Power supply system

Abstract

To provide a power supply system which can suppress an increase of received power from a power system while an electric vehicle is charged with generated power of a solar battery apparatus.SOLUTION: A power supply system in which a power battery apparatus 11, a charge / discharge device 12, a power consumption device 14 and a power supply device 13 for supplying power to an electric vehicle 20 having an accumulator battery 21 for traveling are connected to a power line 2 connected to a power system 1 includes: a controller 15 for controlling supply power from the power supply device 13 to the accumulator battery 21 for traveling of the electric vehicle 20 according to a charge residual amount of the charge / discharge device 12 so that power supply to the accumulator battery 21 for traveling of the electric vehicle 20 connected to the power supply device 13 is suppressed when the charge residual amount of the charge / discharge device 12 is small.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD

[0001] The present invention relates to a power supply system in which a solar cell device, a charge / discharge device, a power consumption device, and a power feeding device for feeding power to an electric vehicle having a traveling storage battery are connected to a power line connected to an electric power system. BACKGROUND ART

[0002] Solar cell devices are installed in facilities such as residences and business establishments, and the power generated by the solar cell devices is consumed by the power consumption devices of the facilities. Furthermore, among the power generated by the solar cell devices, surplus power that exceeds the power consumption of the power consumption devices is reverse-flowed to the electric power system. In addition, when there is an electric vehicle or the like that travels by driving a motor with power stored in a power storage unit mounted on the vehicle, the power generated by the solar cell device can also be fed to the power storage unit of the electric vehicle.

[0003] It should be noted that when power is fed to the power storage unit of an electric vehicle, the received power of the facility from the electric power system increases by that amount. Further, when the power generated by the solar cell device sharply decreases depending on weather, the received power increases by that corresponding amount.

[0004] In order to solve the problem of an increase in received power while the power generated by such a solar cell device is fed to the power storage unit of an electric vehicle, there is a method of providing a charge / discharge device in a facility. Patent Document 1 (International Publication No. WO 2011 / 118627) describes a system in which a solar cell device and a charge / discharge device are provided, and discharging from the charge / discharge device is possible while feeding the power generated by the solar cell device to the power storage unit of an electric vehicle. As described in paragraph 0053 of Patent Document 1, the charge / discharge device causes the charge / discharge device to discharge when power is fed to the power storage unit of the electric vehicle, and after discharging the charge / discharge device, when it recognizes that power is not being fed to the power storage unit of the electric vehicle, it causes the charge / discharge device to be charged.

[0005] Furthermore, paragraphs 0065 onwards of Patent Document 1 describe a method for supplying power to the battery storage unit of an electric vehicle by changing the current. This method aims to suppress an increase in the power received from the power grid by charging the charge / discharge device during periods when the current supplied to the battery storage unit of the electric vehicle is small. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2011 / 118627 [Overview of the project] [Problems that the invention aims to solve]

[0007] If the charge / discharge device has sufficient charge remaining, even if the power generated by the solar panels decreases sharply due to weather conditions, there is sufficient capacity to continuously increase the discharge power from the charge / discharge device to supply power to the electric vehicle's energy storage unit. In other words, there is sufficient capacity to continuously suppress the increase in power received from the power grid by increasing the discharge power from the charge / discharge device. Therefore, if the charge / discharge device has sufficient charge remaining, it is not necessary to reduce the current supplied to the electric vehicle's energy storage unit. On the other hand, if the charge / discharge device has low charge remaining, there is little capacity to continuously suppress the increase in power received from the power grid by increasing the discharge power from the charge / discharge device. In other words, there is little capacity to continuously suppress the increase in power received from the power grid by increasing the discharge power from the charge / discharge device.

[0008] Thus, considering that the power generated by solar panels can decrease sharply depending on the weather, it is necessary to consider the remaining charge level of the charge / discharge device in order to continuously supply power to the battery storage unit of electric vehicles while suppressing the power received from the power grid. However, the system described in Patent Document 1 does not describe any control based on the remaining charge level of the charge / discharge device.

