Battery cooling control system and battery cooling control method

Abstract

To provide a technology for reducing the frequency of unnecessary battery replacement and the lifetime cost of a vehicle by controlling the cooling of a battery mounted in a vehicle and performing appropriate processing according to the degree of deterioration.SOLUTION: A battery cooling control system estimates the degree of battery deterioration on the basis of sensor information. When the estimated degree of battery deterioration is equal to or greater than a first predetermined value, the system increases the output of a cooling device that cools the battery compared to a state in which the degree of battery deterioration is less than the first predetermined value. When the degree of battery deterioration is equal to or greater than a second predetermined value that is equal to or greater than the first predetermined value, the system issues a notification urging a user to replace the battery.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a technique for controlling the cooling of a battery mounted on a vehicle. [Background technology]

[0002] Patent Document 1 discloses a battery pack mounted on a vehicle. A cooler is provided at the bottom of the battery pack, and the battery stack in the battery pack is cooled by the cooler, with the battery case and a heat conductive part separated from each other. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-46659 A Summary of the Invention [Problem to be solved by the invention]

[0004] As the battery cells deteriorate, they expand, forming gaps between the battery cells and the cooling device, reducing the cooling efficiency. This leads to further deterioration of the battery cells and increases the frequency of battery replacement, resulting in an increase in the vehicle's life cycle cost.

[0005] One object of the present disclosure is to provide a technique that can reduce the frequency of replacing batteries installed in vehicles. [Means for solving the problem]

[0006] The first aspect relates to a battery cooling control system applied to a battery mounted on a vehicle. The battery cooling control system includes one or more processors. One or more processors may: A degree of battery deterioration is estimated based on information on battery deterioration parameters that are measured by a sensor and change according to the deterioration of the battery; When the degree of battery deterioration is equal to or greater than a first predetermined value, an output of a cooling device that cools the battery is increased to a level higher than that in a state in which the degree of battery deterioration is less than the first predetermined value; When the degree of battery deterioration is equal to or greater than a second predetermined value, which is equal to or greater than the first predetermined value, a notification is given to encourage battery replacement.

[0007] The second aspect relates to a battery cooling control method applied to a battery mounted on a vehicle. The battery cooling control method includes: an estimation process for estimating a degree of battery deterioration based on information on a battery deterioration parameter that is measured by a sensor and changes according to deterioration of the battery; an output adjustment process for increasing an output of a cooling device that cools the battery when the degree of battery deterioration is equal to or greater than a first predetermined value, compared to a state in which the degree of battery deterioration is less than the first predetermined value; a notification process for issuing a notification to prompt the user to replace the battery when the battery deterioration level is equal to or greater than a second predetermined value, which is equal to or greater than the first predetermined value; Includes. Effect of the Invention

[0008] The present disclosure enables appropriate responses, such as adjusting the cooling output for the battery and issuing a notification to encourage battery replacement, according to the degree of battery degradation. In other words, when the battery is only slightly degraded, the cooling output for the battery can be adjusted to allow the battery to perform as required without replacing it. This makes it possible to reduce the frequency of battery replacement without degrading battery performance as much as possible. This contributes to reducing the life cycle cost of the vehicle. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a battery pack mounted on a vehicle according to an embodiment of the present invention; [Diagram 2] FIG. 1 is a schematic diagram for explaining a problem. [Diagram 3] 1 is a block diagram showing a configuration example of a battery cooling control system according to an embodiment of the present invention; [Figure 4] 1 is a schematic diagram for explaining a specific example of a sensor according to an embodiment of the present invention; [Diagram 5] 4 is a flowchart showing a process performed by the battery cooling control system according to the present embodiment. [Figure 6] 10 is a flowchart showing another example of the process performed by the battery cooling control system according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0011] 1. Basic configuration of the battery pack installed in the vehicle 1 is a schematic diagram of a battery pack 10 mounted on a vehicle 1 according to the present embodiment. The battery pack 10 is used as a power source for an electric vehicle such as a BEV, a PEV, or an HEV.

[0012] The battery pack 10 includes a battery case 11, one or more battery modules 12 (hereinafter simply referred to as battery module 12), and a cooling device 13.

[0013] The battery case 11 includes an upper case 21 and a lower case 22, and the battery case 11 accommodates a battery module 12 therein.

[0014] The battery module 12 includes one or more battery cells 31 (hereinafter simply referred to as battery cells 31) and a battery restraint plate 32. The battery cell 31 is substantially rectangular and has a lid portion 31a and a bottom portion 31b. The battery restraint plate 32 is a plate made of metal or the like for holding down the stacked battery cells 31, and fixes the battery cells 31 by mechanical joints using bolts, nuts, etc.

[0015] The cooling device 13 is a device for cooling the battery modules 12 and the battery cells 31 contained in the battery modules 12, and examples of the mechanism include an air-cooling type, a water-cooling type, and a refrigerant-cooling type.

