Charging control device

Abstract

To provide a charge control device which suppresses extension of a charge time of a storage battery.SOLUTION: A charge control device is mounted on a vehicle to which external power for charging of a storage battery is supplied from an external power source. The charge control device comprises an acquisition unit, an arithmetic unit, and an output unit. The acquisition unit acquires a detection result of a physical quantity sensor for detecting a physical quantity relating to charging the storage battery. In a case where a charging amount of the storage battery is equal to or more than a target charging amount and a difference between a target value of the physical quantity and the detection result is lower than a predetermined value, the arithmetic unit changes the target value of the physical quantity. The output unit outputs to the external power source an instruction signal including an external power control instruction based on the target value.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The disclosure described herein relates to a charge control device that controls charging of a storage battery. [Background technology]

[0002] As shown in Patent Document 1, a charging system is known that includes a vehicle equipped with a battery and an ECU, and a charger that charges the battery. The ECU changes a command value that is output to the charger. The ECU detects the reaction time of the charger to the change in the command value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-124033 A Summary of the Invention [Problem to be solved by the invention]

[0004] The ECU of the charging system described in Patent Document 1 sets a margin to prevent overcharging based on the detected reaction time. The ECU determines a command value related to the charging of the battery after the margin is set based on this margin. Because of the determination of such a command value, there is a risk that the charging time of the battery (storage battery) will be excessively extended depending on the reaction time value used to determine the margin.

[0005] An object of the present disclosure is to provide a charge control device that suppresses extension of the charging time of a storage battery. [Means for solving the problem]

[0006] A charging control device according to an aspect of the present disclosure includes: an acquisition unit (11) that acquires a detection result of a physical quantity sensor (50) that detects a physical quantity related to charging of a storage battery (20) mounted on a vehicle by external power output from an external power source (200); a calculation unit (13) that changes a target value of the physical quantity when the charge amount of the storage battery is equal to or greater than a target charge amount and a difference between the target value of the physical quantity and a detection result is lower than a predetermined value; The power supply control device further includes an output unit (14) that outputs, to the external power supply, an instruction signal including an instruction to control the external power based on the target value of the physical quantity.

[0007] According to this, the external power is controlled based on the actual dynamic response of the external power source (200) when the charge amount of the storage battery (20) is equal to or greater than the target charge amount, and therefore, the extension of the charging time of the storage battery (20) is suppressed compared to, for example, a configuration in which the external power is controlled based on a temporary response of the external power source (200).

[0008] It should be noted that the reference numbers in parentheses above merely indicate the corresponding relationship with the configurations described in the embodiments described below, and do not in any way limit the technical scope. [Brief description of the drawings]

[0009] [Figure 1] 1 is a block diagram for explaining a charging control system mounted on an electric vehicle. [Diagram 2] 5 is a timing chart for explaining changes over time in a closed circuit voltage, an actual current, and a target current when external power is supplied; [Diagram 3] 4 is a flowchart for explaining a rapid charging process. [Figure 4] 4 is a flowchart for explaining a full charge process. [Diagram 5] 10 is a flowchart illustrating a modified example of the full charge process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, the same reference numerals may be used to designate parts corresponding to matters described in the preceding embodiment, and duplicated descriptions may be omitted. In each embodiment, when only a part of the configuration is described, the other embodiment described previously may be applied to the other parts of the configuration.

[0011] It is possible to combine parts of each embodiment that are specifically indicated as being possible to combine with each other. In addition, even if it is not specifically indicated that the combination is possible, it is also possible to partially combine embodiments with each other, embodiments with variations, and variations with each other, as long as there is no particular problem with the combination.

[0012] (First embodiment) A charging control system 100 will be described with reference to Figures 1 to 4. This charging control system 100 is mounted on an electrically powered vehicle such as an electric vehicle or a hybrid vehicle.

[0013] A charging stand 200 located outside the electric vehicle is connected to this charging control system 100. This allows external DC power to be supplied from the charging stand 200 to the charging control system 100. In Fig. 1, the boundary between the electric vehicle and the outside is indicated by a dashed line. The charging stand 200 corresponds to an external power source.