[0009] The present invention has been made in view of the above-mentioned problems, and its objective is to provide a power supply system that can charge an electric vehicle with power generated by a solar cell device while suppressing an increase in power received from the power grid. [Means for solving the problem]

[0010] A characteristic configuration of the power supply system according to the present invention for achieving the above objective is a power supply system in which a solar cell device, a charging / discharging device, a power consumption device, and a power supply device for supplying power to an electric vehicle having a traction battery are connected to a power line connected to a power grid, When the remaining charge of the charge / discharge device is less than a predetermined amount, the power supply from the power supply device to the traction battery of the electric vehicle connected to the power supply device is suppressed, and the control device controls the power supplied from the power supply device to the traction battery of the electric vehicle according to the remaining charge of the charge / discharge device. 、 The control device, when the power supply from the power supply device to the traction battery of the electric vehicle is stopped and the remaining charge of the charge / discharge device is less than a predetermined power supply start amount, will resume power supply from the power supply device to the traction battery of the electric vehicle when the remaining charge of the charge / discharge device increases to or equal to the power supply start amount. The control device sets the remaining power supply amount to be larger during periods when the power generation of the solar cell device fluctuates significantly. It's at a single point.

[0011] According to the above configuration, power can be supplied from the power supply device connected to the power line to the traction battery of the electric vehicle. In other words, the power generated by the solar panel can be supplied to the traction battery of the electric vehicle via the power line. Furthermore, the control device controls the power supplied from the power supply device to the traction battery of the electric vehicle according to the remaining charge of the charge / discharge device, so that when the remaining charge of the charge / discharge device is less than a predetermined amount, the power supplied to the traction battery of the electric vehicle connected to the power supply device is suppressed. In other words, when the remaining charge of the charge / discharge device is less than a predetermined amount, that is, when there is little capacity to suppress the increase in power received from the power system by the discharge from the charge / discharge device, the power supplied from the power supply device to the traction battery of the electric vehicle is suppressed. In addition, according to the above-described configuration, while the remaining charge of the charge / discharge device is below a predetermined starting charge level, power is stopped from the power supply device to the electric vehicle's traction battery. In other words, when the remaining charge of the charge / discharge device is low, that is, when there is little surplus capacity to suppress the increase in power received from the power grid by discharging from the charge / discharge device, power is not supplied from the power supply device to the electric vehicle's traction battery. As a result, if there is a surplus in the power generated by the solar panel during that time, that surplus power is charged into the charge / discharge device, increasing its remaining charge level. Furthermore, when the charge level of the charge / discharge device increases to a level exceeding the initial charge level, meaning there is a large surplus of charge in the charge / discharge device that can suppress the increase in power received from the power grid through discharge, power will be supplied from the power supply device to the electric vehicle's traction battery. As a result, even if the power generated by the solar panels decreases sharply due to weather conditions, and it becomes necessary to increase the discharge power of the charge / discharge device, this can be handled by the sufficiently secured charge level. When the power output of a solar panel fluctuates significantly, the charging and discharging device needs to discharge more power to prevent an increase in the power received from the power grid that occurs when the power output of the solar panel decreases significantly. In this configuration, the control device sets a larger remaining charge for power supply during periods of greater fluctuation in the solar panel's power generation. As a result, power is supplied to the power supply device when the charge / discharge device has a larger remaining charge. This means that power is supplied to the power supply device when there is a greater margin to suppress the increase in power received from the power grid through discharge from the charge / discharge device. Consequently, even if the solar panel's power generation decreases significantly, there is a higher probability that the increase in power received from the power grid can be suppressed. Therefore, it is possible to provide a power supply system that can charge electric vehicles with power generated by solar panels while suppressing an increase in power received from the power grid.

[0014] Another characteristic configuration of the power supply system according to the present invention is that, when power is being supplied from the power supply device to the traction battery of the electric vehicle, the control device stops supplying power from the power supply device to the traction battery of the electric vehicle when the remaining charge of the charge / discharge device decreases to a predetermined remaining charge level that is smaller than the remaining charge level at which power is supplied.

