Charging and discharging device for electric vehicle

Abstract

To provide a charging and discharging device for an electric vehicle capable of efficiently charging and discharging a driving battery while suppressing wear of a contactor of the electric vehicle.SOLUTION: A charging and discharging device for an electric vehicle 10A includes: a power conversion unit 20 connected to a power distribution line 101 of a consumer's house at an AC side input and output end; a cable 50 connected at a base end connected to a DC side input and output end of the power conversion unit 20 and an electric vehicle 120; and a control unit 30A. The control unit 30A includes an opening / closing plan creation unit 31A that creates a plan for each time period regarding the opening and closing of a contactor 123 provided on a power path in the electric vehicle 120, and a contact point control unit 32A that opens and closes the contactor 123 according to the plan, and the contact point control unit 32A closes the contactor 123 in the time period when the contactor 123 is planned to be closed in the time periods of both ends of the time periods even if the contactor 123 is planned to be closed in the time periods to be controlled.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a charging / discharging device for an electric vehicle that is used by connecting it to a photovoltaic power generation device and a load device via a consumer-premises power distribution line that is connected to a commercial power system. [Background technology]

[0002] Electric vehicles, plug-in hybrid vehicles, and other electric vehicles are equipped with a charging port that can be connected to an electric vehicle charging / discharging device called V2H (Vehicle to Home), a large-capacity drive battery connected to the charging port via a contactor, and a control unit (hereinafter referred to as the "electric vehicle-side control unit") that controls the charging and discharging of the drive battery and the opening and closing of the contactor based on the current, voltage, and the like of each part. Such an electric vehicle is described in, for example, Patent Document 1.

[0003] The electric vehicle control unit is capable of controlling charging and discharging when the cable of the electric vehicle charging and discharging device is connected to the charging port and the contactor is closed to form a power supply path between the power conversion unit (such as a bidirectional AC / DC inverter) constituting the electric vehicle charging and discharging device and the drive battery. At this time, the power consumption of the electric vehicle control unit increases compared to when it is unable to control charging and discharging, reaching 200 Wh in one example. The electric vehicle control unit operates by receiving power from the drive battery. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6704799 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, the electric vehicle control unit consumes the power stored in the drive battery during operation. For this reason, in a conventional electric vehicle charging / discharging device, when the electric vehicle cannot supply a certain amount of power to the load device via the electric vehicle charging / discharging device and the consumer's power distribution line (for example, when the load device consumes little power or when the solar power generation device generates a lot of power), the drive battery is discharged, and as a result, the proportion of the power consumed by the electric vehicle control unit in the discharged power of the drive battery can become quite large.

[0006] Furthermore, in conventional charging / discharging devices for electric vehicles, when the solar power generation device is unable to supply a certain amount of power to the electric vehicle via the consumer's power distribution line and the charging / discharging device for electric vehicles (for example, when the power consumption of the load device is high or the power generated by the solar power generation device is low), the drive battery is charged and as a result, most (or all) of the power supplied to the electric vehicle may be consumed by the control unit on the electric vehicle side.

[0007] These two problems can be solved by opening and closing the contactors of the electric vehicle based on the amount of power the electric vehicle supplies to the load device or the amount of power the solar power generation system supplies to the electric vehicle. However, this method has the risk of causing wear on the contactors, which are mechanical contacts, due to frequent opening and closing.

[0008] The present invention has been made in consideration of the above circumstances, and has an object to provide a charging / discharging device for an electric vehicle that can efficiently charge and discharge a drive battery while suppressing wear on the contactors of the electric vehicle. [Means for solving the problem]

[0009] In order to solve the above problem, the charging / discharging device for electric vehicles of the present invention is a device that is used by connecting it to a photovoltaic power generation device and a load device via a consumer's distribution line that is connected to a commercial power system, and includes: a power conversion unit having an AC side input / output terminal and a DC side input / output terminal, and connected to the consumer's distribution line at the AC side input / output terminal; a cable that is a connector having a tip and a base end, the base end being connected to the DC side input / output terminal of the power conversion unit and the tip being configured to engage with a charging port of the electric vehicle; and a control unit, wherein the control unit includes an opening / closing schedule creation unit that creates a plan for each time period as to whether a mechanical contact provided on a power supply path in the electric vehicle connected to the connector should be closed or open based on information provided from the outside, and a contact control unit that closes or opens the mechanical contact in accordance with the created plan, and the contact control unit closes the mechanical contact during a time period in which control is to be performed, if the mechanical contact is planned to be closed during time periods on both sides of the time period on which control is to be performed.

