approximately parallel to the Y direction of the battery cell 16.

[0022] In this way, the electrode laminate 16a is composed of a positive electrode 14, a separator 17, and a negative electrode 15 wound around it and is impregnated with an electrolyte. As shown in FIG. 3, in the electrode laminate 16a of a lithium-ion battery, the thermal conductivity in the coil plane is higher than the thermal conductivity in the stacking direction. That is, the thermal conductivity in the stacking direction is significantly lower than the in-plane thermal conductivity because it is a direction perpendicular to the separator 17, positive electrode 14, negative electrode 15, etc., and heat is not easily transmitted in this direction. These values ​​can be obtained from design values. Alternatively, they can be obtained by directly measuring the thermal conductivity in each of the X, Y, and Z directions.

[0023] In this configuration example, the thermal conductivity in the stacking direction is, for example, thermal conductivity K1 in the stacking direction because heat passes through the separator 17. The thermal conductivity K1 in the stacking direction is, for example, 0.2 to 8 (W / m·K). On the other hand, the thermal conductivity in the in-plane direction along the wound surface of the electrode laminate 16a is, for example, in-plane thermal conductivity K2 because heat is conducted along the aluminum foil or aluminum alloy foil. The in-plane thermal conductivity K2 is, for example, 15 to 160 (W / m·K). These numerical examples of thermal conductivity are merely examples and are not limited to these. For example, the configuration and materials of the electrode laminate 16a may be different from these, and the numerical examples of thermal conductivity will be different from these.

[0024] As described above, heat is not easily transferred in the direction perpendicular to the separator 17, positive electrode 14, negative electrode 15, etc., and is therefore significantly lower than the in-plane thermal conductivity, so in the following embodiments, the thermal conductivity in the direction perpendicular to the separator 17, positive electrode 14, negative electrode 15, etc. in the electrode stack 16a will be described using thermal conductivity K1, and the thermal conductivity in the in-plane direction will be described using K2. Note that, as described above, measured values ​​can also be used for the thermal conductivity in the perpendicular direction and the thermal conductivity in the in-plane direction.

[0025] 4 is a block diagram showing an example of the configuration of a thermal circuit model generating device 100. The thermal circuit model generating device 100 has a CPU (Central Processing Unit) and is, for example, a computer. The thermal circuit model generating device 100 is a device capable of generating a thermal circuit of, for example, an electrode laminate 16a, and includes an operation unit 102, a display unit 104, a communication unit 106, an input unit 108, a region generating unit 110, a thermal resistance generating unit 112, a thermal circuit information generating unit 114, a display processing unit 116, and a storage unit 118. Some or all of these functional units are realized by, for example, a hardware processor such as a CPU executing a program (software) stored in the storage unit 118.

[0026] The program may be downloaded from a device (e.g., an application server) connected via the communication network Nw, or may be stored in a portable storage medium such as an SD card and then installed and implemented in the thermal circuit model generating device 100. Some or all of the functional units of the thermal circuit model generating device 100 may be realized by hardware such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), or an FPGA (Field Programmable Gate Array), or may be realized by a combination of software and hardware.

[0027] The operation unit 102 is configured with input devices such as a keyboard and a mouse. The operation unit 102 inputs signals according to operations by an operator to the input unit 108. The operation unit 102 inputs information such as design values ​​and measurement values ​​required for calculating the thermal resistance of the electrode stack 16a. The operation unit 102 also inputs, for example, layout information for when multiple battery cells are connected in series-parallel, and layout information for when multiple battery modules are connected in series-parallel.

[0028] The display unit 104 is, for example, a monitor. This display unit 104 displays image data supplied from the display processing unit 116. For example, the image displayed on the display unit 104 displays input boxes for inputting information such as design values ​​and measured values ​​required for calculating the thermal resistance of the electrode stack 16a, input boxes for inputting layout information when multiple battery cells are connected in series-parallel, and input boxes for inputting layout information when multiple battery modules are connected in series-parallel. The operator can input information in accordance with these input boxes via the operation unit 102.

[0029] The communication unit 106 can communicate with the management device 200 and the status monitoring device 301 via the communication network Nw. For example, the communication unit 106 supplies the generated thermal circuit information to the management device 200 and the status monitoring device 301 via the communication network Nw.

[0030] The input unit 108 is an interface for the operation unit 102, and stores signals input via the operation unit 102 in a storage unit 118. The input unit 108 also supplies signals input via the operation unit 102 to the region generation unit 110 and the region generation unit 110.

[0031] The region generating unit 110 generates a calculation region corresponding to the electrode stack 16a based on information relating to the design values ​​of the electrode stack 16a and the like input via the operation unit 102 and the communication network Nw, etc. Details of the region generating unit 110 will be described later.

[0032] The thermal resistance generation unit 112 generates thermal resistance using a calculation domain based on information relating to the design values ​​of the electrode stack 16a input via the operation unit 102 and the communication network Nw, etc. The thermal circuit information generation unit 114 generates information on the thermal circuit based on the thermal resistance of the object generated by the thermal resistance generation unit 112. The thermal resistance generation unit 112 and the thermal circuit information generation unit 114 will be described in detail later.

[0033] The display processing unit 116 generates an image relating to the thermal circuit and displays it on the display unit 1118. For example, it is possible to display the image together with the figure in Fig. 13 (described later), thermal resistances 50R to 60R, heat capacity 600, etc.

[0034] The storage unit 118 is configured, for example, with an HDD (hard disk drive), an SSD (solid state drive), etc. The storage unit 118 stores information related to the thermal circuit.

[0035] Here, an example of a thermal circuit and an example of heat propagation characteristics will be explained using Figures 5 and 6. Figure 5 is a diagram showing an example of a general thermal circuit. A thermal circuit (e.g., an ATC model) is composed of, for example, a heat source, thermal resistance, and heat capacity. The thermal circuit can calculate the heat flow for heat given to the heat source of the thermal circuit using the thermal resistance and heat capacity.

[0036] For example, in Figure 5, the thermal circuit of a conductor consists of a heat source Q1, multiple thermal resistors R12, R23, and R34, and multiple thermal capacitances C1, C2, and C3. When heat flow from heat source Q1 flows through thermal capacitances C1, C2, and C3 and temperature nodes T1, T2, and T3, it is possible to calculate the temperature between each of the temperature nodes T1, T2, and T3. For example, the thermal resistance R23 between temperature nodes T2 and T3 generates a temperature gradient, and calculating this gradient allows for temperature calculation of any node. Thus, in a thermal circuit, the configuration generally consists of heat source Q1, thermal resistances R12, R23, and R34, and thermal capacitances C1, C2, and C3. The temperatures of the temperature nodes T1, T2, and T3 can be calculated over time in response to the time series values ​​of the heat supplied by heat source Q1. In general, when heat flows in stages, the thermal resistances are configured in series, and when temperature flows in parallel, the thermal resistances are configured in parallel.Furthermore, in general calculations, when calculating the temperatures of the temperature nodes T1, T2, and T3 in time series, it is common to solve multiple simultaneous partial differential equations by simulation.