[0015] According to the above configuration, when the remaining charge of the charge / discharge device decreases to a predetermined power supply stop level, which is smaller than the power supply start level, power is stopped from the power supply device to the electric vehicle's traction battery. In other words, when the remaining charge of the charge / discharge device is low, that is, when there is little surplus capacity to suppress the increase in power received from the power grid by discharging from the charge / discharge device, power is not supplied from the power supply device to the electric vehicle's traction battery. As a result, if there is a surplus of power generated by the solar panel afterward, that surplus power is charged into the charge / discharge device, increasing its remaining charge. [Brief explanation of the drawing]

[0018] [Figure 1] This is a diagram showing the configuration of a power supply system. [Figure 2] This is a flowchart explaining the power supply control for electric vehicles. [Figure 3] This figure shows the changes in surplus power at the facility, power supplied to electric vehicles, and remaining charge of the charging / discharging device. [Modes for carrying out the invention]

[0019] A power supply system according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of a power supply system. As illustrated, a power supply system is provided in a facility 10 such as a residence or business office, in which a solar cell device 11, a charging / discharging device 12, a power consumption device 14, and a power feeding device 13 for feeding power to an electric vehicle 20 including a traveling storage battery 21 are connected to a power line 2 connected to an electric power grid 1. The power supply system further includes a control device 15.

[0020] The electric vehicle 20 is a vehicle including a traveling storage battery 21. The electric vehicle 20 also includes a vehicle-side terminal 22 that connects the traveling storage battery 21 to an external device. For example, the electric vehicle 20 is an electric vehicle, a plug-in hybrid vehicle, or the like that drives a traveling motor (not shown) using electric power from the traveling storage battery 21.

[0021] Power consumption consumed by the power consumption device 14 is measured by a power consumption measurement unit 5. Generated power supplied from the solar cell device 11 to the power line 2 is measured by a generated power measurement unit 4. Received power supplied from the electric power grid 1 to the power line 2 of the facility 10 is measured by a received power measurement unit 3.

[0022] The facility 10 is provided with a facility-side terminal 16 connected to the power line 2. The power feeding device 13 is provided between the facility-side terminal 16 and the power line 2. When the vehicle-side terminal 22 of the electric vehicle 20 and the facility-side terminal 16 of the facility 10 are connected, the power line 2 of the facility 10 and the traveling storage battery 21 of the electric vehicle 20 are electrically connected via the power feeding device 13.

[0023] The power feeding device 13 includes a power conversion circuit unit and an operation control unit that controls the operation of the power conversion circuit unit, and controls power feeding (charging) operation to the traveling storage battery 21 provided in the electric vehicle 20. That is, the power feeding device 13 can perform charging from the facility 10 to the traveling storage battery 21 of the electric vehicle 20 (i.e., power feeding from the power line 2 of the facility 10 to the traveling storage battery 21 of the electric vehicle 20). Note that in the present embodiment, the power feeding device 13 cannot perform power feeding from the traveling storage battery 21 of the electric vehicle 20 to the facility 10 (i.e., power supply from the traveling storage battery 21 of the electric vehicle 20 to the power line 2 of the facility 10).

[0024] The charge / discharge device 12 controls the discharge power to the power line 2 or the charging power from the power line 2 so that the power measured by the power receiving unit 3 approaches a predetermined value. For example, a specific example of the case where the predetermined value is zero is described below. In that case, if the power generated by the solar cell device 11 is greater than the sum of the power consumed by the power consumption device 14 and the power supplied from the power supply device 13 to the electric vehicle 20, i.e., if surplus power is generated, the charge / discharge device 12 can approach the power measured by the power receiving unit 3 to zero (an example of the "predetermined value") by charging power equivalent to the surplus power. Alternatively, if the power generated by the solar cell device 11 is less than the sum of the power consumed by the power consumption device 14 and the power supplied from the power supply device 13 to the electric vehicle 20, i.e., if a power deficit is generated, the charge / discharge device 12 can approach the power measured by the power receiving unit 3 to zero (an example of the "predetermined value") by discharging power equivalent to the power deficit. Furthermore, the charge / discharge device 12 does not perform either charging or discharging when the power generated by the solar cell device 11 is equal to the sum of the power consumed by the power consumption device 14 and the power supplied from the power supply device 13 to the electric vehicle 20, that is, when there is no surplus or deficit power. In addition, the charge / discharge device 12 controls the discharge power so that the remaining charge does not fall below a predetermined lower limit during normal operation when there is no power outage, in order to leave a reserve of power to supply power to the power consumption device 14 in the event of an emergency such as a power outage.

