Computer program for power supply, power supply system, and power supply method

Abstract

To provide a computer program for a power supply, a power supply system, and a power supply method capable of suppressing deterioration of a storage device.SOLUTION: A computer program for a power supply is programmed to make a computer execute: state acquisition processing for acquiring a capacity maintenance rate SH1 of a storage device 5 for a vehicle; range setting processing for setting an SOC range ΔSOC such that the SOC range ΔSOC which can be charged for the storage device 5 is expanded when the capacity maintenance rate SH1 is equal to or less than a predetermined reference maintenance rate SSH1 based on the capacity maintenance rate SH1 acquired in the state acquisition processing; and power supply processing for controlling a charging / discharging device 20 that supplies power to the storage device 5 such that an SOC of the storage device 5 is within the SOC range ΔSOC set in the range setting processing.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a computer program for power supply, a power supply system, and a power supply method. [Background technology]

[0002] For example, Patent Document 1 discloses a management device that manages the exchange of power between a power system and a secondary battery mounted on a vehicle. In this management device, a first threshold value related to the remaining performance of the secondary battery and a second threshold value indicating that the remaining performance is higher than the first threshold value are set. When the remaining performance of the secondary battery is equal to or greater than the first threshold value and less than the second threshold value, the charging rate of the secondary battery is controlled within a narrower range than when the remaining performance is equal to or greater than the second threshold value.

[0003] For example, Patent Document 2 discloses a battery control system including a storage battery that is connected to a power grid to charge and discharge power, and a control device that controls the charging and discharging of the storage battery. This battery control system is configured to sequentially shift to a control that suppresses the deterioration state of the storage battery when the usage time of the storage battery becomes long and the capacity maintenance rate of the storage battery becomes low. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-195208 A [Patent Document 2] JP 2020-162304 A Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, various techniques have been disclosed for suppressing deterioration of power storage devices such as secondary batteries and storage batteries. The inventors of the present application wish to suppress deterioration of the power storage device using a technique different from the techniques disclosed in Patent Documents 1 and 2. [Means for solving the problem]

[0006] The computer program for power supply proposed here causes a computer to execute a status acquisition process to acquire a capacity maintenance rate of a vehicle storage device, a range setting process to set a SOC range so that a chargeable SOC range for the storage device is wider when the capacity maintenance rate acquired in the status acquisition process is equal to or lower than a predetermined standard maintenance rate, and a power supply process to control a charging / discharging device that supplies power to the storage device so that the SOC of the storage device is within the SOC range set in the range setting process.

[0007] The power supply method proposed here includes a status acquisition process for acquiring a capacity maintenance rate of a vehicle power storage device, a range setting process for setting a SOC range so that a chargeable SOC range for the power storage device is widened when the capacity maintenance rate is lower than a predetermined reference maintenance rate based on the capacity maintenance rate acquired in the status acquisition process, and a power supply process for controlling a charging / discharging device that supplies power to the power storage device so that the SOC of the power storage device is within the SOC range set in the range setting process.

[0008] According to the proposed computer program for power supply and power supply method, when the capacity maintenance rate of the power storage device is higher than a reference maintenance rate, the SOC range is narrowed to suppress deterioration of the power storage device with a high capacity maintenance rate, and when the capacity maintenance rate of the power storage device is equal to or lower than the reference maintenance rate, the SOC range is widened to suppress deterioration of the power storage device with a low capacity maintenance rate that has been degraded. [Brief description of the drawings]

[0009] [Figure 1] 1 is a conceptual diagram showing a power supply system according to an embodiment. [Diagram 2] 1 is a block diagram showing a power supply system according to an embodiment; [Diagram 3] 4 is a flowchart showing a procedure for supplying electric power to the power storage device. [Figure 4] FIG. 1 is a graph showing the relationship between the capacity retention rate and the SOC range. [Diagram 5] FIG. 1 is a graph showing the relationship between the capacity retention rate and the SOC range. [Figure 6] FIG. 1 is a graph showing the relationship between the capacity retention rate and the SOC range. [Figure 7] FIG. 1 is a diagram showing the relationship between the elapsed time and the capacity maintenance rate in the high SOC range, the medium SOC range, and the low SOC range. [Figure 8] FIG. 13 is a diagram showing the relationship between the elapsed time and the rate of increase in resistance when the SOC range is a high SOC range, a medium SOC range, and a low SOC range. [Figure 9] 10 is a flowchart showing an example of a procedure for determining an upper limit SOC and a lower limit SOC of an SOC range. [Figure 10] FIG. 13 is a graph showing the relationship between outside air temperature and SOC range. [Figure 11] FIG. 13 is a diagram showing the relationship between expected mileage and SOC range. [Figure 12] FIG. 11 is a diagram showing the relationship between the capacity maintenance rate and the SOC range in a modified example. [Figure 13] FIG. 11 is a diagram showing the relationship between the capacity maintenance rate and the SOC range in a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the power supply system disclosed herein will be described with reference to the drawings. The embodiment described herein is, of course, not intended to limit the present invention in particular. The present invention is not limited to the embodiment described herein unless otherwise specified. Furthermore, the same reference numerals will be appropriately used for members and parts that perform the same function, and duplicated descriptions will be appropriately omitted.

[0011] Fig. 1 is a conceptual diagram showing a power supply system 10 according to the present embodiment. As shown in Fig. 1, the power supply system 10 according to the present embodiment is a system that supplies power to a power storage device 5. The power supply system 10 is a system that manages charging of the power storage device 5. However, the power supply system 10 may also manage discharging of the power storage device 5.

[0012] The power storage device 5 is capable of being charged and discharged. The type of the power storage device 5 is not particularly limited. For example, a secondary battery that can be repeatedly charged and discharged by the movement of charge carriers between a pair of electrodes (for example, a positive electrode and a negative electrode) via an electrolyte can be used as the power storage device 5. For example, a lithium ion secondary battery or a nickel-metal hydride battery can be used as the power storage device 5.

[0013] The power storage device 5 is for use in a vehicle, for example. In this embodiment, the power storage device 5 is mounted on an electric vehicle 6. The electric vehicle 6 includes vehicles that use electric power as an energy source, such as electric automobiles, hybrid vehicles, and plug-in hybrid vehicles. The electric vehicle 6 may be a four-wheeled vehicle or a two-wheeled vehicle. The electric vehicle 6 may be a bicycle.

[0014] In this embodiment, as shown in FIG. 1, a power supply system 10 includes a power source 15, a charging / discharging device 20, and a control device 30.

[0015] The power source 15 supplies power to the vehicle power storage device 5. The number of power sources 15 is not particularly limited, and may be one or more. The specific type of power source 15 is also not particularly limited. The power source 15 is, for example, various types of power generation facilities. The power generation type of the power generation facilities may be natural gas, coal, oil, atomic power, hydroelectric power, or renewable energy other than hydroelectric power. Examples of renewable energy include solar power, bio, wind power, and geothermal power. The owner (or owner organization) of the power source 15 may be a company such as an electric power company, or may be a household. In FIG. 1, a solar power generation facility is illustrated as the power source 15. The power source 15 includes a solar power generation facility owned by a company or a household.

[0016] The charging / discharging device 20 is a device that charges or discharges the power storage device 5 of the electric vehicle 6. Here, the charging / discharging device 20 is connected to the power source 15. The charging / discharging device 20 is a device that supplies power supplied from the power source 15 to the power storage device 5 and receives power from the power storage device 5. The number of charging / discharging devices 20 is not particularly limited, and may be one or more. The charging / discharging device 20 is installed in, for example, a charging / discharging spot 21. The charging / discharging spot 21 may be, for example, a parking lot in which the charging / discharging device 20 is installed. The parking lot of the charging / discharging spot 21 includes parking lots of stores that sell products, parking lots of stores that provide services such as beauty salons, parking lots of commercial facilities, and parking lots of residential buildings. The electric vehicle 6 equipped with the power storage device 5 is stopped in the parking lot of the charging / discharging spot 21 and connected to the charging / discharging device 20. With the charging / discharging device 20 connected to the electric vehicle 6, the charging / discharging device 20 supplies power to the power storage device 5, thereby charging the power storage device 5, or the power storage device 5 supplies power to the charging / discharging device 20, thereby discharging the power storage device 5. Although not shown in the figures, the charging / discharging device 20 may be provided with a power storage device for the charging / discharging device 20 for temporarily storing the power supplied from the power source 15.