[0010] In this configuration, even if the mechanical contacts are scheduled to be open during a time period when control should be performed (for example, 18:30 to 19:00), if the mechanical contacts are scheduled to be closed during the two adjacent time periods (18:00 to 18:30 and 19:00 to 19:30), the mechanical contacts will be closed during those time periods (18:30 to 19:00). Therefore, with this configuration, the frequency of opening and closing the mechanical contacts can be reduced, and as a result, the wear of the mechanical contacts can be slowed down.

[0011] The control unit of the electric vehicle charging / discharging device may further include a power conversion control unit that operates the power conversion unit to supply power from the electric vehicle to the load device so as to prevent reverse power flow to the commercial power grid when the mechanical contact is in a closed state, and in this case, it is preferable that the power conversion control unit stops the power conversion unit when power actually supplied from the electric vehicle to the load device falls below a predetermined first threshold value.

[0012] According to this configuration, when a forecast based on externally provided information turns out to be incorrect, it is possible to prevent the drive battery of the electric vehicle from being discharged under inefficient conditions.

[0013] In addition, the control unit of the electric vehicle charging / discharging device may further include a power conversion control unit that operates the power conversion unit to supply power from the solar power generation device to the electric vehicle when the mechanical contact is in a closed state, and in this case, it is preferable that the power conversion control unit stops the power conversion unit when the power actually supplied from the solar power generation device to the electric vehicle falls below a predetermined second threshold value.

[0014] According to this configuration, when a forecast based on externally provided information turns out to be incorrect, it is possible to prevent the drive battery of the electric vehicle from being charged under inefficient conditions. Effect of the Invention

[0015] According to the present invention, it is possible to provide a charging / discharging device for an electric vehicle that is capable of efficiently charging and discharging a drive battery while suppressing wear on the contactors of the electric vehicle. [Brief description of the drawings]

[0016] [Figure 1] 1 is a diagram showing the configuration of an electric vehicle charging / discharging device and its surroundings according to a first embodiment. [Diagram 2] 3 is a diagram showing an example of data stored in an opening and closing schedule creation unit constituting the electric vehicle charging and discharging device according to the first embodiment; FIG. [Diagram 3] 3 is a diagram for explaining the operation of an opening and closing schedule creation unit and a contact control unit that configure the electric vehicle charging and discharging device according to the first embodiment. FIG. [Figure 4] 5 is a graph showing the relationship between a threshold value and discharge efficiency and power consumption in the first embodiment. [Diagram 5] FIG. 11 is a diagram showing the configuration of an electric vehicle charging / discharging device and its surroundings according to a second embodiment. [Figure 6]FIG. 11 is a diagram showing an example of data stored in an opening and closing schedule creation unit constituting an electric vehicle charging / discharging device according to a second embodiment. [Figure 7] 13 is a diagram for explaining the operation of an opening and closing schedule creation unit and a contact control unit that configure an electric vehicle charging and discharging device according to a second embodiment. FIG. [Figure 8] 13 is a graph showing the relationship between a threshold and charging efficiency and power consumption in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a charging / discharging device for an electric vehicle according to the present invention will be described with reference to the accompanying drawings.

[0018] [First Example] 1 shows an electric vehicle charging / discharging device 10A according to a first embodiment of the present invention and its peripheral configuration. The electric vehicle charging / discharging device 10A is installed and used so as to be connected to a photovoltaic power generation device 110 and one or more load devices 111 via a consumer-premises power distribution line 101 that is connected to a commercial power system 100 via a switch 102. An electric vehicle 120 is also connected to the electric vehicle charging / discharging device 10A.

[0019] The electric vehicle 120 is a typical device that includes a large-capacity driving battery 121 that supplies the power required for the traveling motor, a charging port 122, a contactor 123 having a mechanical contact provided between them (i.e., on the power supply path), and an electric vehicle-side control unit 124 consisting of an MPU (Micro Processing Unit) or the like. The electric vehicle-side control unit 124 operates by consuming the power stored in the driving battery 121, and can control the charging and discharging of the driving battery 121, monitor the state of the driving battery 121, and open and close the contactor 123. The electric vehicle-side control unit 124 can also communicate with a control unit 30A (particularly a contact control unit 32A) of an electric vehicle charging / discharging device 10A described later.

