Battery charger

Abstract

To provide a battery charger capable of preventing a battery from becoming too hot and preventing a charging time from becoming too long due to a charging current limit.SOLUTION: A battery charger includes a charger information acquisition unit that acquires information regarding the output of a charger, a SOC information acquisition unit that acquires information regarding the current SOC of the battery, and a cooling control unit that controls a cooling device that cools the battery, and when the output of the charger is equal to or greater than a predetermined value and the current SOC of the battery is equal to or less than the predetermined value, the cooling control unit sets the cooling start temperature of the battery low.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a battery charging device. [Background technology]

[0002] Patent Document 1 discloses a technique for creating a target temperature profile that indicates the relationship between charging time and the temperature of a secondary battery, and controlling the charging current so that the temperature changes in accordance with the target temperature profile. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-191147 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology disclosed in Patent Document 1 limits the charging current in accordance with the battery temperature, so when the amount of heat generated during charging becomes large, the charging current is limited, which may result in a longer charging time.

[0005] The present disclosure has been made in consideration of the above, and aims to provide a battery charging device that can prevent the battery from becoming too hot and prevent the charging time from being extended due to charging current limiting. [Means for solving the problem]

[0006] The battery charging device of the present disclosure comprises a charger information acquisition unit that acquires information regarding the output of a charger, a SOC information acquisition unit that acquires information regarding the current SOC of the battery, and a cooling control unit that controls a cooling device that cools the battery, and when the output of the charger is greater than or equal to a predetermined value and the current SOC of the battery is less than or equal to a predetermined value, the cooling control unit sets a low cooling start temperature for the battery. Effect of the Invention

[0007] In the present disclosure, when the current flow is large and the amount of heat generated by the battery increases, i.e., when the charger output is high and the current SOC of the battery is low, the battery cooling start temperature by the cooling device is set low and cooling begins early, thereby preventing the battery from becoming too hot and preventing the charging time from being extended due to the charging current limit. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of a battery charging device according to an embodiment. [Diagram 2] FIG. 2 is a graph showing an example of a battery charging device according to an embodiment in which the cooling start temperature of the cooling device is set uniformly to a predetermined low value. [Diagram 3] FIG. 3 is a graph showing an example of a battery charging device according to an embodiment in which the cooling start temperature of the cooling device is set uniformly to a predetermined high value. [Figure 4] FIG. 4 is a graph showing an image of setting the cooling start temperature in the battery charging device according to the embodiment. [Diagram 5] FIG. 5 is a flowchart showing an example of a battery cooling method executed by the battery charging device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A battery charging device according to an embodiment of the present disclosure will be described with reference to the drawings. Note that the components in the following embodiments include those that are easily replaceable by a person skilled in the art, or those that are substantially the same.

[0010] (Battery charging device) The configuration of a battery charging device according to an embodiment will be described with reference to Figures 1 to 4. The battery charging device according to an embodiment is provided in a vehicle equipped with a battery, such as a plug-in hybrid electric vehicle (PHEV) or a battery electric vehicle (BEV).

[0011] 1, the charging device 1 includes a control unit 10, a battery 20, and a cooling device 30. The charging device 1 is connected to a charger 2 installed at an external charging stand or the like, whereby the battery 20 is charged.

[0012] The control unit 10 is an electronic control unit (ECU) whose main components are a microcomputer including, for example, a central processing unit (CPU), a read only memory (ROM), and a random access memory (RAM).

[0013] The control unit 10 loads a program into a working area of ​​the main storage unit, executes the program, and realizes functions that meet a predetermined purpose by controlling each component through the execution of the program. The control unit 10 functions as a charger information acquisition unit 11, an SOC information acquisition unit 12, and a cooling control unit 13 through the execution of the program.

[0014] When the charging device 1 is connected to the charger 2, the charger information acquisition unit 11 acquires information about the output of the charger 2. This information about the output of the charger 2 is used when switching the cooling start temperature in the cooling control unit 13, as described later.

[0015] The SOC information acquisition unit 12 acquires information about the current SOC (State Of Charge) of the battery 20. This SOC information is used when switching the cooling start temperature in the cooling control unit 13, as described later.

[0016] The cooling control unit 13 controls the cooling device 30. Here, in the charging device 1, in order to appropriately protect the battery 20, the limit amount of the charging current to the battery 20 changes according to the temperature of the battery 20. Therefore, in order to shorten the charging time to the battery 20, it is necessary to keep the temperature of the battery 20 at an appropriate temperature and reduce the current limit amount.

[0017] For example, as shown in FIG. 2, if the cooling start temperature of the cooling device 30 is uniformly set to a predetermined low value, the temperature of the battery 20 will be low in a scene where the amount of heat generated during charging is small, and the current limit amount (low temperature current limit) will be large.

[0018] On the other hand, for example, as shown in FIG. 3, if the cooling start temperature of the cooling device 30 is uniformly set to a predetermined high value, the temperature of the battery 20 will become high in a scene where the amount of heat generated during charging is large, and the current limit amount (high temperature current limit) will become large.

[0019] 2, if the cooling start timing is early, the temperature of the battery 20 remains in a sufficiently low range, so the high temperature current limit does not intervene, but the low temperature current limit does intervene, which may lengthen the charging time of the battery 20. This is particularly noticeable in the high SOC range where the charging current to the battery 20 is restricted, or when the output of the charger 2 is small.