[0017] The control device 30 is a device that performs control related to charging or discharging the power storage device 5 of the electric vehicle 6. The control device 30 mainly performs control to supply the power supplied from the power source 15 to the power storage device 5 from the charging / discharging device 20. The configuration of the control device 30 is not particularly limited. Here, the control device 30 is, for example, a microcomputer. The control device 30 includes, for example, an input / output interface, a CPU, a ROM, and a RAM. The control device 30 may be realized by a single computer, or may be realized by a plurality of computers working together.

[0018] The control device 30 is connected to the charging / discharging device 20 and the electric vehicle 6 so as to be able to communicate with them. In this embodiment, as shown in FIG. 1, the control device 30 is electrically connected to the charging / discharging device 20 and the electric vehicle 6 via the Internet 2. Here, the electric vehicle 6 and the power storage device 5 are connected so as to be able to communicate with each other, and the control device 30 is connected to the power storage device 5 so as to be able to communicate with each other via the electric vehicle 6. However, the control device 30 may be directly connected to the power storage device 5 so as to be able to communicate with each other. The control device 30 controls the charging / discharging device 20 to charge / discharge the power storage device 5. The control device 30 also controls the electric vehicle 6 and the power storage device 5, and is capable of acquiring information relating to the electric vehicle 6 and the power storage device 5 from the electric vehicle 6 and the power storage device 5.

[0019] In this embodiment, the power supply system 10 may be realized, for example, by a client-server system or by so-called cloud computing. As shown in Fig. 1, the control device 30 may be a server installed on a cloud and connected via the Internet 2. However, the control device 30 may be incorporated in the charging / discharging device 20.

[0020] Incidentally, the vehicle power storage device 5 deteriorates due to repeated charging and discharging. It is preferable to suppress the deterioration of the power storage device 5 as much as possible, and by suppressing the deterioration of the power storage device 5, the same power storage device 5 can be used for a long period of time. Therefore, in this embodiment, the power supply system 10 realizes suppression of the deterioration of the power storage device 5.

[0021] In this embodiment, the capacity maintenance rate of the power storage device 5 is acquired, and the SOC range of the power storage device 5 is set according to the capacity maintenance rate. Here, the capacity maintenance rate means SOH (State Of Health) and is an index indicating the deterioration state of the power storage device 5. The capacity maintenance rate is a ratio of the current full charge capacity when the initial full charge capacity of the power storage device 5 is set to 100%. The initial state of the power storage device 5 here means, for example, a new power storage device 5, and refers to the power storage device 5 at the time of shipment. The initial state of the power storage device 5 may also mean the time of final inspection before shipment. The full charge capacity means the amount of power charged to the power storage device 5 when the SOC of the power storage device 5 rises from 0% to 100%. It is presumed that the lower the capacity maintenance rate, the more deteriorated the power storage device 5 is. The SOC range means the range of the amount of power that can be charged to the power storage device 5. The SOC range is, for example, a range set between 0% and 100%. The inventors of the present application have studied various means for suppressing deterioration of the power storage device 5. As a result, the applicant of the present application found that it is possible to suppress the deterioration of the power storage device 5 by setting the SOC range narrower when the capacity maintenance rate of the power storage device 5 is high, i.e., when the power storage device 5 is not deteriorated, and by setting the SOC range wider when the capacity maintenance rate of the power storage device 5 is low, i.e., when the power storage device 5 is deteriorated. In this embodiment, "suppressing the deterioration of the power storage device 5" means suppressing the deterioration of the power storage device 5 to a degree that ensures the amount of power required by the user and does not reduce usability.

[0022] Fig. 2 is a block diagram showing the power supply system 10 according to the present embodiment. As shown in Fig. 2, the control device 30 of the power supply system 10 includes a storage unit 31, a state acquisition unit 33, a range setting unit 35, and a power supply unit 37. Each of the units 31 to 37 of the control device 30 may be realized by one or a plurality of processors, or may be realized by being incorporated into a circuit.

[0023] Next, a procedure for supplying power to the power storage device 5 by the power supply system 10 according to this embodiment, that is, a procedure for charging the power storage device 5, will be described with reference to the flowchart of FIG.

[0024] First, in step S101 of FIG. 3, a state acquisition process is executed. In the state acquisition process, a capacity maintenance rate SH1 of the vehicle power storage device 5 is acquired. Here, the state acquisition process is embodied by the state acquisition unit 33 of FIG. 2. The state acquisition unit 33 acquires the current capacity maintenance rate SH1 of the power storage device 5. In this embodiment, as described above, the electric vehicle 6 and the power storage device 5 are connected to be able to communicate with each other. Although not shown in the figure, the electric vehicle 6 is provided with a means for periodically acquiring the capacity maintenance rate SH1 of the power storage device 5, and the capacity maintenance rate SH1 of the power storage device 5 is periodically stored in a storage unit (not shown) of the electric vehicle 6. The state acquisition unit 33 acquires the capacity maintenance rate SH1 of the power storage device 5 from the electric vehicle 6. However, the capacity maintenance rate SH1 of the power storage device 5 may not be stored in the electric vehicle 6, and the state acquisition unit 33 may acquire the capacity maintenance rate SH1 of the power storage device 5 detected by the electric vehicle 6. Furthermore, the status acquisition unit 33 may directly acquire the capacity maintenance rate SH1 from the power storage device 5. The status acquisition unit 33 may be configured to detect, for example, the capacity maintenance rate SH1 of the power storage device 5. The current capacity maintenance rate SH1 of the power storage device 5 acquired by the status acquisition unit 33 is stored in the storage unit 31 of FIG. 2.

[0025] The status acquisition unit 33 may acquire information other than the capacity maintenance rate SH1 of the power storage device 5, for example, information related to the electric vehicle 6 (for example, the driving history, year, and model of the electric vehicle 6), or information related to charging and discharging the power storage device 5. Here, the driving history refers to the total driving distance of the electric vehicle 6, the driving distance for each predetermined period (for example, each day), and the like. The status acquisition unit 33 can also acquire the current battery capacity of the power storage device 5, the outside air temperature of the electric vehicle 6, and the like.

[0026] Next, in step S103 of FIG. 3, a range setting process is executed. In the range setting process, the SOC range ΔSOC of the power storage device 5 is set based on the capacity maintenance rate SH1 of the power storage device 5. In this embodiment, the range setting process is embodied by the range setting unit 35 of FIG. 2. The range setting unit 35 sets the range (in other words, the width) of the SOC range ΔSOC based on the capacity maintenance rate SH1 acquired by the state acquisition unit 33. FIGS. 4, 5, and 6 are diagrams showing the relationship between the capacity maintenance rate SH1 and the SOC range ΔSOC. In FIGS. 4 to 6, the horizontal axis indicates the capacity maintenance rate SH1, and the vertical axis indicates the SOC range ΔSOC. On the horizontal axis, the capacity maintenance rate SH1 decreases as the arrow moves in the direction (here, right). In this embodiment, as shown in FIG. 4, the SOC range ΔSOC has an upper limit SOC (Max1) and a lower limit SOC (Min1). The upper limit SOC (Max1) indicates the upper limit of the SOC range ΔSOC. The lower limit SOC (Min1) indicates the lower limit of the SOC range ΔSOC. Therefore, the SOC range ΔSOC is the range between the upper limit SOC (Max1) and the lower limit SOC (Min1). The range setting unit 35 in FIG. 2 changes the upper limit SOC (Max1) or the lower limit SOC (Min1) based on the capacity maintenance rate SH1 to adjust the width (e.g., range) of the SOC range ΔSOC.