[0014] The charging control system 100 includes a charging control device 10, a storage battery 20, a charger 30, an in-vehicle device 40, and a physical quantity sensor 50. The storage battery 20 of the charging control system 100 is charged by external power supplied from a charging stand 200. In the drawings, the storage battery 20 is denoted as SB, the charger 30 is denoted as BC, the in-vehicle device 40 is denoted as VM, and the charging stand 200 is denoted as CS.

[0015] The charging control device 10 is an EVECU. EV is an abbreviation for Electric vehicle. ECU is an abbreviation for Electronic Control Unit. The charging control device 10 controls the driving of the charging stand 200. In this way, the charging control device 10 controls the charging of the storage battery 20.

[0016] The storage battery 20 includes a plurality of secondary batteries connected in series. For example, lithium ion batteries can be used as the secondary batteries. The output power of the storage battery 20 is input to the charger 30 and the in-vehicle device 40.

[0017] The charger 30 is a power conversion device including an inverter. The charger 30 converts the DC output power input from the storage battery 20 into AC power. This AC power is supplied to a motor (not shown). This motor is connected to the running wheels via an axle. The charger 30 converts the AC power generated by the motor into DC power. This DC power is supplied to the storage battery 20.

[0018] The in-vehicle device 40 is an electric power load such as an air conditioner. When the charging stand 200 is connected to the electric vehicle, the electric vehicle is in a stopped state. In this case, the in-vehicle accessories that operate at a low voltage, such as the air conditioner, can be switched between a driven state and a non-driven state.

[0019] The physical quantity sensor 50 detects a physical quantity related to the charging of the storage battery 20. The physical quantity sensor 50 has a voltage sensor 51 and a current sensor 52. The voltage sensor 51 detects the voltage output from the storage battery 20. The current sensor 52 detects the current flowing through the storage battery 20. These voltages and currents change when the storage battery 20 is being charged. The detection results of the voltage sensor 51 and the current sensor 52 are input to the charging control device 10. In the drawings, the voltage sensor 51 is denoted as VS, and the current sensor 52 is denoted as CS.

[0020] <OCV、CCV、SOC> The storage battery 20 has an internal resistance. Therefore, there is a difference between the actual output voltage according to the SOC of the storage battery 20 and the output voltage detected by the voltage sensor 51, the difference being a voltage drop according to the internal resistance and the current flowing through the storage battery 20.

[0021] In the following, where necessary, the actual output voltage according to the SOC of storage battery 20 will be referred to as open circuit voltage OCV. The output voltage detected by voltage sensor 51 will be referred to as closed circuit voltage CCV. The resistance within storage battery 20 will be referred to as internal resistance R, and the current that actually flows through storage battery 20 will be referred to as actual current I. OCV is an abbreviation for Open Circuit Voltage. CCV is an abbreviation for Closed Circuit Voltage. SOC is an abbreviation for State Of Charge. SOC corresponds to the charge amount.

[0022] The relationship between the closed circuit voltage CCV and the open circuit voltage OCV is expressed as CCV = OCV ± I × R. When the storage battery 20 is discharging, CCV = OCV - I × R. When the storage battery 20 is charging, CCV = OCV + I × R. In this way, there is a difference of the voltage drop I × R between the closed circuit voltage CCV and the open circuit voltage OCV, not only when the storage battery 20 is discharging or charging.

[0023] The closed circuit voltage CCV is detected by the voltage sensor 51, and this closed circuit voltage CCV is higher than the open circuit voltage OCV by a voltage drop I×R when the storage battery 20 is being charged. The actual current I included in the voltage drop can be detected by the current sensor 52, but the internal resistance R of the storage battery 20 varies depending on temperature and aging. This makes it difficult to calculate the voltage drop I×R with high accuracy. It makes it difficult to determine the SOC of the storage battery 20 with high accuracy based on the open circuit voltage OCV.

[0024] Therefore, as will be described in detail later, the charge control device 10 first charges the storage battery 20 until the closed circuit voltage CCV reaches the target voltage. After that, the charge control device 10 gradually reduces the actual current I flowing through the storage battery 20 while maintaining the closed circuit voltage CCV at the target voltage. In this way, the difference between the closed circuit voltage CCV and the open circuit voltage OCV becomes as small as possible. The SOC of the storage battery 20 becomes as close as possible to the SOC when the circuit voltage OCV is at the target voltage.