[0020] The solar power generation device 110 supplies AC power generated according to the amount of solar radiation to the commercial power system 100, a load device 111, or an electric vehicle charging / discharging device 10A (a driving battery 121 of an electric vehicle 120).

[0021] The load device 111 operates by receiving supply of system power from the commercial power system 100, power generated by the solar power generation device 110, or output power (discharge power of the driving battery 121) from the electric vehicle charging / discharging device 10A. An example of the load device 111 is an electrical appliance used in a consumer's home.

[0022] The electric vehicle charging / discharging device 10A is called a V2H device, and includes a power conversion unit 20, a control unit 30A, a relay 40, and a cable 50.

[0023] The power conversion unit 20 includes an AC / DC inverter 21 and a DC / DC converter 22 capable of bidirectional operation. The AC / DC inverter 21 has an AC side input / output terminal and a DC side input / output terminal. When the electric vehicle charging / discharging device 10A is installed, the AC side input / output terminal of the AC / DC inverter 21 is connected to a consumer-side power distribution line 101. The DC / DC converter 22 has a first input / output terminal and a second input / output terminal. The first input / output terminal of the DC / DC converter 22 is connected to a DC side input / output terminal of the AC / DC inverter 21, and the second input / output terminal is connected to a relay 40. The AC side input / output terminal of the AC / DC inverter 21 corresponds to the "AC side input / output terminal (of the power conversion unit 20)" of the present invention. The second input / output terminal of the DC / DC converter 22 corresponds to the "DC side input / output terminal (of the power conversion unit 20)" of the present invention.

[0024] The power conversion unit 20 can convert AC power supplied to the AC side input / output terminal into DC power and output it from the DC side input / output terminal, or convert DC power supplied to the DC side input / output terminal into AC power and output it from the AC side input / output terminal, by the AC / DC inverter 21 and the DC / DC converter 22 performing power conversion operations under the control of the control unit 30A (in particular, the power conversion control unit 33A described later).

[0025] The cable 50 has a distal end and a proximal end. The distal end of the cable 50 is a connector 51 configured to engage with a charging port 122 of the electric vehicle 120.

[0026] The relay 40 is provided between the second input / output terminal of the DC / DC converter 22 and the base end of the cable 50. The relay 40 can be in a closed state or an open state under the control of the control unit 30A (particularly, a contact control unit 32A described later). When the relay 40 is in a closed state, the DC / DC converter 22 and the cable 50 are electrically connected.

[0027] The control unit 30A is configured with an MPU and associated memory, and includes an opening / closing schedule creation unit 31A, the contact control unit 32A, and the power conversion control unit 33A. The control unit 30A controls the power conversion operation of the power conversion unit 20 and the opening / closing of the relay 40 while referring to a current value at the AC side input / output terminal of the power conversion unit 20 measured by a current measurement unit (not shown), a voltage value of the consumer distribution line 101 measured by a voltage measurement unit (not shown), and a current value measured by a current measurement unit 103 provided between the switch 102 and the commercial power system 100. The control unit 30A also communicates with the electric vehicle side control unit 124 of the electric vehicle 120, and causes the electric vehicle side control unit 124 to open and close the contactor 123. That is, the control unit 30A indirectly controls the opening and closing of the contactor 123. The current value measured by the current measurement unit 103 corresponds to the "information provided from the outside" of the present invention.

[0028] The configuration and operation of the control unit 30A in this embodiment will now be described in more detail.

[0029] The opening and closing schedule creation unit 31A of the control unit 30A stores past data corresponding to the shortfall of the power generated by the photovoltaic power generation device 110 with respect to the power consumption of the load device 111 for every 30 minutes for the past three weeks. For example, if today is June 1, 2023 (Thursday), the opening and closing schedule creation unit 31A stores past data from May 11, 2023 (Thursday) to May 31, 2023 (Wednesday). FIG. 2 shows an example of past data stored in the opening and closing schedule creation unit 31A. This past data indicates that the shortfall from 14:30 to 15:00 on May 11, 2023 (Thursday) was 400 Wh on average, and that the shortfall from 15:00 to 15:30 on the same day was 100 Wh on average, etc.