[0037] The unit of thermal resistance is (K / W), for example, and the thermal resistance R1 = L / kA can be calculated using the thermal conductivity k (W / mK), the heat transfer distance (thickness) L (m), and the heat transfer area A (m^2). Furthermore, if a fluid such as air or water is present on or near a given heat transfer area and the heat transfer by that fluid is to be expressed in terms of thermal resistance, R1 = 1 / hA, which is the reciprocal of the convective heat transfer coefficient h (W / m^2K) and the heat transfer area A (m^2), and can be converted to thermal resistance. In this embodiment, the hat symbol "^" denotes exponentiation. For example, m^2 is the square of m. In this embodiment, the units may be omitted.

[0038] Figure 6 is a diagram illustrating an example of the decomposition law of heat flow used in this embodiment. It shows an isothermal surface on a two-dimensional XY plane with isotherms T1, T2, and T3. For example, when thermal conductivity k (W / m K) is given as a constant on the two-dimensional XY plane, it is known that the heat flow generated on the surface has the relationships shown in equations (1) to (3) below.

number

number

number

[0039] The region generation unit 110 according to this embodiment uses such heat propagation characteristics to divide, for example, an object propagating a main propagation component q of a heat flow into a calculation region where the heat flow qX propagates in the X-axis direction and a calculation region where the heat flow qY propagates in the Y-axis direction. The object is, for example, a material that inputs and outputs electric current, such as the electrode stack 16a of a battery cell.

[0040] Here, the region generation unit 110 will be described in detail with reference to FIGS. 7 to 11. The region generation unit 110 according to this embodiment generates multiple calculation regions in which heat flow propagates from a single material body in the X-axis, Y-axis, and Z-axis directions. That is, the region generation unit 110 generates multiple calculation regions corresponding to the material body for calculating thermal resistance from the origin O along the X-axis, Y-axis, and Z-axis. Here, the electrode stack 16a will be described as an example of a single material body, but the present invention is not limited to this.

[0041] The thermal resistance generating unit 112 generates thermal resistances in the X-axis direction, Y-axis direction, and Z-axis direction based on the calculation domain generated by the domain generating unit 110. The thermal resistance generating unit 112 generates thermal resistances in the X-axis direction, Y-axis direction, and Z-axis direction using information within the domain division of the material body.

[0042] 7 is a diagram showing an example of dividing the electrode stack 16a into calculation regions 160, 162, and 164. The winding axis B of the electrode stack 16a is defined as the Y-axis direction, the direction along the long side surface of the electrode stack 16a is defined as the Z-axis direction, and the direction perpendicular to the Y-axis and Z-axis is defined as the X-axis. The origin O of the electrode stack 16a is defined as the midpoint of the winding axis B within the electrode stack 16a. These divisions are examples of divisions for generating multiple calculation regions for calculating thermal resistance from the origin O along the X-, Y-, and Z-coordinate axes, but are not limited to these.

[0043] Generally, when a battery module is configured by arranging multiple battery cells 16 in series and parallel, the winding axes B are arranged parallel, and the multiple battery cells 16 are arranged parallel in either the X-axis direction, the Y-axis direction, or the Z-axis direction. Therefore, when generating a thermal circuit combining multiple battery cells 16, generating thermal resistances along the X-axis, the Y-axis, and the Z-axis from the origin O facilitates the process of combining the thermal circuits of the multiple battery cells 16. For this reason, as described above, the region generation unit 110 generates multiple calculation regions for calculating thermal resistances along the X-axis, the Y-axis, and the Z-axis from the origin O. For this reason, the X-axis, the Y-axis, and the Z-axis can be set according to the purpose of the process.

[0044] Details of the thermal circuit synthesis process will be described in the second embodiment. As will be described later, the thermal capacity of the battery cell 16 is placed at the origin O. This allows the thermal resistances along the X, Y, and Z coordinate axes from point O to be directly connected between multiple battery cells 16, enabling synthesis of the thermal resistances. In this case, the thermal capacity can be the combined thermal capacity of multiple battery cells 16. In this embodiment, this process may be referred to as degeneration processing. This degeneration processing makes it possible to generate temperatures at target temperature nodes, etc., at a processing speed that maintains real-time performance.

[0045] As shown in FIG. 7, in this embodiment, the region generation unit 110 separates the calculation region 160 and calculation region 162 into a rectangular parallelepiped calculation region 164 and a calculation region 160 having curved surfaces 160a and 162a on the XZ-axis plane, for example. That is, the calculation region 160 and calculation region 162 are sections of the coil turn region (see FIG. 3) where the positive electrode 14, the negative electrode 15, and the separator 17 turn. The calculation region 164 is a region where the positive electrode 14, the negative electrode 15, and the separator 17 (see FIG. 3) are stacked almost parallel to the Z-axis direction. The calculation region 160 and calculation region 162 have XZ planes 160a and 162a, and the calculation region 164 has an XZ plane 162a. The calculation region 164 also has a YZ plane 164b.

[0046] FIG. 8 is a diagram showing the arrangement of XZ projection planes 160a, 162a, and 164a and YZ projection planes 160b, 162b, and 164b of the calculation domain 160, calculation domain 162, and calculation domain 164. That is, the XZ projection planes 160a and 162a are planes obtained by projecting the electrode stack 16a onto the XZ planes 160a and 162a (see FIG. 7), and the YZ projection plane 164b is a plane obtained by projecting the electrode stack 16a onto the YZ plane 164b. Here, the arrows indicate the direction of thermal conductivity from the origin. In FIG. 8, the case of in-plane thermal conductivity K2 (see FIG. 3) is shown by a solid line, and the case of stacking direction thermal conductivity K1 (see FIG. 3) is shown by a dashed line.

[0047] 9 is a conceptual diagram of generating two calculation domains from the region on the X side of the calculation domain 160. As shown in FIG. 9, the heat flows flowing on the X side of the XZ projection plane 160a are designated as heat flows q1 to qn. The heat flows q1 to qn are heat flows that flow in a direction perpendicular to the laminate having thermal conductivity K1 in the stacking direction. In the region on the X side of the calculation domain 160, the main propagation component of the heat flow, which is the sum of the heat flows q1 to qn, is designated as qr.

[0048] Due to the thermal characteristic relationships of the above-mentioned equations (1) to (3), the heat flow can be separated into an X-axis propagation component qX, which is the heat flow in the X-axis direction, and a Z-axis propagation component qZ, which is the heat flow in the Z-axis direction. In this case, the computational domain 160 is reset to have a first heat conduction surface perpendicular to the Z-axis for the Z-axis propagation component qZ and a first heat conduction distance in the Z-axis direction so as to satisfy equations (1) to (3). Similarly, the computational domain 160 is reset to have a second heat conduction surface perpendicular to the X-axis for the X-axis propagation component qX and a second heat conduction distance in the X-axis direction so as to satisfy equations (1) to (3).

