Power supply equipment and power systems

Abstract

The use of a vehicle battery as a power source for a consumer receiving power from a single-phase three-wire power grid. [Solution] The power supply device according to this disclosure comprises a charging / discharging cable, a grid-side switch, a self-contained switch, and a control unit. When a vehicle is connected via the charging / discharging cable, the control unit turns on the grid-side switch to control grid-connected operation, which supplies AC power of a first voltage supplied from the power grid via the first distribution board to the vehicle, or grid-connected operation, which supplies AC power of a first voltage supplied from the vehicle to the first distribution board. When a power outage in the power grid is detected, the control unit turns on the self-contained switch to output a control signal instructing the vehicle to operate independently, and controls independent operation, which supplies AC power of a second voltage supplied from the vehicle to the second distribution board. The second voltage is the potential difference between each of the pair of voltage lines at the input / output terminals on the grid side in grid-connected operation or grid-connected operation, and the neutral line at the input / output terminals on the grid side.

Description

Technical Field

[0001] The present disclosure relates to a power supply device and a power system.

Background Art

[0002] Conventionally, there has been known a technology for charging a battery mounted on an electric vehicle such as an electric vehicle (EV) or a plug-in hybrid vehicle (PHEV) using commercial power from a power grid at home or the like, or discharging the battery to use it as a power source for a home. In a consumer who receives power supply from a single-phase three-wire power system such as a home, both a single-phase 200V between a pair of voltage lines and a single-phase 100V between one of the pair of voltage lines and a neutral line are used via a distribution board.

[0003] Among these, even if single-phase 200V is supplied from an in-vehicle charger to between a pair of voltage lines of a consumer using the power of an in-vehicle battery, the potential of the neutral line becomes indefinite in the consumer, so there is a problem that the voltage between the voltage line and the neutral line cannot be used as single-phase 100V. For example, in Patent Document 1, a charge / discharge system is disclosed that enables a storage device to be used as a power source when power is not supplied from both a single-phase 200V and a single-phase 100V power system by functionally grounding the neutral point of a power conversion unit to chassis potential.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, according to the specifications for on-board chargers, there was a problem in that the neutral point of the power conversion unit could not be functionally grounded to the chassis potential. Therefore, there was room for improvement in its use as a power source for on-board batteries by consumers receiving power from a single-phase three-wire power system.

[0006] This disclosure is made in view of the above, and one of its purposes is to enable consumers receiving power from a single-phase three-wire power system to use an on-board battery as a power source. [Means for solving the problem]

[0007] The power supply device according to this disclosure comprises a charge / discharge cable, a grid-side switch, a standalone-side switch, and a second control unit. The charge / discharge cable has a pair of power lines, a protective earth wire at ground potential, and a control line. The grid-side switch is provided between the grid-side input / output terminal, which is electrically connected to the power grid via a first distribution board, and the charge / discharge cable. The standalone-side switch is provided between the output terminal for standalone operation, which is electrically connected to a second distribution board different from the first distribution board, and the charge / discharge cable. The second control unit controls the operation of the grid-side switch and the standalone-side switch, and communicates with the first control unit of a power converter mounted on a vehicle to which the charge / discharge cable is connected, via the control line. The pair of voltage lines at the grid-side input / output terminal are electrically connected to the pair of power lines of the charge / discharge cable via the grid-side switch. The pair of voltage lines at the standalone-side output terminal are electrically connected to the pair of power lines of the charge / discharge cable via the standalone-side switch. The pair of power lines of the charging / discharging cable are electrically connected to the pair of power lines at the AC input / output terminals that input and output AC power in the power converter of the vehicle to which the charging / discharging cable is connected. The neutral wire at the grid-side input / output terminal and the protective earth wire of the charging / discharging cable are connected to ground potential. When a vehicle is connected via the charging / discharging cable, the second control unit turns on the grid-side switch to create conductivity between the first distribution board and the charging / discharging cable, and controls either grid connection operation, which supplies AC power of the first voltage supplied from the power system via the first distribution board to the vehicle to which the charging / discharging cable is connected, or grid connection operation, which supplies AC power of the first voltage supplied from the vehicle via the charging / discharging cable to the first distribution board. When a power outage in the power system is detected, the second control unit turns on the self-sustaining switch to create electrical conductivity between the second distribution board and the charging / discharging cable, outputs a control signal to the first control unit of the power converter mounted on the vehicle to which the charging / discharging cable is connected, instructing it to perform self-sustaining operation, and controls the self-sustaining operation to supply AC power supplied from the vehicle via the charging / discharging cable to the second distribution board.The control signal that instructs the aforementioned independent operation instructs the output voltage value to be the second voltage, which is the potential difference between each of the pair of voltage lines at the input / output terminals on the grid side in the grid-connected operation or the grid-interconnected operation, and the neutral line at the input / output terminals on the grid side. [Effects of the Invention]

[0008] According to this disclosure, consumers receiving power from a single-phase three-wire power grid can use an on-board battery as a power source. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 shows an example of the configuration of a power system according to the first embodiment. [Figure 2] Figure 2 shows an example of the configuration of a power system according to the first embodiment. [Figure 3] Figure 3 is a flowchart showing an example of the operation of the power system during independent operation according to the first embodiment. [Figure 4] Figure 4 shows an example of the connection state during autonomous operation when the first vehicle is connected to the power system according to the first embodiment. [Figure 5] Figure 5 shows an example of the configuration of a power system according to a modified version of the first embodiment. [Figure 6] Figure 6 shows an example of the configuration of a power system according to the second embodiment. [Figure 7] Figure 7 is a flowchart showing an example of the operation of the power system during independent operation according to the second embodiment. [Figure 8] Figure 8 shows an example of the connection state during autonomous operation when a second vehicle is connected to the power system according to the second embodiment. [Figure 9] Figure 9 shows an example of the configuration of a power system according to the third embodiment. [Figure 10] Figure 10 is a flowchart showing an example of the operation of a power system during standalone operation according to the third embodiment. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the power converter (on-board charger), vehicle, power supply device, and power system relating to this disclosure will be described with reference to the drawings.

[0011] In this disclosure, components having the same or substantially the same function as those described above in previously shown drawings are denoted by the same reference numerals, and explanations may be omitted as appropriate. Furthermore, even when representing the same or substantially the same parts, the dimensions and proportions may be shown differently in different drawings. In addition, for example, from the viewpoint of ensuring the readability of the drawings, reference numerals may be assigned only to the main components in the explanation of each drawing, and reference numerals may not be assigned to components having the same or substantially the same function as those described above in previously shown drawings.

[0012] In addition, in the descriptions of this disclosure, components having the same or substantially the same function may be distinguished by adding alphanumeric characters and / or symbols to the end of the reference numeral. Alternatively, if multiple components having the same or substantially the same function are not to be distinguished, they may be described together by omitting the alphanumeric characters and / or symbols to the end of the reference numeral.

[0013] (First embodiment) Figures 1 and 2 show an example of the configuration of the power system 1 according to the first embodiment. Figure 1 illustrates the case when the first vehicle is connected. Figure 2 illustrates the case when the second vehicle is connected. Figures 1 and 2 illustrate the connection state during grid connection operation or grid interconnection operation.

[0014] As shown in Figures 1 and 2, the power system 1 includes a vehicle 2, an EVSE (Electric Vehicle Supply Equipment) 4, a distribution board 61, a critical load distribution board 62, a 100V load 7a, a 200V load 7b, a 100V critical load 7c, and a 200V critical load 7d.

[0015] The power system 1 is electrically connected to the grid 9. The power system 1 is a single-phase three-wire system that receives AC power from the grid 9. In the present disclosure, it is assumed that the power system 1 is supplied with single-phase 200V AC power from the grid 9, the potential difference between a pair of voltage lines is 200V in single-phase, and the potential difference between either one of the pair of voltage lines and the neutral line is 100V in single-phase.

[0016] The grid 9 is a power grid that transmits AC power (e.g., commercial power) from power facilities such as power plants and substations and supplies it to consumers such as houses. Note that the AC power supplied from the grid 9 to the power system 1 is not limited to single-phase 200V and may be other AC power such as single-phase 240V.

[0017] The vehicle 2 is, as an example, an electric vehicle (EV) or a plug-in hybrid electric vehicle (PHEV). Here, the vehicle 2 according to the embodiment is an example of a moving body. This moving body may be any of various moving bodies configured to be driven using power from the high-voltage battery 22, and may be, for example, a passenger car, a cargo vehicle, a bus, a motorcycle, an electric kick scooter, a ship, an aircraft, a construction machine, an agricultural machine, etc. Note that the technology according to the embodiment is not limited to moving bodies such as the vehicle 2, and can also be applied to various power conversion devices provided in, for example, amusement facilities and uninterruptible power supply devices.

[0018] As shown in FIGS. 1 and 2, the vehicle 2 has a bidirectional charger 21, a high-voltage battery 22, and a charge / discharge socket 23.

[0019] The bidirectional charger 21 is electrically connected between the high-voltage battery 22 and the charge / discharge socket 23. The AC-side input / output terminals 20a of the bidirectional charger 21 are electrically connected to the charge / discharge socket 23 via a pair of power lines L1, L2, a protective earth line (PE), and a control pilot line (CP). Also, the DC-side input / output terminals 20b of the bidirectional charger 21 are electrically connected to the high-voltage battery 22 via a pair of power lines.