[0027] In this embodiment, the range setting unit 35 sets the SOC range ΔSOC such that the SOC range ΔSOC becomes wider (i.e., the range becomes larger) as the capacity maintenance ratio SH1 becomes lower. For example, as shown in Fig. 5, the range setting unit 35 sets the SOC range ΔSOC such that the upper limit SOC (Max1) becomes higher as the capacity maintenance ratio SH1 becomes lower. In addition, the range setting unit 35 sets the SOC range ΔSOC such that the lower limit SOC (Min1) becomes higher as the capacity maintenance ratio SH1 becomes lower.

[0028] For example, the storage unit 31 in FIG. 2 stores a reference maintenance rate SSH1 in advance. The reference maintenance rate SSH1 is a numerical value that is a reference for changing the range of the SOC range ΔSOC. A specific numerical value of the reference maintenance rate SSH1 is appropriately set according to the type of the power storage device 5, the initial full charge capacity, and the like. Here, when the capacity maintenance rate SH1 acquired by the state acquisition unit 33 is equal to or lower than the reference maintenance rate SSH1, the range setting unit 35 sets the SOC range ΔSOC so that the SOC range ΔSOC is wider. For example, as shown in FIG. 4, when the capacity maintenance rate SH1 is equal to or lower than the reference maintenance rate SSH1 (here, the second reference maintenance rate SSH12), the range setting unit 35 may set the SOC range ΔSOC so that the upper limit SOC (Max1) of the SOC range ΔSOC is higher. In addition, when the capacity maintenance rate SH1 is equal to or lower than the reference maintenance rate SSH1 (here, the first reference maintenance rate SSH11), the range setting unit 35 may set the SOC range ΔSOC so that the lower limit SOC (Min1) of the SOC range ΔSOC is lower.

[0029] The reference maintenance rate SSH1 may be one or more. The reference maintenance rate SSH1 may be set separately for the upper limit SOC (Max1) and the lower limit SOC (Min1). The SOC range ΔSOC may be set to gradually increase in size according to the capacity maintenance rate SH1. For example, as shown in FIG. 4, the reference maintenance rate SSH1 has a first reference maintenance rate SSH11 and a second reference maintenance rate SSH12. Here, the second reference maintenance rate SSH12 is lower than the first reference maintenance rate SSH11. For example, the first reference maintenance rate SSH11 is 85%, and the second reference maintenance rate SSH12 is 70%.

[0030] In the example of FIG. 4, the range setting unit 35 in FIG. 2 sets an initial SOC range ΔSOC 0 Set the initial SOC range ΔSOC 0 is set for the SOC range ΔSOC for a brand new power storage device 5 (for example, a power storage device 5 with a capacity maintenance rate SH1 of 100%). For example, the initial SOC range ΔSOC 0is Δ60%, the upper limit SOC (Max1) is 80%, and the lower limit SOC (Min1) is 20%. When the capacity maintenance rate SH1 of the power storage device 5 becomes equal to or lower than the first reference maintenance rate SSH11, the range setting unit 35 changes the SOC range ΔSOC to the initial SOC range ΔSOC 0 From the first SOC range ΔSOC 1 For example, the first SOC range ΔSOC 1 is Δ80%, the upper limit SOC (Max1) is 80%, and the lower limit SOC (Min1) is 0%. When the capacity maintenance rate SH1 becomes equal to or lower than the second reference maintenance rate SSH12, the range setting unit 35 sets the SOC range ΔSOC to the first SOC range ΔSOC 1 From the second SOC range ΔSOC 2 For example, the second SOC range ΔSOC 2 is 100%, the upper limit SOC (Max1) at this time is 100% and the lower limit SOC (Min1) is 0%.

[0031] In this manner, in this embodiment, when the capacity maintenance rate SH1 of the power storage device 5 becomes low, the range setting unit 35 first lowers the lower limit SOC (Min1) of the SOC range ΔSOC to widen the range of the SOC range ΔSOC. Then, when the capacity maintenance rate SH1 of the power storage device 5 becomes low, the range setting unit 35 lowers the lower limit SOC (Min1) to a minimum value (e.g., 0%) and then increases the upper limit SOC (Max1) to widen the range of the SOC range ΔSOC. In detail, when the capacity maintenance rate SH1 of the power storage device 5 is the first reference maintenance rate SSH11, the range setting unit 35 lowers the lower limit SOC (Min1) to widen the range of the SOC range ΔSOC to the initial SOC range ΔSOC 0 From the first SOC range ΔSOC 1 When the capacity maintenance rate SH1 is a second reference maintenance rate SSH12 that is lower than the first reference maintenance rate SSH11, the range setting unit 35 does not change the lower limit SOC (Min1) but increases the upper limit SOC (Max1), thereby widening the SOC range ΔSOC to the first SOC range ΔSOC 1 From the second SOC range ΔSOC 2 Expand to.

[0032] When lowering the lower limit SOC(Min1), the range setting unit 35 may lower the lower limit SOC(Min1) all at once at the timing when the capacity maintenance rate SH1 becomes the first reference maintenance rate SSH11, as in the example of FIG. 4. When lowering the lower limit SOC(Min1), the range setting unit 35 may gradually lower the lower limit SOC(Min1) according to the capacity maintenance rate SH1, as shown in FIG. 5 and FIG. 6. For example, as in the example of FIG. 5, when the capacity maintenance rate SH1 is in a range greater than the first reference maintenance rate SSH11 (here, the range from the initial time (100%) to the first reference maintenance rate SSH11), the range setting unit 35 may gradually (for example, continuously) lower the lower limit SOC(Min1) as the capacity maintenance rate SH1 decreases (i.e., the capacity maintenance rate SH1 approaches the first reference maintenance rate SSH11). At this time, the lower limit SOC(Min1) may decrease at a constant rate as the capacity maintenance rate SH1 decreases, that is, decrease linearly with a constant gradient. Also, as shown in FIG. 6, the lower limit SOC(Min1) may decrease at a variable rate as the capacity maintenance ratio SH1 decreases, that is, may decrease curvilinearly with a variable slope according to the capacity maintenance ratio SH1.

[0033] Similarly, when increasing the upper limit SOC(Max1), the range setting unit 35 may increase the upper limit SOC(Max1) at once at the timing when the capacity maintenance rate SH1 becomes the second reference maintenance rate SSH12, as in the example of FIG. 4. Also, when increasing the upper limit SOC(Max1), the range setting unit 35 may increase it gradually according to the capacity maintenance rate SH1, as shown in FIG. 5 and FIG. 6. For example, as in the example of FIG. 5, the range setting unit 35 may increase the upper limit SOC(Max1) gradually (for example, continuously) as the capacity maintenance rate SH1 decreases (i.e., the capacity maintenance rate SH1 approaches the second reference maintenance rate SSH12) in the range where the capacity maintenance rate SH1 is between the first reference maintenance rate SSH11 and the second reference maintenance rate SSH12. At this time, the upper limit SOC(Max1) may increase at a constant rate as the capacity maintenance rate SH1 decreases, that is, increase linearly with a constant gradient. 6, the upper limit SOC(Max1) may increase at a variable rate as the capacity maintenance ratio SH1 decreases, that is, may increase in a curved manner with a variable slope according to the capacity maintenance ratio SH1. Note that the specific procedure for calculating the upper limit SOC(Max1) and the lower limit SOC(Min1) of the SOC range ΔSOC will be described later.

[0034] Next, in step S105 of FIG. 3, a power supply process is executed. The power supply process is a process of supplying power to the power storage device 5, that is, a process of charging the power storage device 5. In this embodiment, the power supply process is embodied by the power supply unit 37 of FIG. 2. The power supply unit 37 controls the charging / discharging device 20 (see FIG. 1) that supplies power to the power storage device 5 so that the SOC of the power storage device 5 falls within the SOC range ΔSOC set in the range setting process. Here, the power supply unit 37 controls the charging / discharging device 20 to adjust the amount of power supplied to the power storage device 5 so that the SOC of the power storage device 5 does not exceed the upper limit SOC (Max1) of the SOC range ΔSOC. Note that, in this embodiment, it is possible to discharge the power storage device 5. Therefore, the power supply unit 37 controls the charging / discharging device 20 to adjust the amount of discharge from the power storage device 5 so that the SOC of the power storage device 5 does not fall below the lower limit SOC (Min1) of the SOC range ΔSOC.