[0049] The calculation domain 160 is redefined based on the partial differential relationship shown in equations (1) and (2) by resetting the first heat conduction surface (width L2 × length L4) (see FIG. 8) perpendicular to the Z axis and the right-hand calculation domain in the Z direction with the first heat conduction distance L1 in the Z axis direction. The thermal conductivity in the Z axis direction is set to K1, which is the thermal conductivity in the propagation direction of the main propagation component qr of the heat flow. In this way, the domain generation unit 110 generates the first heat conduction surface (L2 × L4) (see FIG. 8) perpendicular to the Z axis, the first heat conduction distance L1 in the Z axis direction, and the right-hand calculation domain with the thermal conductivity K1, so that a heat flow corresponding to the Z-axis propagation component qZ can be generated.

[0050] Similarly, the heat flow ql flowing on the -X side of the XZ projection plane 160a has properties equivalent to those of the heat flow qZ, so the heat flow ql flowing on the -X side can also be calculated using a left-side calculation domain in the Z direction that has a structure equivalent to that of the right-side calculation domain in the Z direction. As a result, the domain generation unit 110 generates a left-side calculation domain with a first heat conduction surface (L2 × L4) (see FIG. 8) perpendicular to the Z axis, a first heat transfer distance L1 in the Z axis direction, and a thermal conductivity K1 so as to be able to generate a heat flow corresponding to the Z-axis propagation component qZ.

[0051] Similarly, the computational domain 160 is reset to the right-hand computational domain in the X direction, which includes the second heat conduction surface (width L1 × length L4) perpendicular to the X axis (see FIG. 8) and the second heat conduction distance L2, first heat conduction distance L1, and thermal conductivity K1 in the X-axis direction, based on the partial differential relationship shown in equations (1) and (2). The heat flow ql flowing on the -X side also becomes the left-hand computational domain in the X direction, which has the same structure as the right-hand computational domain in the X direction. As a result, the domain generation unit 110 resets the left-hand computational domain in the -X direction, which includes the second heat conduction distance L2, first heat conduction distance L1, and thermal conductivity K1 in the -X axis direction, so that a heat flow corresponding to the X-axis propagation component qX flowing on the -X side can be generated.

[0052] 10 is a diagram showing the final computational domain of the computational domain 160. The right computational domain in the Z direction and the left computational domain in the Z direction have the same heat flow direction and structure, so they are considered to be a single computational domain 160Z in the Z direction.

[0053] Since calculation domain 160Z has a heat transfer area of ​​A1, a heat transfer distance (thickness) of L1, and a thermal conductivity of K1, thermal resistance generation unit 112 calculates the Z-direction thermal resistance of calculation domain 160Z as 50R = L1 / (K1 × A1). Since calculation domain 162 has the same structure as calculation domain 160, the calculation domain of calculation domain 162 will also be shown as calculation domain 160Z having a thermal resistance of 50R in the Z direction. The XZ plane of calculation domain 160Z is designated 160Za, and the YZ plane is designated 160Zb.

[0054] That is, the thermal resistance generator 112 calculates the thermal resistance 50R in the Z direction of the calculation domain 160Z as 50R = L1 / (K1 × 2 × L2 × L4). This is half the Z-direction thermal resistance in the right-hand calculation domain of the first heat conduction surface (L2 × L4) and heat conduction distance L1, which is set to be able to generate a heat flow corresponding to the Z-axis propagation component qZ. In other words, this is equivalent to connecting in parallel the right-hand calculation domain of the first heat conduction surface (L2 × L4) and heat conduction distance L1 and the left-hand calculation domain of the first heat conduction surface (L2 × L4) and heat conduction distance L1.

[0055] On the other hand, the right computational domain 60XR in the X direction of the computational domain 160 and the left computational domain 160XL in the X direction have opposite heat flow directions, so they are distinguished as the right computational domain 160XRL and the left computational domain 160XL.

[0056] Since the calculation region 160XR has a heat transfer area of ​​B1, a heat transfer distance (thickness) of L2, and a thermal conductivity of K1, the thermal resistance generator 112 calculates the X-direction thermal resistance of the calculation region 160XR as 160RX=L2 / (K1×L1×L4). Similarly, the thermal resistance generator 112 can calculate the X-direction thermal resistance of the calculation region 160XL as 160RX=L2 / (K1×L1×L4).

[0057] Fig. 11 is a diagram illustrating the arrangement of two upper and lower computational domains 160Z, as well as XZ projection planes 164Za, 164Za, and 164a and YZ projection planes 160Zb, 160Zb, and 164b of the computational domain 164. As shown in Fig. 11, the heat flow in the Z direction is represented by a heat flow flowing in the Z direction from the origin of the computational domain 164 (see Fig. 7) and a heat flow flowing in the Z direction through the computational domain 160Z (see Fig. 10). Similarly, the heat flow in the -Z direction is represented by a heat flow flowing in the -Z direction from the origin of the computational domain 164 and a heat flow flowing in the -Z direction through the computational domain 160Z (see Fig. 10).

[0058] Here, thermal resistance 56R in the upper half of calculation region 164 has a heat transfer area of ​​A1, a heat transfer distance (thickness) of L3 / 2, and a thermal conductivity of K2. Therefore, thermal resistance generator 112 calculates the X-direction thermal resistance of calculation region 160XR as 56R = L2 / (2 × K2 × A1). Note that A1 = L2 × L3. Similarly, thermal resistance 57R in the lower half of calculation region 164 is calculated as 57R = L2 / (2 × K2 × A1). As can be seen from these, the Z-direction resistance of electrode stack 16a is the series thermal resistance of 56R and 50R in the Z direction from the origin, and the series thermal resistance of 57R and 50R in the -Z direction from the origin.

[0059] On the other hand, the Y direction and -Y direction from the origin are configured with an in-plane thermal conductivity of K2. Therefore, thermal resistance 59R in the Y direction from the origin has a heat transfer area of ​​Z1, a heat transfer distance (thickness) of L4 / 2, and a thermal conductivity of K2. Therefore, the thermal resistance generator 112 calculates thermal resistance 59R in the Y direction of electrode stack 16a as 59R = L4 / (2 × K2 × Z1). Similarly, the thermal resistance generator 112 calculates thermal resistance 58R in the -Y direction of electrode stack 16a as 58R = L4 / (2 × K2 × Z1). Note that heat transfer area Z1 is the cross-sectional area of ​​the ZX-axis plane of electrode stack 16a (see FIG. 3) and can be calculated geometrically, so a unique constant value can be obtained.

[0060] 12 is a diagram illustrating the arrangement of two upper and lower calculation regions 160XR on the right side, two upper and lower calculation regions 160XL on the left side, and XZ projection planes 164Xa, 164Xa, 164Xa, 164Xa, 164aL, and 164aR of the calculation region 164. The XZ projection planes 164aL and 164aR are regions obtained by dividing the XZ projection plane 164a (see FIG. 7) of the calculation region 164 into two, left and right.