[0020] Here, the bidirectional charger 21 is a charger mounted on the vehicle 2 (onboard charger) and is an example of a power conversion device. Also, each of the pair of power lines L1 and L2 is an example of a voltage line through which single-phase current flows. Furthermore, the control pilot line (CP) is an example of a control line.

[0021] As shown in Figures 1 and 2, the bidirectional charger 21 has a control unit 211 and a power conversion unit 212. Here, the control unit 211 is an example of a first control unit.

[0022] The control unit 211 is a control IC (integrated circuit) configured to control the operation of each part of the bidirectional charger 21. The control unit 211 is electrically connected to the power conversion unit 212 via control lines. The control unit 211 controls the operation of the power conversion unit 212. For example, the control unit 211 controls the operation of the power conversion unit 212 according to control signals received from EVSE 4a via control pilot lines.

[0023] As an example, the control unit 211 controls grid-connected operation. In grid-connected operation, the control unit 211 converts the AC power input to the power conversion unit 212 from the AC-side input / output terminal 20a into DC power and outputs it from the DC-side input / output terminal 20b. In grid-connected operation, the potential difference between the pair of power lines L1 and L2 at the AC-side input / output terminal 20a of the power conversion unit 212 is, for example, single-phase 200V, which is an example of a first voltage. The DC power output from the DC-side input / output terminal 20b is supplied to the high-voltage battery 22.

[0024] As an example, the control unit 211 controls grid-connected operation. In grid-connected operation, the control unit 211 converts the DC power from the high-voltage battery 22, which is input to the power conversion unit 212 from the DC-side input / output terminal 20b, into AC power and outputs it from the AC-side input / output terminal 20a. In grid-connected operation, the potential difference between the pair of power lines L1 and L2 at the AC-side input / output terminal 20a of the power conversion unit 212 is, for example, single-phase 200V, which is an example of a first voltage. The AC power output from the AC-side input / output terminal 20a is supplied to the EVSE 4a via the charge / discharge cable 49.

[0025] The power conversion unit 212 operates according to the control of the control unit 211. The power conversion unit 212 has an AC-side input / output terminal 200a and a DC-side input / output terminal 200b. The AC-side input / output terminal 200a is electrically connected to the AC-side input / output terminal 20a of the bidirectional charger 21. The DC-side input / output terminal 200b is electrically connected to the DC-side input / output terminal 20b of the bidirectional charger 21.

[0026] The AC-side input / output terminal 200a inputs and outputs AC power. The DC-side input / output terminal 200b inputs and outputs DC power. The power conversion unit 212 converts the power input from either the AC-side input / output terminal 200a or the DC-side input / output terminal 200b to AC / DC and outputs the AC / DC converted power from the other input / output terminal of either the AC-side input / output terminal 200a or the DC-side input / output terminal 200b.

[0027] As shown in Figure 1, in the first vehicle 2a, the bidirectional charger 21 is further equipped with a neutral point connection switch 213. On the other hand, as shown in Figure 2, in the second vehicle 2b, the bidirectional charger 21 does not have a neutral point connection switch. In other words, the first vehicle 2a is a vehicle 2 equipped with a neutral point connection switch 213. Similarly, the second vehicle 2b is a vehicle 2 that is not equipped with a neutral point connection switch 213.

[0028] The neutral point connection switch 213 operates according to the control of the control unit 211 of the first vehicle 2a. The neutral point connection switch 213 is located between the neutral point NP of the pair of power lines L1 and L2 at the AC input / output terminal 200a of the power conversion unit 212 and the functional grounding wire FG at the chassis potential. The neutral point connection switch 213 switches between conduction and interruption between the neutral point NP of the pair of power lines L1 and L2 at the AC input / output terminal 200a of the power conversion unit 212 and the functional grounding wire FG at the chassis potential.

[0029] In the first vehicle 2a, the functional grounding wire FG of the chassis potential is electrically connected to the protective grounding terminal of the charge / discharge socket 23 via the protective grounding wire PE. In other words, the neutral point connection switch 213 is provided between the neutral point NP of the pair of power lines L1 and L2 at the AC side input / output terminal 200a of the power conversion unit 212 and the protective grounding wire PE. The neutral point connection switch 213 also switches between conduction and interruption between the neutral point NP of the pair of power lines L1 and L2 at the AC side input / output terminal 200a of the power conversion unit 212 and the protective grounding wire PE.

[0030] The control unit 211 of the first vehicle 2a is electrically connected to the neutral point connection switch 213 via a control line. The control unit 211 of the first vehicle 2a further controls the operation of the neutral point connection switch 213.

[0031] As an example, in grid-connected operation, the control unit 211 of the first vehicle 2a turns off the neutral point connection switch 213, thereby disconnecting the neutral point NP of the AC-side input / output terminal 200a from the protective earth wire PE. In this state, the control unit 211 of the first vehicle 2a converts the AC power input from the AC-side input / output terminal 200a to the power conversion unit 212 into DC power and outputs it from the DC-side input / output terminal 200b.

[0032] As an example, in grid-connected operation, the control unit 211 of the first vehicle 2a turns off the neutral point connection switch 213, thereby disconnecting the neutral point NP of the AC-side input / output terminal 200a from the protective earth wire PE. In this state, the control unit 211 of the first vehicle 2a converts the DC power input from the DC-side input / output terminal 200b to the power conversion unit 212 into AC power and outputs it from the AC-side input / output terminal 200a.

[0033] As an example, the control unit 211 of the first vehicle 2a turns on the neutral point connection switch 213 when it is instructed to perform autonomous operation (see Figures 3 and 4) by a control signal from EVSE 4a (external). In other words, in autonomous operation, the control unit 211 of the first vehicle 2a turns on the neutral point connection switch 213, creating a conductive connection between the neutral point NP of the AC input / output terminal 200a and the protective earth wire PE. In this state, the control unit 211 of the first vehicle 2a converts the DC power input from the DC input / output terminal 200b to the power conversion unit 212 into AC power and outputs it from the AC input / output terminal 200a.

[0034] The control signal from EVSE4a (external) instructing independent operation instructs the bidirectional charger 21 to output a single-phase 200V (first voltage), which is the potential difference between the pair of voltage lines L1 and L2 at the input / output terminal 40a on the grid side of EVSE4a during grid-connected operation or grid-linked operation. In other words, during independent operation, the potential difference between the pair of power lines L1 and L2 at the input / output terminal 200a on the AC side of the power conversion unit 212 of the first vehicle 2a is single-phase 200V (first voltage). Therefore, during independent operation, the potential difference between the pair of power lines L1 and L2 at the input / output terminal 20a on the AC side of the bidirectional charger 21 of the first vehicle 2a is single-phase 200V (first voltage).

[0035] Furthermore, in autonomous operation, the neutral point connection switch 213 is turned on. Therefore, the AC power output from the power conversion unit 212 is AC power generated with reference to the neutral point NP. Consequently, in autonomous operation, the potential difference between each of the pair of power lines L1 and L2 at the AC side input / output terminal 200a of the power conversion unit 212 of the first vehicle 2a and the neutral point NP of the pair of power lines L1 and L2 at the AC side input / output terminal 200a is single-phase 100V (second voltage).

[0036] Thus, in independent operation, the AC power output from the AC input / output terminal 20a of the bidirectional charger 21 of the first vehicle 2a includes single-phase 200V (first voltage), which is the potential difference between a pair of power lines L1 and L2, and single-phase 100V (second voltage), which is the potential difference between each of the pair of power lines L1 and L2 and the neutral point NP. In other words, in independent operation, the AC power supplied from the bidirectional charger 21 of the first vehicle 2a to the EVSE 4a via the pair of power lines L1 and L2 of the charge / discharge cable 49 is single-phase 200V (first voltage) AC power from which single-phase 100V (second voltage) can be extracted with respect to the protective earth wire PE. Therefore, the first vehicle 2a, equipped with a neutral point connection switch 213, can appropriately determine the potential of the neutral wire N at a consumer in independent operation when supplying power to a consumer receiving power from a single-phase three-wire system 9. In other words, the independent operation of the first vehicle 2a, which is equipped with a neutral point connection switch 213, allows consumers receiving power from a single-phase three-wire system 9 to use both single-phase 100V and single-phase 200V equipment.

[0037] The high-voltage battery 22 is electrically connected to the DC-side input / output terminal 200b of the power conversion unit 212 via the DC-side input / output terminal 20b of the bidirectional charger 21. The high-voltage battery 22 stores the power supplied from the EVSE 4a via the bidirectional charger 21. The high-voltage battery 22 only needs to be able to store power for supplying (discharging) power to the drive motor (main motor) and EVSE 4a mounted on the vehicle 2. Any battery such as a lithium-ion battery, nickel-metal hydride battery, or solid-state battery can be used as the high-voltage battery 22. Here, the high-voltage battery 22 is an example of an on-board battery and an example of a battery electrically connected to the DC-side input / output terminal 200b of the power conversion unit 212.

[0038] The charge / discharge socket 23 is a power socket for charging and / or discharging mounted on the vehicle 2. The charge / discharge socket 23 is detachably connected to the charge / discharge cable 49. For example, the bidirectional charger 21 may be connected to external power equipment and / or an external load such as an EVSE 4a via the charge / discharge power socket located in a position accessible from outside the vehicle 2. The charge / discharge socket 23 has a pair of power terminals, a protective earth terminal, and a control terminal.

