Charging device, charge control method, and control program

Abstract

To provide a charging device capable of effectively charging a secondary battery, a charge control method, and a control program.SOLUTION: A charging device comprises: a calculation section for calculating a deterioration integrated value representing a deterioration state of a secondary battery; a first determination section for determining whether or not the deterioration integrated value is equal to or more than a first threshold; a second determination section for determining, in a case where the deterioration integrated value is equal to or more than the first threshold, whether or not a value of current flowing through the secondary battery being charged is equal to or more than a second threshold; a third determination section for determining, in a case where the deterioration integrated value is less than the first threshold, whether or not a value of voltage applied to the secondary battery being charged is equal to or more than a third threshold; and a charge restriction section for performing the restriction of charging to the secondary battery, if it is determined that the value of the current flowing through the secondary battery being charged is equal to or more than the second threshold in the case where the deterioration integrated value is equal to or more than the first threshold or if it is determined that the value of the voltage applied to the secondary battery being charged is equal to or more than the third threshold in the case where the deterioration integrated value is less than the first threshold.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a charging device, a charging control method, and a control program. [Background technology]

[0002] Patent Document 1 discloses a power supply system including a secondary battery and a control unit. When the temperature of the secondary battery is below a predetermined temperature, the control unit controls the voltage of the secondary battery to be between an upper limit voltage and a lower limit voltage, and when the temperature of the secondary battery is equal to or higher than the predetermined temperature, the control unit controls the charge / discharge current of the secondary battery to be equal to or lower than the upper limit current. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-103833 A Summary of the Invention [Problem to be solved by the invention]

[0004] The power supply system disclosed in Patent Document 1 merely controls the voltage of the secondary battery and the charge / discharge current of the secondary battery according to the temperature of the secondary battery, and does not limit charging in consideration of the deterioration state of the secondary battery (i.e., the internal resistance of the secondary battery). Therefore, even if the resistance value of the secondary battery increases significantly due to high-rate deterioration caused by charging and discharging a large current, the power supply system disclosed in Patent Document 1 may limit charging of the secondary battery based on the state of the voltage applied to the secondary battery during charging. In that case, the current flowing through the secondary battery during charging is excessively limited, so that the actual charging amount is less than the chargeable amount at which Li (lithium) does not precipitate on the negative electrode of the secondary battery. Therefore, the power supply system disclosed in Patent Document 1 has a problem in that it is not possible to effectively charge the secondary battery.

[0005] The present disclosure has been made in consideration of the above background, and has an object to provide a charging device, a charging control method, and a control program that are capable of effectively charging a secondary battery. [Means for solving the problem]

[0006] A charging device according to the present disclosure is a charging device that charges a secondary battery, and includes a calculation unit that calculates a deterioration integrated value that indicates a deterioration state of the secondary battery, a first determination unit that determines whether the deterioration integrated value is equal to or greater than a first threshold, a second determination unit that determines whether a value of a current flowing through the secondary battery during charging is equal to or greater than a second threshold when the deterioration integrated value is equal to or greater than the first threshold, a third determination unit that determines whether a value of a voltage applied to the secondary battery during charging is equal to or greater than a third threshold when the deterioration integrated value is less than the first threshold, and a charge limiting unit that limits charging of the secondary battery when the value of the current flowing through the secondary battery during charging is determined to be equal to or greater than the second threshold when the deterioration integrated value is equal to or greater than the first threshold, or when the value of the voltage applied to the secondary battery during charging is determined to be equal to or greater than the third threshold when the deterioration integrated value is less than the first threshold. This charging device can prevent excessive limiting of charging of the secondary battery by limiting charging of the secondary battery based on the value of the current flowing through the secondary battery during charging when the resistance value of the secondary battery increases due to high-rate deterioration caused by charging and discharging a large current, for example. In other words, this charging device can effectively charge the secondary battery.

[0007] The charge control method according to the present disclosure is a charge control method by a charging device that charges a secondary battery, which calculates a deterioration integrated value that indicates a deterioration state of the secondary battery, determines whether the deterioration integrated value is equal to or greater than a first threshold, and if the deterioration integrated value is equal to or greater than the first threshold, determines whether a value of a current flowing through the secondary battery during charging is equal to or greater than a second threshold, and if the deterioration integrated value is less than the first threshold, determines whether a value of a voltage applied to the secondary battery during charging is equal to or greater than a third threshold, and restricts charging of the secondary battery when the deterioration integrated value is equal to or greater than the first threshold and the value of the current flowing through the secondary battery during charging is determined to be equal to or greater than the second threshold, or when the deterioration integrated value is less than the first threshold and the value of the voltage applied to the secondary battery during charging is determined to be equal to or greater than the third threshold. This charge control method can prevent excessive restriction of charging of the secondary battery by restricting charging of the secondary battery based on the value of the current flowing through the secondary battery during charging when the resistance value of the secondary battery increases due to high-rate deterioration caused by charging and discharging a large current, for example. In other words, this charging control method can effectively charge the secondary battery.