[0030] Here, if there is no power exchange between electric vehicle charging / discharging device 10A and consumer power distribution line 101, the shortage is equal to the amount of power supplied by commercial power system 100 to load device 111, i.e., the amount of power purchased by the consumer from the power company. In this case, the shortage can be calculated based on the current value measured by current measurement unit 103 (i.e., information provided from outside) and the voltage value of consumer power distribution line 101 measured by a voltage measurement unit (not shown). On the other hand, if there is power exchange between electric vehicle charging / discharging device 10A and consumer power distribution line 101, the shortage can be calculated based on the amount of power exchanged and the amount of purchased power.

[0031] The opening and closing schedule creation unit 31A of the control unit 30A further refers to the stored past data and creates a schedule for each time period as to whether the contactor 123 and the relay 40 are to be in the closed state or the open state.

[0032] Specifically, if the day on which control should be performed (hereinafter referred to as the "control date") is Thursday, June 1, 2023, the opening and closing plan creation unit 31A refers to the past data for Thursday, May 11, 2023, which is exactly three weeks before the control date (hereinafter referred to as the "first past data"), the past data for Thursday, May 18, 2023, which is exactly two weeks before the control date (hereinafter referred to as the "second past data"), and the past data for Thursday, May 25, 2023, which is exactly one week before the control date (hereinafter referred to as the "third past data") (see Figure 3(A)). Then, the opening / closing schedule creation unit 31A compares the shortages from 14:30 to 15:00 contained in the first to third past data (400 Wh, 200 Wh, 200 Wh) with a predetermined threshold value (400 Wh in this embodiment), and based on the fact that the number of days when the shortage was 400 Wh or more was less than two (the number of days was one day), creates a schedule to open the contactor 123 and relay 40 from 14:30 to 15:00 on the control day (see FIG. 3(B)). Similarly, the opening and closing schedule preparation unit 31A compares the shortages (400Wh, 200Wh, 400Wh) from 16:30 to 17:00 included in the first to third past data with 400Wh, and creates a schedule to close the contactor 123 and the relay 40 from 16:30 to 17:00 on the control day based on the fact that the number of days when the shortage was 400Wh or more was two or more (the number of days was two) (see FIG. 3(B)). The opening and closing schedule preparation unit 31A creates this plan late at night (for example, 23:30 to 24:00) on the day before the control day.

[0033] The contact control unit 32A of the control unit 30A closes or opens the relay 40 in accordance with the plan created by the opening and closing schedule creation unit 31 A. In other words, the contact control unit 32A directly controls the opening and closing of the relay 40 in accordance with the plan.

[0034] Furthermore, the contact control unit 32A of the control unit 30A closes or opens the contactor 123 according to the plan created by the opening and closing schedule creation unit 31 A. In other words, the contact control unit 32A indirectly controls the opening and closing of the contactor 123 according to the plan.

[0035] When the contactor 123 and the relay 40 are in a closed state, the power conversion control unit 33A of the control unit 30A causes the AC / DC inverter 21 and the DC / DC converter 22 to perform power conversion operations so as to prevent reverse power flow to the commercial power system 100, thereby converting the DC power supplied to the DC side input / output terminal (i.e., the discharge power of the driving battery 121 of the electric vehicle 120) into AC power and outputting it from the AC side input / output terminal.

[0036] This makes it possible to discharge the driving battery 121 of the electric vehicle 120 only during times when it is expected that a certain amount of power can be discharged. In other words, it becomes possible to discharge the driving battery 121 efficiently.

[0037] However, if the contactor 123 having mechanical contacts is opened and closed according to the above schedule, frequent opening and closing may cause wear on the contactor 123. For this reason, the contact control unit 32A performs a predetermined adjustment process on the schedule shown in Fig. 3(B) and opens and closes the contactor 123 based on the result (see Fig. 3(C)). Although the possibility of wear is lower than that of the contactor 123, it is preferable to perform a similar adjustment process on the relay 40.