[0039] The pair of power terminals of the charge / discharge socket 23 are electrically connected to the pair of power lines L1 and L2 of the AC input / output terminal 200a of the power conversion unit 212 in the first vehicle 2a and the second vehicle 2b. In addition, the pair of power terminals of the charge / discharge socket 23 are electrically connected to the pair of power lines L1 and L2 of the charge / discharge cable 49 connected to the vehicle 2.

[0040] The protective earth terminal of the charge / discharge socket 23 is electrically connected to the functional earth wire FG of the chassis potential in the first vehicle 2a and the second vehicle 2b. In addition, the protective earth terminal of the charge / discharge socket 23 is electrically connected to the protective earth wire PE of the charge / discharge cable 49 connected to vehicle 2.

[0041] Furthermore, in the first vehicle 2a, the protective earth terminal of the charge / discharge socket 23 is electrically connected to the neutral point NP of the AC side input / output terminal 200a of the power conversion unit 212 via the neutral point connection switch 213.

[0042] The control terminals of the charge / discharge socket 23 are electrically connected to the control unit 211 in the first vehicle 2a and the second vehicle 2b. The control terminals of the charge / discharge socket 23 are also electrically connected to the control pilot line CP of the charge / discharge cable 49 connected to vehicle 2. The control terminals of the charge / discharge socket 23 receive control signals from the EVSE 4a (external) via the charge / discharge cable 49.

[0043] The EVSE4a according to the first embodiment is an example of the EVSE4 according to this disclosure. The EVSE4a is a power supply device electrically connected to a vehicle 2 via a charge / discharge cable 49. The vehicle-side input / output terminal 40b of the EVSE4a is electrically connected to the vehicle 2 via a pair of power lines L1, L2, a protective earth wire PE, and a control pilot wire CP of the charge / discharge cable 49. The grid-side input / output terminal 40a of the EVSE4a is electrically connected to a distribution board 61 via a pair of power lines L1, L2 and a neutral wire N. The output terminal 40c for independent operation of the EVSE4a is electrically connected to a critical load distribution board 62 via a pair of power lines L1, L2 and a neutral wire N.

[0044] In grid-connected operation, EVSE4a receives AC power from grid 9 via the distribution board 61 and supplies it to vehicle 2 via the charging / discharging cable 49. In grid-connected operation, EVSE4a receives AC power from vehicle 2 via the charging / discharging cable 49 and supplies it to 100V load 7a, 200V load 7b, 100V critical load 7c, and 200V critical load 7d via the distribution board 61. In standalone operation, EVSE4a receives AC power from vehicle 2 via the charging / discharging cable 49 and supplies it to 100V critical load 7c and 200V critical load 7d via the critical load distribution board 62. In addition, EVSE4a may also supply AC power received from vehicle 2 via the charging / discharging cable 49 to grid 9 in grid-connected operation.

[0045] As shown in Figures 1 and 2, the EVSE 4a includes a control unit 41, a grid-side relay 42, and a standalone relay 43. Here, the grid-side relay 42 is an example of a grid-side switch. The standalone relay 43 is also an example of a standalone switch.

[0046] The control unit 41 is a control IC (integrated circuit) configured to control the operation of each part of the EVSE 4a. The control unit 41 is electrically connected to the control unit 211 of the vehicle 2 via the control pilot line CP of the charge / discharge cable 49. The control unit 41 communicates with the control unit 211 of the vehicle 2. The control unit 41 is also electrically connected to the grid-side relay 42 and the independent-side relay 43 via control lines. The control unit 41 controls the operation of the grid-side relay 42 and the independent-side relay 43. Here, the control unit 41 of the EVSE 4a is an example of a second control unit.

[0047] As an example, the control unit 41 controls grid-connected operation. In grid-connected operation, when a vehicle 2 is connected via the charge / discharge cable 49, the control unit 41 turns on the grid-side relay 42 to create electrical conductivity between the distribution board 61 and the charge / discharge cable 49. In this state, the control unit 41 also supplies AC power supplied from the grid 9 via the distribution board 61 to the vehicle 2 to which the charge / discharge cable 49 is connected.

[0048] As an example, the control unit 41 controls grid-connected operation. In grid-connected operation, when the vehicle 2 is connected via the charge / discharge cable 49, the control unit 41 turns on the grid-side relay 42 to create electrical conductivity between the distribution board 61 and the charge / discharge cable 49. In this state, the control unit 41 also supplies the AC power supplied from the vehicle 2 via the charge / discharge cable 49 to the distribution board 61.

[0049] For example, if a power outage in system 9 is detected, the control unit 41 controls the independent operation of vehicle 2. In independent operation, if a power outage in system 9 is detected, the control unit 41 checks for the presence or absence of the neutral point connection switch 213 in vehicle 2 to which the charge / discharge cable 49 is connected.

[0050] For example, if the vehicle 2 to which the charge / discharge cable 49 is connected is the first vehicle 2a equipped with a neutral point connection switch 213, the control unit 41 turns on the self-contained relay 43 to create electrical conductivity between the critical load distribution panel 62 and the charge / discharge cable 49. In this state, the control unit 41 also outputs a control signal to the control unit 211 of the bidirectional charger 21 mounted on the first vehicle 2a to which the charge / discharge cable 49 is connected, instructing it to operate independently. The control unit 41 then supplies AC power supplied from the first vehicle 2a via the charge / discharge cable 49 to the critical load distribution panel 62.

[0051] For example, the control unit 41 does not output a control signal to instruct autonomous operation if the vehicle 2 to which the charge / discharge cable 49 is connected is the second vehicle 2b, which is not equipped with a neutral point connection switch 213. In other words, the control unit 41 does not permit autonomous operation if the vehicle 2 to which the charge / discharge cable 49 is connected does not have a neutral point connection switch 213.

[0052] Furthermore, the control unit 41 has a backup power supply 411. In the event of a power outage in the system 9 or when the power supply from the system 9 is interrupted, the control unit 41 can operate using power from the backup power supply 411.

[0053] The system-side relay 42 is installed between the system-side input / output terminal 40a of the EVSE 4a and the vehicle-side input / output terminal 40b. In other words, the system-side relay 42 is installed between the distribution board 61 and the charge / discharge cable 49. The system-side relay 42 switches the continuity / continuity between the distribution board 61 and the charge / discharge cable 49. Specifically, the system-side relay 42 switches the continuity / continuity between the power line L1 (voltage line) of the system-side input / output terminal 40a and the power line L1 of the vehicle-side input / output terminal 40b. The system-side relay 42 also switches the continuity / continuity between the power line L2 (voltage line) of the system-side input / output terminal 40a and the power line L2 of the vehicle-side input / output terminal 40b. The neutral wire N of the system-side input / output terminal 40a of the EVSE 4a and the protective earth wire PE of the vehicle-side input / output terminal 40b are electrically connected to an earth wire at ground potential.

[0054] The self-sustaining relay 43 is installed between the output terminal 40c for self-sustaining operation of the EVSE 4a and the input / output terminal 40b on the vehicle side. In other words, the self-sustaining relay 43 is installed between the critical load distribution panel 62 and the charge / discharge cable 49. The self-sustaining relay 43 switches the continuity / continuity between the critical load distribution panel 62 and the charge / discharge cable 49. Specifically, the self-sustaining relay 43 switches the continuity / continuity between the power line L1 (voltage line) of the output terminal 40c for self-sustaining operation and the power line L1 of the input / output terminal 40b on the vehicle side. The self-sustaining relay 43 also switches the continuity / continuity between the power line L2 (voltage line) of the output terminal 40c for self-sustaining operation and the power line L2 of the input / output terminal 40b on the vehicle side. Furthermore, the self-contained relay 43 switches between continuity / interruption between the neutral wire N of the output terminal 40c for self-contained operation and the protective earth wire PE (and the earth wire at ground potential) of the vehicle-side input / output terminal 40b.

[0055] The distribution board 61 is installed between the system 9 and EVSE4a. At least one load can be electrically connected to the distribution board 61. Loads electrically connected to the distribution board 61 can operate using AC power supplied from the distribution board 61. Figures 1 and 2 illustrate at least one load as a 100V load 7a and a 200V load 7b. The 100V load 7a is a power device that operates using single-phase 100V AC power from the distribution board 61. The 200V load 7b is a power device that operates using single-phase 200V AC power from the distribution board 61. As an example, AC power from the distribution board 61 can be supplied to each load in a house (consumer) via outlets inside the house. Here, the distribution board 61 is an example of a first distribution board.

[0056] The critical load distribution panel 62 is installed between the distribution panel 61 and the EVSE 4a. In other words, the critical load distribution panel 62 is electrically connected to the system 9 via the distribution panel 61. At least one critical load can be electrically connected to the critical load distribution panel 62. Here, a critical load is a load that a consumer will receive power from the vehicle 2 via the EVSE 4a and the critical load distribution panel 62 when the power supply from the system 9 is stopped, such as during a power outage. Loads electrically connected to the critical load distribution panel 62 can operate using the AC power supplied from the critical load distribution panel 62. Figures 1 and 2 illustrate 100V critical load 7c and 200V critical load 7d as examples of at least one critical load. The 100V critical load 7c is a power device that operates using single-phase 100V AC power from the critical load distribution panel 62. The 200V critical load 7d is a power device that operates using single-phase 200V AC power from the critical load distribution panel 62. For example, the AC power from the critical load distribution panel 62 can be supplied to each critical load in a house (consumer) via outlets within the house. Here, the critical load distribution panel 62 is an example of a second distribution panel.