[0035] In this embodiment, for example, the power supply unit 37 determines the amount of power so that the SOC of the power storage device 5 falls within the SOC range ΔSOC. For example, this amount of power becomes smaller as the SOC of the power storage device 5 approaches the upper limit SOC (Max1), and becomes larger as the SOC of the power storage device 5 approaches the lower limit SOC (Min1). The power supply unit 37 transmits the amount of power to be supplied to the power storage device 5 to the charging / discharging device 20. The charging / discharging device 20 obtains the amount of power transmitted from the power supply unit 37 from the power source 15 and transmits it to the power storage device 5. As a result, the power storage device 5 is supplied with power equal to the amount of power transmitted from the power supply unit 37. As a result, the power storage device 5 is supplied with power so that the SOC falls within the SOC range ΔSOC.

[0036] There may be a plurality of modes (e.g., control procedures) for supplying power to the power storage device 5. The modes here may include, for example, a manual mode and an automatic mode. The manual mode is a mode in which the user operates, for example, an application (not shown) for operating the charging / discharging device 20 to start charging the power storage device 5. The above application is pre-installed in a terminal such as a smartphone used by the user. The user operates the terminal to start charging / discharging the power storage device 5 through the above application, and the power supply unit 37 in FIG. 2 controls charging / discharging the power storage device 5 so that the SOC of the power storage device 5 does not become higher than the upper limit SOC (Max1) of the SOC range ΔSOC and does not become lower than the lower limit SOC (Min1).

[0037] On the other hand, the automatic mode is a mode in which the control device 30 automatically starts charging and discharging the power storage device 5 without the user operating the above-mentioned application or the like. In the automatic mode, a charge and discharge plan is automatically created based on the frequency of use of the electric vehicle 6 by the user. This charge and discharge plan is created so that the SOC of the power storage device 5 does not become higher than the upper limit SOC (Max1) of the SOC range ΔSOC and does not become lower than the lower limit SOC (Min1). In the automatic mode, the power supply unit 37 controls the charge and discharge device 20 to charge and discharge the power storage device 5 in accordance with the charge and discharge plan created as described above.

[0038] As described above, in the present embodiment, in the state acquisition process, the capacity maintenance rate SH1 of the vehicle power storage device 5 is acquired as in step S101 of FIG. 3. In the range setting process, as in step S103 of FIG. 3, based on the capacity maintenance rate SH1 acquired in the state acquisition process, as shown in FIG. 5, when the capacity maintenance rate SH1 is equal to or less than a predetermined reference maintenance rate SSH1, an SOC range ΔSOC is set so that the SOC range ΔSOC in which the power storage device 5 can be charged is widened. In the power supply process, as in step S105 of FIG. 3, the charging / discharging device 20 (see FIG. 1) that supplies power to the power storage device 5 is controlled so that the SOC of the power storage device 5 falls within the SOC range ΔSOC set in the range setting process. As a result, when the capacity maintenance rate SH1 of the power storage device 5 is higher than the reference maintenance rate SSH1, the SOC range ΔSOC is narrowed, thereby making it possible to suppress deterioration of the power storage device 5 with a high capacity maintenance rate SH1 (for example, a brand new power storage device 5). In addition, when the capacity maintenance rate SH1 of the power storage device 5 is equal to or lower than the reference maintenance rate SSH1, by widening the SOC range ΔSOC, it is possible to suppress further deterioration of the power storage device 5 that has been deteriorated and has a low capacity maintenance rate SH1.

[0039] In the present embodiment, in the range setting process, as shown in Fig. 5, when the capacity maintenance rate SH1 is equal to or lower than the reference maintenance rate SSH1 (here, the second reference maintenance rate SSH12), the SOC range ΔSOC is set so that the upper limit SOC (Max1) which is the upper limit of the SOC range ΔSOC is high. In this way, by increasing the upper limit SOC (Max1), the power storage device 5 can be charged until the SOC of the power storage device 5 becomes high. Therefore, the amount of power that can be charged to the power storage device 5 can be increased.

[0040] 5, in the range setting process, the SOC range ΔSOC is set so that the lower limit SOC (Min1), which is the lower limit of the SOC range ΔSOC, is lowered when the capacity maintenance rate SH1 is equal to or lower than a reference maintenance rate SSH1 (here, a first reference maintenance rate SSH11). In this way, by lowering the lower limit SOC (Min1), it is possible to widen the range on the lower limit side of the SOC range ΔSOC in the power storage device 5. Thus, it is possible to widen the SOC range ΔSOC.

[0041] In this embodiment, the reference maintenance rate SSH1 has a first reference maintenance rate SSH11 and a second reference maintenance rate SSH12 lower than the first reference maintenance rate SSH11. In the range setting process, when the capacity maintenance rate SH1 is equal to or lower than the first reference maintenance rate SSH11, the SOC range ΔSOC is set so that the lower limit SOC (Min1) of the SOC range ΔSOC is lowered. In addition, in the range setting process, when the capacity maintenance rate SH1 is equal to or lower than the second reference maintenance rate SSH12, the SOC range ΔSOC is set so that the upper limit SOC (Max1) of the SOC range ΔSOC is higher. In this manner, in this embodiment, when the capacity maintenance rate SH1 is lowered, the lower limit SOC (Min1) is first lowered to widen the SOC range ΔSOC, and then the upper limit SOC (Max1) is increased to further widen the SOC range ΔSOC.

[0042] FIG. 7 is a diagram showing the relationship between elapsed time and the capacity maintenance rate SH1 when the SOC range ΔSOC is in the high SOC range ΔSC3, the medium SOC range ΔSC2, and the low SOC range ΔSC1. FIG. 8 is a diagram showing the relationship between elapsed time and the resistance increase rate when the SOC range ΔSOC is in the high SOC range ΔSC3, the medium SOC range ΔSC2, and the low SOC range ΔSC1. FIG. 7 shows the transition of the capacity maintenance rate SH1 over time when the SOC range ΔSOC of the power storage device 5 is in the high SOC range ΔSC3 (SOC in the range of 40% to 90%), the medium SOC range ΔSC2 (SOC in the range of 25% to 75%), and the low SOC range ΔSC1 (SOC in the range of 10% to 60%). FIG. 8 shows the transition of the resistance increase rate of the power storage device 5 over time when the SOC range ΔSOC of the power storage device 5 is in the high SOC range ΔSC3, the medium SOC range ΔSC2, and the low SOC range ΔSC1. As shown in FIG. 7, by setting the SOC range ΔSOC to the low SOC range ΔSC1, the capacity maintenance rate SH1 is less likely to decrease over time. On the other hand, by setting the SOC range ΔSOC to the high SOC range ΔSC3, the capacity maintenance rate SH1 is more likely to decrease over time than in other ranges (medium SOC range ΔSC2 and low SOC range ΔSC1). As shown in FIG. 8, the resistance increase rate over time can be suppressed in the order of the SOC range ΔSOC from the medium SOC range ΔSC2 to the low SOC range ΔSC1 to the high SOC range ΔSC3. That is, when the SOC range ΔSOC is in the medium SOC range ΔSC2, the resistance increase rate can be suppressed most. From these facts, the capacity maintenance rate SH1 is less likely to decrease and the resistance increase rate can be suppressed by setting the SOC range ΔSOC to the low SOC range ΔSC1 compared to setting it to the high SOC range ΔSC3, so that the deterioration of the power storage device 5 can be suppressed.

[0043] Therefore, as shown in FIG. 5, when the capacity maintenance rate SH1 of the storage device 5 becomes low, the lower limit SOC (Min1) is first lowered and the SOC range ΔSOC is widened from the medium SOC range ΔSC2 to the low SOC range ΔSC1, thereby making it possible to make the storage device 5 less susceptible to deterioration.