[0038] That is, even if the contactor 123 and the relay 40 are scheduled to be in the open state during a time period in which control should be performed, if the contactor 123 and the relay 40 are scheduled to be in the closed state during two time periods adjacent to the time period, the contact control unit 32A determines to close the contactor 123 and the relay 40 during the time period instead of opening them, and if either of them is in the open state, determines to open the contactor 123 and the relay 40 during the time period according to the above plan. For example, since the plans for 18:00-18:30 and 19:00-19:30 are for the closed state, the contact control unit 32A determines to close the contactor 123 and the relay 40 from 18:30 to 19:00. On the other hand, since the plan for 16:30 to 17:00 is the closed state but the plan for 17:30 to 18:00 is the open state, contact control unit 32A determines to open contactor 123 and relay 40 from 17:00 to 17:30 in accordance with the plan.

[0039] By opening and closing the contactor 123 and the relay 40 based on the result of the adjustment process, it is possible to reduce the frequency of opening and closing the contactor 123 and the relay 40 compared to opening and closing the contactor 123 and the relay 40 according to the plan. As a result, although the discharge efficiency of the driving battery 121 decreases slightly, wear on the contactor 123 and the relay 40 (particularly the contactor 123) can be suppressed (the lifespan can be improved).

[0040] The threshold value used when creating the plan (here, P th1 ) is The daytime electricity rate is 26.33 yen / Wh, Nighttime electricity rates are 15.2 yen / Wh, The charging efficiency of the driving battery 121 via the power conversion unit 20 is 90%, The discharge efficiency of the driving battery 121 via the power conversion unit 20 is 85%; When the power consumption of the electric vehicle side control unit 124 is 200 Wh, For example, by solving equation (1), it can be determined to be 522 Wh.

number

[0041] FIG. 4 shows the threshold P th1 1 is a graph showing the results of calculating the threshold P th1 The lower the power consumption of the electric vehicle side control unit 124, the lower the threshold value P th1 This shows that it is possible to set the

[0042] [Second Example] 5 shows the configuration of an electric vehicle charging / discharging device 10B and its surroundings according to a second embodiment of the present invention. Electric vehicle charging / discharging device 10B differs from electric vehicle charging / discharging device 10A in that it includes a control unit 30B instead of control unit 30A, but is otherwise common to electric vehicle charging / discharging device 10A.

[0043] The control unit 30B is configured with an MPU and associated memory, and includes an opening / closing schedule creation unit 31B, a contact control unit 32B, and a power conversion control unit 33B. The control unit 30B controls the power conversion operation of the power conversion unit 20 and the opening / closing of the relay 40 while referring to a current value at the AC side input / output terminal of the power conversion unit 20 measured by a current measurement unit (not shown), a voltage value of the consumer's distribution line 101 measured by a voltage measurement unit (not shown), and a current value measured by a current measurement unit 103 provided between the switch 102 and the commercial power system 100. The control unit 30B also communicates with the electric vehicle side control unit 124 of the electric vehicle 120, and causes the electric vehicle side control unit 124 to open and close the contactor 123. That is, the control unit 30B indirectly controls the opening and closing of the contactor 123. The current value measured by the current measurement unit 103 corresponds to "information provided from the outside" in the present invention.

[0044] The configuration and operation of the control unit 30B in this embodiment will now be described in more detail.

[0045] The opening and closing schedule creation unit 31B of the control unit 30B stores past data corresponding to the surplus amount of the power generated by the photovoltaic power generation device 110 for every 30 minutes with respect to the power consumption of the load device 111 for the past three weeks. For example, if today is June 1, 2023 (Thursday), the opening and closing schedule creation unit 31B stores past data from May 11, 2023 (Thursday) to May 31, 2023 (Wednesday). FIG. 6 shows an example of past data excerpted from the opening and closing schedule creation unit 31B. This past data indicates that the surplus amount from 9:30 to 10:00 on May 11, 2023 (Thursday) was 1000 Wh on average, and that the surplus amount from 12:00 to 12:30 on the same day was 600 Wh on average, and so on.