[0057] Furthermore, the critical load distribution panel 62 can switch the AC power supplied to the critical load between AC power from the distribution panel 61 and AC power from EVSE4a. This switching can be performed, for example, by user operation, but it may also be performed automatically when the critical load distribution panel 62 detects a power outage in system 9, or in accordance with a control signal from EVSE4a, or in accordance with a control signal from a HEMS (Home Energy Management System) that controls, monitors, and manages each of the customer's power facilities and power equipment.

[0058] The control unit 211 of the bidirectional charger 21 and the control unit 41 of the EVSE 4a each have, for example, at least one processor (not shown) and at least one memory (not shown), and have a hardware configuration using a normal computer. For each of the control units 211 and 41, for example, a DSP (Digital Signal Processor) can be used. Each of the control units 211 and 41 may realize its functions by, for example, a processor such as a CPU (Central Processing Unit) loading a program stored in an auxiliary storage device such as ROM (Read Only Memory) into a main memory device such as RAM (Random Access Memory) and executing the loaded program, or each function may be realized by a dedicated hardware circuit (semiconductor integrated circuit, etc.).

[0059] The control unit 211 may be implemented by a computer such as an ECU (Electronic Control Unit) or a DCU (Domain Control Unit) such as a CDC (Cockpit Domain Controller) that integrates multiple ECUs, or an OBU (On Board Unit), all located inside the vehicle 2. The control unit 211 may also transmit and receive information to and from other ECUs mounted in the vehicle 2 or to external devices connected to the vehicle 2 (e.g., EVSE4a) via an in-vehicle network including CAN (Controller Area Network), Ethernet (registered trademark), or USB (Universal Serial Bus (registered trademark)) within the vehicle 2, or it may communicate with an information processing device outside the vehicle 2 via a network such as the Internet.

[0060] Next, we will explain an example of the operation of the power system 1 configured as described above.

[0061] Figure 3 is a flowchart illustrating an example of the operation of the power system 1 according to the first embodiment during independent operation. Figure 4 is a diagram showing an example of the connection state during independent operation when the first vehicle 2a is connected to the power system 1 according to the first embodiment.

[0062] The flow shown in Figure 3 is as follows: If the charging and discharging of vehicle 2 is not stopped due to a power outage or the like (S101: No), the system will wait. On the other hand, if the power supply from system 9 is stopped due to a power outage or the like, the system will proceed to step S102 after the charging and discharging of vehicle 2 has stopped (S101: Yes).

[0063] The control unit 41 of EVSE4a may detect whether power supply from grid 9 has been stopped due to a power outage or the like based on the measurement results of a voltage sensor that is provided to measure the potential difference between a pair of power lines L1 and L2 (a pair of voltage lines) at the grid-side input / output terminal 40a. Alternatively, the control unit 41 of EVSE4a may detect whether power supply from grid 9 has been stopped due to a power outage or the like based on a notification (control signal) from HEMS. Alternatively, the control unit 211 of vehicle 2 may detect whether power supply from grid 9 has been stopped due to a power outage or the like based on the measurement results of a voltage sensor that is provided to measure the potential difference between a pair of power lines L1 and L2 of the power conversion unit 212. Furthermore, whether charging and discharging of vehicle 2 is stopped may be determined from the input results to EVSE4a and HEMS by the user, or from the notification (control signal) from vehicle 2 to EVSE4a and HEMS.

[0064] The flow shown in Figure 3 is as follows: If the charging and discharging of vehicle 2 is stopped due to a power outage or the like and the critical load distribution panel 62 has not switched to the critical load side (S102: No), the process returns to step S101. On the other hand, as shown in Figure 4, if the charging and discharging of vehicle 2 is stopped due to a power outage or the like and the critical load distribution panel 62 has switched to the critical load side (S102: Yes), the process proceeds to step S103.

[0065] The control unit 41 of EVSE4a may determine whether the critical load distribution board 62 has switched to the critical load side based on the user's input to EVSE4a or HEMS, or it may determine based on the notification (control signal) from the critical load distribution board 62 or HEMS to EVSE4a.

[0066] The flow shown in Figure 3 is as follows: If the charging and discharging of vehicle 2 is stopped due to a power outage or the like, and the critical load distribution panel 62 is switched to the critical load side, and the start of independent operation is not instructed (S103: No), the process returns to step S101. On the other hand, if the charging and discharging of vehicle 2 is stopped due to a power outage or the like, and the critical load distribution panel 62 is switched to the critical load side, and the start of independent operation is instructed (S103: Yes), the process proceeds to step S104.

[0067] The control unit 41 of EVSE4a may determine whether the start of independent operation has been instructed based on the user's input to EVSE4a or HEMS, or based on notifications (control signals) sent to EVSE4a from the critical load distribution board 62 or HEMS. In configurations where the critical load distribution board 62 automatically switches to the critical load side upon detection of a power outage, the control unit 41 of EVSE4a may determine that the start of independent operation has been instructed upon detection of a power outage.

[0068] When autonomous operation is initiated, the control unit 41 of the EVSE4a checks for the presence or absence of the neutral point connection switch 213 in the vehicle 2 connected via the charge / discharge cable 49 (S104).

[0069] The control unit 41 of the EVSE4a may determine the presence or absence of the neutral point connection switch 213 from information (control signal) indicating the presence or absence of the neutral point connection switch 213 received from the vehicle 2 via the control pilot line CP. Alternatively, the control unit 41 of the EVSE4a may determine the presence or absence of the neutral point connection switch 213 from information (control signal) indicating the type of vehicle 2 received from the vehicle 2 via the control pilot line CP, information indicating the correspondence between the type of vehicle 2 and the presence or absence of the neutral point connection switch 213, which is pre-stored in the internal memory. Alternatively, the control unit 41 of the EVSE4a may determine the presence or absence of the neutral point connection switch 213 from the user's input results to the EVSE4a or HEMS (or pre-registered results). The presence or absence of the neutral point connection switch 213 may be confirmed in advance when connecting the charge / discharge cable 49, and the confirmation result may be stored in the internal memory.

[0070] As shown in Figure 4, in the case of the first vehicle 2a equipped with a neutral point connection switch 213 (S105:Yes), the control unit 41 of EVSE4a confirms that the grid-side relay 42 of EVSE4a is in the off state (it is turned off when a power outage is detected, so it is off at S101:Yes), and turns on the independent-side relay 43 (S106). Then, the control unit 41 of EVSE4a transmits a control signal to the control unit 211 of the bidirectional charger 21 of the first vehicle 2a to instruct discharge at single-phase 200V (first voltage), that is, a control signal to instruct independent operation (S107).

[0071] Upon receiving a control signal from EVSE4a instructing autonomous operation, the control unit 211 of the first vehicle 2a turns on the neutral point connection switch 213 (S108), then controls the power conversion of the power conversion unit 212 to generate single-phase 200V (first voltage) and starts autonomous operation by supplying it to EVSE4a (S109). After that, the flow shown in Figure 3 ends.

[0072] On the other hand, if it is not the first vehicle 2a equipped with the neutral point connection switch 213, that is, the second vehicle 2b (S105: No), the flow shown in Figure 3 ends. In other words, if the second vehicle 2b, which is not equipped with the neutral point connection switch 213, is connected, the control unit 41 of EVSE 4a does not permit autonomous operation and stops the autonomous operation process.

[0073] The control unit 41 of EVSE4a may determine the end of independent operation based on the user's input results to EVSE4a and HEMS, or the detection of power supply from grid 9 (restoration from a power outage). When independent operation ends, the control unit 41 of EVSE4a sends a control signal to the control unit 211 of vehicle 2 instructing it to end independent operation. Upon receiving this, the control unit 211 of vehicle 2 stops the operation of the power conversion unit 212 and turns off the neutral point connection switch 213. Subsequently, the control unit 41 of EVSE4a turns off the independent-side relay 43 of EVSE4a and turns on the grid-side relay 42. Then, the critical load distribution panel 62 is switched to the normal load side (see Figures 1 and 2). Note that the switching of the critical load distribution panel 62 may occur before the control signal instructing the end of independent operation is sent from the control unit 41 of EVSE4a to the control unit 211 of vehicle 2. Furthermore, the control unit 41 of EVSE4a may determine the end of independent operation based on the switching of the critical load distribution panel 62.

[0074] Thus, the power system 1 according to this embodiment allows autonomous operation by vehicle 2 when a first vehicle 2a equipped with a neutral point connection switch 213 is connected. In autonomous operation, the neutral point connection switch 213 is turned on, and conduction is established between the neutral point NP of the AC side input / output terminal 200a of the power conversion unit 212 and the protective earth wire PE of the charge / discharge cable 49 which is functionally grounded to the chassis potential.

[0075] Conventionally, the charging connector of a single-phase 200V vehicle 2 lacked a neutral (N) terminal. Therefore, in self-sustaining operation by a vehicle 2 connected to a consumer such as a house via a single-phase 200V EVSE4a, it was not possible to use both single-phase 200V and single-phase 100V equipment. Furthermore, while a configuration in which the neutral point NP of the power conversion unit 212 of the onboard bidirectional charger 21 is connected to the chassis potential of the vehicle 2 allows the neutral point NP of the power conversion unit 212 and the neutral (N) phase of the single-phase 3-wire system on the EVSE4a side to be set to the same potential, this configuration presented a problem: the onboard bidirectional charger 21 would violate the standard when charging single-phase 200V.