[0044] In the present embodiment, in the range setting process, as shown in FIG. 5, in a range where the capacity maintenance rate SH1 is greater than the first reference maintenance rate SSH1 (here, a range between 100% and the first reference maintenance rate SSH1), the SOC range ΔSOC is set so that the lower limit SOC (Min1) becomes lower as the capacity maintenance rate SH1 approaches the first reference maintenance rate SSH11. Also, in the range setting process, in a range where the capacity maintenance rate SH1 is between the first reference maintenance rate SSH11 and the second reference maintenance rate SSH12, the SOC range ΔSOC is set so that the upper limit SOC (Max1) becomes higher as the capacity maintenance rate SH1 approaches the second reference maintenance rate SSH12. In this way, in the present embodiment, the SOC range ΔSOC can be gradually widened by gradually lowering the lower limit SOC (Min1). Also, the SOC range ΔSOC can be gradually widened by gradually increasing the upper limit SOC (Max1). Therefore, since the SOC range ΔSOC can be broadened in stages according to the capacity maintenance ratio SH1, the width of the SOC range ΔSOC can be appropriately set according to the capacity maintenance ratio SH1.

[0045] Next, an example of a procedure for determining the upper limit SOC (Max1) and the lower limit SOC (Min1) of the SOC range ΔSOC will be described with reference to the flowchart of FIG.

[0046] Here, vehicle information related to the power storage device 5 and the electric vehicle 6 is stored in advance in the storage unit 31 in Fig. 2. This vehicle information is, for example, information acquired from the power storage device 5 or the electric vehicle 6 by the state acquisition unit 33 in Fig. 2. Examples of the vehicle information include an expected mileage D1 of the electric vehicle 6 for a predetermined period (for example, one day), an outside temperature T1 of the electric vehicle 6, a required amount of energy E1, a current capacity maintenance rate SH1 of the power storage device 5, a current battery capacity C1 of the power storage device 5, an SOC range ΔSOC, an initial SOC range ΔSOC, 0 , SOC standard value SOC 1The outside air temperature T1 refers to the air temperature around the electric vehicle 6, for example, the environmental temperature when the electric vehicle 6 is stopped. The outside air temperature T1 is, for example, the average air temperature of that day. The required amount of power E1 refers to the battery capacity of the power storage device 5 required when the electric vehicle 6 travels an expected travel distance D1 in a predetermined period (for example, one day).

[0047] As described above, the SOC range ΔSOC is determined in advance according to the current capacity maintenance rate SH1 of the power storage device 5. However, the upper limit SOC (Max1) and the lower limit SOC (Min1) in the SOC range ΔSOC are not determined. 0 is the range of the SOC range ΔSOC when the capacity maintenance rate SH1 is 100%, and is determined in advance. 0 The upper limit SOC (Max1) and the lower limit SOC (Min1) in the SOC reference value SOC 1 is a reference value used when determining the upper limit SOC (Max1) and the lower limit SOC (Min1) of the SOC range ΔSOC. Note that the SOC range ΔSOC is the initial SOC range ΔSOC 0 and the capacity maintenance rate SH1. The SOC range ΔSOC may be calculated based on, for example, ΔSOC=ΔSOC 0 It can be calculated by the formula: ×(1 / SH1).

[0048] SOC standard valueSOC 1 For example, the initial SOC range ΔSOC 0 Here, the SOC reference value SOC 1 is the initial SOC range ΔSOC 0 The midpoint of the initial SOC range, ΔSOC 0 SOC standard value SOC is half the difference between the upper limit SOC (Max1) and the lower limit SOC (Min1). 1 is, for example, a value between 40% and 60%.

[0049] In this embodiment, the control for determining the upper limit SOC (Max1) and the lower limit SOC (Min1) of the SOC range ΔSOC is performed by the range setting unit 35 in FIG. 2. First, in step S201 in FIG. 9, the range setting unit 35 determines whether the SOC range ΔSOC is equal to or greater than the required ratio R1, which is the ratio of the required amount of power E1 to the current battery capacity C1. Here, the required ratio R1 is a value obtained by dividing the required amount of power E1 by the battery capacity C1, and can be expressed as E1 / C1. Here, if the SOC range ΔSOC is less than the required ratio R1, the process proceeds to step S203 in FIG. 9. If the SOC range ΔSOC is less than the required ratio R1, it is highly likely that the required amount of power E1 cannot be charged to the power storage device 5 even if the maximum amount of power within the SOC range ΔSOC is charged. In this case, the range setting unit 35 changes the specific value of the SOC range ΔSOC to the required ratio R1. After changing the value of the SOC range ΔSOC to the required ratio R1 in this manner, the process proceeds to step S205 in FIG.

[0050] On the other hand, if it is determined in step S201 that the SOC range ΔSOC is equal to or greater than the required ratio R1, the process proceeds to step S205 without changing the specific value of the SOC range ΔSOC. In step S205, the range setting unit 35 calculates the difference B1. The difference B1 is the difference between the set SOC range ΔSOC and the initial SOC range ΔSOC 0 The difference B1 is, for example, B1=ΔSOC-ΔSOC 0 In this embodiment, as described above, as shown in FIG. 5, when the capacity maintenance rate SH1 is low, the range of the SOC range ΔSOC is widened. On the other hand, the initial SOC range ΔSOC 0 is a fixed value. Therefore, the difference B1 indicates the degree to which the capacity maintenance rate SH1 is lowered and the power storage device 5 is deteriorated. The larger the difference B1, the greater the degree of deterioration of the power storage device 5. The difference B1 calculated here is stored in the storage unit 31 in FIG. 2.

[0051] Next, in step S207 in Fig. 9, the range setting unit 35 judges the difference B1. Here, the difference B1 is the SOC reference value SOC 1 From the initial SOC range ΔSOC0 SOC is calculated by subtracting half of the value from the 1 -ΔSOC 0 Here, it is judged whether the SOC is less than or equal to "SOC 1 -ΔSOC 0 / 2" is a comparison value for preventing the lower limit SOC (Min1) from being set to less than 0%. 1 -ΔSOC 0 9. If it is determined that the difference is equal to or less than "1 / 2", the process proceeds to step S209 in FIG.

[0052] In step S209, the range setting unit 35 determines the upper limit SOC (Max1) and the lower limit SOC (Min1) of the SOC range ΔSOC so that the lower limit SOC (Min1) is low. In step S209, the range setting unit 35 sets the upper limit SOC (Max1) to a fixed value and sets the lower limit SOC (Min1) to a lower value. That is, in step S209, the upper limit SOC (Max1) and the lower limit SOC (Min1) are set for the capacity maintenance rate SH1 in FIG. 5 between 100% and the first reference maintenance rate SSH11. Here, the range setting unit 35 sets the upper limit SOC (Max1) to the SOC reference value SOC 1 , initial SOC range ΔSOC 0 In other words, the upper limit SOC (Max1) is set to the value obtained by adding half of the SOC. 1 +ΔSOC 0 On the other hand, the range setting unit 35 sets the lower limit SOC (Min1) to the SOC reference value SOC 1 From the initial SOC range ΔSOC 0 The lower limit SOC (Min1) is set to half the value minus the difference B1. 1 -ΔSOC 0 It is calculated using the formula / 2-B1 and is a variable value.

[0053] On the other hand, in step S207 of FIG. 9, the difference B1 is "SOC 1 -ΔSOC 09. In step S211, the range setting unit 35 determines the upper limit SOC(Max1) and the lower limit SOC(Min1) of the SOC range ΔSOC so that the upper limit SOC(Max1) is high. In step S211, the range setting unit 35 sets the value of the lower limit SOC(Min1) to be fixed and the value of the upper limit SOC(Max) to be high. That is, in step S211, the upper limit SOC(Max1) and the lower limit SOC(Min1) are set when the capacity maintenance rate SH1 in FIG. 5 is between the first reference maintenance rate SSH11 and the second reference maintenance rate SSH12. Here, the range setting unit 35 sets the value of the lower limit SOC(Min1) to 0%. The range setting unit 35 sets the upper limit SOC(Max1) to be within the range of the initial SOC range ΔSOC 0 In other words, the upper limit SOC (Max1) is set to the value obtained by adding the difference B1 to the upper limit SOC. 0 +B1, and is a variable value. In this manner, the upper limit SOC (Max1) and the lower limit SOC (Min1) of the SOC range ΔSOC can be set.