[0061] As shown in FIG. 12, the heat flow in the X direction is expressed as a heat flow flowing from the origin of the computational domain 164 (see FIG. 7) through the XZ projection plane 164aR in the X direction, a heat flow flowing in the -X direction through the XZ projection plane 164aL, a heat flow flowing in the X direction through the upper and lower computational domains 160XR (see FIG. 10), a heat flow flowing in the X direction through the upper and lower computational domains 160XL (see FIG. 10), and a heat flow flowing in the X direction. In this case, the width of the computational domain 164 from the origin in the X direction is equal to the width of the two computational domains 160XR in the X direction and has a thermal conductivity of K1, so parallel calculation is possible. This allows the computational domain to be consolidated into a single projection plane 166R. Similarly, parallel calculation is also possible for the heat flow flowing in the -X direction, and the computational domain can be consolidated into a single projection plane 166L.

[0062] Therefore, the thermal resistance 60R of the upper half in the X direction from the origin has a heat transfer area of ​​L3×L4, a heat transfer distance (thickness) of L2, and a thermal conductivity of K1, so the thermal resistance generator 112 calculates the thermal resistance 60R of the electrode stack 16a in the X direction as 60R=L2 / (K2×L3×L4). Similarly, the thermal resistance 60R of the electrode stack 16a in the -X direction is calculated as 60R=L2 / (K2×L3×L4).

[0063] 13 is a diagram showing an example of thermal circuit information generated by the thermal circuit information generator 114. As shown in FIG. 13, using the thermal resistances 50R to 60R described above, the thermal circuit information generator 114 generates thermal circuit information on the magnitudes of the thermal resistances 50R to 60R arranged in the plus and minus directions of the X, Y, and Z axes from the origin Or, and on the thermal capacity 600. A thermal circuit information signal containing this information is transmitted to the management device 200 and the status monitoring device 301 via the communication unit 106. The thermal capacity 600 can be calculated using design information. Alternatively, it can be measured experimentally.

[0064] The connection point of the thermal resistor 59R is formed on the short side surface S16a of the electrode laminate 16a, the connection point of one of the thermal resistors 60R is formed on the long side surface S16b, and the connection point of one of the thermal resistors 50R and 56R is formed on the top surface S16c of the electrode laminate 16a. The same applies to the thermal resistor 58R, the other thermal resistor 60R, the thermal resistor 67R, and the other thermal resistor 50R.

[0065] In this embodiment, the calculation region 160 is divided into two equal parts by a YZ-axis plane passing through the origin, and the calculation region on the X side corresponds to the first calculation region. Similarly, the calculation region 164 is divided into two equal parts by a YZ-axis plane passing through the origin, and the calculation region on the X side corresponds to the second calculation region. Similarly, the Z-axis corresponds to the first axis, the X-axis corresponds to the second axis, and the Y-axis corresponds to the third axis.

[0066] Based on the origin, the first and second calculation regions and the third and fourth calculation regions are symmetrical with respect to a first plane (YZ-axis plane) parallel to the Z-axis (first axis) and Y-axis (third axis) passing through the origin. The fifth and sixth calculation regions are symmetrical with respect to a second plane (XY-axis plane) parallel to the X-axis (second axis) and Y-axis (third axis) passing through the origin. The seventh and eighth calculation regions are symmetrical with respect to the first plane (YZ-axis plane) with respect to the fifth and sixth calculation regions.

[0067] As a result, the thermal resistance generation unit 112 generates a seventh thermal resistance (50R) by treating the first calculation region and the third calculation region as parallel regions in the first axis direction and setting the thermal resistance from the origin in the Z-axis (first axis) direction to half the first thermal resistance (2 × 50R). The thermal resistance generation unit 112 also generates an eighth thermal resistance (56R) by treating the second calculation region and the fourth calculation region as parallel regions in the first axis direction and setting the thermal resistance from the origin in the Z-axis (first axis) direction to half the third thermal resistance (2 × 56R). Furthermore, the thermal resistance generation unit 112 generates a ninth thermal resistance (59R) by treating the first calculation region, the second calculation region, the fifth calculation region, and the sixth calculation region as parallel regions in the X-axis (second axis) direction and setting the thermal resistance from the origin in the X-axis (second axis) direction to half the fifth thermal resistance (2 × 59R). Furthermore, the first to eighth regions are parallel regions in the Y-axis (third axis) direction, and a tenth thermal resistance (60R) is generated in the Y-axis (third axis) direction from the origin.

[0068] The thermal circuit information generation unit 114 designates the thermal resistance from the origin in the Z-axis (first axis) direction and in the opposite direction to the Z-axis (first axis) direction as the seventh thermal resistance (50R), and designates the thermal resistances connected in series to the seventh thermal resistance (50R) in the Z-axis (first axis) direction from the origin and in the opposite direction to the Z-axis (first axis) direction as the eighth thermal resistances (56R, 57R).

[0069] The thermal circuit information generation unit 114 generates the thermal resistance from the origin in the X-axis (second axis) direction and in the direction opposite to the X-axis (second axis) direction as the ninth thermal resistance (59R), and the thermal resistance from the origin in the Y-axis (third axis) direction and in the direction opposite to the Y-axis (third axis) direction as the tenth thermal resistance (60R). Furthermore, the thermal circuit information generation unit 114 connects these thermal resistances 50R to 60R to the origin, and generates information on a thermal circuit in which a heat capacity 600 based on the electrode stack 16a (target object) is further connected to the origin.

[0070] Here, the state monitoring device 301 will be described in detail. Fig. 14 is a block diagram showing an example of the configuration of the state monitoring device 301. This state monitoring device 301 is a device that can monitor the state of a battery 302 using thermal circuit information generated by the thermal circuit model generation device 100. The thermal circuit model generation device 100 has, for example, a CPU (Central Processing Unit) and is, for example, a computer. Some or all of the functional units of the state monitoring device 301 may be realized by hardware such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), or an FPGA (Field Programmable Gate Array), or may be realized by a combination of software and hardware.

[0071] The state monitoring device 301 is capable of generating temperatures of at least predetermined temperature nodes of each battery cell 16 using information from a number of temperature sensors that is fewer than the number of battery cells 16. It includes a communication unit 303, a thermal circuit model generation unit 304, a heat generation amount generation unit 306, a temperature generation unit 308, a state processing unit 310, a state monitoring unit 312, a display processing unit 314, and a storage unit 316. Some or all of these functional units are implemented by a hardware processor, such as a CPU, executing a program (software) stored in the storage unit 316. The program may be downloaded from a device (e.g., an application server) connected via the communication network Nw, or may be stored on a portable storage medium such as an SD card and installed in the thermal circuit model generation device 100. Alternatively, all functions of the state monitoring device 301 may be configured as separate electronic circuits to increase speed. In this case, it is possible to configure a thermal circuit model in advance in the temperature generation unit 308 without configuring the thermal circuit model generation unit 304.

[0072] The communication unit 106 can communicate with the thermal circuit model generation device 100 and the management device 200 via the communication network Nw. For example, the communication unit 106 supplies status monitoring information to the management device 200 via the communication network Nw. The communication unit 106 also acquires information about the thermal circuit model from the thermal circuit model generation device 100 via the communication network Nw. The communication unit 106 according to this embodiment also functions as an acquisition unit that acquires data from the voltage sensor 302a, the current sensor 302b, and the temperature sensor 302c (see FIG. 1) in real time. The data acquired in real time is stored in the storage unit 316.