[0025] The control device 15 receives information from the charge / discharge device 12 regarding the remaining charge level of the charge / discharge device 12. The control device 15 also receives information from the power supply device 13 regarding whether or not the electric vehicle 20 is connected to the power supply device 13, that is, whether or not the facility-side terminal 16 is connected to the vehicle-side terminal 22. In addition, the control device 15 also receives information from the charge / discharge device 12 regarding the operating status of the charge / discharge device 12, such as whether the charge / discharge device 12 is charging, discharging, or neither.

[0026] The control device 15 can control the power supplied from the power supply device 13 to the traction battery 21 of the electric vehicle 20 by controlling the operation of the power supply device 13. For example, while the traction battery 21 of the electric vehicle 20 is connected to the power supply device 13, the control device 15 can transmit commands to the power supply device 13 to execute power supply to the traction battery 21 of the electric vehicle 20, to stop power supply to the traction battery 21 of the electric vehicle 20, to increase the power supplied to the traction battery 21 of the electric vehicle 20, and to decrease the power supplied to the traction battery 21 of the electric vehicle 20.

[0027] When the power supply device 13 receives a command from the control device 15 to supply power to the traction battery 21 of the electric vehicle 20, it supplies power to the electric vehicle 20 at or above a predetermined minimum power supply level while the traction battery 21 of the electric vehicle 20 is connected to the power supply device 13.

[0028] When the power supply device 13 receives a command from the control device 15 to stop supplying power to the traction battery 21 of the electric vehicle 20, it stops supplying power to the traction battery 21 of the electric vehicle 20.

[0029] When the power supply device 13 receives a command from the control device 15 to increase the power supplied to the traction battery 21 of the electric vehicle 20, it increases the power supplied to the traction battery 21 of the electric vehicle 20 to a predetermined maximum power supply at a predetermined rate. When the power supply device 13 receives a command from the control device 15 to decrease the power supplied to the traction battery 21 of the electric vehicle 20, it decreases the power supplied to the traction battery 21 of the electric vehicle 20 to the minimum power supply at a predetermined rate.

[0030] For example, if the power supply device 13 is supplying power to the traction battery 21 of the electric vehicle 20 and the charge / discharge device 12 is charging, that is, if a surplus power as described above is generated, the control device 15 transmits a command to the power supply device 13 to increase the power supplied to the traction battery 21 of the electric vehicle 20. Conversely, if the power supply device 13 is supplying power to the traction battery 21 of the electric vehicle 20 and the charge / discharge device 12 is discharging, that is, if a power shortage as described above is generated, the control device 15 transmits a command to the power supply device 13 to decrease the power supplied to the traction battery 21 of the electric vehicle 20.

[0031] Next, with reference to Figure 2, we will explain the power supply control to the electric vehicle 20 that the control device 15 instructs the power supply device 13 to perform. Figure 2 is a flowchart illustrating the power supply control to the electric vehicle 20.

[0032] As will be explained in detail below, the control device 15 is configured to control the power supplied from the power supply device 13 to the traction battery 21 of the electric vehicle 20 according to the remaining charge of the charge / discharge device 12, so as to suppress the power supply to the traction battery 21 of the electric vehicle 20 connected to the power supply device 13 when the remaining charge of the charge / discharge device 12 is less than a predetermined amount.

[0033] Furthermore, if the power supply from the power supply device 13 to the traction battery 21 of the electric vehicle 20 is stopped and the remaining charge of the charge / discharge device 12 is less than a predetermined power supply start amount, the control device 15 will supply power from the power supply device 13 to the traction battery 21 of the electric vehicle 20 to increase the remaining charge of the traction battery 21 once the remaining charge of the charge / discharge device 12 increases to or above the power supply start amount. In addition, if power is being supplied from the power supply device 13 to the traction battery 21 of the electric vehicle 20, the control device 15 will stop supplying power from the power supply device 13 to the traction battery 21 of the electric vehicle 20 once the remaining charge of the charge / discharge device 12 decreases to or below a predetermined power supply stop amount which is smaller than the power supply start amount. As described above, the charge / discharge device 12 controls the discharge power so that the remaining charge does not fall below a predetermined lower limit during normal operation when no power outage occurs, in order to leave a reserve of power to supply the power consumption device 14 in the event of an emergency such as a power outage. This remaining power supply is above the aforementioned lower limit.