[0046] Here, if there is no power exchange between electric vehicle charging / discharging device 10B and consumer power distribution line 101, the surplus amount is equal to the amount of power supplied by photovoltaic power generation device 110 to commercial power system 100, i.e., the amount of power sold by the consumer to the power company. In this case, the surplus amount can be calculated based on the current value measured by current measurement unit 103 (i.e., information provided from outside) and the voltage value of consumer power distribution line 101 measured by a voltage measurement unit (not shown). On the other hand, if there is power exchange between electric vehicle charging / discharging device 10B and consumer power distribution line 101, the surplus amount can be calculated based on the amount of power exchanged and the amount of power sold.

[0047] The opening and closing schedule creation unit 31B of the control unit 30B further refers to the stored past data and creates a schedule for each time period as to whether the contactor 123 and the relay 40 are to be in the closed state or the open state.

[0048] Specifically, if the control date is Thursday, June 1, 2023, the opening / closing plan creation unit 31B refers to the past data for Thursday, May 11, 2023, which is exactly three weeks before the control date (hereinafter referred to as the "first past data"), the past data for Thursday, May 18, 2023, which is exactly two weeks before the control date (hereinafter referred to as the "second past data"), and the past data for Thursday, May 25, 2023, which is exactly one week before the control date (hereinafter referred to as the "third past data") (see Figure 7(A)). Then, the opening and closing schedule creation unit 31B compares the surplus amounts (1000 Wh, 0 Wh, 600 Wh) from 9:30 to 10:00 contained in the first to third past data with a predetermined threshold value (800 Wh in this embodiment), and based on the fact that the number of days when the surplus amount was 800 Wh or more was less than two (the number of days was one), creates a schedule to open the contactor 123 and relay 40 from 9:30 to 10:00 on the control day (see Figure 7(B)). Similarly, the opening and closing schedule creation unit 31B compares the surplus amounts (1000Wh, 0Wh, 900Wh) from 10:00 to 10:30 contained in the first to third past data with 800Wh, and creates a schedule for closing the contactor 123 and the relay 40 from 10:00 to 10:30 on the control day based on the fact that the number of days when the surplus amount was 800Wh or more was two or more (the number of days was two) (see FIG. 7(B)). The opening and closing schedule creation unit 31B creates this schedule late at night (for example, 23:30 to 24:00) on the day before the control day.

[0049] The contact control unit 32B of the control unit 30B closes or opens the relay 40 in accordance with the plan created by the opening and closing schedule creation unit 31B. In other words, the contact control unit 32B directly controls the opening and closing of the relay 40 in accordance with the plan.

[0050] Furthermore, the contact control unit 32B of the control unit 30B closes or opens the contactor 123 in accordance with the plan created by the opening and closing schedule creation unit 31B. In other words, the contact control unit 32B indirectly controls the opening and closing of the contactor 123 in accordance with the plan.

[0051] When the contactor 123 and the relay 40 are in a closed state, the power conversion control unit 33B of the control unit 30B causes the AC / DC inverter 21 and the DC / DC converter 22 to perform power conversion operations, thereby converting the AC power supplied to the AC side input / output terminal (i.e., the portion of the power generated by the solar power generation device 110 that is not consumed by the load device 111) into DC power and outputting it from the DC side input / output terminal.

[0052] This makes it possible to charge the driving battery 121 of the electric vehicle 120 only during times when it is expected that charging can be performed with a relatively large amount of power. In other words, it becomes possible to charge the driving battery 121 efficiently.

[0053] However, if the contactor 123 having mechanical contacts is opened and closed according to the above schedule, frequent opening and closing may cause wear on the contactor 123. For this reason, the contact control unit 32B performs a predetermined adjustment process on the schedule shown in Fig. 7(B) and opens and closes the contactor 123 based on the result (see Fig. 7(C)). Although the possibility of wear is lower than that of the contactor 123, it is preferable to perform a similar adjustment process on the relay 40.

[0054] That is, even if the contactor 123 and the relay 40 are scheduled to be in the open state during a time period in which control should be performed, if the contactor 123 and the relay 40 are scheduled to be in the closed state during time periods on both sides of the time period, the contact control unit 32B determines to close the contactor 123 and the relay 40 during the time period, rather than to open them, and if either of them is in the open state, determines to open the contactor 123 and the relay 40 during the time period according to the above plan. For example, since the plans for 14:00-14:30 and 15:00-15:30 are for the closed state, the contact control unit 32B determines to close the contactor 123 and the relay 40 from 14:30 to 15:00. On the other hand, since the plan for 11:00 to 11:30 is the closed state but the plan for 12:00 to 12:30 is the open state, contact control unit 32B determines to open contactor 123 and relay 40 from 11:30 to 12:00 in accordance with the plan.