[0025] <Charging control device> As shown in Fig. 1, the charge control device 10 has an acquisition unit 11, a storage unit 12, a calculation unit 13, and an output unit 14. In the drawing, the acquisition unit 11 is written as FS. The storage unit 12 is written as MU. The calculation unit 13 is written as OP. The output unit 14 is written as OS.

[0026] The acquisition unit 11 receives various information from the physical quantity sensor 50 and various other ECUs and sensors (not shown). That is, the closed circuit voltage CCV and the actual current I are input to the acquisition unit 11 from the physical quantity sensor 50. The acquisition unit 11 receives various information such as battery information including the capacity of the storage battery 20 and vehicle information including the driving state of the electric vehicle from various ECUs and sensors. In the drawings, the battery information is represented as BI. The vehicle information is represented as VI.

[0027] The storage unit 12 is a non-transient substantial storage medium that non-temporarily stores a program that can be read by a computer or a processor. The storage unit 12 stores various information acquired by the acquisition unit 11 and the processing results of the calculation unit 13. The storage unit 12 also stores in advance a judgment value for the calculation unit 13 to perform calculation processing.

[0028] The calculation unit 13 includes a processor. The calculation unit 13 performs various calculation processes based on the information stored in the memory unit 12. The calculation unit 13 generates an instruction signal that instructs the operation of the charging stand 200 based on the information stored in the memory unit 12. The instruction signal includes a target voltage that determines the value of the voltage included in the external power output from the charging stand 200 to the storage battery 20, and a target current that determines the amount of current included in the external power. The target current corresponds to a target value of a physical quantity.

[0029] The target voltage is determined according to the capacity of the storage battery 20 mounted on the electric vehicle. The target voltage is determined based on the OCV when the SOC of the storage battery 20 is fully charged. When the closed circuit voltage CCV reaches the target voltage through rapid charging, the SOC of the storage battery 20 is expected to be approximately 80%. The SOC of the storage battery 20 when the closed circuit voltage CCV reaches the target voltage through this rapid charging corresponds to the target charge amount.

[0030] The output unit 14 outputs various electric signals including the results of the calculations performed by the calculation unit 13. The output unit 14 outputs an instruction signal generated by the calculation unit 13 to the charging stand 200. The charging stand 200 outputs external power based on the target voltage and target current included in the instruction signal to the storage battery 20.

[0031] <Charging process> Next, the charging process executed by the calculation unit 13 will be described with reference to Fig. 2 to Fig. 4. The charging process includes a quick charge process and a full charge process. When the charging stand 200 is electrically connected to the electric vehicle, the calculation unit 13 executes the quick charge process. After this, the calculation unit 13 executes the full charge process.

[0032] First, the quick charge process and full charge process will be outlined with reference to Figure 2. The vertical axis of Figure 2 indicates arbitrary units, and the horizontal axis indicates time. The arbitrary units are denoted as au, and the time as t. The closed circuit voltage CCV and actual current I of the storage battery 20 are indicated by solid lines. The target voltage is denoted as TV, and the target current is denoted as TC. These target voltages and target currents are indicated by dashed and dotted lines.

[0033] At time t0 in Fig. 2, the charging stand 200 is not electrically connected to the electric vehicle. Also, no current flows through the storage battery 20. Therefore, the target voltage, target current, and actual current I are all zero. Since charge is stored in the storage battery 20, the closed circuit voltage CCV is finite.

[0034] When time t0 passes to time t1, the charging cable of charging stand 200 is connected to the electric vehicle. At this time, calculation unit 13 starts executing the rapid charging process. Calculation unit 13 outputs an instruction signal including a target voltage and a target current as control instructions to charging stand 200.

[0035] In the rapid charging process, the target voltage and the target current are almost constant. In order to realize rapid charging, the target current in the rapid charging process is set to a high value. This target current is determined depending on how fast the storage battery 20 is to be rapidly charged. In the following, the target current during the rapid charging process is referred to as an initial target current. This initial target current is included in the instruction signal output from the charging control device 10 to the charging stand 200 at time t1 shown in FIG. 2.