[0076] In this context, according to the above configuration of this embodiment, a single-phase 200V (first voltage) AC power can be generated between the pair of power lines L1 and L2 at the AC input / output terminal 200a of the power conversion unit 212 of the vehicle 2, with the chassis potential as the reference. Furthermore, in the EVSE 4a to which this AC power is supplied, a single-phase 100V (second voltage) AC power can be extracted along with the single-phase 200V (first voltage), with the potential of the protective earth wire PE electrically connected to the neutral point NP of the power conversion unit 212 as the reference.

[0077] Therefore, according to the power system 1 of this embodiment, the potential of the neutral wire at the customer can be appropriately determined when supplying power from an on-board charger to a customer receiving power from a single-phase three-wire power system. In other words, according to the power system 1 of this embodiment, both single-phase 100V and 200V equipment can be used during autonomous operation of the vehicle. Furthermore, in other modes, including single-phase 200V charging, the neutral point connection switch 213 is turned off, so that none of the power lines L1, L2 and the neutral wire NP of the power conversion unit 212 are functionally grounded to the chassis potential, thus enabling a configuration that conforms to standards.

[0078] Modifications and other embodiments of this disclosure will be described below. In the following descriptions of modifications and embodiments, the differences will be explained primarily, and any content that overlaps with the above description will be omitted as appropriate.

[0079] (modified version) Figure 5 shows an example of the configuration of the power system 1 according to a modified version of the first embodiment. Figure 5 illustrates the connection state during autonomous operation when the first vehicle 2a is connected to the power system 1 according to this modified version.

[0080] As shown in Figure 5, in the power system 1 according to this modified example, the bidirectional charger 21 of the first vehicle 2a further includes a current sensor 214.

[0081] In the bidirectional charger 21, the current sensor 214 is installed in series with the functional grounding wire FG of the chassis potential. In other words, the current sensor 214 is installed between the functional grounding wire FG of the chassis potential and the protective grounding wire PE of the neutral point connection switch 213. To put it another way, the current sensor 214 detects the current (insulation failure) flowing through the functional grounding wire FG of the chassis potential.

[0082] In the bidirectional charger 21, the control unit 211 determines to stop independent operation if the current sensor 214 detects a current exceeding a predetermined threshold stored in the internal memory while the neutral point connection switch 213 is ON. If it determines to offer independent operation, the control unit 211 stops power conversion by the power conversion unit 212 and also turns off the neutral point connection switch 213.

[0083] In this modified power system 1, the bidirectional charger 21 of the first vehicle 2a is equipped with a current sensor 214 for detecting insulation failures between the neutral point connection switch 213 and the functional grounding wire FG of the chassis potential. This configuration allows for the detection of insulation failures and improves safety during autonomous operation by the first vehicle 2a.

[0084] (Second embodiment) Figure 6 shows an example of the configuration of the power system 1 according to the second embodiment. Figure 6 illustrates the connection state during autonomous operation when the first vehicle 2a is connected to the power system 1 according to the second embodiment.

[0085] The EVSE4b according to the second embodiment is a power supply device that, when it is determined that independent operation is to be performed, switches the connection with the consumer side between a single-phase three-wire 200V system and a single-phase 100V system depending on the presence or absence of the neutral point connection switch 213. In other words, the EVSE4b according to the second embodiment is a power supply device that indicates an output voltage value depending on the presence or absence of the neutral point connection switch 213. The EVSE4b according to the second embodiment is an example of the EVSE4 according to this disclosure.

[0086] As shown in Figure 6, the EVSE4b according to this embodiment further includes an LN short-circuit switch 44.

[0087] The LN short-circuit switch 44 is provided between the standalone output terminal 40c and the standalone relay 43, or between the standalone relay 43 and the vehicle-side input / output terminal 40b. Figure 6 illustrates an LN short-circuit switch 44 provided between the standalone output terminal 40c and the standalone relay 43. The LN short-circuit switch 44 is a short-circuit switch that electrically connects one of the pair of power lines L1, L2 of the charge / discharge cable 49 to one of the pair of power lines L1, L2 (a pair of voltage lines) of the corresponding standalone output terminal 40c, or to the neutral line N of the standalone output terminal 40c, via the standalone relay 43.

[0088] In the example in Figure 6, an LN short-circuit switch 44 is shown that electrically connects the power line L2 of the charge / discharge cable 49 to the power line L2 (voltage line) of the standalone output terminal 40c, or to the neutral line N, via a standalone relay 43.

[0089] The control unit 41 of the EVSE4b is electrically connected to the grid-side relay 42, the independent-side relay 43, and the LN short-circuit switch 44 via control lines. The control unit 41 controls the operation of the grid-side relay 42, the independent-side relay 43, and the LN short-circuit switch 44. Here, the control unit 41 of the EVSE4b is an example of a second control unit.

[0090] As an example, the control unit 41 of the EVSE4b controls grid-connected operation. In grid-connected operation, when a vehicle 2 is connected via the charge / discharge cable 49, the control unit 41 turns on the grid-side relay 42 to create conductivity between the distribution board 61 and the charge / discharge cable 49. In this state, the control unit 41 also supplies single-phase 200V (first voltage) AC power supplied from the grid 9 via the distribution board 61 to the vehicle 2 to which the charge / discharge cable 49 is connected. In other words, in grid-connected operation, for each vehicle 2 of the first vehicle 2a and the second vehicle 2b, the potential difference between the pair of power lines L1 and L2 at the AC side input / output terminal 20a of the bidirectional charger 21 is single-phase 200V (first voltage).

[0091] As an example, the control unit 41 of the EVSE4b controls grid-connected operation. In grid-connected operation, when a vehicle 2 is connected via the charge / discharge cable 49, the control unit 41 turns on the grid-side relay 42 to create conductivity between the distribution board 61 and the charge / discharge cable 49. In this state, the control unit 41 also supplies the single-phase 200V (first voltage) AC power supplied from the vehicle 2 via the charge / discharge cable 49 to the distribution board 61. In other words, in grid-connected operation, for each vehicle 2 of the first vehicle 2a and the second vehicle 2b, the potential difference between the pair of power lines L1 and L2 at the AC side input / output terminal 20a of the bidirectional charger 21 is single-phase 200V (first voltage).

[0092] For example, the control unit 41 of EVSE4b controls the autonomous operation of vehicle 2 when a power outage in system 9 is detected.

[0093] As an example, in autonomous operation, if a power outage in the power system 9 is detected, the control unit 41 of the EVSE4b checks for the presence or absence of the neutral point connection switch 213 in the vehicle 2 to which the charge / discharge cable 49 is connected.

[0094] As an example, in autonomous operation, the control unit 41 turns on the autonomous relay 43 to create electrical conductivity between the critical load distribution panel 62 and the charge / discharge cable 49. In this state, the control unit 41 outputs a control signal to the control unit 211 of the bidirectional charger 21 mounted on the vehicle 2 to which the charge / discharge cable 49 is connected, instructing it to operate autonomously. The control unit 41 then supplies AC power with a voltage value corresponding to the presence or absence of the neutral point connection switch 213 supplied from the vehicle 2 via the charge / discharge cable 49 to the critical load distribution panel 62.

[0095] For example, the control signal that instructs independent operation specifies an output voltage value depending on whether or not the neutral point connection switch 213 is present.

[0096] For example, if the vehicle 2 connected via the charge / discharge cable 49 is the first vehicle 2a having a neutral point connection switch 213, the control signal indicates single-phase 200V (first voltage) as the output voltage value. This single-phase 200V (first voltage) is the potential difference between the pair of power lines L1 and L2 (a pair of voltage lines) at the grid-side input / output terminal 40a during grid-connected operation or grid-linked operation. In other words, in independent operation, the potential difference between the pair of power lines L1 and L2 at the AC-side input / output terminal 20a of the bidirectional charger 21 of the first vehicle 2a is single-phase 200V (first voltage). Also, in independent operation, the potential difference between each of the pair of power lines L1 and L2 at the AC-side input / output terminal 20a of the bidirectional charger 21 of the first vehicle 2a and the neutral point NP is single-phase 100V (second voltage).

[0097] For example, in the case of a second vehicle 2b that does not have a neutral point connection switch 213, the control signal indicates single-phase 100V (second voltage) as the output voltage value. This single-phase 100V (second voltage) is the potential difference between each of the pair of power lines L1 and L2 (a pair of voltage lines) at the grid-side input / output terminal 40a and the neutral line N during grid-connected operation or grid-linked operation. In other words, in independent operation, the potential difference between the pair of power lines L1 and L2 at the AC-side input / output terminal 20a of the bidirectional charger 21 of the second vehicle 2b is single-phase 100V (second voltage).

[0098] As an example, in autonomous operation, the control unit 41 of the EVSE4b turns off the LN short-circuit switch 44 if the vehicle 2 connected via the charge / discharge cable 49 is the first vehicle 2a which has a neutral point connection switch 213. The control unit 41 then outputs a control signal instructing autonomous operation with either one of the pair of power lines L1, L2 of the charge / discharge cable 49 electrically connected to either one of the pair of power lines L1, L2 (a pair of voltage lines) of the corresponding autonomous output terminal 40c, i.e., with either the power lines L1 to each other or the power lines L2 to each other.