[0054] In this embodiment, the SOC range ΔSOC and the upper limit SOC (Max1) and lower limit SOC (Min1) of the SOC range ΔSOC can be set according to the outside air temperature T1. FIG. 10 is a diagram showing the relationship between the outside air temperature T1 and the SOC range ΔSOC. In FIG. 10, the horizontal axis indicates the outside air temperature T1, and the outside air temperature T1 increases as the arrow moves in the direction (to the right in this case). As shown in FIG. 10, when the outside air temperature T1 is high, the range setting unit 35 in FIG. 2 lowers the upper limit SOC (Max1) and the lower limit SOC (Min1) at a constant rate. On the other hand, when the outside air temperature T1 is low, the range setting unit 35 raises the upper limit SOC (Max1) and the lower limit SOC (Min1) at a constant rate.

[0055] Here, for example, the upper limit SOC taking into account the outside temperature T1 is referred to as the upper limit SOC(Max2), and the lower limit SOC taking into account the outside temperature T1 is referred to as the lower limit SOC(Min2). The upper limit SOC(Max2) taking into account the outside temperature T1 is calculated based on the upper limit SOC(Max1) not taking into account the outside temperature T1, for example, by the following formula (1). Max2 = Max1 + a × T1 (1)

[0056] The lower limit SOC (Min2) taking into account the outside air temperature T1 is calculated based on the lower limit SOC (Min1) not taking into account the outside air temperature T1, and is calculated, for example, by the following formula (2). Min2 = Min1 + b × T1 (2)

[0057] Here, in formulas (1) and (2), a and b indicate coefficients, and may be negative or positive. The lower the outside air temperature T1, the larger the coefficients a and b are set. The coefficients a and b may be the same or different. In this embodiment, when the SOC range ΔSOC is changed and the battery characteristics such as the voltage value and internal resistance of the power storage device 5 change according to the SOC, the amount of power available in the SOC range ΔSOC changes. Therefore, it is preferable that the coefficients a and b are determined taking these factors into consideration.

[0058] In the following description, the upper limit SOC (Max1) and the lower limit SOC (Min1) are described, but the upper limit SOC (Max1) can be replaced with the upper limit SOC (Max2), and the lower limit SOC (Min1) can be replaced with the lower limit SOC (Min2). In this embodiment, as shown in FIG. 10, a first reference temperature ST1 and a second reference temperature ST2 are set for an outside air temperature T1. The first reference temperature ST1 is a reference value for increasing the upper limit SOC (Max1) and the lower limit SOC (Min1) when the outside air temperature T1 is low. The second reference temperature ST2 is a value higher than the first reference temperature ST1. The second reference temperature ST2 is a reference value for decreasing the upper limit SOC (Max1) and the lower limit SOC (Min1) when the outside air temperature T1 is high.

[0059] For example, when the outside air temperature T1 is equal to or higher than the first reference temperature ST1 and equal to or lower than the second reference temperature ST2, the upper limit SOC (Max1) and the lower limit SOC (Min1) of the SOC range ΔSOC are not changed, and the SOC range ΔSOC is set to approximately the medium SOC range ΔSC2. When the outside air temperature T1 is lower than the first reference temperature ST1, the range setting unit 35 does not change the width of the SOC range ΔSOC, but increases the upper limit SOC (Max1) and the lower limit SOC (Min1) by the temperature difference ΔT10. This makes it possible to shift the SOC range ΔSOC to the high SOC range ΔSC3 side when the outside air temperature T1 is lower than the first reference temperature ST1. However, when the upper limit SOC (Max1) is increased by the temperature difference ΔT10 and exceeds 100%, the upper limit SOC (Max1) is increased so that the upper limit SOC (Max1) becomes 100%. Then, the lower limit SOC (Min1) is increased by the amount that the upper limit SOC (Max1) is increased.

[0060] Furthermore, when the outside air temperature T1 is higher than the second reference temperature ST2, the range setting unit 35 does not change the width of the SOC range ΔSOC, but lowers the upper limit SOC (Max1) and the lower limit SOC (Min1) by the temperature difference ΔT10. This allows the SOC range ΔSOC to be shifted toward the low SOC range ΔSC1 when the outside air temperature T1 is higher than the second reference temperature ST2. However, when the lower limit SOC (Min1) is lowered by the temperature difference ΔT10 and falls below 0%, the lower limit SOC (Min1) is lowered so that the lower limit SOC (Min1) becomes 0%. Then, the upper limit SOC (Max1) is lowered by the amount that the lower limit SOC (Min1) was lowered.

[0061] In this embodiment, in the range setting process, when the outside air temperature T1 of the electric vehicle 6 equipped with the power storage device 5 is less than the first reference temperature ST1, the upper limit SOC (Max1) and the lower limit SOC (Min1) are each increased by the predetermined temperature difference ΔT10 in the range setting process when the outside air temperature T1 of the electric vehicle 6 is less than the first reference temperature ST1. This makes it possible to shift the SOC range ΔSOC to the high SOC range ΔSC3 when the outside air temperature T1 is low. When the outside air temperature T1 is low, the power storage device 5 is less likely to deteriorate and the internal resistance of the power storage device 5 is likely to increase. As shown in FIG. 7 and FIG. 8, in the high SOC range ΔSC3, the capacity maintenance rate SH1 of the power storage device 5 tends to be relatively low and the resistance increase rate tends to be high. Therefore, even if the SOC range ΔSOC is shifted toward the high SOC range ΔSC3 when the outside air temperature T1 is low and the storage device 5 is less likely to deteriorate, as in this embodiment, the storage device 5 can be made less likely to deteriorate compared to when the outside air temperature T1 is high.

[0062] In this embodiment, in the range setting process, as shown in FIG. 10, when the outside air temperature T1 of the electric vehicle 6 is higher than the second reference temperature ST2, which is higher than the first reference temperature ST1, the upper limit SOC (Max1) and the lower limit SOC (Min1) are each lowered by a predetermined temperature difference ΔT10 in the range setting process when the outside air temperature T1 of the electric vehicle 6 is higher than the second reference temperature ST2. This makes it possible to shift the SOC range ΔSOC to the low SOC range ΔSC1 side when the outside air temperature T1 is high. When the outside air temperature T1 is high, the power storage device 5 is relatively prone to deterioration. As shown in FIG. 7 and FIG. 8, in the low SOC range ΔSC1, the capacity maintenance rate SH1 of the power storage device 5 is unlikely to become low, and the power storage device 5 is unlikely to deteriorate. Also, in the low SOC range ΔSC1, the resistance increase rate can be suppressed. Therefore, as in this embodiment, when the outside air temperature T1 is high, the SOC range ΔSOC is shifted toward the low SOC range ΔSC1, so that the deterioration of the power storage device 5 can be suppressed even when the outside air temperature T1 is high.

[0063] In this embodiment, the width of the SOC range ΔSOC may be changed according to the expected mileage D1 of the electric vehicle 6 in a predetermined period (for example, one day). The expected mileage D1 varies from day to day, for example. For one user, the expected mileage D1 is shorter on weekdays and longer on holidays, and for another user, the expected mileage D1 is longer on weekdays and shorter on holidays. Therefore, in this embodiment, when the expected mileage D1 is long, the range setting unit 35 in FIG. 2 may change the SOC range ΔSOC to be wider in order to increase the amount of electric power in the power storage device 5.