[0034] The control device 15 repeatedly executes the flowchart shown in Figure 2 at set timings. In step #10 of Figure 2, the control device 15 determines whether the electric vehicle 20 is connected to the facility 10. For example, the power supply device 13 can detect whether the vehicle-side terminal 22 of the electric vehicle 20 is connected to the facility-side terminal 16. Based on the information transmitted from the power supply device 13 regarding whether the vehicle-side terminal 22 of the electric vehicle 20 is connected to the facility-side terminal 16, the control device 15 can determine whether the electric vehicle 20 is connected to the facility 10. If the electric vehicle 20 is connected to the facility 10 (i.e., "Yes" in step #10), the control device 15 proceeds to step #11, and if the electric vehicle 20 is not connected to the facility 10 (i.e., "No" in step #10), the control device 15 terminates this flowchart.

[0035] In step #11, the control device 15 determines whether the power supply device 13 is currently supplying power to the electric vehicle 20. If the power supply device 13 is currently supplying power to the electric vehicle 20, the control device 15 proceeds to step #14; otherwise, it proceeds to step #12.

[0036] In step #12, the control device 15 determines whether the remaining charge of the charge / discharge device 12 is equal to or greater than a predetermined power supply start amount. For example, the control device 15 can determine whether the remaining charge of the charge / discharge device 12 is equal to or greater than the power supply start amount based on information about the remaining charge of the charge / discharge device 12 transmitted from the charge / discharge device 12. If the remaining charge of the charge / discharge device 12 is equal to or greater than the power supply start amount, the control device 15 proceeds to step #13 to supply power to the electric vehicle 20. Specifically, the control device 15 transmits a command to the power supply device 13 to supply power to the traction battery 21 of the electric vehicle 20. As a result, the power supply device 13 supplies power to the traction battery 21 of the electric vehicle 20. If the control device 15 determines in step #12 that the remaining charge of the charge / discharge device 12 is less than the power supply start amount, it terminates this flowchart without having the power supply device 13 supply power to the traction battery 21 of the electric vehicle 20.

[0037] Next, in step #14, the control device 15 determines whether the remaining charge of the charge / discharge device 12 is less than or equal to a predetermined power supply stop amount, which is smaller than the power supply start amount. If the remaining charge of the charge / discharge device 12 is less than or equal to the power supply stop amount, the control device 15 proceeds to step #15 and instructs the power supply device 13 to stop supplying power to the electric vehicle 20. If the remaining charge of the charge / discharge device 12 is not less than or equal to the power supply stop amount, this flowchart ends (i.e., power supply to the electric vehicle 20 continues).

[0038] Figure 3 shows the changes in surplus power from facility 10, power supplied to electric vehicle 20, and remaining charge of charge / discharge device 12. In Figure 3, the surplus power shown by the solid line is the value obtained by subtracting the power consumption of power consumption device 14 from the power generated by solar cell device 11. In Figure 3, the power supplied by the dashed line is the power supplied from power supply device 13 to electric vehicle 20. Figure 3 also shows the power corresponding to charging power and discharging power.

[0039] As shown in the figure, at time t1, the control device 15 determines that the electric vehicle 20 is connected to the facility 10. At this point, power is not supplied to the electric vehicle 20. In this case, the control device 15 determines whether the remaining charge of the charge / discharge device 12 is equal to or greater than the remaining charge for starting power supply (step #12 in Figure 2). In the example shown in Figure 3, the remaining charge of the charge / discharge device 12 is not equal to or greater than the remaining charge for starting power supply, so the control device 15 does not supply power to the electric vehicle 20. Therefore, all surplus power generated at the facility 10 is charged by the charge / discharge device 12, and the remaining charge of the charge / discharge device 12 increases.