[0099] As an example, in autonomous operation, the control unit 41 of EVSE4b turns on the LN short-circuit switch 44 if the vehicle 2 connected via the charge / discharge cable 49 is a second vehicle 2b that does not have a neutral point connection switch 213. Then, with one of the pair of power lines L1 and L2 of the charge / discharge cable 49 electrically connected to the neutral line N of the autonomous output terminal 40c, the control unit 41 outputs a control signal instructing autonomous operation.

[0100] Figure 7 is a flowchart showing an example of the operation of the power system 1 according to the second embodiment during autonomous operation. Figure 8 is a diagram showing an example of the connection state during autonomous operation when the second vehicle 2b is connected to the power system 1 according to the second embodiment.

[0101] In the case of the first vehicle 2a equipped with a neutral point connection switch 213 (S105: Yes), the control unit 41 of EVSE4b turns off the LN short-circuit switch 44 to connect the corresponding power lines (power lines L2 in Figure 6) (S201), confirms that the system-side relay 42 is in the off state, and turns on the independent-side relay 43 (S106). Steps S107 to S109 are the same as in Figure 3, so their explanation is omitted here.

[0102] On the other hand, if it is not the first vehicle 2a equipped with the neutral point connection switch 213, i.e., the second vehicle 2b (S105: No), the control unit 41 of EVSE 4b turns on the LN short-circuit switch 44 to short-circuit one power line (power line L2 in Figure 8) to the neutral line N (S202), as shown in Figure 8, confirms that the grid-side relay 42 is in the off state, and turns on the self-sustaining relay 43 (S203). Then, the control unit 41 of EVSE 4b transmits a control signal to instruct discharge at single-phase 100V (second voltage), i.e., a control signal to instruct self-sustaining operation, to the control unit 211 of the bidirectional charger 21 of the second vehicle 2b (S204).

[0103] Upon receiving a control signal from EVSE4b instructing autonomous operation, the control unit 211 of the second vehicle 2b controls the power conversion of the power conversion unit 212 to generate single-phase 100V (second voltage) and starts autonomous operation by supplying it to EVSE4b (S205). After that, the flow shown in Figure 7 ends.

[0104] As described above, the EVSE4b according to the second embodiment instructs the output voltage value according to the presence or absence of the neutral point connection switch 213 during autonomous operation. Specifically, when the first vehicle 2a equipped with the neutral point connection switch 213 is connected, the EVSE4b instructs the output voltage value to be single-phase 200V without short-circuiting the power line L2 and the neutral line N by the LN short-circuit switch 44, and when the second vehicle 2b without the neutral point connection switch 213 is connected, the EVSE4b instructs the vehicle 2 with the output voltage value to be single-phase 100V with the switch short-circuited.

[0105] In this configuration, if the EVSE4b connected to the single-phase 3-wire 200V (L1, L2) of system 9 and the onboard bidirectional charger 21 determine that independent operation is required, the EVSE4b switches the connection with the customer side from the single-phase 3-wire 200V system to the single-phase 100V system. The EVSE4b then issues a command to the bidirectional charger 21 for independent operation at single-phase 100V. The EVSE4b also supplies the single-phase 100V output from the bidirectional charger 21, which has received this command, to the 100V critical load 7c connected to the critical load distribution board 62. In other words, the above configuration makes it possible to operate both single-phase 200V charging (system-connected operation) and independent operation that allows the use of at least 100V equipment.

[0106] (Third embodiment) Figure 9 shows an example of the configuration of the power system 1 according to the third embodiment. Figure 9 illustrates the connection state during autonomous operation when the second vehicle 2b is connected to the power system 1 according to the third embodiment.

[0107] The EVSE4c according to the third embodiment is a power supply device that, regardless of the presence or absence of the neutral point connection switch 213, switches the connection with the customer side from a single-phase 3-wire 200V system for grid-connected operation or grid-linked operation to a single-phase 100V system for independent operation when it is determined that independent operation should be performed. The EVSE4c according to the third embodiment is an example of the EVSE4 according to this disclosure.

[0108] As shown in Figure 9, the power system 1 according to this embodiment has a standalone outlet 63 instead of a critical load distribution board 62. Here, the standalone outlet 63 is an example of a second distribution board.

[0109] The freestanding outlet 63 is electrically connected to EVSE4c, but unlike the critical load distribution board 62, it is not connected to the distribution board 61. At least one critical load can be electrically connected to the freestanding outlet 63. The critical loads connected to the freestanding outlet 63 include the 100V critical load 7c, but do not include the 200V critical load 7d. In other words, the freestanding outlet 63 supplies AC power from EVSE4c to the 100V critical load 7c.

[0110] In the EVSE4c, the self-sustaining relay 43 is located between the output terminal 40c for self-sustaining operation of the EVSE4c and the input / output terminal 40b on the vehicle side. In other words, the self-sustaining relay 43 is located between the self-sustaining outlet 63 and the charging / discharging cable 49. The self-sustaining relay 43 switches between continuity and interruption between the self-sustaining outlet 63 and the charging / discharging cable 49. Specifically, the self-sustaining relay 43 switches between continuity and interruption between the power line L1 (voltage line) of the output terminal 40c for self-sustaining operation and the power line L1 of the input / output terminal 40b on the vehicle side. The self-sustaining relay 43 also switches between continuity and interruption between the neutral line N of the output terminal 40c for self-sustaining operation and the power line L2 of the input / output terminal 40b on the vehicle side.

[0111] Therefore, in this embodiment, the EVSE4c electrically connects the pair of power lines L1 and L2 on the vehicle 2 side to the pair of power lines L1 and L2 (a pair of voltage lines) on the grid 9 side during grid-connected operation or grid-linked operation. In addition, in standalone operation, the EVSE4c electrically connects one of the pair of power lines L1 and L2 on the vehicle 2 side to one of the corresponding pair of power lines L1 and L2 (a pair of voltage lines) on the 100V critical load 7c side, and electrically connects the other to the neutral line N. As a result, the EVSE4c in this embodiment can connect to the consumer side as a single-phase three-wire 200V system during grid-connected operation or grid-linked operation, and as a single-phase 100V system during standalone operation.

[0112] Figure 10 is a flowchart showing an example of the operation of the power system 1 during standalone operation according to the third embodiment.

[0113] If the power supply from system 9 is interrupted due to a power outage or other reasons, the charging and discharging of vehicle 2 will stop (S101: Yes), and then the process will proceed to step S103.

[0114] The flow shown in Figure 10 is as follows: If the charging and discharging of vehicle 2 is stopped due to a power outage or the like, and the start of independent operation is not instructed (S103: No), the process returns to step S101. On the other hand, if the charging and discharging of vehicle 2 is stopped due to a power outage or the like, and the start of independent operation is instructed (S103: Yes), the process proceeds to step S203.

[0115] When independent operation is initiated, the control unit 41 of EVSE4c confirms that the grid-side relay 42 is in the off state, as shown in Figure 9, and turns on the independent-side relay 43 (S203). Then, the control unit 41 of EVSE4c transmits a control signal instructing discharge at single-phase 100V (second voltage), that is, a control signal instructing independent operation, to the control unit 211 of the bidirectional charger 21 of the first vehicle 2a or the second vehicle 2b, which is connected via the charge / discharge cable 49 (S301).

[0116] Upon receiving a control signal from EVSE4c instructing autonomous operation, the control unit 211 of the first vehicle 2a or the second vehicle 2b controls the power conversion of the power conversion unit 212 to generate single-phase 100V (second voltage) and starts autonomous operation by supplying it to EVSE4c (S302). After that, the flow shown in Figure 10 ends.

[0117] Thus, in the second embodiment, regardless of the presence or absence of the neutral point connection switch 213, if it is determined that independent operation is to be performed, the EVSE4b switches the connection with the customer side from the single-phase 3-wire 200V system for grid-connected operation or grid-linked operation to the single-phase 100V system for independent operation.

[0118] This configuration allows for both single-phase 200V charging (grid-connected operation) and standalone operation that enables the use of 100V equipment.

[0119] In this disclosure, "is A" means at least one of "is A" or "is not A". In other words, in each of the embodiments described above, the determination of "is A" may be achieved by determining that "is A", by determining that "is not A", or by determining both of these.

[0120] The programs executed in each device of the power system 1 of this disclosure may be provided as files in an installable or executable format, recorded on a computer-readable non-transient recording medium such as a CD-ROM, floppy disk, CD-R, or DVD.

[0121] Furthermore, the programs executed by each device of the power system 1 of this disclosure may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Alternatively, the programs executed by each device of the power system 1 of this disclosure may be provided or distributed via a network such as the Internet.

[0122] Furthermore, the program to be executed in each device of the power system 1 of this disclosure may be provided pre-loaded into ROM or the like.

[0123] According to at least one embodiment described above, a consumer receiving power from a single-phase three-wire power system can use an on-board battery as a power source.