[0064] FIG. 11 is a diagram showing the relationship between the estimated mileage D1 and the SOC range ΔSOC. In FIG. 11, the horizontal axis indicates the estimated mileage D1, and the estimated mileage D1 increases as the arrow moves in the direction (here, to the right). As shown in FIG. 11, for example, a reference distance SD1 is set in advance for the estimated mileage D1. The reference distance SD1 is a reference value for determining whether or not to widen the SOC range ΔSOC. For example, when the estimated mileage D1 is equal to or less than the reference distance SD1, the range setting unit 35 does not change the range of the SOC range ΔSOC, and does not change the upper limit SOC (Max1) and the lower limit SOC (Min1). On the other hand, when the estimated mileage D1 is longer than the reference distance SD1, the range setting unit 35 changes the upper limit SOC (Max1) and the lower limit SOC (Min1) so as to widen the SOC range ΔSOC. The range setting unit 35 increases the upper limit SOC (Max1) and decreases the lower limit SOC (Min1) to widen the range of the SOC range ΔSOC. Specifically, when the predicted travel distance D1 is longer than the reference distance SD1, the range setting unit 35 increases the upper limit SOC (Max1) by the distance difference ΔD10 and decreases the lower limit SOC (Min1) by the distance difference ΔD10 to widen the range of the SOC range ΔSOC. However, when the upper limit SOC (Max1) is increased by the distance difference ΔD10 and the upper limit SOC (Max1) exceeds 100%, the upper limit SOC (Max1) is increased so that it becomes 100%. Similarly, when the lower limit SOC (Min1) is decreased by the distance difference ΔD10 and the lower limit SOC (Min1) falls below 0%, the lower limit SOC (Min1) is decreased so that it becomes 0%.

[0065] In this embodiment, in the range setting process, as shown in FIG. 11, when the estimated mileage D1 in a predetermined period of the electric vehicle 6 equipped with the power storage device 5 is longer than the predetermined reference distance SD1, the SOC range ΔSOC is widened. When the estimated mileage D1 is long, it is considered that a larger amount of electric power is required. Therefore, when the estimated mileage D1 is long, a larger amount of electric power can be charged to the power storage device 5 by widening the SOC range ΔSOC. Therefore, even if the electric vehicle 6 attempts to travel the estimated mileage D1, the power storage device 5 can secure a sufficient amount of electric power, and therefore the electric vehicle 6 can actually travel the estimated mileage D1.

[0066] In the present embodiment, in the range setting process, when the estimated travel distance D1 is longer than the reference distance SD1, the upper limit SOC (Max1) is increased by a predetermined distance difference ΔD10, and the lower limit SOC (Min1) is decreased by the distance difference ΔD10. In this manner, the upper limit SOC (Max1) and the lower limit SOC (Min1) are increased or decreased by the same distance difference ΔD10, so that the SOC range ΔSOC can be widened while maintaining the SOC range ΔSOC in the middle SOC range ΔSC2 (see FIGS. 7 and 8). Therefore, even when the SOC range ΔSOC is widened, the power storage device 5 can be made relatively less susceptible to deterioration.

[0067] In this embodiment, as shown in FIG. 4, when the capacity maintenance rate SH1 becomes low, the lower limit SOC (Min1) is first lowered to widen the SOC range ΔSOC. Then, when the capacity maintenance rate SH1 becomes even lower, the upper limit SOC (Max1) is increased to further widen the SOC range ΔSOC. However, as shown in the modified example of FIG. 12, when the capacity maintenance rate SH1 becomes low, the lower limit SOC (Min1) and the upper limit SOC (Max1) may both be lowered and increased to widen the SOC range ΔSOC. For example, when the capacity maintenance rate SH1 is equal to or lower than the first reference maintenance rate SSH11, the upper limit SOC (Max1) is increased by the difference ΔS10 and the lower limit SOC (Min1) is decreased by the difference ΔS10 to widen the SOC range ΔSOC to the initial SOC range ΔSOC. 0From the first SOC range ΔSOC 1 In addition, when the capacity maintenance rate SH1 is equal to or lower than the second reference maintenance rate SSH12, the upper limit SOC (Max1) is further increased by the difference ΔS10 and the lower limit SOC (Min1) is further decreased by the difference ΔS10 to set the SOC range ΔSOC to the first SOC range ΔSOC 1 From the second SOC range ΔSOC 2 It may be expanded to.

[0068] In this embodiment, as shown in FIG. 5, when the capacity maintenance rate SH1 is 100%, the lower limit SOC (Min1) is started to be lowered, and when the capacity maintenance rate SH1 is the first reference maintenance rate SSH11, the upper limit SOC (Max1) is started to be increased. However, the timing to start lowering the lower limit SOC (Min1) may be a timing when the capacity maintenance rate SH1 is lower than 100%. The timing to start increasing the upper limit SOC (Max1) may be a timing when the capacity maintenance rate SH1 is higher than the first reference maintenance rate SSH11, or may be a timing when the capacity maintenance rate SH1 is lower than the first reference maintenance rate SSH11. For example, as shown in FIG. 13, the timing to start lowering the lower limit SOC (Min1) may be a timing SH21 when the capacity maintenance rate SH1 is lower than 100% and higher than the first reference maintenance rate SSH11. The timing to start increasing the upper limit SOC(Max1) may be a timing SH22 when the capacity maintenance rate SH1 is lower than the first reference maintenance rate SSH11 and higher than the second reference maintenance rate SSH12. Note that the timing SH22 may be a timing higher than the first reference maintenance rate SSH11.

[0069] In this embodiment, as shown in FIG. 5, the timing at which the lower limit SOC (Min1) starts to be lowered is different from the timing at which the upper limit SOC (Max1) starts to be increased. However, the timing at which the lower limit SOC (Min1) starts to be lowered and the timing at which the upper limit SOC (Max1) starts to be increased may be the same. For example, when the capacity maintenance rate SH1 reaches the first reference maintenance rate SSH11, the lower limit SOC (Min1) may start to be lowered and the upper limit SOC (Max1) may start to be increased. At this time, the amount of change in the upper limit SOC (Max1) and the amount of change in the lower limit SOC (Min1) may be relatively the same or different. For example, the amount of change in the upper limit SOC (Max1) may be relatively smaller than the amount of change in the lower limit SOC (Min1).

[0070] The present embodiment includes a computer program for power supply executed by the control device 30 of the power supply system 10. This computer program for power supply is a computer program executed by a computer that realizes the control device 30. The computer program for power supply is a program that causes the computer to execute a status acquisition process executed by the status acquisition unit 33, a range setting process executed by the range setting unit 35, and a power supply process executed by the power supply unit 37.

[0071] The present embodiment also includes a power supply method. The power supply method includes a status acquisition step, a range setting step, and a power supply step. The status acquisition step is realized by a status acquisition process executed by the status acquisition unit 33. The range setting step is realized by a range setting process executed by the range setting unit 35. The power supply step is realized by a power supply process executed by the power supply unit 37.

[0072] The invention disclosed herein has been described in various ways. Unless otherwise specified, the embodiments described herein do not limit the present invention. Furthermore, the embodiments of the invention disclosed herein can be modified in various ways, and each component or each process described herein can be omitted or combined as appropriate, unless a particular problem occurs.

[0073] As described above, this specification includes the disclosures set forth in the following sections. Section 1: A status acquisition process for acquiring a capacity maintenance rate of a vehicle power storage device; a range setting process for setting an SOC range so that a chargeable SOC range for the power storage device is widened when the capacity maintenance rate is equal to or lower than a predetermined reference maintenance rate based on the capacity maintenance rate acquired in the state acquisition process; a power supply process for controlling a charging / discharging device that supplies power to the power storage device so that the SOC of the power storage device falls within the SOC range set in the range setting process; A computer program for supplying power that causes a computer to execute the above.

[0074] Section 2: Item 2. The computer program for power supply according to item 1, wherein, in the range setting process, when the capacity maintenance rate is equal to or lower than the reference maintenance rate, the SOC range is set so that an upper limit SOC, which is an upper limit of the SOC range, is high.

[0075] Section 3: 3. The computer program for power supply according to item 1 or 2, wherein, in the range setting process, when the capacity maintenance rate is equal to or lower than the reference maintenance rate, the SOC range is set so that a lower limit SOC that is a lower limit of the SOC range is lowered.