[0008] The control program of the present disclosure is a control program that causes a computer to execute a charging control process in a charging device that charges a secondary battery, and causes the computer to execute the following processes: a process of calculating a deterioration integrated value that indicates a deterioration state of the secondary battery; a process of determining whether the deterioration integrated value is greater than or equal to a first threshold; a process of determining whether a value of a current flowing through the secondary battery during charging is greater than or equal to a second threshold if the deterioration integrated value is greater than or equal to the first threshold; a process of determining whether a value of a voltage applied to the secondary battery during charging is greater than or equal to a third threshold if the deterioration integrated value is less than the first threshold; and a process of restricting charging of the secondary battery if the value of the current flowing through the secondary battery during charging is determined to be greater than or equal to the second threshold when the deterioration integrated value is greater than or equal to the first threshold, or if the value of the voltage applied to the secondary battery during charging is determined to be greater than or equal to the third threshold when the deterioration integrated value is less than the first threshold. This control program can prevent excessive charging of the secondary battery by limiting the charging of the secondary battery based on the value of the current flowing through the secondary battery during charging, for example, when the resistance value of the secondary battery rises due to high-rate degradation caused by charging and discharging a large current. In other words, this control program can effectively charge the secondary battery. Effect of the Invention

[0009] The present disclosure makes it possible to provide a charging device, a charging control method, and a control program capable of effectively charging a secondary battery. [Brief description of the drawings]

[0010] [Figure 1] 1 is a block diagram showing a configuration example of a charging system provided with a charging device according to the present disclosure. [Diagram 2] 4 is a flowchart showing the operation of a charging device according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described below through embodiments of the invention, but the invention according to the claims is not limited to the following embodiments. In addition, not all of the configurations described in the embodiments are necessarily essential means for solving the problems. For clarity of explanation, the following description and drawings are omitted and simplified as appropriate. In each drawing, the same elements are given the same reference numerals, and repeated explanations are omitted as necessary.

[0012] FIG. 1 is a block diagram showing a configuration example of a charging system 1 provided with a charging device according to the present disclosure. The charging device according to the present disclosure can prevent excessive charging of the secondary battery from being restricted when the resistance value of the secondary battery increases due to high-rate deterioration caused by charging and discharging a large current, for example. In other words, the charging device according to the present disclosure can effectively charge the secondary battery. The following is a specific description.

[0013] 1, the charging system 1 includes a charging device 10 and a secondary battery 20 to be charged. The secondary battery 20 is a chargeable and dischargeable battery, such as a lithium ion battery.

[0014] The charging device 10 is a device that charges a secondary battery 20. Specifically, the charging device 10 includes a calculation unit 11, a first determination unit 12, a second determination unit 13, a third determination unit 14, and a charge limiting unit 15.

[0015] The calculation unit 11 calculates a degradation integrated value (ΣD) representing the degradation state of the secondary battery 20. Here, the degradation state of the secondary battery 20 means the degree of increase in the resistance value of the internal resistance of the secondary battery 20. In general, the more the secondary battery 20 deteriorates with age, the higher the resistance value of the secondary battery 20 becomes. In particular, the resistance value of the secondary battery 20 increases further due to high-rate deterioration caused by charging and discharging a large current. Note that a larger degradation integrated value indicates a higher resistance value of the secondary battery 20, and a smaller degradation integrated value indicates a lower resistance value of the secondary battery 20.

[0016] The first determination unit 12 determines whether or not the deterioration integrated value is equal to or greater than a first threshold value (threshold value of the deterioration integrated value). In other words, the first determination unit 12 determines whether or not the resistance value of the secondary battery 20 is equal to or greater than a predetermined value.

[0017] The second determination unit 13 monitors the current flowing through the secondary battery 20 during charging. Specifically, when the first determination unit 12 determines that the deterioration integrated value is equal to or greater than the first threshold, the second determination unit 13 determines (monitors) whether or not the value of the current flowing through the secondary battery 20 during charging is equal to or greater than a second threshold (lower limit of unacceptable current).

[0018] The third determination unit 14 monitors the voltage applied to the secondary battery 20 during charging. Specifically, when the first determination unit 12 determines that the deterioration integrated value is less than the first threshold, the third determination unit 14 determines (monitors) whether or not the value of the voltage applied to the secondary battery 20 during charging is equal to or greater than a third threshold (lower limit of unacceptable voltage).

[0019] The charge limiting unit 15 limits charging of the secondary battery 20 based on the determination result of the second determination unit 13 and the determination result of the third determination unit .