[0016] 1, the cooling device 13 is disposed below the lower case 22 that is disposed below the battery module 12. That is, the battery module 12 is cooled by the cooling device 13 across the lower case 22. However, as another embodiment, the cooling device 13 and the battery module 12 may be in direct contact with each other without the lower case 22 in between. Also, as shown in Patent Document 1, a thermally conductive layer may be present between the cooling device 13 and the lower case 22.

[0017] 2. Challenges The inventors of the present application have discovered the following problem regarding the cooling of the battery module 12 mounted on the vehicle 1 as described above. The problem is that the battery cells 31 included in the battery module 12 expand with deterioration, forming gaps between the battery cells 31 and the cooling device 13, reducing the cooling efficiency.

[0018] FIG. 2 is a schematic diagram for explaining the problem. When the battery cell 31 deteriorates, the internal pressure of the battery cell 31 increases due to the generation of gas. When the internal pressure of the battery cell 31 increases, the cover portion 31a and the bottom portion 31b of the battery cell 31 restrained by the battery restraining plate 32 expand and deform. At this time, a part of the bottom portion 31b of the battery cell 31 separates from the lower case 22, and the cooling efficiency decreases. The decrease in the cooling efficiency for the battery cell 31 (i.e., weakened cooling) may cause further deterioration of the battery cell 31. As a result, the life of the battery cell 31 becomes shorter and the frequency of replacement increases, which leads to an increase in the lifetime cost (life cycle cost) of the vehicle 1.

[0019] In order to solve the above-mentioned problems, in this embodiment, a sensor measures information that changes according to the deterioration of the battery cells 31, and the deterioration level of the battery is estimated based on the information. Furthermore, processing is executed according to the magnitude relationship between the estimated deterioration level of the battery and a preset predetermined value. In particular, by setting multiple predetermined values, two types of processing are possible: adjusting the output of the cooling device 13 and issuing a notification to prompt the user to replace the battery cells 31.

[0020] 3. Example of battery cooling control system configuration 3 is a block diagram showing an example of the configuration of a battery cooling control system 100 according to the present embodiment. The battery cooling control system 100 is applied to a battery pack 10 mounted on a vehicle 1. The battery cooling control system 100 includes a cooling device 13, a sensor 40, a control device 50, and a notification device 70.

[0021] The sensor 40 is installed near the battery cell 31 and measures a battery deterioration parameter X1 that changes in accordance with deterioration of the battery cell 31. Typically, the battery deterioration parameter X1 is information on the amount of expansion associated with deterioration of the battery cell 31. Specific examples of the sensor 40 and the battery deterioration parameter X1 will be described later.

[0022] The control device 50 includes one or more processors 51 (hereinafter simply referred to as processor 51) and one or more storage devices 52 (hereinafter simply referred to as storage devices 52). The processor 51 executes various processes. For example, the processor 51 includes a CPU (Central Processing Unit). The control device 50 may include one or more ECUs (Electronic Control Units).

[0023] The storage device 52 stores various information. Examples of the storage device 52 include a volatile memory, a non-volatile memory, a hard disk drive (HDD), a solid state drive (SSD), etc. The processor 51 executes a control program, which is a computer program, to realize processing by the control device 50. The control program is stored in the storage device 52, or recorded in a computer-readable recording medium.

[0024] The processor 51 included in the control device 50 performs an "estimation process" to estimate a battery degradation level X2 based on information about a battery degradation parameter X1 measured by the sensor 40. The processor 51 also performs a "determination process" to determine whether the battery degradation level X2 is larger or smaller than various predetermined values ​​described below. Based on the result of the determination process, the processor 51 further performs an "output adjustment process" to adjust the cooling output P of the cooling device 13 that cools the battery module 12, and a "notification process" to give an instruction to the notification device 70 to notify that replacement of the battery cell 31 is necessary.

[0025] The storage device 52 stores the predetermined value information 101. The predetermined value information 101 includes numerical information of a first predetermined value TH1 and a second predetermined value TH2, which are reference values ​​for the judgment process based on the battery deterioration level X2. Here, the second predetermined value TH2 is a value equal to or greater than the first predetermined value TH1. First, when the battery deterioration level X2 is less than the first predetermined value TH1, the cooling efficiency is equal to or greater than the design standard value, and no special measures are required (hereinafter referred to as a healthy state). Next, when the battery deterioration level X2 is equal to or greater than the first predetermined value TH1 and less than the second predetermined value TH2, the cooling efficiency falls below the design standard value, but the battery cell 31 can perform at least a certain level of performance by adjusting the cooling output P (hereinafter referred to as a mildly deteriorated state). Finally, when the battery deterioration level X2 is equal to or greater than the second predetermined value TH2, the cooling efficiency falls significantly below the design standard value, and there is a possibility that the safety performance will be affected due to thermal runaway of the battery cell 31, and therefore the battery cell 31 should be replaced (hereinafter referred to as a severely deteriorated state).

