JP2021141760A - Charge/discharge system - Google Patents

Abstract

To provide a charge/discharge system that can improve the convenience.SOLUTION: A charge/discharge system 1 includes a DC bus db1, a first DC connector 11, and a second DC connector 12. The DC bus db1 includes a node N1 connected to a DC terminal 34 of an AC/DC converter 3. The first DC connector 11 is connected to the node N1. The first DC connector 11 can be connected to at least a power storage device 4 of an electric vehicle C1. The second DC connector 12 is connected to the node N1. The second DC connector 12 performs at least one of supplying power to the first DC connector 11 and receiving power supply from the first DC connector 11 via the DC bus db1.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a charge / discharge system in general, and more particularly to a charge / discharge system including a DC connector that can be connected to a power storage device of an electric vehicle.

The electric vehicle power supply system (charge / discharge system) described in Patent Document 1 includes a bidirectional power supply device and a control device. The bidirectional power feeding device performs either a charging operation or a power feeding operation. The charging operation is an operation of supplying DC power supplied from a DC distribution board to the charging / discharging section of an electric vehicle. The power supply operation is an operation of supplying the DC power supplied from the charging / discharging section of the electric vehicle to the DC distribution board. The control device generates a switching signal for switching the operation of the bidirectional power feeding device to either a charging operation or a power feeding operation.

Japanese Unexamined Patent Publication No. 2011-130647

It is an object of the present disclosure to provide a charge / discharge system capable of improving convenience.

The charge / discharge system according to one aspect of the present disclosure includes a DC bus, a first DC connector, and a second DC connector. The DC bus has a node connected to the DC terminal of the AC / DC converter. The first DC connector is connected to the node. The first DC connector can be connected to at least a power storage device of an electric vehicle. The second DC connector is connected to the node. The second DC connector performs at least one of supplying power to the first DC connector and receiving power supply from the first DC connector via the DC bus.

The present disclosure has the advantage that convenience can be improved.

FIG. 1 is a block diagram showing a usage example of the charge / discharge system according to the first embodiment. FIG. 2 is an explanatory diagram showing an operation example of the same charge / discharge system. FIG. 3 is an explanatory diagram showing an operation example of the same charge / discharge system. FIG. 4 is an explanatory diagram showing an operation example of the same charge / discharge system. FIG. 5 is an explanatory diagram showing an operation example of the same charge / discharge system. FIG. 6 is a flowchart showing an operation example of the same charge / discharge system. FIG. 7 is an explanatory diagram showing an operation example of the charge / discharge system according to the second embodiment. FIG. 8 is a block diagram showing a usage example of the charge / discharge system according to the third embodiment. FIG. 9 is an explanatory diagram showing an operation example of the same charge / discharge system. FIG. 10 is a block diagram showing a usage example of the charge / discharge system according to the fourth embodiment. FIG. 11 is a block diagram showing a usage example of the charge / discharge system according to the fifth embodiment. FIG. 12 is a block diagram showing a usage example of the charge / discharge system according to the sixth embodiment.

(Embodiment 1)
Hereinafter, the charge / discharge system 1 according to the first embodiment will be described with reference to the drawings. However, the following embodiments are only one of the various embodiments of the present disclosure. The following embodiments can be variously modified according to the design and the like as long as the object of the present disclosure can be achieved.

(1) Outline As shown in FIG. 1, the charge / discharge system 1 of the present embodiment includes a DC bus db1, a first DC connector 11, and a second DC connector 12. The DC bus db1 has a node N1 connected to the DC terminal 34 of the AC / DC converter 3. The first DC connector 11 is connected to the node N1. The first DC connector 11 can be connected to at least the power storage device 4 of the electric vehicle C1. The second DC connector 12 is connected to the node N1. The second DC connector 12 performs at least one of supplying power to the first DC connector 11 and receiving power supply from the first DC connector 11 via the DC bus db1.

According to the above configuration, the power storage device 4 (first power storage device 401) of the electric vehicle C1 and the configuration connected to the second DC connector 12 (for example, the power storage device 4 (second power storage device 402) or the fuel cell). Power can be interchanged with the system). Moreover, since the power storage device 4 and the configuration connected to the second DC connector 12 are connected to each other via the connector, the connection is easier than in the case of directly connecting the electric wires. , Convenience can be improved.

Further, the charging / discharging system 1 of the present embodiment controls the charging current and the discharging current of each of the plurality of power storage devices 4 connected to each other via the power line (DC bus db1). The charge / discharge system 1 includes a determination unit 321 and a control unit 22. The determination unit 321 determines the droop characteristics as described below. The droop characteristic is a characteristic that increases or decreases the charge current or the discharge current of each of the plurality of power storage devices 4 as the predetermined observation amount increases. The control unit 22 performs charge control and discharge control based on the droop characteristics determined by the determination unit 321. The charge control is a control for charging at least one of the plurality of power storage devices 4 by the current supplied from the power line. The discharge control is a control in which at least one of the plurality of power storage devices 4 is discharged to supply a current to the power line.