[0020] Therefore, the cooling control unit 13 switches the cooling start temperature of the battery 20 based on the output of the charger 2 and the current SOC of the battery 20. That is, when the output of the charger 2 is equal to or greater than a predetermined value and the current SOC of the battery 20 is equal to or less than a predetermined value, the cooling control unit 13 sets the cooling start temperature of the battery 20 lower than when the output of the charger 2 is less than the predetermined value or when the current SOC of the battery 20 exceeds the predetermined value. Note that the "cooling start temperature" is the temperature at which cooling of the battery 20 starts (cooling temperature threshold value) and indicates the timing of starting cooling.

[0021] 4 shows an image of the setting of the cooling start temperature in the battery charging device according to the embodiment. As shown in the figure, for example, when the output of the charger 2 is high and the current SOC is low, the current flow is large, and the amount of heat generated by the battery 20 is also large. In this case, the cooling control unit 13 sets the cooling start temperature low and starts cooling the battery 20 early, thereby preventing the battery 20 from becoming too hot.

[0022] On the other hand, in cases other than those mentioned above, that is, in the following cases (1) to (3), the cooling control unit 13 sets the cooling start temperature high to prevent overcooling. (1) When the output and current SOC of Charger 2 are both high (2) When the output and current SOC of Charger 2 are both low (3) When the output of Charger 2 is low and the current SOC is high

[0023] The battery 20 is, for example, a lithium ion secondary battery including a plurality of battery cells. The battery 20 also includes, for example, a lithium polymer battery that uses a polymer gel as an electrolyte.

[0024] The cooling device 30 is a device for cooling the battery 20. The specific configuration of the cooling device 30 is not limited, and examples thereof include a water-cooling type using a water pump or the like, and a refrigerant type using a cooling fan or the like.

[0025] (Battery cooling method) The flow of the battery cooling method executed by the battery charging device according to the embodiment will be described with reference to FIG.

[0026] First, the charger information acquisition unit 11 determines whether the battery 20 is being charged (step S1). In this way, by reading a signal indicating the charging state of the battery 20 in step S1, the cooling temperature threshold (cooling start temperature) can be distinguished between "charging" and "not charging" in step S4 described later. If it is determined in step S1 that the battery 20 is being charged (Yes in step S1), the charger information acquisition unit 11 reads the output signal of the charger 2 (step S2).

[0027] Next, the SOC information acquisition unit 12 reads the SOC signal of the battery 20 (step S3). Next, the cooling control unit 13 determines the threshold value of the cooling temperature (cooling start temperature) of the battery 20 based on the output of the charger 2 and the current SOC of the battery 20 (step S4). In step S4, the cooling control unit 13 sets the threshold value of the cooling temperature low when the output of the charger 2 is equal to or higher than a predetermined value and the current SOC of the battery 20 is equal to or lower than a predetermined value.

[0028] Next, the cooling control unit 13 determines whether the cooling device 30 is operating (step S5). If it is determined in step S5 that the cooling device 30 is operating (Yes in step S5), the cooling control unit 13 determines whether the battery temperature Tb is less than a cooling temperature threshold (cooling start temperature) (step S6).

[0029] In step S6, when it is determined that the battery temperature Tb is lower than the cooling temperature threshold value (Yes in step S6), the cooling control unit 13 stops the cooling device 30 (step S7), and ends this process.

[0030] In the above-mentioned step S1, if it is determined that the battery 20 is not being charged (No in step S1), the charger information acquisition unit 11 proceeds to the process of step S4. In addition, in the above-mentioned step S5, if it is determined that the cooling device 30 is not operating (No in step S5), the cooling control unit 13 determines whether the battery temperature Tb is equal to or higher than the cooling temperature threshold value (cooling start temperature) (step S8).

[0031] In step S8, when it is determined that the battery temperature Tb is equal to or higher than the cooling temperature threshold value (Yes in step S8), the cooling control unit 13 operates the cooling device 30 (step S9) and completes this process.

[0032] In the above-mentioned step S6, if it is determined that the battery temperature Tb is not less than the cooling temperature threshold (is equal to or greater than the cooling temperature threshold) (No in step S6), the cooling control unit 13 proceeds to the process of step S9. In addition, in the above-mentioned step S8, if it is determined that the battery temperature Tb is not equal to or greater than the cooling temperature threshold (is less than the cooling temperature) (No in step S8), the cooling control unit 13 completes this process.

[0033] In the battery charging device according to the embodiment described above, when the current flow is large and the amount of heat generated by the battery 20 increases, i.e., when the output of the charger 2 is high and the current SOC of the battery 20 is low, the cooling start temperature of the battery 20 by the cooling device 30 is set low and cooling begins early. This makes it possible to prevent the battery 20 from becoming too hot and to prevent the charging time from being extended due to the charging current limit.

[0034] Further advantages and modifications may readily occur to those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof. [Explanation of symbols]

[0035] 1 Charging device 10 Control section 11 Charger information acquisition section 12 SOC information acquisition department 13 Cooling control unit 20 batteries 30 Cooling device 2 charger

Claims

[Claim 1] A charger information acquisition unit that acquires information related to an output of the charger; an SOC information acquisition unit that acquires information regarding a current SOC of a battery; A cooling control unit that controls a cooling device that cools the battery; Equipped with the cooling control unit sets a cooling start temperature of the battery low when an output of the charger is equal to or higher than a predetermined value and a current SOC of the battery is equal to or lower than a predetermined value; Battery charging device.

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