[0036] Although the closed circuit voltage CCV varies depending on the resistance of the storage battery 20, the target voltage in the quick charge process is set to a value that indicates that the SOC of the storage battery 20 is about 80% when the closed circuit voltage CCV is the target voltage. In this embodiment, the target voltage in the quick charge process is equal to the target voltage in the full charge process. In terms of the open circuit voltage OCV, the target voltage in the full charge process is set to a value that indicates that the SOC of the storage battery 20 is about 100% when the open circuit voltage OCV is the target voltage. Note that a value of about 100% SOC is a value lower than the SOC of the storage battery 20 in an overcharged state. After time t1, this target voltage is included in the instruction signal output from the charging control device 10 to the charging stand 200.

[0037] When time elapses from time t1 to time t2, the target current becomes the initial target current. Following this, the amount of external power supplied from the charging stand 200 to the storage battery 20 increases rapidly. The actual current I flowing through the storage battery 20 becomes the initial target current.

[0038] Such supply of external power increases the SOC of the storage battery 20. Accordingly, the closed circuit voltage CCV of the storage battery 20 increases.

[0039] At time t3, the closed circuit voltage CCV exceeds the target voltage. When the calculation unit 13 detects this, it switches from the quick charge process to the full charge process. The calculation unit 13 calculates a target current that is lower than the initial target current. The calculation unit 13 then outputs an instruction signal including this target current to the charging stand 200. Hereinafter, this target current will be referred to as the first target current.

[0040] When time elapses from time t3 to time t4, the target current becomes the first target current. However, the actual current I does not decrease due to a response delay of the charging station 200. The closed circuit voltage CCV continues to increase due to an increase in the SOC of the storage battery 20.

[0041] At time t5, the amount of current of the external power output from the charging station 200 becomes the amount of current based on the first target current. As a result, the actual current I starts to decrease. Accordingly, the closed circuit voltage CCV also starts to decrease.

[0042] When the time elapses from time t5 to time t6, the closing voltage CCV falls below the target voltage. When the calculation unit 13 detects this, it maintains the target current at the first target current. As a result, the actual current I also becomes constant at the first target current.

[0043] After time t5, even if the closed circuit voltage CCV temporarily drops due to a decrease in the amount of current supplied, the SOC of the storage battery 20 continues to improve. Therefore, the closed circuit voltage CCV rises again as the SOC of the storage battery 20 improves.

[0044] From time t6 to time t7, the closed circuit voltage CCV again exceeds the target voltage. When the calculation unit 13 detects this, it sets the target current to a second target current that is lower than the first target current that was set up until that point. The calculation unit 13 outputs an instruction signal including this second target current to the charging stand 200.

[0045] After that, at time t8, the actual current I starts to decrease due to a response of the charging stand 200 based on the input second target current. Accordingly, the closed circuit voltage CCV starts to decrease.

[0046] When the time elapses from time t8 to time t9, the closing voltage CCV falls below the target voltage. When the calculation unit 13 detects this, it maintains the target current at the second target current. As a result, the actual current I also becomes constant at the second target current.

[0047] Although illustrations and explanations are omitted from here on, the target current is gradually reduced in accordance with the actual dynamic response of the charging stand 200 while continuing to charge the storage battery 20 by maintaining the closed circuit voltage CCV near the target voltage. In this way, the difference between the closed circuit voltage CCV detected by the voltage sensor 51 and the open circuit voltage OCV corresponding to the actual SOC of the storage battery 20 is reduced as much as possible. The SOC of the storage battery 20 is brought as close as possible to the SOC when the open circuit voltage OCV is the target voltage.

[0048] <Quick charging process> Next, the rapid charging process will be described with reference to Fig. 3. When the charging cable of the charging stand 200 is connected to the electric vehicle, the calculation unit 13 starts executing the rapid charging process.

[0049] In step S10, the calculation unit 13 outputs an instruction signal including a target voltage and an initial target current to the charging stand 200. The target voltage and initial target current may be calculated based on the performance of the storage battery 20, the stored SOC, etc., when performing this quick charging process. Alternatively, the target voltage and initial target current may be stored in advance in the storage unit 12. After outputting the instruction signal to the charging stand 200, the calculation unit 13 proceeds to step S20.