According to the above configuration, it is not necessary for the determination unit 321 to constantly instruct the control unit 22 to charge and discharge currents, so that the amount of communication between the determination unit 321 and the control unit 22 can be suppressed.

The droop characteristic refers to a characteristic (change) that increases or decreases a physical quantity as the observed quantity increases when a certain physical quantity is set as an operation target and an observed quantity corresponding to the physical quantity is specified. Control of physical quantities based on droop characteristics is called droop control. Here, the physical quantity is the charge current and the discharge current of each of the plurality of power storage devices 4. Further, in the present embodiment, the observed amount is the voltage of the DC bus db1. The physical quantity may increase or decrease monotonically, and the physical quantity may not increase or decrease when the observed amount is changed only within a part of the range.

The charge / discharge system 1 of the present embodiment is installed in, for example, facility F1. That is, the charge / discharge system 1 is installed indoors or outdoors in the facility F1. Facility F1 is, for example, a residential facility such as a detached house or an apartment house, or a non-residential facility such as an office, a store, a nursing care facility, or a factory. In the present embodiment, as an example, a case where the facility F1 is a detached house will be described.

A plurality of (two in this embodiment) power storage devices 4 can be connected to the charge / discharge system 1. By using the charge / discharge system 1, electric power can be exchanged between a plurality of power storage devices 4.

In FIG. 1, a first power storage device 401 and a second power storage device 402 are connected to the charge / discharge system 1 as two power storage devices 4. That is, the first power storage device 401 is connected to the first DC connector 11, and the second power storage device 402 is connected to the second DC connector 12. The first power storage device 401 is a power storage device included in the electric vehicle C1 stopped at the facility F1. The second power storage device 402 is installed in the facility F1. The second power storage device 402 is, for example, a stationary power storage device.

The configuration of the first DC connector 11 and the second DC connector 12 is not limited to the configuration in which only the power storage device 4 can be connected, and for example, a power generation system such as a solar cell system or a fuel cell system, or a load can be connected. There may be.

(2) Charging / Discharging System As an example, the charging / discharging system 1 includes a DC bus (DC bus) db1, a first DC connector 11, a second DC connector 12, an AC connection portion 13, and a plurality (two) DCs. It includes a DC converter 2, an AC / DC converter 3, a housing 10, a plurality of (two) cables 15, a first connector holding portion 16, and a second connector holding portion 17.

The DC bus db1 is a kind of power line. The DC bus db1 has a node N1. The node N1 is connected to the DC terminal 34 of the AC / DC converter 3 and the main circuit 21 of the two DC / DC converters 2.

The housing 10 is a single housing and holds the DC bus db1, the first DC connector 11, and the second DC connector 12. Further, the housing 10 holds an AC connection unit 13, a plurality of DC / DC converters 2, an AC / DC converter 3, and two cables 15. More specifically, the housing 10 accommodates a DC bus db1, a plurality of DC / DC converters 2, an AC / DC converter 3, and an AC connection portion 13.

Each of the two cables 15 is, for example, a cabtire cable or a CV cable. The first end of one of the two cables 15 is held by the housing 10, and the first DC connector 11 is connected to the second end. The first end of the other cable 15 is held by the housing 10, and the second DC connector 12 is connected to the second end. That is, the housing 10 holds the first DC connector 11 and the second DC connector 12 via the cable 15.

Each of the first DC connector 11 and the second DC connector 12 is a connector. In the present disclosure, the "connector" means a component that connects a plurality of electric circuits. Other connectors, electric wires, or conductors (metal plates, etc.) to be connected can be connected to the connector. The first DC connector 11 and the second DC connector 12 are detachably connected to the connection target.

At least one of the first DC connector 11 and the second DC connector 12 (both in this embodiment) complies with a predetermined standard for at least one of connector connection and communication. The first DC connector 11 and the second DC connector 12 can be used by connecting to a connection target corresponding to a predetermined standard. In the present embodiment, the predetermined standard is a standard corresponding to the connection portion 43 (inlet) provided as the power supply port of the first power storage device 401 of the electric vehicle C1. That is, the shapes of the first DC connector 11 and the second DC connector 12 are shapes that can be directly connected to the inlet. An example of a predetermined standard is CHAdeMO®. Further, in the present embodiment, the shapes of the first DC connector 11 and the second DC connector 12 are the same as each other.