[0026] The storage device 52 also stores battery degradation parameter information 102, which is information on a battery degradation parameter X1 measured by the sensor 40, and battery degradation level information 103, which is information on a battery degradation level X2 estimated by the processor 51 based on the battery degradation parameter information 102.

[0027] When the battery cell 31 needs to be replaced, the notification device 70 receives an instruction from the processor 51 and notifies the driver accordingly. That is, the processor 51 issues a notification via the notification device 70. Examples of the notification method include notifying the driver by displaying the information in the vehicle, or notifying an information device owned by the driver. In addition to notifying the driver directly, the information may be sent once to a vehicle management center or the like, and then notified to the driver or an information device owned by the driver afterwards.

[0028] As described above as a problem, the battery cells 31 tend to expand as they deteriorate, and therefore information on the amount of expansion of the battery cells 31 is exemplified as one type of battery deterioration parameter measured by the sensor 40. Specific parameters and a measurement method are shown in FIG.

[0029] 4A shows a case where the sensor 40 is a distance sensor 40A such as a laser range finder. In this case, the battery deterioration parameter X1 is the distance between a fixed point and the surface of the battery cell 31. It can be said that the larger the battery deterioration parameter X1 (distance), the higher the battery deterioration level X2.

[0030] 4B shows a case where the sensor 40 is a pressure sensor 40B that measures the pressure inside the container. In this case, the battery deterioration parameter X1 is the expansion pressure of the battery cell 31. It can be said that the larger the battery deterioration parameter X1 (expansion pressure), the higher the battery deterioration level X2.

[0031] 4C shows a case where the sensor 40 is a strain sensor 40C that measures strain on the surface of an object. In this case, the battery deterioration parameter X1 is the expansion strain value of the surface of the battery cell 31. It can be said that the larger the battery deterioration parameter X1 (strain value), the higher the battery deterioration level X2.

[0032] The location of measurement by the sensor 40 is preferably the lid portion 31a where stable data can be obtained. Furthermore, the measurement should be performed when there is no vibration input during driving. For example, in the case of an electric vehicle, it is recommended to perform the measurement with the power switch turned off.

[0033] The object of measurement by the sensor 40 is preferably the battery cell 31 located in the center of the battery module 12 where heat tends to accumulate, but the position and number of the target battery cells 31 are not limited to those in this embodiment.

[0034] 4. Processing flow FIG. 5 is a flowchart showing the processing performed by the battery cooling control system 100 according to the present embodiment.

[0035] In step S10, the battery cooling control system 100 estimates the battery degradation level X2 based on the information of the battery degradation parameter X1 measured by the sensor 40 (estimation process). As described above, the battery degradation level X2 increases as the battery degradation parameter X1 increases. The battery degradation parameter X1 itself may be used as the battery degradation level X2.

[0036] In step S20, the battery cooling control system 100 compares the battery degradation level X2 with a first predetermined value TH1, and makes the following judgment based on the result. If the battery degradation level X2 is equal to or greater than the first predetermined value TH1 (step S20; Yes), the process proceeds to step S30. On the other hand, if the battery degradation level X2 is less than the first predetermined value TH1 (healthy state, step S20; No), the process returns to step S10.

[0037] In step S30, the battery cooling control system 100 compares the battery degradation level X2 with a second predetermined value TH2, and makes the following judgment based on the result. If the battery degradation level X2 is equal to or greater than the second predetermined value TH2 (severely degraded state, step S30; Yes), the process proceeds to step S40-1. On the other hand, if the battery degradation level X2 is less than the second predetermined value TH2 (slightly degraded state, step S30; No), the process proceeds to step S40-2.

[0038] In step S40-1, the battery cooling control system 100 instructs the notification device 70 to execute a notification urging replacement of the battery cell 31 (notification process). After that, the process returns to step S10.

[0039] In step S40-2, the battery cooling control system 100 sets the cooling output P of the cooling device 13 to a strong cooling output P+ (output adjustment process). After that, the process returns to step S10. The strong cooling output P+ means that the level of the cooling output P is higher than that in a healthy state (a state in which the battery deterioration level X2 is lower than the first predetermined value TH1).

[0040] Through the above-mentioned series of processes, two flexible responses are possible depending on the deterioration state of the battery cell 31. That is, when the battery cell 31 is in a "mildly deteriorated state", the processor 51 executes an "output adjustment process" to adjust the cooling output P for the battery cell 31, thereby enabling the battery cell 31 to exhibit a predetermined performance without replacing it. Also, when the battery cell 31 is in a "severely deteriorated state", the processor 51 executes a "notification process" to prompt the battery cell 31 to be replaced. The battery cooling control system 100 including such a processor 51 can reduce the frequency of replacing the battery cell 31 without deteriorating the performance of the entire battery pack 10 as much as possible. This contributes to reducing the lifetime cost (life cycle cost) of the vehicle 1.