[0050] In step S20, the calculation unit 13 acquires the detection result of the physical quantity sensor 50 input to the acquisition unit 11. That is, the calculation unit 13 acquires the closed circuit voltage CCV and the actual current I of the storage battery 20. After this, the calculation unit 13 proceeds to step S30.

[0051] When the process proceeds to step S30, the calculation unit 13 compares the closing voltage CCV acquired in step S20 with the target voltage included in the instruction signal in step S10. If the closing voltage CCV is equal to or higher than the target voltage, the calculation unit 13 proceeds to step S40. If the closing voltage CCV is lower than the target voltage, the calculation unit 13 returns to step S10. The calculation unit 13 repeats steps S10 to S30 until the closing voltage CCV becomes equal to or higher than the target voltage.

[0052] When the process proceeds to step S40, the calculation unit 13 determines that the quick charge is completed. Then, the calculation unit 13 ends the quick charge process and starts the full charge process. This quick charge process corresponds to the process from time t1 to time t3 in the example shown in Fig. 2. The full charge process described next corresponds to the process after time t3.

[0053] <Full charge process> 4, the calculation unit 13 acquires the closed circuit voltage CCV and the actual current I of the storage battery 20. After that, the calculation unit 13 proceeds to step S120.

[0054] When the process proceeds to step S120, the calculation unit 13 compares the closing voltage CCV acquired in step S110 with the target voltage included in the command signal being output. If the closing voltage CCV is equal to or higher than the target voltage, the calculation unit 13 proceeds to step S130. If the closing voltage CCV is lower than the target voltage, the calculation unit 13 returns to step S110. The calculation unit 13 repeats steps S110 to S120 until the closing voltage CCV becomes equal to or higher than the target voltage.

[0055] In step S130, the calculation unit 13 calculates a difference value by subtracting the target current from the actual current I acquired in step S110. The calculation unit 13 then determines whether this difference value is lower than a predetermined current. If the difference value is lower than the predetermined current, the calculation unit 13 allows the target current to be reduced, and the process proceeds to step S140. If the difference value is equal to or greater than the predetermined current, the calculation unit 13 prohibits the target current from being reduced, and the process proceeds to step S150. This prohibition of the target current from being reduced corresponds to leaving the target value of the physical quantity unchanged.

[0056] The predetermined current is determined based on the performance of the charging stand 200, the detection accuracy of the current sensor 52, and the like. The performance of the charging stand 200 includes the responsiveness of the charging stand 200, the stability of the time change of the current and voltage supplied from the charging stand 200, and the like. For that reason, the calculation unit 13 may calculate the performance of the charging stand 200, for example, during quick charging, and determine the predetermined current based on the calculation result. Alternatively, the designer of the charging control device 10 may calculate in advance the predetermined current according to the performance of various charging stands 200 connected to the electric vehicle, and store it in the storage unit 12. The predetermined current corresponds to the predetermined value. The actual current I corresponds to the physical quantity.

[0057] When the quick charge process is ended and the full charge process is started, the closed circuit voltage CCV is equal to or higher than the target voltage. At the same time, the difference value is lower than the predetermined current. Therefore, when the full charge process is started, the calculation unit 13 proceeds from step S120 to step S130. The calculation unit 13 proceeds from step S130 to step S140.

[0058] When the process proceeds to step S140, the calculation unit 13 reduces the target current included in the instruction signal output to the charging stand 200. Then, the calculation unit 13 proceeds to step S160.

[0059] In step S160, the calculation unit 13 determines whether the actual current I is lower than the determination current. If the actual current I is lower than the determination current, the calculation unit 13 ends the full charge process. The calculation unit 13 cuts off the electrical connection between the charging stand 200 and the storage battery 20, and ends the charging of the storage battery 20. If the actual current I is equal to or greater than the determination current, the calculation unit 13 determines that the storage battery 20 has not yet reached full charge. In this case, the calculation unit 13 returns to step S110.

[0060] The determination current is a determination value for determining whether or not the difference between the closed circuit voltage CCV detected by the voltage sensor 51 and the open circuit voltage OCV according to the actual SOC of the storage battery 20 has become as small as possible. This determination current is a finite value close to 0 A. The value of the determination current can be appropriately determined by the manufacturer of the electric vehicle or the user of the electric vehicle.