[0020] For example, when the accumulated deterioration value is equal to or greater than the first threshold value and the value of the current flowing through the secondary battery 20 during charging is determined to be equal to or greater than the second threshold value, the charging limiting unit 15 limits the charging of the secondary battery 20 so that the value of the current flowing through the secondary battery 20 during charging becomes less than the second threshold value.

[0021] In addition, when the accumulated deterioration value is less than the first threshold value and the value of the voltage applied to the secondary battery 20 during charging is determined to be equal to or greater than the third threshold value, the charging limiting unit 15 limits the charging of the secondary battery 20 so that the value of the voltage applied to the secondary battery 20 during charging is less than the third threshold value.

[0022] Here, if the resistance value of the secondary battery 20 increases significantly due to high-rate degradation caused by charging and discharging a large current, the charge limitation based on the voltage applied to the secondary battery 20 during charging will excessively limit the current flowing through the secondary battery 20 during charging, and the actual charge amount will be less than the chargeable amount at which Li is not precipitated on the negative electrode of the secondary battery 20.

[0023] Therefore, when the resistance value of the secondary battery 20 has increased significantly due to high-rate degradation resulting from charging and discharging a large current (specifically, when the accumulated degradation value is equal to or greater than the first threshold value), the charge limiting unit 15 limits the charging of the secondary battery 20 based on the current flowing through the secondary battery 20 during charging, not based on the voltage applied to the secondary battery 20 during charging. This allows the charging device 10 to prevent excessive restriction of the current flowing through the secondary battery 20 during charging, and therefore allows the secondary battery 20 to be charged effectively.

[0024] Next, the operation of the charging device 10 will be described with reference to Fig. 2. Fig. 2 is a flowchart showing the operation of the charging device 10.

[0025] First, the charging device 10 calculates a deterioration integrated value (ΣD) representing the deterioration state of the secondary battery 20 to be charged (step S101). Specifically, the charging device 10 calculates a resistance value of the secondary battery 20 to be charged.

[0026] After that, the charging device 10 determines whether or not the deterioration integrated value is equal to or greater than a first threshold value (step S102).

[0027] For example, if the deterioration integrated value is less than the first threshold value (NO in step S102), that is, if the resistance value of the secondary battery 20 is relatively small, the charging device 10 monitors the voltage applied to the secondary battery 20 during charging (step S103).

[0028] Specifically, the charging device 10 determines (monitors) whether or not the value of the voltage applied to the secondary battery 20 being charged is equal to or greater than a third threshold (step S104). For example, if the value of the voltage applied to the secondary battery 20 being charged is less than the third threshold (YES in step S104), that is, if the value of the voltage applied to the secondary battery 20 being charged is within the allowable range, the charging device 10 does not limit the charging of the secondary battery 20. On the other hand, if the value of the voltage applied to the secondary battery 20 being charged is equal to or greater than the third threshold (YES in step S104), that is, if the value of the voltage applied to the secondary battery 20 being charged is outside the allowable range, the charging device 10 limits the charging of the secondary battery 20 so that the value of the voltage applied to the secondary battery 20 being charged falls within the allowable range (step S105).

[0029] Furthermore, if the deterioration integrated value is equal to or greater than the first threshold value (YES in step S102), that is, if the resistance value of the secondary battery 20 is relatively large due to high-rate deterioration or the like, the charging device 10 monitors the current flowing through the secondary battery 20 during charging (step S106).

[0030] Specifically, the charging device 10 determines (monitors) whether or not the value of the current flowing through the secondary battery 20 being charged is equal to or greater than a second threshold (step S107). For example, if the value of the current flowing through the secondary battery 20 being charged is less than the second threshold (NO in step S107), that is, if the value of the current flowing through the secondary battery being charged is within the allowable range, the charging device 10 does not limit the charging of the secondary battery 20. On the other hand, if the value of the current flowing through the secondary battery 20 being charged is equal to or greater than the second threshold (YES in step S107), that is, if the value of the current flowing through the secondary battery 20 being charged is outside the allowable range, the charging device 10 limits the charging of the secondary battery 20 so that the value of the current flowing through the secondary battery 20 being charged falls within the allowable range (step S108).

[0031] Thereafter, if charging of the secondary battery 20 is not completed (NO in step S109), the charging device 10 repeats the processes of steps S101 to S109, and if charging of the secondary battery 20 is completed (YES in step S109), the charging process ends.

[0032] In this way, when the internal resistance of the secondary battery 20 increases significantly due to, for example, high-rate degradation caused by charging and discharging a large current, the charging device 10 according to the present disclosure limits the charging of the secondary battery 20 based on the current flowing through the secondary battery 20 during charging. This allows the charging device 10 according to the present disclosure to prevent excessive limiting of the current flowing through the secondary battery 20 during charging, thereby enabling the secondary battery to be charged effectively.