[0041] The relationship between the battery deterioration parameter X1 and the cooling efficiency for the battery cell 31 is derived from data obtained by experiments and analyses. The first predetermined value TH1, the second predetermined value TH2, and numerical values ​​such as the strong cooling output P+ corresponding thereto are set based on the relationship.

[0042] 4-1. Modifications of the processing flow Fig. 6 is another example of a flowchart showing the processing by the battery cooling control system 100 according to the present embodiment. Here, unlike the flowchart in Fig. 5, the order of the determination based on the second predetermined value TH2 precedes the determination based on the first predetermined value TH1, but the effect of the present disclosure is exerted even in this case. The processing flow in this case will be described.

[0043] In step S11, the battery cooling control system 100 estimates the battery degradation level X2 based on the information of the battery degradation parameter X1 measured by the sensor 40 (estimation process).

[0044] In step S21, the battery cooling control system 100 compares the battery degradation level X2 with a second predetermined value TH2, and makes the following judgment based on the result. If the battery degradation level X2 is equal to or greater than the second predetermined value (severely degraded state, step S21; Yes), the process proceeds to step S41-1. On the other hand, if the battery degradation level X2 is less than the second predetermined value (step S21; No), the process proceeds to step S31.

[0045] In step S41-1, the battery cooling control system 100 instructs the notification device 70 to execute a notification urging replacement of the battery cell 31 (notification process). After that, the process returns to step S11.

[0046] In step S31, the battery cooling control system 100 compares the battery degradation level X2 with a first predetermined value TH1, and makes the following judgment based on the result. If the battery degradation level X2 is equal to or greater than the first predetermined value TH1 (mildly degraded state, step S31; Yes), the process proceeds to step S41-2. On the other hand, if the battery degradation level X2 is less than the first predetermined value TH1 (healthy state, step S31; No), the process returns to step S11.

[0047] In step S41-2, the battery cooling control system 100 sets the cooling output P of the cooling device 13 to a strong cooling output P+ (output adjustment process). After that, the process returns to step S11. The strong cooling output P+ means that the level of the cooling output P is higher than that in a healthy state (a state in which the battery deterioration level X2 is lower than the first predetermined value TH1). [Explanation of symbols]

[0048] 1 vehicle 10 Battery pack 11 Battery case 12 Battery module 13 Cooling device 21 Upper Case 22 Lower case 31 Battery Cell 31a Lid 31b bottom 32 Battery Retaining Plate 40 Sensors 50 Control device 51 Processors 52 Storage device 70 Notification device

Claims

1. A battery cooling control system applied to a battery mounted on a vehicle, One or more processors; The one or more processors: estimating a degree of battery deterioration based on information on a battery deterioration parameter that is measured by a sensor and changes in accordance with deterioration of the battery; When the degree of battery deterioration is equal to or greater than a first predetermined value, an output of a cooling device that cools the battery is increased to a value higher than that in a state in which the degree of battery deterioration is less than the first predetermined value; When the degree of deterioration of the battery is equal to or greater than a second predetermined value, which is equal to or greater than the first predetermined value, a notification is issued to encourage replacement of the battery. Battery cooling control system.

2. 2. The battery cooling control system according to claim 1, the sensor is a distance sensor; The battery deterioration parameter is a distance between a surface of a battery cell included in the battery and a fixed point, the distance being measured by the distance sensor. Battery cooling control system.

3. 2. The battery cooling control system according to claim 1, the sensor is a pressure sensor; The battery deterioration parameter is an expansion pressure of a battery cell included in the battery, the expansion pressure being measured by the pressure sensor. Battery cooling control system.

4. 2. The battery cooling control system according to claim 1, the sensor is a strain sensor; The battery deterioration parameter is an expansion strain value of a surface of a battery cell included in the battery, the expansion strain value being measured by the strain sensor. Battery cooling control system.

5. A battery cooling control method applied to a battery mounted on a vehicle, comprising: an estimation process for estimating a degree of deterioration of a battery based on information on a battery deterioration parameter that is measured by a sensor and changes depending on deterioration of the battery; an output adjustment process for increasing an output of a cooling device that cools the battery when the degree of battery deterioration is equal to or greater than a first predetermined value, compared to a state in which the degree of battery deterioration is less than the first predetermined value; a notification process for issuing a notification to prompt the user to replace the battery when the battery deterioration level is equal to or greater than a second predetermined value, the second predetermined value being equal to or greater than the first predetermined value; Includes Battery cooling control method.

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