[0061] When the quick charge process is ended and the full charge process is started, the actual current I used for the determination in step S160 does not reflect the decrease in the target current in step S140. Therefore, the calculation unit 13 returns from step S160 to step S110. Then, the calculation unit 13 executes the processes from step S110 onwards again.

[0062] Although calculation unit 13 acquires actual current I in step S110, the decrease in the target current in step S140 is not necessarily reflected in this actual current I. This is because there is a delay in the response of charging stand 200 to a change in the target current.

[0063] Due to this response delay, the closing voltage CCV and the actual current I detected in step S110 immediately after the target current is lowered are almost the same as the closing voltage CCV and the actual current I detected in step S110 before the target current is lowered.

[0064] Therefore, unless the actual current I follows the target current as a result of the charging stand 200 responding to the lowered target current and the difference between the two becomes smaller than the predetermined current, the calculation unit 13 proceeds from step S130 to step S150.

[0065] When the process proceeds to step S150, the calculation unit 13 starts measuring the standby time. The measurement of the standby time starts when it is determined for the first time in step S130 that the difference value is equal to or greater than the predetermined current. The measurement of the standby time starts when the reduction of the target current is prohibited. After this, the calculation unit 13 proceeds to step S170.

[0066] In step S170, the calculation unit 13 determines whether the standby time has reached or exceeded the expected response time. This expected response time is the time during which a reliable response is expected at the charging stand 200, regardless of the type of charging stand 200. Note that the calculation unit 13 may calculate the expected response time of the charging stand 200 connected to the electric vehicle, for example, during quick charging.

[0067] If the standby time is equal to or longer than the expected response time, the calculation unit 13 determines that the instruction to the charging station 200 to reduce the target current is delayed, and proceeds to step S180. If the standby time is shorter than the expected response time, the calculation unit 13 returns to step S110. At this time, the calculation unit 13 repeats steps S110 to S120, or steps S110 to S130, S150, and S170. The calculation unit 13 enters a standby state.

[0068] If the charging stand 200 responds normally to the reduction in the target current while the calculation unit 13 is in the standby state in this manner, the actual current I changes to follow the target current. The actual current I corresponding to the reduced target current is detected in step S110. When the difference between the actual current I and the target current becomes smaller than the predetermined current, the calculation unit 13 proceeds from step S130 to step S140. In this step S140, the calculation unit 13 reduces the target current again. By executing the process described above, the target current is gradually reduced. Note that the calculation unit 13 resets the standby time when reducing the target current again.

[0069] When the process proceeds to step S180 because the standby time has become equal to or longer than the expected response time, the calculation unit 13 forcibly reduces the target current included in the instruction signal that is being continuously output to the charging stand 200. After this, the calculation unit 13 proceeds to step S160.

[0070] The amount of reduction in the target current in step S180 may be the same as or different from the amount of reduction in the target current in step S140. In this embodiment, the amount of reduction in the target current in step S180 is set lower than the amount of reduction in the target current in step S140. Note that the forced reduction in the target current in step S180 is not reflected in the timing chart shown in FIG.

[0071] <Action and effect> As described above, when the closed circuit voltage CCV of the storage battery 20 becomes equal to or higher than the target voltage, and the SOC of the storage battery 20 becomes equal to or higher than the target SOC during rapid charging, the calculation unit 13 executes the full charge process.

[0072] In the full charge process, the calculation unit 13 changes (reduces) the target current included in the instruction signal output to the charging stand 200. If the difference between the actual current I and the target current subsequently becomes lower than the predetermined current, the calculation unit 13 determines that the charging stand 200 has reduced the amount of current included in the external power supplied to the storage battery 20 in response to the reduction in the target current. Each time this determination is made, the calculation unit 13 gradually reduces the target current.

[0073] In this way, the calculation unit 13 reduces the target current during full charge processing based on the actual dynamic response of the charging stand 200 during full charge processing. Therefore, compared to a configuration in which the target current during full charge processing is reduced based on, for example, a temporary response of the charging stand 200 prior to the full charge processing, the target current during full charge processing is prevented from decreasing too quickly. As a result, the charging time of the storage battery 20 during full charge processing is prevented from being extended. In addition, the voltage state of the storage battery 20 during full charge processing is stabilized.