[0073] The thermal circuit model generation unit 304 generates a thermal circuit model based on the information about the thermal circuit generated by the thermal circuit model generation device 100. The thermal circuit model generation unit 304 will be described in detail later.

[0074] The heat generation unit 306 generates the amount of heat supplied by the heat source of the thermal circuit model generated by the thermal circuit model generation unit 304. The heat generation unit 306 can generate the amount of heat in time series based on the voltage between both ends of each battery cell 16, the charge current, the discharge current, etc.

[0075] The temperature generating unit 308 generates temperatures of at least predetermined temperature nodes of each battery cell 16 using the thermal circuit model of each battery cell 16 and the time-series heat quantity of the heat source generated by the heat quantity generating unit 306 .

[0076] The state processing unit 310 calculates a state estimation quantity that indicates the deterioration of the battery. The state processing unit 310 has an SOC estimation unit 310a that estimates the state of charge (SOC) and an SOH processing unit 310b that estimates the resistivity (SOH) that indicates the rate of increase in internal resistance from the initial internal resistance.

[0077] The SOC estimation unit 310a calculates, for example, the SOC (State of Charge) at temperature Tk [°C] and time t [sec] as the charging rate SOC(t, Tk). The temperature Tk is the temperature of the temperature node of each battery cell 16, and is generated by the temperature generation unit 308 using a thermal circuit model of each battery cell 16. The SOC(t, Tk) is formulated, for example, as a lookup table of the temperature Tk. Thus, the SOC estimation unit 310a converts, for example, the temperature Tk generated by the temperature generation unit 308 into the charging rate SOC(t, Tk).

[0078] The status monitoring unit 312 monitors the temperature state of a predetermined temperature node generated by the temperature generating unit 308, and generates information about signs of abnormality and abnormalities. The status monitoring unit 312 supplies the information about signs of abnormality and abnormalities to the management device 200 via the communication unit 106 and the communication network Nw. Furthermore, the status monitoring unit 312 stops power generation of the battery unit 302 when there is a battery cell 16 that shows signs of abnormality or abnormalities.

[0079] The display processing unit 314 generates an image (see FIG. 18) showing a sign of an abnormality or an abnormal state, and supplies the image to the management device 200 via the communication unit 106 and the communication network Nw. The display unit 200 (see FIG. 1) of the management device 200 displays the image (see FIG. 18) showing the sign of an abnormality or an abnormal state.

[0080] The storage unit 316 is configured with, for example, a ROM (Read Only Memory) and a RAM (Random Access Memory). The storage unit 316 stores various information related to the thermal circuit model, programs, and parameters required for driving the thermal circuit model. It also stores the state quantities of the battery unit 302 in chronological order. These state quantities can be used to predict an abnormality or to analyze the cause of an abnormality when it occurs.

[0081] Here, the thermal circuit model generation unit 304 will be described in detail. Fig. 15 is a diagram showing an example of the thermal circuit of a rectangular can model. The storage unit 316 stores information about the thermal circuit of the rectangular can model in advance. The rectangular can model is assumed to have natural convection of air around it, with thermal resistance corresponding to the thermal conduction of the contact thermal resistance between the coil on six sides and the can, and the outputs of the six temperature nodes T1 to T6 are connected to the outside temperature ground via heat transfer by natural convection.

[0082] The thermal circuit model generation unit 304 generates a thermal circuit model by combining the thermal circuit information of the battery cell 16 (see FIG. 13) supplied from the thermal circuit model generation device 100 with the temperature nodes T1 to T6 in the thermal circuit of the square can model shown in FIG. 15.

[0083] 16 is a diagram showing an example of a thermal circuit model generated by the thermal circuit model generating unit 304. Thermal resistances Rt1 to Rt6 are thermal resistances connected to temperature nodes T1 to T6 in the thermal circuit of the rectangular can model.

[0084] The internal heat quantity Qin is the internal heat quantity generated by the battery cell 16 and is generated by the heat generation quantity generation unit 306. The heat input quantity Qamb is the heat input quantity calculated based on the environmental temperature of the battery cell 16, for example, the temperature inside the thermostatic chamber. That is, in this embodiment, the heat generation quantity generation unit 306 generates the heat input quantity Qamb based on temperature information from the temperature sensor 302c. For example, the heat generation quantity generation unit 306 can generate the relationship between the heat input quantity Qamb and the temperature of the temperature sensor 302c more quickly by using a lookup table.

[0085] FIG. 17 is a diagram illustrating the functional relationship between the heat generation unit 306, the temperature generation unit 308, and the status processing unit 310. As shown in process P306, the heat generation unit 306 models the battery cell 16 using an electrical equivalent circuit to generate the heat generation amount Qin [W] of the battery cell. The heat generation amount Qin [W] of the battery cell 16 is expressed as the sum of the battery reaction heat and Joule heat. However, assuming that the battery reaction heat is sufficiently small and Joule heat is dominant, the heat generation amount of the battery cell is expressed by equations (4) and (5) using the open circuit voltage OCV [V], the battery terminal voltage V [V], and the current I [A] flowing through the battery cell, where OCV - V = Vdv. Here, the battery terminal voltage V [V] is the voltage measured by the voltage sensor 302a of each battery cell 16, and the current I [A] is the current measured by the current sensor 302b.

[0086]

number

number

[0087] That is, the calculation of the resistance R includes the temperature Tk of a predetermined temperature node that the temperature generation unit 308 generates using a thermal circuit model of each battery cell 16. The heat generation unit 306 generates the internal heat quantity Qin [W] using a two-dimensional lookup table of the temperature Tk and SOC(t, Tk).

[0088] Next, as shown in process P308, the heat generation amount generation unit 306 generates the heat input amount Qamb based on the temperature information from the temperature sensor 302c. Then, the temperature generation unit 308 uses the heat input amount Qamb and the heat generation amount Qin of each battery cell 16 using a thermal circuit model of each battery cell 16 to generate the temperature Tk of the temperature node for each battery cell 16.

[0089] Next, as shown in process P310a, the state of charge SOC(t, Tk) at time m [sec] is calculated using the temperature Tk [°C] of each battery cell 16. Subsequently, as shown in process P310b, the SOH processing unit 310b estimates the resistivity (SOH) that represents the rate of increase in internal resistance from the initial internal resistance. The internal resistance at this time is calculated using the temperature Tk [°C] and the state of charge SOC(t, Tk) of each battery cell 16, for example, as shown in equation (5). In this way, by using the thermal circuit model of the battery cell 16, the temperature Tk of each battery cell 16 can be generated more quickly by using, for example, a single temperature sensor 302c, without having to provide a temperature sensor for each battery cell 16.

[0090] Next, as shown in process P312, the status monitoring unit 312 monitors the status by comparing the temperature Tk [°C] of a predetermined temperature node generated by the temperature generation unit 308 with thresholds Th1 and Th2, and generates information about signs of abnormality and abnormalities.