[0076] Section 4: The standard maintenance rate is The first standard maintenance rate, A second standard maintenance rate that is lower than the first standard maintenance rate; having In the range setting process, When the capacity maintenance rate is equal to or lower than the first reference maintenance rate, the SOC range is set so that a lower limit SOC, which is a lower limit of the SOC range, is low; 4. The computer program for power supply according to any one of items 1 to 3, wherein when the capacity maintenance rate is equal to or lower than the second reference maintenance rate, the SOC range is set so that an upper limit SOC, which is an upper limit of the SOC range, is increased.

[0077] Section 5: In the range setting process, setting the SOC range such that, in a range in which the capacity maintenance ratio is greater than the first reference maintenance ratio, the lower limit SOC becomes lower as the capacity maintenance ratio approaches the first reference maintenance ratio; Item 5. The computer program for power supply according to item 4, wherein the SOC range is set such that, in a range between the first reference maintenance rate and the second reference maintenance rate, the upper limit SOC becomes higher as the capacity maintenance rate approaches the second reference maintenance rate.

[0078] Item 6: 6. The computer program for power supply according to any one of items 1 to 5, wherein, in the range setting process, when an outside air temperature of an electric vehicle equipped with the power storage device is lower than a predetermined first reference temperature, the upper limit SOC and the lower limit SOC are each increased.

[0079] Section 7: 7. The computer program for power supply according to claim 6, wherein, in the range setting process, when the outside air temperature of the electric vehicle is lower than the first reference temperature, the upper limit SOC and the lower limit SOC are each increased by a predetermined temperature difference.

[0080] Section 8: 8. The computer program for power supply according to claim 6 or 7, wherein, in the range setting process, when the outside air temperature of the electric vehicle is higher than a second reference temperature that is higher than the first reference temperature, the upper limit SOC and the lower limit SOC are each lowered.

[0081] Section 9: Item 9. The computer program for power supply according to item 8, wherein, in the range setting process, when the outside air temperature of the electric vehicle is higher than the second reference temperature, the upper limit SOC and the lower limit SOC are each lowered by a predetermined temperature difference.

[0082] Section 10: 10. The computer program for power supply according to any one of items 1 to 9, wherein in the range setting process, when an expected mileage of an electric vehicle equipped with the power storage device in a specified period is longer than a predetermined reference mileage, the SOC range is widened.

[0083] Section 11: Item 11. The computer program for power supply according to item 10, wherein, in the range setting process, when the predicted mileage is longer than the reference distance, the upper limit SOC is increased by a predetermined distance difference and the lower limit SOC is decreased by the distance difference.

[0084] Section 12: A control device that executes a computer program for power supply according to any one of items 1 to 11; A vehicle power storage device; A charging / discharging device that supplies power to the power storage device; A power supply system comprising:

[0085] Section 13: a state acquisition step of acquiring a capacity maintenance rate of a power storage device for a vehicle; a range setting step of setting, based on the capacity maintenance rate acquired in the state acquisition step, an SOC range so that a chargeable SOC range for the power storage device is widened when the capacity maintenance rate is equal to or lower than a predetermined reference maintenance rate; a power supplying step of controlling a charging / discharging device that supplies power to the power storage device so that the SOC of the power storage device falls within the SOC range set in the range setting step; The power supply method includes the steps of: [Explanation of symbols]

[0086] 5. Energy storage device 6 Electric vehicles 10. Power Supply System 20 Charge / discharge device 30 Control device 31 Storage section 33 Status acquisition unit 35 Range setting section 37 Power supply section D1 Estimated mileage SD1 Reference Distance Max1 Upper limit SOC Min1 Lower limit SOC SH1 capacity maintenance rate SSH1 standard maintenance rate SSH11 1st standard maintenance rate SSH12 2nd standard maintenance rate T1 Outside temperature ST1 1st reference temperature ST2 2nd reference temperature ΔSOC SOC range

Claims

1. A status acquisition process for acquiring a capacity maintenance rate of a vehicle power storage device; a range setting process for setting an SOC range so that a chargeable SOC range for the power storage device is widened when the capacity maintenance rate is equal to or lower than a predetermined reference maintenance rate based on the capacity maintenance rate acquired in the state acquisition process; a power supply process for controlling a charging / discharging device that supplies power to the power storage device so that the SOC of the power storage device falls within the SOC range set in the range setting process; A computer program for supplying power that causes a computer to execute the above.

2. 2. The computer program product for power supply according to claim 1, wherein, in the range setting process, when the capacity maintenance rate is equal to or lower than the reference maintenance rate, the SOC range is set so that an upper limit SOC that is an upper limit of the SOC range is high.

3. 2. The computer program product for power supply according to claim 1, wherein, in the range setting process, when the capacity maintenance rate is equal to or lower than the reference maintenance rate, the SOC range is set so that a lower limit SOC that is a lower limit of the SOC range is lowered.

4. The standard maintenance rate is A first standard maintenance rate; and A second standard maintenance rate that is lower than the first standard maintenance rate; having In the range setting process, When the capacity maintenance rate is equal to or lower than the first reference maintenance rate, the SOC range is set so that a lower limit SOC that is a lower limit of the SOC range is lowered; 2 . The computer program product for supplying electric power according to claim 1 , wherein when the capacity maintenance rate is equal to or lower than the second reference maintenance rate, the SOC range is set so that an upper limit SOC that is an upper limit of the SOC range is increased.

5. In the range setting process, setting the SOC range such that, in a range in which the capacity maintenance ratio is greater than the first reference maintenance ratio, the lower limit SOC becomes lower as the capacity maintenance ratio approaches the first reference maintenance ratio; 5. The computer program for power supply according to claim 4, wherein the SOC range is set such that, in a range between the first reference maintenance rate and the second reference maintenance rate, the upper limit SOC becomes higher as the capacity maintenance rate approaches the second reference maintenance rate.

6. 2. The computer program product for power supply according to claim 1, wherein, in the range setting process, when an outside air temperature of an electric vehicle equipped with the power storage device is lower than a predetermined first reference temperature, each of the upper limit SOC and the lower limit SOC is increased.

7. 7. The computer program product for power supply according to claim 6, wherein, in the range setting process, when the outside air temperature of the electric vehicle is lower than the first reference temperature, each of the upper limit SOC and the lower limit SOC is increased by a predetermined temperature difference.

8. 7. The computer program product for power supply according to claim 6, wherein, in the range setting process, when the outside air temperature of the electric vehicle is higher than a second reference temperature that is higher than the first reference temperature, each of the upper limit SOC and the lower limit SOC is lowered.

9. 9. The computer program product for power supply according to claim 8, wherein, in the range setting process, when the outside air temperature of the electric vehicle is higher than the second reference temperature, each of the upper limit SOC and the lower limit SOC is lowered by a predetermined temperature difference.

10. 2. The computer program product for power supply according to claim 1, wherein, in the range setting process, when an expected travel distance in a predetermined period of time of an electric vehicle equipped with the power storage device is longer than a predetermined reference distance, the SOC range is widened.

11. 11. The computer program for power supply according to claim 10, wherein, in the range setting process, when the estimated travel distance is longer than the reference distance, the upper limit SOC is increased by a predetermined distance difference and the lower limit SOC is decreased by the distance difference.

12. A control device that executes a computer program for power supply according to any one of claims 1 to 11; A vehicle power storage device; A charging / discharging device that supplies power to the power storage device; A power supply system comprising:

13. a state acquisition step of acquiring a capacity maintenance rate of a power storage device for a vehicle; a range setting step of setting an SOC range so that a chargeable SOC range for the power storage device is widened when the capacity maintenance rate is equal to or lower than a predetermined reference maintenance rate, based on the capacity maintenance rate acquired in the state acquisition step; a power supplying step of controlling a charging / discharging device that supplies power to the power storage device so that the SOC of the power storage device falls within the SOC range set in the range setting step; The power supply method includes the steps of:

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