[0074] If the difference between the actual current I and the target current does not become equal to or less than the predetermined current even after the expected response time has elapsed after the calculation unit 13 has reduced the target current, the calculation unit 13 forcibly reduces the target current. This makes it possible to promote the response of the charging stand 200 and the reduction in the actual current I.

[0075] (Modification) In the present embodiment, an example has been shown in which the actual current I is used as the physical quantity for determining the responsiveness of the charging station 200. However, the closed circuit voltage CCV may also be used as the physical quantity for determining the responsiveness of the charging station 200.

[0076] In this modified example, the calculation unit 13 executes the full charge process shown in Fig. 5. In this full charge process, step S190 shown in Fig. 5 is executed instead of step S130 of the full charge process shown in Fig. 4.

[0077] In step S190, the calculation unit 13 detects a change over time in the closing voltage CCV based on the closing voltage CCV detected in the repeated step S110. This change over time in the closing voltage CCV is, for example, a value obtained by subtracting the closing voltage CCV at time t2 from the closing voltage CCV at time t3 shown in FIG.

[0078] If the response of the charging station 200 to the instruction signal is delayed, the time change of the closing voltage CCV remains large. However, if the charging station 200 responds to the instruction signal, the time change of the closing voltage CCV is expected to become small.

[0079] Therefore, if the time change in the closing voltage CCV is lower than a predetermined voltage, the calculation unit 13 determines that the actual current I is changing in accordance with the target current, and proceeds to step S140. If the time change in the closing voltage CCV is equal to or greater than the predetermined voltage, the calculation unit 13 determines that the actual current I is not changing in accordance with the target current, and proceeds to step S150.

[0080] The above-mentioned predetermined voltage is determined based on the performance of charging stand 200, the detection accuracy of voltage sensor 51, and the like, in the same manner as the predetermined current. In this modified example, the predetermined voltage corresponds to the predetermined value. The closed circuit voltage CCV corresponds to the physical quantity.

[0081] Although the present disclosure has been described based on the embodiment, it is understood that the present disclosure is not limited to the embodiment or structure. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, although various combinations and forms are shown in the present disclosure, other combinations and forms including only one element, more than one element, or less than one element are also within the scope and concept of the present disclosure. [Explanation of symbols]

[0082] 10...charging control device, 11...acquisition unit, 12...storage unit, 13...calculation unit, 14...output unit, 20...storage battery, 30...charger, 40...vehicle-mounted device, 50...physical quantity sensor, 51...voltage sensor, 52...current sensor, 100...charging control system, 200...charging stand

Claims

1. an acquisition unit (11) that acquires a detection result of a physical quantity sensor (50) that detects a physical quantity related to charging of a storage battery (20) mounted on a vehicle by external power output from an external power source (200); a calculation unit (13) that changes the target value of the physical quantity when the charge amount of the storage battery is equal to or greater than a target charge amount and a difference between the target value of the physical quantity and the detection result is lower than a predetermined value; an output unit (14) that outputs, to the external power supply, an instruction signal including an instruction to control the external power based on the target value of the physical quantity.

2. 2. The charging control device according to claim 1, wherein the calculation unit keeps the target value of the physical quantity unchanged when the charge amount of the storage battery is equal to or greater than the target charge amount and when a difference between the target value of the physical quantity and the detection result is equal to or greater than the predetermined value.

3. 3. The charging control device according to claim 2, wherein the calculation unit reduces the target value of the physical quantity when the charge amount of the storage battery is equal to or greater than the target charge amount and the time during which a value obtained by subtracting the detection result from the target value of the physical quantity is equal to or greater than the predetermined value exceeds an expected response time of the external power supply.

4. 4. The charging control device according to claim 2, wherein the calculation unit reduces the target value of the physical quantity when the charge amount of the storage battery is equal to or greater than the target charge amount and the difference between the target value of the physical quantity and the detection result is lower than the predetermined value.

5. 5. The charge control device according to claim 1, wherein the physical quantity is a current flowing through the storage battery.

6. 6. The charge control device according to claim 1, wherein the predetermined value is determined based on the performance of the external power supply.

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