[0055] By opening and closing the contactor 123 and the relay 40 based on the result of the above adjustment process, it is possible to reduce the frequency of opening and closing the contactor 123 and the relay 40 compared to opening and closing the contactor 123 and the relay 40 according to the above plan. As a result, although the charging efficiency of the driving battery 121 decreases slightly, wear on the contactor 123 and the relay 40 (particularly the contactor 123) can be suppressed (the lifespan can be improved).

[0056] The threshold value used when creating the plan (here, P th2 ) is The charging efficiency of the driving battery 121 via the power conversion unit 20 is 80%, The power consumption of the electric vehicle side control unit 124 is 200 Wh, When the power to be supplied to the drive battery 121 is 500 Wh or more, For example, by solving equation (2), it can be determined to be 875Wh.

number

[0057] FIG. 8 shows the relationship between the threshold value P th2 1 is a graph showing the results of calculating the threshold P th2 The lower the power consumption of the electric vehicle side control unit 124, the lower the threshold value P th2 This shows that it is possible to set the

[0058] [Variations] Although the electric vehicle charging / discharging devices 10A, 10B according to the first and second embodiments of the present invention have been described above, the configurations of the present invention are not limited to these.

[0059] For example, the power conversion control unit 33A of the electric vehicle charging / discharging device 10A may stop the power conversion operation of the AC / DC inverter 21 and the DC / DC converter 22 and stop the discharge of the driving battery 121 when the power actually supplied from the electric vehicle 120 to the load device 111 falls below a predetermined first threshold even during a time period when the contactor 123 and the relay 40 are closed based on the result of the adjustment process, that is, during a time period when it is expected that a certain amount of power can be discharged. This makes it possible to prevent inefficient discharge. Since the power conversion operation of the AC / DC inverter 21 and the DC / DC converter 22 is simply stopped rather than switching the contactor 123 and the relay 40 from a closed state to an open state, the contactor 123 and the relay 40 are not damaged even when such control is performed.

[0060] Similarly, the power conversion control unit 33B of the electric vehicle charging / discharging device 10B may stop the power conversion operation of the AC / DC inverter 21 and the DC / DC converter 22 and stop charging of the drive battery 121 when the power actually supplied from the solar power generation device 110 to the electric vehicle 120 falls below a predetermined second threshold even during a time period when the contactor 123 and the relay 40 are closed based on the result of the adjustment process, that is, during a time period when charging is expected to be possible with a certain amount of power. This makes it possible to prevent inefficient charging. Since the power conversion operation of the AC / DC inverter 21 and the DC / DC converter 22 is simply stopped rather than switching the contactor 123 and the relay 40 from a closed state to an open state, the contactor 123 and the relay 40 are not damaged even when such control is performed.

[0061] In the present invention, the relationship between the threshold value used when creating a plan and the first threshold value, and the relationship between the threshold value used when creating a plan and the second threshold value are not particularly limited. That is, the first threshold value may be the same as the threshold value used when creating a plan or may be different from the threshold value. Also, the second threshold value may be the same as the threshold value used when creating a plan or may be different from the threshold value.

[0062] The threshold values ​​used in creating the plan in the first embodiment and the method of determining the same, and the threshold values ​​used in creating the plan in the second embodiment and the method of determining the same, are merely examples.

[0063] The past data stored in the opening and closing schedule creation unit 31A and the creation of a plan using the past data are not limited to those described above. Modifications thereof include, for example, the following. -Compare the shortage amount contained in the stored data for the past week with the threshold value. Each of the multiple (e.g., 2 to 5) shortage amounts contained in the stored past data for the past several weeks (e.g., 2 to 5 weeks) is compared with a threshold value. The average value, median, etc. of multiple (e.g., 2 to 5) shortage amounts contained in the stored past data for the past several weeks (e.g., 2 to 5 weeks) is compared with the threshold value. When calculating the average or median, the largest and smallest shortages may be excluded. Furthermore, the past data does not have to be the shortages for every 30 minutes, and may be the shortages for every 5 minutes or every hour, for example.