[0040] Subsequently, at time t2, the control device 15 determines that the remaining charge of the charge / discharge device 12 is equal to or greater than the remaining charge for starting power supply. The control device 15 then instructs the power supply device 13 to begin supplying power to the electric vehicle 20. For example, the power supply device 13 starts supplying power to the electric vehicle 20 at the minimum power supply level. At time t2, a portion of the surplus power of the facility 10 (i.e., the minimum power supply level) is supplied from the power supply device 13 to the electric vehicle 20, and the remaining surplus power of the facility 10 is charged by the charge / discharge device 12. Since the charge / discharge device 12 is charging, there is capacity to increase the power supplied from the power supply device 13 to the electric vehicle 20, so the control device 15 transmits a command to the power supply device 13 to increase the power supplied to the traction battery 21 of the electric vehicle 20. As a result, the power supplied from the power supply device 13 to the electric vehicle 20 gradually increases, and the charging power of the charge / discharge device 12 gradually decreases.

[0041] At time t3, the surplus power (=power generated by solar cell 11 - power consumed by power consumption device 14) decreases rapidly, for example, due to clouds blocking sunlight to the solar cell 11. In this case, since the power supply device 13 maintains the power supplied to the electric vehicle 20 at the same level as before time t3, the charge / discharge device 12 discharges power to make the power measured by the power receiving unit 3 zero, for example, and the power discharged by the charge / discharge device 12 and the power generated by the solar cell 11 are supplied from the power supply device 13 to the electric vehicle 20. As a result of the discharge, the remaining charge of the charge / discharge device 12 gradually decreases.

[0042] Furthermore, if the power supply device 13 is supplying power to the traction battery 21 of the electric vehicle 20, and the charge / discharge device 12 is discharging, i.e., if a power shortage occurs, the control device 15 transmits a command to the power supply device 13 to reduce the power supplied to the traction battery 21 of the electric vehicle 20. As a result, the power supplied from the power supply device 13 to the electric vehicle 20 gradually decreases to the minimum power supply. Also, since the charge / discharge device 12 is discharging after time t3, the remaining charge of the charge / discharge device 12 gradually decreases.

[0043] Subsequently, at time t4, the power generated by the solar cell device 11 increases, and the charge / discharge device 12 begins to charge with the surplus power, causing the remaining charge of the charge / discharge device 12 to gradually increase.

[0044] As the control device 15, charge / discharge device 12, and power supply device 13 operate as described above, the remaining charge of the charge / discharge device 12 repeatedly increases and decreases. In the example shown in Figure 3, at time t8, the remaining charge of the charge / discharge device 12 is below the power supply stop level. Therefore, the control device 15 instructs the power supply device 13 to stop supplying power to the electric vehicle 20 (step #15 in Figure 2). The control device 15 then returns to step #10 in Figure 2, and if the remaining charge of the charge / discharge device 12 increases to above the power supply start level (step #10 → step #11 → step #12 → step #13), it resumes supplying power to the traction battery 21 of the electric vehicle 20 in step #13.

[0045] As described above, in the power supply system of this embodiment, power can be supplied from the power supply device 13 connected to the power line 2 to the traction battery 21 of the electric vehicle 20. In other words, the power generated by the solar cell device 11 can be supplied to the traction battery 21 of the electric vehicle 20 via the power line 2. Furthermore, the control device 15 controls the power supplied from the power supply device 13 to the traction battery 21 of the electric vehicle 20 according to the remaining charge of the charge / discharge device 12, so as to suppress the power supply to the traction battery 21 of the electric vehicle 20 connected to the power supply device 13 when the remaining charge of the charge / discharge device 12 is low. In other words, when the remaining charge of the charge / discharge device 12 is low, that is, when there is little capacity to suppress the increase in power received from the power system 1 by the discharge from the charge / discharge device 12, the power supplied from the power supply device 13 to the traction battery 21 of the electric vehicle 20 is suppressed. Therefore, it is possible to provide a power supply system that can charge the electric vehicle 20 with the power generated by the solar cell device 11 while suppressing an increase in the power received from the power grid 1.

[0046] <Another Embodiment> <1> In the above embodiment, the configuration of the power supply system was described with specific examples, but the configuration can be changed as appropriate.