[0091] FIG. 18 is a diagram showing an example of an image generated by the display processing unit 314. As shown in FIG. 18, the display processing unit 314 generates a diagram showing the state of the temperature Tk [°C] of the temperature node when the status monitoring unit 312 detects a sign of an abnormality or an abnormality. Here, the temperature Tk [°C] is displayed as, for example, a cell temperature, as shown in FIG. 18. Then, as described above, the display processing unit 314 can display this image (see FIG. 18) on the display unit 200 (see FIG. 1) of the management device 200 via the communication unit 106 and the communication network Nw.

[0092] The configuration of this embodiment has been described above, and an example of control processing will now be described. Fig. 19 is a flowchart showing an example of processing by the thermal circuit model generating device 100. As shown in Fig. 19, first, the input unit 108 inputs design information for the electrode stack 16a via the operation unit 102 (step S100). Next, the region generating unit 112 generates a calculation region based on the design information for the electrode stack 16a (step S102).

[0093] Next, the thermal resistance generating unit 112 generates a thermal resistance for each calculation domain based on the design information (step S104). Then, the thermal circuit information generating unit 114 transmits a signal including information on the thermal resistance generated by the thermal resistance generating unit 112 to the state monitoring device 301 and the management device 200 via the communication unit 106 and the communication network Nw (step S106).

[0094] Fig. 20 is a flowchart showing an example of processing by the state monitoring device 301. As shown in Fig. 20, the communication unit 303 of the state monitoring device 301 acquires the current of each battery cell 16 and the ambient temperature from the current sensor 302b and the temperature sensor 302c (step S200). Next, the heat generation unit 306 generates the internal heat quantity Qin and the heat input quantity Qamb using information on the current of each battery cell 16 and the ambient temperature (step S202). Note that the temperature of the temperature sensor 302c can be used to calculate the internal heat quantity Qin at the beginning of operation (step S204).

[0095] Next, the temperature generation unit 308 generates a temperature Tk based on the values ​​of the internal heat quantity Qin and the heat input quantity Qamb using a thermal circuit model of each battery cell 16 (step S206). The state monitoring unit 312 monitors the state by comparing the temperature Tk [°C] of a predetermined temperature node generated by the temperature generation unit 308 with thresholds Th1 and Th2, and generates information related to signs of abnormality and abnormalities (step S208). Then, when the state monitoring unit 312 detects a sign of abnormality or an abnormality, the display processing unit 314 generates an image (see FIG. 18) showing the temperature state and transmits it to the management device 200 via the communication unit 106 and the communication network Nw (step S210).

[0096] As described above, according to this embodiment, the region generation unit 110 generates multiple calculation regions along a first axis (e.g., the Z axis) of the corresponding region corresponding to the electrode stack 16a. The thermal resistance generation unit 112 generates, in at least one of the multiple calculation regions, a first thermal resistance in the first axis direction corresponding to the first heat conduction surface A1 perpendicular to the first axis and the first heat transfer distance L1 in the first axis direction, based on the main propagation component qr of the heat flow propagating in a direction different from the first axis and the second axis perpendicular to the first axis. This makes it possible to generate a thermal resistance along the first axis even when the main propagation component qr of the heat flow propagates in a direction different from the first axis. Therefore, even when the electrode stack 16a has a curved stack region, the thermal resistance generation unit 112 can generate each thermal resistance of the electrode stack 16a as a thermal resistance along, for example, the X axis, Y axis, or Z axis.

[0097] (Second embodiment) The battery system 1 according to the second embodiment differs from the battery system 1 according to the first embodiment in that a thermal model is generated for a battery device in which a plurality of battery modules 400 are arranged. The differences from the battery system 1 according to the first embodiment will be described below.

[0098] 21 is a schematic block diagram of a battery unit 302 according to the second embodiment. The battery unit 302 is an example in which a plurality of battery modules 400 are connected in series, for example. Each battery module 400 has a cell monitoring unit (CMU) 418. The cell monitoring unit 418 is also connected to a battery management unit (BMU) 417, and the state monitoring unit 301 (see FIG. 1) is configured within the cell monitoring unit 418, for example.

[0099] The battery unit 302 further includes a current sensor 414, a voltage sensor 416, and a temperature sensor 419. A breaker 413(-) is also connected to the battery unit 302 via a fuse 415. A breaker 413(+) is also connected to the (+) side of the main circuit.

[0100] Modeling of the thermal circuit of the battery module 400 will be described using Fig. 22. Fig. 22 is a diagram showing an example of the arrangement of the top plate, side surfaces, and battery cells 16 of the battery module 400. As shown in the cell group 504, for example, eight battery cells 16 are arranged in each row on the module top plate 500 of the battery module 400. In other words, 24 battery cells 16 are arranged in this battery module 400.

[0101] 23 is a diagram schematically illustrating the modeling concept. The module case of the battery module 400 is a rectangular parallelepiped and has two long sides, two short sides, a top plate, and a bottom plate. Heat flow propagates to the outside via one of the two long sides, two short sides, the top plate, or the bottom plate.

[0102] 23, the thermal circuit information generation unit 114 according to this embodiment (see FIG. 4) connects at least one of the thermal resistors 50R to 60R (see FIG. 13) in series depending on the direction of the series arrangement when multiple battery cells 16 are arranged in series with respect to the origin of the battery module based on the arrangement information of the battery module 400. Similarly, when multiple battery cells 16 are arranged in parallel with respect to the origin, the thermal circuit information generation unit 114 regenerates a thermal circuit by connecting at least one of the thermal resistors 50R to 60R in parallel depending on the direction of the parallel arrangement.

[0103] In this way, the thermal circuit information generation unit 114 reconnects the thermal resistances 50R to 60R (see FIG. 13) that are arranged in the plus and minus directions of the X, Y, and Z axes from the origin Or in accordance with the series-parallel arrangement of the multiple battery cells 16 in the X-axis, Y-axis, and Z-axis directions. That is, the thermal circuit information generation unit 114 uses the center of the battery module 400 as a new origin and connects the thermal resistances in that direction in series in the direction in which the multiple battery cells 16 are arranged in series, and connects the thermal resistances in that direction in parallel in the direction in which the multiple battery cells 16 are arranged in parallel.

[0104] Next, as shown in Fig. 23, the thermal resistance generating unit 112 according to this embodiment regenerates the parallel resistance and the series resistance as one resistance for each of the X-axis, Y-axis, and Z-axis. That is, the thermal resistance generating unit 112 synthesizes six thermal resistances in the X-axis, Y-axis, and Z-axis directions from the origin of the battery module 400. Since the multiple thermal resistances on the X-axis, Y-axis, and Z-axis are all connected in series or parallel, the thermal resistance generating unit 112 can synthesize the thermal resistances. The thermal circuit information generating unit 114 generates new thermal circuit information for the six thermal resistances in the X-axis, Y-axis, and Z-axis directions from the origin of the battery module 400.