[0124] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0125] (Note) Based on the above description of embodiments, the following technologies are disclosed. (A1) A power conversion unit having an AC-side input / output terminal for inputting and outputting AC power, and a DC-side input / output terminal for inputting and outputting DC power, which are electrically connected to a charge / discharge socket to which a charge / discharge cable is detachably connected, and which converts the power input from either the AC-side or DC-side input / output terminal to AC / DC, and outputs the converted AC / DC power from the other input / output terminal of either the AC-side or DC-side, A neutral point connection switch is provided between the neutral point of the pair of power lines at the input / output terminals on the AC side and the functional ground wire of the chassis potential which is electrically connected to the protective ground wire of the charge / discharge cable connected to the charge / discharge socket, The system comprises a first control unit that controls the operation of the power conversion unit and the neutral point connection switch, The first control unit controls the self-sustaining operation in which it converts the DC power input from the DC input / output terminals to AC power and outputs it from the AC input / output terminals to the power conversion unit, while the neutral point connection switch is turned on to create conductivity between the neutral point of the AC input / output terminals and the functional ground wire of the chassis potential. Power converter. (A2) In the aforementioned independent operation, the AC power output from the AC input / output terminals includes a first voltage, which is the potential difference between a pair of power lines at the AC input / output terminals, and a second voltage, which is the potential difference between each of the pair of power lines at the AC input / output terminals and the neutral point. The amplitude of the first voltage is twice the amplitude of the second voltage. The power conversion device described in (A1) above. (A3) The first control unit further controls the grid connection operation, which involves turning off the neutral point connection switch to isolate the neutral point at the AC input / output terminals from the chassis potential functional ground wire, and converting the AC power input from the AC input / output terminals to DC power and outputting it from the DC input / output terminals. A power conversion device as described in (A1) or (A2) above. (A4) The first control unit further controls the grid-connected operation in which the DC power input from the DC input / output terminal is converted into AC power and output from the AC input / output terminal, while the neutral point connection switch is turned off to disconnect the neutral point of the AC input / output terminal and the functional grounding wire of the chassis potential. A power conversion device as described in any one of the above items (A1) to (A3). (A5) The system further includes a current sensor connected in series with the functional grounding wire of the chassis potential, The first control unit stops the self-sustaining operation when the neutral point connection switch is turned on and the current sensor detects a current exceeding a predetermined threshold. A power conversion device as described in any one of the above items (A1) to (A4). (A6) A power conversion device as described in any one of the above items (A1) to (A5), A battery electrically connected to the DC input / output terminal, The charging and discharging socket comprises, The aforementioned charging / discharging socket is A pair of power terminals electrically connected to a pair of power lines in the aforementioned charging / discharging cable, A protective earth terminal electrically connected to the protective earth wire of the charging / discharging cable, It has a control terminal that is electrically connected to the control line of the charging / discharging cable, The pair of power terminals of the charge / discharge socket are electrically connected to the pair of power lines at the AC input / output terminals of the power converter. The protective earth terminal of the charge / discharge socket is electrically connected to the functional earth wire of the chassis potential. The control terminal of the charge / discharge socket is electrically connected to the first control unit of the power converter, and receives external control signals via the charge / discharge cable. vehicle. (A7) The first control unit of the power converter turns on the neutral point connection switch when the independent operation is instructed by the external control signal. The vehicle described in (A6) above. (A8) The first vehicle is the vehicle described in (A6) above, A power supply device electrically connected to the vehicle via the charging and discharging cable, A first distribution board is provided between the power system and the power supply device, The system includes a second distribution board located between the first distribution board and the power supply device, The aforementioned power supply device is A system-side switch is provided between the first distribution board and the charging / discharging cable, A self-supporting switch is provided between the second distribution board and the charging / discharging cable, The system includes a second control unit that controls the operation of the system-side switch and the independent-side switch, The second control unit is: When the first vehicle is connected via the charging / discharging cable, the system-side switch is turned on to create electrical conductivity between the first distribution board and the charging / discharging cable, and the system connection operation is controlled to supply AC power from the power system via the first distribution board to the first vehicle to which the charging / discharging cable is connected, or to supply AC power supplied from the first vehicle via the charging / discharging cable to the first distribution board. When a power outage in the power system is detected, the self-sustaining switch is turned on to create electrical conductivity between the second distribution board and the charging / discharging cable, and a control signal is output to the first control unit of the power converter mounted on the first vehicle to which the charging / discharging cable is connected, instructing the self-sustaining operation to be performed, thereby controlling the self-sustaining operation to supply AC power supplied from the first vehicle via the charging / discharging cable to the second distribution board. Power system. (A9) In the first vehicle, the first control unit of the power converter turns on the neutral point connection switch when autonomous operation is instructed by the external control signal. The power system described in (A8) above. (A10) When a second vehicle equipped with a power converter without a neutral point connection switch is connected via the charge / discharge cable, the second control unit turns on the system-side switch to create conductivity between the first distribution board and the charge / discharge cable, and controls either a system connection operation in which AC power supplied from the power system via the first distribution board is supplied to the second vehicle to which the charge / discharge cable is connected, or a grid connection operation in which AC power supplied from the second vehicle via the charge / discharge cable is supplied to the first distribution board. The power system described in (A8) or (A9) above. (A11) When a power outage in the power system is detected, the second control unit checks for the presence or absence of the neutral point connection switch in the vehicle to which the charging / discharging cable is connected, and if the neutral point connection switch is not present, it does not output a control signal to instruct the vehicle to operate independently. A power system as described in any one of the above items (A8) to (A10). (B1) A charging / discharging cable having a pair of power lines, a protective earth wire at ground potential, and a control line, A system-side switch is provided between the input / output terminal on the system side, which is electrically connected to the power system via the first distribution board, and the charging / discharging cable. A standalone operation output terminal electrically connected to a second distribution panel different from the first distribution panel, and a standalone side switch provided between the charging and discharging cable, The system includes a second control unit that controls the operation of the system-side switch and the independent-side switch, and communicates with a first control unit of a power converter mounted on a vehicle to which the charge / discharge cable is connected via the control line, The pair of voltage lines at the input / output terminals on the grid side are electrically connected to the pair of power lines of the charge / discharge cable via the grid-side switch. The pair of voltage lines at the output terminal of the self-supporting side are electrically connected to the pair of power lines of the charge / discharge cable via the self-supporting side switch. The pair of power lines of the charging / discharging cable are electrically connected to the pair of power lines at the AC input / output terminals that input and output AC power in the power converter of the vehicle to which the charging / discharging cable is connected. The neutral wire at the input / output terminal on the system side and the protective earth wire of the charge / discharge cable are connected to ground potential. The second control unit is: When a vehicle is connected via the charging / discharging cable, the system-side switch is turned on to create conductivity between the first distribution board and the charging / discharging cable, and the system connection operation is controlled to supply AC power of the first voltage supplied from the power system via the first distribution board to the vehicle to which the charging / discharging cable is connected, or the system connection operation is controlled to supply AC power of the first voltage supplied from the vehicle via the charging / discharging cable to the first distribution board. When a power outage in the power system is detected, the self-sustaining switch is turned on to create electrical conductivity between the second distribution board and the charging / discharging cable, and a control signal is output to the first control unit of the power converter mounted on the vehicle to which the charging / discharging cable is connected, instructing the self-sustaining operation to be performed, thereby controlling the self-sustaining operation to supply AC power supplied from the vehicle via the charging / discharging cable to the second distribution board. The control signal instructing the aforementioned independent operation specifies the output voltage value as the second voltage, which is the potential difference between each of the pair of voltage lines at the input / output terminals on the grid side in the aforementioned grid-connected operation or grid-interconnected operation, and the neutral line at the input / output terminals on the grid side. Power supply device. (B2) The neutral wire at the output terminal of the self-supporting side is electrically connected to the protective earth wire of the charge / discharge cable via the self-supporting side switch. The protective ground wire of the charging / discharging cable is electrically connected to the functional ground wire of the chassis potential in the power converter of the vehicle to which the charging / discharging cable is connected. The second control unit checks whether a neutral point connection switch is provided between the neutral point of the pair of power lines at the AC input / output terminals of the power converter of the vehicle to which the charge / discharge cable is connected, and the functional grounding wire of the chassis potential. The control signal that instructs the aforementioned autonomous operation is, If the vehicle connected via the charging / discharging cable is the first vehicle having the neutral point connection switch, the first voltage, which is the potential difference between the pair of voltage lines at the input / output terminals on the grid side during grid connection operation or grid interconnection operation, is indicated as the output voltage value. If the vehicle connected via the charging / discharging cable is a second vehicle that does not have the neutral point connection switch, the second voltage is indicated as the output voltage value. The power supply device described in (B1) above. (B3) The system further includes a short-circuit switch provided between the output terminal of the self-supporting side and the self-supporting side switch, or between the self-supporting side switch and the input / output terminal of the vehicle side, which electrically connects one of the pair of power lines of the charging / discharging cable to one of the pair of voltage lines of the corresponding output terminal of the self-supporting side, or to the neutral line of the output terminal of the self-supporting side, via the self-supporting side switch. The second control unit is: When the first vehicle is connected via the charging / discharging cable, the short-circuit switch is turned off and one of the pair of power lines of the charging / discharging cable is electrically connected to one of the pair of voltage lines of the corresponding standalone output terminal, and a control signal instructing standalone operation is output. When the second vehicle is connected via the charging / discharging cable, the short-circuit switch is turned on to electrically connect one of the pair of power lines of the charging / discharging cable to the neutral wire at the output terminal of the self-sustaining side, and a control signal instructing self-sustaining operation is output. The power supply device described in (B2) above. (B4) The power supply device described in (B2) or (B3) above, The vehicle is electrically connected to the power supply device via the charging and discharging cable, The first distribution board is provided between the power system and the power supply device, The system includes a second distribution board located between the first distribution board and the power supply device, In the aforementioned grid connection operation or grid interconnection operation, the potential difference between the pair of power lines at the AC side input / output terminals of the power converter of the vehicle is the first voltage. In the aforementioned autonomous operation, the potential difference between the pair of power lines at the AC side input / output terminals of the power converter of the first vehicle is the first voltage. In the autonomous operation described above, the potential difference between each of the pair of power lines at the AC input / output terminals of the power converter of the first vehicle and the neutral point of the pair of power lines at the AC input / output terminals is the second voltage. In the aforementioned autonomous operation, the potential difference between the pair of power lines at the AC side input / output terminals of the power converter of the second vehicle is the second voltage. Power system. (B5) The power converter of the first vehicle includes the neutral point connection switch, The first control unit of the first vehicle turns on the neutral point connection switch during autonomous operation to conduct electricity between the neutral point of the AC input / output terminal of the power converter and the functional grounding wire of the chassis potential, and turns off the neutral point connection switch during grid-connected operation or grid-connected operation to disconnect the neutral point of the AC input / output terminal of the power converter and the functional grounding wire of the chassis potential. The power system described in (B4) above. (B6) The power supply device described in (B1) above, The vehicle is electrically connected to the power supply device via the charging and discharging cable, The first distribution board is provided between the power system and the power supply device, The aforementioned second distribution board, In the aforementioned grid connection operation or grid interconnection operation, the potential difference between the pair of power lines at the AC side input / output terminals of the power converter of the vehicle is the first voltage. In the aforementioned autonomous operation, the potential difference between the pair of power lines at the AC input / output terminals of the power converter of the vehicle is the second voltage. Power system. (B7) The vehicle is a first vehicle equipped with a power converter in which a neutral point connection switch is provided between the neutral point of a pair of power lines at the input / output terminals on the AC side and a functional grounding wire of chassis potential. The first control unit of the first vehicle turns on the neutral point connection switch during autonomous operation to conduct electricity between the neutral point of the AC input / output terminal of the power converter and the functional grounding wire of the chassis potential, and turns off the neutral point connection switch during grid-connected operation or grid-connected operation to disconnect the neutral point of the AC input / output terminal of the power converter and the functional grounding wire of the chassis potential. The power system described in (B6) above. [Explanation of Symbols]