[0047] For example, in the above embodiment, the control device 15 may be shared with a control unit that controls the operation of the charge / discharge device 12, etc. Alternatively, the control device 15 may be implemented by a HEMS (Home Energy Management System) installed in the facility 10. For example, the HEMS can communicate information via communication lines with the solar cell device 11, the charge / discharge device 12, the power supply device 13, the power consumption device 14, the power receiving measurement unit 3, the power generating measurement unit 4, the power consumption measurement unit 5, etc., receive information from each of them, and transmit information to the charge / discharge device 12, the power supply device 13, the power consumption device 14, etc.

[0048] <2> The above-mentioned remaining power supply amount for starting power supply and remaining power supply amount for stopping power supply can be set as appropriate. Furthermore, the remaining power supply amount for starting power supply and remaining power supply amount for stopping power supply may be fixed values ​​or values ​​that can be changed as needed. For example, the remaining power supply amount for starting power supply may be set to a large value during periods when the power generated by the solar cell system 11 fluctuates greatly, and to a small value during periods when the power generated by the solar cell system 11 fluctuates little. In other words, the control device 15 may set the remaining power supply amount for starting power supply to be larger during periods when the power generated by the solar cell system 11 fluctuates greatly.

[0049] To explain with a specific example, the control device 15 receives information about the power generated and supplied from the solar cell device 11 to the power line 2, which is measured by the power generation measurement unit 4. Therefore, the control device 15 recognizes the maximum and minimum values ​​of power generated within a predetermined period in the past from the present. As a result, the control device 15 can derive the fluctuation range (= maximum value - minimum value) of the power generated by the solar cell device 11 within a predetermined period in the past from the present. When the power generated by the solar cell device 11 fluctuates greatly, the charge / discharge device 12 needs to discharge more power in order to suppress the increase in power received from the power system 1 that accompanies the large decrease in the power generated by the solar cell device 11. However, as described above, if the control device 15 sets the remaining charge at the start of power supply to be larger during periods when the power generated by the solar cell device 11 fluctuates greatly, power supply to the power supply device 13 will start when the remaining charge of the charge / discharge device 12 is larger. In other words, power supply to the power supply device 13 will start when there is a greater margin to suppress the increase in power received from the power system 1 through discharge from the charge / discharge device 12. As a result, even if the power generated by the solar cell device 11 decreases significantly, there is a higher possibility that the increase in power received from the power grid 1 can be suppressed.

[0050] <3> In the above embodiment, an example of the operation of the charge / discharge device 12 was specifically described, but the details are provided for illustrative purposes only and can be modified as appropriate.

[0051] <4> The configurations disclosed in the above embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. Furthermore, the embodiments disclosed herein are illustrative, and the embodiments of the present invention are not limited thereto and can be modified as appropriate without departing from the purpose of the present invention. [Industrial applicability]

[0052] This invention can be used in a power supply system that can charge electric vehicles with power generated by a solar cell while suppressing an increase in power received from the power grid. [Explanation of Symbols]

[0053] 1: Power system 2: Power lines 11: Solar cell device 12: Charge / discharge device 13: Power supply device 14:Power consumption device 15: Control device 20: Electric vehicles

Claims

1. A power supply system in which a solar cell device, a charging / discharging device, a power consumption device, and a power supply device for supplying power to an electric vehicle having a traction battery are connected to a power line connected to the power grid, When the remaining charge of the charge / discharge device is less than a predetermined amount, the power supply from the power supply device to the traction battery of the electric vehicle connected to the power supply device is suppressed, and the power supply from the power supply device to the traction battery of the electric vehicle is controlled according to the remaining charge of the charge / discharge device, The control device, when the power supply from the power supply device to the traction battery of the electric vehicle is stopped and the remaining charge of the charge / discharge device is less than a predetermined power supply start amount, will resume power supply from the power supply device to the traction battery of the electric vehicle when the remaining charge of the charge / discharge device increases to or equal to the power supply start amount. The control device is a power supply system that sets the remaining power supply amount to be larger during periods when the power generated by the solar cell device fluctuates significantly.

2. The power supply system according to claim 1, wherein, when power is being supplied from the power supply device to the traction battery of the electric vehicle, the control device stops supplying power from the power supply device to the traction battery of the electric vehicle when the remaining charge of the charge / discharge device decreases to a predetermined remaining charge that is smaller than the remaining charge at the start of power supply.

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