[0105] FIG. 24 is a diagram showing the heat capacities of the lid, case, battery cell, etc. used in the heat capacity synthesis. The horizontal axis represents the name of each component, and the vertical axis represents the heat capacity of each component. As shown in FIG. 24, the thermal circuit information generator 114 generates the heat capacity Qmod of the origin of the battery module 400 by synthesizing the heat capacities corresponding to the busbar, monitoring board, resin, case, etc. This thermal circuit information is sent to the status monitoring device 301.

[0106] Referring again to FIG. 14 , the thermal circuit model generation unit 304 generates a thermal circuit model of the battery module 400 based on the thermal circuit information generated by the thermal circuit model generation device 100. In the first embodiment, the temperature generation unit 308 generated the temperature Tk for each of the plurality of battery cells 16. The same generation method is used to generate temperature information for each battery module 400. That is, the thermal circuit model generation unit 304 generates the battery module 400 as a thermal circuit with six thermal resistances in the X-axis, Y-axis, and Z-axis directions, enabling processing of the plurality of battery modules 400 in the same manner as processing of the plurality of battery cells 16. This allows the heat generation amount generation unit 306, temperature generation unit 308, status processing unit 310, and status monitoring unit 312 to perform processing of the battery module 400 in the same manner as in the first embodiment. In this way, the battery module 400 can be processed in the same manner as a temperature calculation model for the battery cells 16. As a result, whereas conventionally, for example, a battery device having more than 100 battery modules would require 100 or more temperature sensors, it is now possible to generate the temperature of each battery module with, for example, a single temperature sensor.

[0107] Furthermore, in the conventional case of a typical eight-thermal resistance, one-thermal capacitance model (ATC model) shown in FIG. 5 , for example, 100 battery cells would result in a large-scale thermal circuit consisting of 800 thermal resistances and 100 thermal capacitances. This would increase the number of nodal (differential) equations and the scale of calculations. In contrast, in this embodiment, the thermal capacitance is placed at the origin, allowing each thermal resistance to be connected in series and parallel, and the thermal resistance can be modeled as six resistances from the new origin. This enables high-speed calculations without the need to calculate complex nodal (differential) equations. This allows the temperature of the battery module 400 to be calculated at time intervals equivalent to the measurement interval of the temperature sensor. In other words, the temperature of the battery module 400 can be calculated in real time. Furthermore, because the battery module 400 is modeled as six thermal resistances located in six directions on a Cartesian coordinate system extending from the new origin, a battery container containing multiple battery modules 400 can also be modeled as six resistances from the new origin.

[0108] 25 is a block diagram showing another example of the configuration of a battery unit 302 according to the second embodiment. A plurality of battery modules 400 are arranged on a battery panel 422 and separated by shelves 420. A battery management unit 417 and a cell monitoring unit 418 are arranged on a control panel 421. The control panel 421 and the battery panel 422 are configured to be separable. A state monitoring unit 301 is arranged in either the battery management unit 417 or the cell monitoring unit 418.

[0109] 26 is a block diagram showing yet another example configuration of the battery unit 302. A battery management unit 417 and a cell monitoring unit 418 are configured in a control room 424. The multiple battery modules 400 and the control room 424 are separated by a partition wall 425 and configured on a substrate 426. The state monitoring unit 301 is configured in either the battery management unit 417 or the cell monitoring unit 418.

[0110] 27 is a block diagram showing yet another example of the configuration of the battery unit 302. A battery management unit 417 is configured in a control room (MBU) 424. The multiple battery modules 400 and the control room 424 are separated by a partition wall and are configured on the same panel. On the other hand, the cell monitoring unit 418 is configured on a CTR control panel 427, which is separated from the control room 424. The state monitor 301 is configured in either the battery management device 417 or the cell monitor 418.

[0111] As described above, according to this embodiment, the thermal circuit model of the battery module 400 is reconstructed as six thermal resistors connected from the origin of the battery module 400. This allows the battery module 400 to be processed in the same way as the thermal circuit model of the battery cells 16. This also allows the temperature of each of the multiple battery modules 400 to be generated using a smaller number of temperature sensors than the number of battery modules 400. While this embodiment describes a battery module 400 containing 24 battery cells 16, the scope of the present invention is not limited to the arrangement of 24 battery cells 16 shown in the drawings. Even when a different number of battery cells 16 or a different arrangement is used, the calculation method in which the origin is located at the center of the battery module 400 and thermal resistances are located on the six axes of the three Cartesian coordinates can be applied to other battery module configurations. [Explanation of symbols]

[0112] 1: battery system, 16: battery cell, 16a: electrode stack, 100: thermal circuit model generation device, 110: area generation unit, 112: thermal resistance generation unit, 114: thermal circuit information generation unit, 200: management device, 300: battery system device, 301: status monitoring device, 302: battery unit, 302a: voltage sensor, 302b: current sensor, 302c: temperature sensor, 304: thermal circuit model generation unit, 306: heat generation unit, 308: temperature generation unit, 310: status processing unit, 312: status monitoring unit, 600: heat capacity, Qamb: heat input, Qin: internal heat

Claims

1. A thermal circuit model generation device that generates thermal circuit information of an object that inputs and outputs current, comprising: a region generating unit that generates at least a first calculation region and a second calculation region along a first axis of a corresponding region corresponding to the object; a thermal resistance generating unit that generates, in the first calculation domain, a first heat conduction surface orthogonal to the first axis and a first thermal resistance in the first axial direction according to a first heat transfer distance in the first axial direction, based on a main propagation component of a heat flow propagating in a direction different from the first axis and a second axis orthogonal to the first axis; A thermal circuit model generating device comprising:

2. 2. The thermal circuit model generation device according to claim 1, wherein the thermal resistance generation unit generates a second thermal resistance in the second axis direction using a second heat conduction surface orthogonal to the second axis and a second heat transfer distance in the second axis direction, the second heat conduction surface being set based on the main propagation component.

3. The thermal circuit model generating device according to claim 2 , wherein the thermal resistance generating unit generates the first thermal resistance and the second thermal resistance based on a first thermal conductivity in the propagation direction of the main propagation component.

4. 4. The thermal circuit model generating device according to claim 3, wherein the object is a region in which a plurality of laminates are stacked, the first calculation region is a region in which the plurality of laminates are curved, and the principal propagation component is a component that propagates in a direction perpendicular to a stacking surface of the curved laminate.

5. 5. The thermal circuit model generating device according to claim 4, wherein the first heat conduction surface and the first heat transfer distance are generated in correspondence with a heat flow corresponding to a propagation component of the main propagation component in the first axial direction.

6. 6. The thermal circuit model generating device according to claim 5, wherein the second heat conduction surface and the second heat transfer distance are generated in correspondence with a heat flow corresponding to a propagation component of the main propagation component in the second axial direction.

7. The thermal resistance generating unit is 7. The thermal circuit model generation device according to claim 6, wherein in the second calculation domain, a third thermal resistance in the first axis direction is generated using a third heat conduction surface perpendicular to the first axis and a third heat transfer distance in the first axis direction.