[0064] The past data stored in the opening and closing schedule creation unit 31B and the creation of a plan using the past data are not limited to those described above. Modifications thereof include, for example, the following. -Compare the surplus amount contained in the stored data for the past week with the threshold value. Each of the multiple (e.g., 2 to 5) surplus amounts contained in the stored past data for the past several weeks (e.g., 2 to 5 weeks) is compared with a threshold value. The average value, median value, etc. of multiple (e.g., 2 to 5) surplus amounts contained in the stored past data for the past several weeks (e.g., 2 to 5 weeks) is compared with the threshold value. When calculating the average or median, the largest and smallest surplus amounts may be excluded. Furthermore, the past data does not have to be the surplus amount for every 30 minutes, and may be, for example, the surplus amount for every 5 minutes or every hour.

[0065] The past data may be stored outside the electric vehicle charging / discharging devices 10A, 10B (for example, on the cloud) instead of being stored in the opening and closing schedule creation units 31A, 31B. In this case, the opening and closing schedule creation units 31A, 31B create a plan based on the past data acquired from the cloud. In this case, the past data acquired from the cloud corresponds to "information provided from outside" of the present invention.

[0066] The "information provided from outside" of the present invention is not limited to past data. Other examples of the "information provided from outside" include solar radiation forecast data provided by the Japan Meteorological Agency, power shortage forecast data provided by a power company, and weather forecast data (particularly temperature data). The opening and closing schedule creation units 31A and 31B may create a schedule based on any one of the above data, or may create a schedule based on any combination of the above data.

[0067] The opening and closing schedule preparation units 31A and 31B may prepare a schedule during a time period other than late night (e.g., 23:30 to 24:00) on the day before the control day. For example, the opening and closing schedule preparation units 31A and 31B may prepare a schedule during the period from 0:00 to 2:00 on the control day. [Explanation of symbols]

[0068] 10A,10B Charging / discharging device for electric vehicles 20 Power conversion section 21 AC / DC inverter 22 DC / DC converter 30A, 30B Control section 31A, 31B Opening and Closing Plan Creation Department 32A, 32B Contact control section 33A, 33B Power conversion control unit 40 Relay 50 Cable 51 Connector 100 Commercial power system 101 Customer side distribution line 102 Switch 103 Current measurement section 110 Solar power generation equipment 111 Load device 120 Electric vehicle 121 Drive battery 122 Charging port 123 Contactor (mechanical contact) 124 Electric vehicle side control unit

Claims

1. A charging / discharging device for an electric vehicle that is connected to a photovoltaic power generation device and a load device via a consumer's distribution line that is connected to a commercial power system, a power conversion unit having an AC side input / output terminal and a DC side input / output terminal, the power conversion unit being connected to the consumer's distribution line at the AC side input / output terminal; a cable that is a connector having a tip end and a base end, the base end being connected to the DC side input / output terminal of the power conversion unit and the tip end being configured to engage with a charging port of an electric vehicle; Control unit and Equipped with The control unit is an opening and closing schedule creation unit that creates a schedule for each time period as to whether a mechanical contact provided on a power supply path in the electric vehicle connected to the connector should be closed or opened based on information provided from an external source; a contact control unit that sets the mechanical contact in a closed or open state according to the created plan; Including, Even if the mechanical contact is scheduled to be in an open state during a time period in which control should be performed, if the mechanical contact is scheduled to be in a closed state during time periods on both sides of the time period, the contact control unit does not close the mechanical contact during the time period. A charging and discharging device for an electric vehicle.

2. The control unit is a power conversion control unit that operates the power conversion unit to supply power from the electric vehicle to the load device so as to prevent a reverse power flow to the commercial power system when the mechanical contact is in a closed state. Further comprising: The power conversion control unit stops the power conversion unit when the power actually supplied from the electric vehicle to the load device falls below a predetermined first threshold value.

2. The charging / discharging device for an electric vehicle according to claim 1.

3. The control unit is a power conversion control unit that operates the power conversion unit to supply electric power from the solar power generation device to the electric vehicle when the mechanical contact is in a closed state; Further comprising: The power conversion control unit stops the power conversion unit when the power actually supplied from the solar power generation device to the electric vehicle falls below a predetermined second threshold value.

2. The charging / discharging device for an electric vehicle according to claim 1.

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