[0033] In addition, in the present disclosure, a part or all of the processing of the charging device 10 can be realized by causing a CPU (Central Processing Unit) to execute a computer program.

[0034] The above-mentioned program includes a set of instructions (or software code) for making the computer perform one or more functions described in the embodiment when the program is loaded into the computer. The program may be stored in a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, the computer-readable medium or the tangible storage medium includes a random-access memory (RAM), a read-only memory (ROM), a flash memory, a solid-state drive (SSD) or other memory technology, a CD-ROM, a digital versatile disc (DVD), a Blu-ray® disk or other optical disk storage, a magnetic cassette, a magnetic tape, a magnetic disk storage or other magnetic storage device. The program may be transmitted on a transitory computer-readable medium or a communication medium. By way of example and not limitation, the transitory computer-readable medium or the communication medium includes an electrical, optical, acoustic, or other form of propagating signal. [Explanation of symbols]

[0035] 1 Charging System 10 Charging device 11 Calculation section 12 1st Judgment Section 13 Second Judgment Section 14 Third Judgment Section 15 Charging Limiting Unit 20 Secondary battery

Claims

1. A charging device for charging a secondary battery, A calculation unit that calculates a deterioration integrated value that represents a deterioration state of the secondary battery; a first determination unit that determines whether the deterioration integrated value is equal to or greater than a first threshold; a second determination unit that determines whether a value of a current flowing through the secondary battery during charging is equal to or greater than a second threshold when the deterioration integrated value is equal to or greater than a first threshold; a third determination unit that determines whether a value of a voltage applied to the secondary battery during charging is equal to or greater than a third threshold when the deterioration integrated value is less than a first threshold; a charge limiting unit that limits charging of the secondary battery when the deterioration integrated value is equal to or greater than a first threshold and a value of a current flowing through the secondary battery during charging is determined to be equal to or greater than a second threshold, or when the deterioration integrated value is less than the first threshold and a value of a voltage applied to the secondary battery during charging is determined to be equal to or greater than a third threshold; A charging device comprising:

2. A larger deterioration integrated value indicates a higher resistance value of the secondary battery, and a smaller deterioration integrated value indicates a lower resistance value of the secondary battery. The charging device according to claim 1 .

3. when the deterioration integrated value is less than the first threshold and the value of the current flowing through the secondary battery during charging is determined to be greater than or equal to a second threshold, the charge limiting unit limits the charging of the secondary battery so that the value of the current flowing through the secondary battery during charging is less than the second threshold; when the deterioration integrated value is less than the first threshold and the value of the voltage applied to the secondary battery during charging is determined to be greater than or equal to a third threshold, the charge limiting unit limits the charging of the secondary battery so that the value of the voltage applied to the secondary battery during charging is less than the third threshold. The charging device according to claim 1 .

4. A charging control method for a charging device that charges a secondary battery, comprising: Calculating an integrated deterioration value representing a deterioration state of the secondary battery; determining whether the deterioration integrated value is equal to or greater than a first threshold value; When the deterioration integrated value is equal to or greater than a first threshold, determining whether or not a value of a current flowing through the secondary battery during charging is equal to or greater than a second threshold; When the deterioration integrated value is less than a first threshold, determining whether or not a value of a voltage applied to the secondary battery during charging is equal to or greater than a third threshold; when the deterioration integrated value is equal to or greater than a first threshold and a value of a current flowing through the secondary battery during charging is determined to be equal to or greater than a second threshold, or when the deterioration integrated value is less than the first threshold and a value of a voltage applied to the secondary battery during charging is determined to be equal to or greater than a third threshold, restricting charging of the secondary battery. Charging control method.

5. A control program for causing a computer to execute a charging control process in a charging device that charges a secondary battery, comprising: A process of calculating a deterioration integrated value representing a deterioration state of the secondary battery; A process of determining whether the deterioration integrated value is equal to or greater than a first threshold value; a process of determining whether or not a value of a current flowing through the secondary battery during charging is equal to or greater than a second threshold value when the deterioration integrated value is equal to or greater than a first threshold value; a process of determining whether or not a value of a voltage applied to the secondary battery during charging is equal to or greater than a third threshold value when the deterioration integrated value is less than a first threshold value; a process of limiting charging of the secondary battery when the deterioration integrated value is equal to or greater than a first threshold and a value of a current flowing through the secondary battery during charging is determined to be equal to or greater than a second threshold, or when the deterioration integrated value is less than the first threshold and a value of a voltage applied to the secondary battery during charging is determined to be equal to or greater than a third threshold; A control program that causes a computer to execute the above.

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