[0126] 1. Power Systems 2 vehicles 2a First vehicle 2b Second vehicle 21 two-way charger 211 Control Unit 212 Power Conversion Unit 213 Neutral point connection switch 214 Current Sensor 22 High-voltage batteries 23 Charge / Discharge Sockets 4,4a,4b,4c EVSE 41 Control Unit 411 Backup power supply 42 System-side relay 43 Independent relay 44 LN short-circuit switch 49 Charging and discharging cable 61 Distribution board 62. Critical Load Distribution Panel 63 Freestanding outlet 7a 100V load 7b 200V load 7c 100V critical load 7d 200V critical load 9 System

Claims

1. A charging / discharging cable having a pair of power lines, a protective earth wire at ground potential, and a control line, A grid-side switch is provided between the grid-side input / output terminal, which is electrically connected to the power grid via the first distribution board, and the charging / discharging cable. A standalone operation output terminal electrically connected to a second distribution panel different from the first distribution panel, and a standalone side switch provided between the charging and discharging cable, The system includes a second control unit that controls the operation of the system-side switch and the independent-side switch, and communicates via the control line with a first control unit of a power converter mounted on a vehicle to which the charge / discharge cable is connected. The pair of voltage lines at the input / output terminals on the grid side are electrically connected to the pair of power lines of the charge / discharge cable via the grid-side switch. The pair of voltage lines at the output terminal of the self-supporting side are electrically connected to the pair of power lines of the charge / discharge cable via the self-supporting side switch. The pair of power lines of the charging / discharging cable are electrically connected to the pair of power lines at the AC input / output terminals that input and output AC power in the power converter of the vehicle to which the charging / discharging cable is connected. The neutral wire at the input / output terminal on the system side and the protective earth wire of the charge / discharge cable are connected to ground potential. The second control unit is, When a vehicle is connected via the charging / discharging cable, the system-side switch is turned on to create conductivity between the first distribution board and the charging / discharging cable, and the system connection operation is controlled to supply AC power of the first voltage supplied from the power system via the first distribution board to the vehicle to which the charging / discharging cable is connected, or the system connection operation is controlled to supply AC power of the first voltage supplied from the vehicle via the charging / discharging cable to the first distribution board. When a power outage in the power system is detected, the self-sustaining switch is turned on to create electrical conductivity between the second distribution board and the charging / discharging cable, and a control signal is output to the first control unit of the power converter mounted on the vehicle to which the charging / discharging cable is connected, instructing it to perform self-sustaining operation, thereby controlling the self-sustaining operation to supply AC power supplied from the vehicle via the charging / discharging cable to the second distribution board. The control signal instructing the aforementioned independent operation specifies the output voltage value as the second voltage, which is the potential difference between each of the pair of voltage lines at the input / output terminals on the grid side in the aforementioned grid-connected operation or grid-interconnected operation, and the neutral line at the input / output terminals on the grid side. Power supply device.

2. The neutral wire at the output terminal of the self-supporting side is electrically connected to the protective earth wire of the charge / discharge cable via the self-supporting side switch. The protective ground wire of the charging / discharging cable is electrically connected to the functional ground wire of the chassis potential in the power converter of the vehicle to which the charging / discharging cable is connected. The second control unit checks whether a neutral point connection switch is provided between the neutral point of the pair of power lines at the AC input / output terminals of the power converter of the vehicle to which the charge / discharge cable is connected, and the functional grounding wire of the chassis potential. The control signal that instructs the aforementioned autonomous operation is, If the vehicle connected via the charging / discharging cable is the first vehicle having the neutral point connection switch, the first voltage, which is the potential difference between the pair of voltage lines at the input / output terminals on the grid side during grid connection operation or grid interconnection operation, is indicated as the output voltage value. If the vehicle connected via the charging / discharging cable is a second vehicle that does not have the neutral point connection switch, the second voltage is indicated as the output voltage value. The power supply device according to claim 1.

3. The system further includes a short-circuit switch provided between the output terminal of the self-supporting side and the self-supporting side switch, or between the self-supporting side switch and the input / output terminal of the vehicle side, which electrically connects one of the pair of power lines of the charging / discharging cable to one of the pair of voltage lines of the corresponding output terminal of the self-supporting side, or to the neutral line of the output terminal of the self-supporting side, via the self-supporting side switch. The second control unit is, When the first vehicle is connected via the charging / discharging cable, the short-circuit switch is turned off and one of the pair of power lines of the charging / discharging cable is electrically connected to one of the pair of voltage lines of the corresponding standalone output terminal, and a control signal instructing standalone operation is output. When the second vehicle is connected via the charging / discharging cable, the short-circuit switch is turned on to electrically connect one of the pair of power lines of the charging / discharging cable to the neutral wire at the output terminal of the self-sustaining side, and a control signal instructing self-sustaining operation is output. The power supply device according to claim 2.

4. A power supply device according to claim 2 or claim 3, The vehicle is electrically connected to the power supply device via the charging and discharging cable, The first distribution board is provided between the power system and the power supply device, The system includes a second distribution board located between the first distribution board and the power supply device, In the aforementioned grid connection operation or grid interconnection operation, the potential difference between the pair of power lines at the AC side input / output terminals of the power converter of the vehicle is the first voltage. In the autonomous operation described above, the potential difference between the pair of power lines at the AC side input / output terminals of the power converter of the first vehicle is the first voltage. In the autonomous operation described above, the potential difference between each of the pair of power lines at the AC input / output terminals of the power converter of the first vehicle and the neutral point of the pair of power lines at the AC input / output terminals is the second voltage. In the aforementioned autonomous operation, the potential difference between the pair of power lines at the AC side input / output terminals of the power converter of the second vehicle is the second voltage. Power system.

5. The power converter of the first vehicle includes the neutral point connection switch, The first control unit of the first vehicle turns on the neutral point connection switch during autonomous operation to conduct electricity between the neutral point of the AC input / output terminal of the power converter and the functional grounding wire of the chassis potential, and turns off the neutral point connection switch during grid-connected operation or grid-connected operation to disconnect the neutral point of the AC input / output terminal of the power converter and the functional grounding wire of the chassis potential. The power system according to claim 4.

6. The power supply device according to claim 1, The vehicle is electrically connected to the power supply device via the charging and discharging cable, The first distribution board is provided between the power system and the power supply device, The aforementioned second distribution board, In the aforementioned grid connection operation or grid interconnection operation, the potential difference between the pair of power lines at the AC side input / output terminals of the power converter of the vehicle is the first voltage. In the aforementioned autonomous operation, the potential difference between the pair of power lines at the AC input / output terminals of the power converter of the vehicle is the second voltage. Power system.

7. The vehicle is a first vehicle equipped with a power converter in which a neutral point connection switch is provided between the neutral point of a pair of power lines at the input / output terminals on the AC side and a functional grounding wire at the chassis potential. The first control unit of the first vehicle turns on the neutral point connection switch during autonomous operation to conduct electricity between the neutral point of the AC input / output terminal of the power converter and the functional grounding wire of the chassis potential, and turns off the neutral point connection switch during grid-connected operation or grid-connected operation to disconnect the neutral point of the AC input / output terminal of the power converter and the functional grounding wire of the chassis potential. The power system according to claim 6.

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