8. The thermal resistance generating unit is 8. The thermal circuit model generation device according to claim 7, wherein in the second calculation domain, a fourth thermal resistance in the second axis direction is generated using a fourth heat conduction surface perpendicular to the second axis and a fourth heat transfer distance in the second axis direction.

9. The thermal circuit model generating device according to claim 8 , wherein the thermal resistance generating unit generates the second thermal resistance and the fourth thermal resistance based on a second thermal conductivity in the second axial direction.

10. 10. The thermal circuit model generating device according to claim 9, wherein the thermal resistance generating unit is capable of generating the first thermal resistance and the third thermal resistance as a thermal resistance connected in series.

11. The thermal circuit model generating device according to claim 10 , wherein the thermal resistance generating unit generates the second thermal resistance and the fourth thermal resistance in parallel as a fifth thermal resistance in the second axial direction.

12. 12. The thermal circuit model generating device according to claim 11, wherein when the second heat transfer distance and the fourth heat transfer distance are equal, the thermal resistance generating unit generates the fifth thermal resistance based on a sum of the second heat transfer surface and the fourth heat transfer surface, one of the second heat transfer distance and the fourth heat transfer distance, and the second thermal conductivity.

13. 13. The thermal circuit model generation device according to claim 12, wherein the thermal resistance generation unit generates a sixth thermal resistance on a third axis perpendicular to the first axis and the second axis, based on a fifth conduction surface between the first calculation domain and the second calculation domain that is perpendicular to the third axis, a fifth heat transfer distance in the third axis direction, and the second thermal conductivity.

14. a thermal circuit information generating unit that generates information about a thermal circuit of the object based on the first thermal resistance; the region generation unit, based on an origin within the object, generates the first and second calculation regions, a third and fourth calculation region which are regions line-symmetric with respect to a first plane which passes through the origin and is parallel to the first and third axes, the first and second calculation regions, a fifth and sixth calculation region which are regions line-symmetric with respect to a second plane which passes through the origin and is parallel to the second and third axes, and the fifth and sixth calculation regions, a seventh and eighth calculation region which are regions line-symmetric with respect to the first plane, the thermal resistance generating unit generates a seventh thermal resistance by setting the first calculation domain and the third calculation domain as parallel domains in the first axis direction, and setting the thermal resistance from the origin in the first axis direction to half of the first thermal resistance; The second calculation domain and the fourth calculation domain are parallel domains in the first axis direction, and the thermal resistance in the first axis direction from the origin is set to half of the third thermal resistance to generate an eighth thermal resistance; The first calculation domain, the second calculation domain, the fifth calculation domain, and the sixth calculation domain are parallel domains in the second axis direction, and a ninth thermal resistance is generated by setting the thermal resistance in the second axis direction from the origin to half of the fifth thermal resistance; The first to eighth calculation domains are parallel domains in the third axis direction, and a tenth thermal resistance is generated from the origin in the third axis direction; the thermal circuit information generating unit defines a thermal resistance from the origin in the first axis direction and in a direction opposite to the first axis direction as a seventh thermal resistance, The eighth thermal resistance is connected in series to the seventh thermal resistance, and the eighth thermal resistance is connected in series to the seventh thermal resistance in the first axial direction from the origin and in the opposite direction to the first axial direction from the origin. a thermal resistance from the origin in the second axis direction and in the direction opposite to the second axis direction is defined as a ninth thermal resistance; The thermal resistance from the origin in the third axis direction and in the direction opposite to the third axis direction is defined as the tenth thermal resistance, generating a thermal circuit connecting thermal capacitances based on the object connected to the origin; The thermal circuit model generating device according to claim 13.

15. the object is a battery cell, When configuring a battery module in which a plurality of the battery cells are arranged in at least one direction of the first axis, the second axis, and the third axis, The thermal circuit information generation unit When the seventh to tenth thermal resistors are arranged in series with respect to the second origin of the battery module, at least one of the seventh to tenth thermal resistors is connected in series according to the direction; 15. The thermal circuit model generating device according to claim 14, wherein when the seventh to tenth thermal resistors are arranged in parallel with respect to the second origin, a thermal circuit is generated by connecting at least one of the seventh to tenth thermal resistors in parallel according to the direction.

16. The thermal resistance generating unit is The parallel resistance and the series resistance of the battery module are each reproduced as one resistance for each of the first axis, the second axis, and the third axis; The thermal circuit information generation unit When configuring a battery device in which a plurality of the battery modules are arranged in at least one direction of the first axis, the second axis, and the third axis, When the regenerated thermal resistance is arranged in series with respect to the third origin of the battery device, the regenerated thermal resistance is connected in series according to the direction; 16. The thermal circuit model generating device according to claim 15, wherein when the regenerated thermal resistances are arranged in parallel with respect to the third origin, the thermal circuit is generated by connecting the regenerated thermal resistances in parallel according to the direction.

17. A status monitoring device that monitors the status of an object that inputs and outputs a current, a thermal circuit generating unit that generates a thermal circuit having a plurality of thermal resistances connected from an origin of the object in directions perpendicular to each other from the origin and a thermal capacitance connected to the origin based on information about the thermal circuit of the object; a heat generating unit that generates heat in accordance with the current; a temperature generating unit that supplies the generated heat to a predetermined point in the thermal circuit to generate a temperature at the predetermined temperature point in the thermal circuit; a state monitoring unit that monitors the temperature of the temperature point as the state of the object.

18. the target object is a battery cell, a battery module configured with a plurality of the battery cells, or a battery device configured with a plurality of the battery modules, The thermal circuit comprises: based on a first thermal resistance generated by at least a first calculation area along a first axis of the corresponding area corresponding to the battery cell; The first thermal resistance is 18. The condition monitoring device of claim 17, wherein the condition monitoring value is generated based on a main propagation component of a heat flow propagating in a direction different from the first axis and a second axis perpendicular to the first axis, according to a first heat conduction surface perpendicular to the first axis and a first heat transfer distance in the first axial direction.

19. A thermal circuit model generation method for generating a thermal circuit of an object, comprising: a region generating step of generating at least a first calculation region and a second calculation region along a first axis of a corresponding region corresponding to the object; a thermal resistance generating step of generating, in the first calculation domain, a first heat conduction surface orthogonal to the first axis and a first thermal resistance in the first axial direction according to a first heat transfer distance in the first axial direction, based on a main propagation component of a heat flow propagating in a direction different from the first axis and a second axis orthogonal to the first axis; A thermal circuit model generation method comprising:

20. A thermal circuit model generation program for generating thermal circuit information of an object, a region generating step of generating at least a first calculation region and a second calculation region along a first axis of a corresponding region corresponding to the object; a thermal resistance generating step of generating, in the first calculation domain, a first heat conduction surface orthogonal to the first axis and a first thermal resistance in the first axial direction according to a first heat transfer distance in the first axial direction, based on a main propagation component of a heat flow propagating in a direction different from the first axis and a second axis orthogonal to the first axis; A thermal circuit model generation program that executes the above on a computer.

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