The first DC connector 11 is held by a first connector holding portion 16 provided at the tip (second end) of one of the two cables 15. The second DC connector 12 is held by a second connector holding portion 17 provided at the tip (second end) of the other cable 15 of the two cables 15. The first connector holding portion 16 includes a main body for holding the first DC connector 11 and a grip. The second connector holding portion 17 includes a main body for holding the second DC connector 12 and a grip. The shape of the first connector holding portion 16 and the second connector holding portion 17 is, for example, a pistol type.

The AC connection portion 13 is, for example, a terminal such as a quick-connect terminal, a crimp terminal, or a screw terminal. The AC connection unit 13 is connected to a connection target (connection unit 71, which will be described later).

Each of the plurality (two) DC / DC converters 2 has a main circuit 21, a control unit 22, and an acquisition unit 23. Hereinafter, the two DC / DC converters 2 may be distinguished, and one of the two DC / DC converters 2 may be referred to as a first DC / DC converter 201 and the other as a second DC / DC converter 202. be.

The main circuit 21 is a circuit that performs DC / DC conversion. More specifically, the main circuit 21 performs bidirectional DC / DC conversion. That is, the DC / DC converter 2 is a bidirectional DC / DC converter.

The first DC / DC converter 201 is connected between the node N1 of the DC bus db1 and the first DC connector 11. That is, the first end (two first input / output terminals) of the main circuit 21 of the first DC / DC converter 201 is connected to the first DC connector 11 via the cable 15, and the second end (two second ends). 2 input / output terminals) are connected to the node N1. The main circuit 21 of the first DC / DC converter 201 converts the power input from one of the first DC connector 11 and the DC bus db1 into a predetermined power and outputs the power to the other.

Further, the second DC / DC converter 202 is connected between the node N1 and the second DC connector 12. That is, the first end of the main circuit 21 of the second DC / DC converter 202 is connected to the second DC connector 12 via the cable 15, and the second end is connected to the node N1. The main circuit 21 of the second DC / DC converter 202 converts the power input from one of the second DC connector 12 and the DC bus db1 into a predetermined power and outputs the power to the other.

The control unit 22 includes a computer system having one or more processors and memories. When the processor of the computer system executes the program recorded in the memory of the computer system, at least a part of the functions of the control unit 22 are realized. The program may be recorded in a memory, provided through a telecommunication line such as the Internet, or may be recorded and provided on a non-temporary recording medium such as a memory card.

The control unit 22 controls the operation of the main circuit 21. As a specific example, the control unit 22 controls one or more switching elements included in the main circuit 21 by PWM (Pulse Width Modulation). As a result, the control unit 22 controls the charge current and the discharge current of the first power storage device 401 or the second power storage device 402 connected via the first DC connector 11 or the second DC connector 12. Details of the function of the control unit 22 will be described later.

The acquisition unit 23 has a function of communicating with the AC / DC converter 3. The communication method may be wired communication via a power line such as DC bus db1 or a signal line, or may be wireless communication. The acquisition unit 23 acquires the droop characteristic information from the AC / DC converter 3. Further, the acquisition unit 23 has a function of acquiring the voltage of the DC bus db1 (that is, the bus voltage). In FIG. 1, the magnitude of the bus voltage is represented as Vdb1. The acquisition unit 23 is, for example, a voltage between two first input / output terminals provided at the first end of the main circuit 21, or between two second input / output terminals provided at the second end of the main circuit 21. The bus voltage is obtained by measuring the voltage of the above as the bus voltage.

The AC / DC converter 3 has a main circuit 31, a control circuit 32, and an acquisition unit 33.

The main circuit 31 is a circuit that performs power conversion between DC power and AC power. More specifically, the main circuit 31 performs an operation of converting DC power into AC power and an operation of converting AC power into DC power. That is, the AC / DC converter 3 is a bidirectional AC / DC converter. The first end (two DC terminals 34 of the main circuit 31 (only one is shown in FIG. 1)) is an input / output end of DC power and is connected to the node N1 of the DC bus db1. The second end of the main circuit 31 (two AC terminals 35 (only one is shown in FIG. 1)) is an input / output end for AC power and is connected to the AC connection portion 13. The main circuit 31 converts the DC power input from the DC bus db1 into a predetermined AC power and outputs the DC power to the AC connection unit 13. Further, the main circuit 31 converts the AC power input from the AC connection unit 13 into a predetermined DC power and outputs the AC power to the DC bus db1.

The control circuit 32 includes a computer system having one or more processors and memory. When the processor of the computer system executes the program recorded in the memory of the computer system, at least a part of the functions of the control circuit 32 are realized. The program may be recorded in a memory, provided through a telecommunication line such as the Internet, or may be recorded and provided on a non-temporary recording medium such as a memory card.

The control circuit 32 includes a determination unit 321 and a main circuit control unit 322. It should be noted that the determination unit 321 and the main circuit control unit 322 merely indicate the functions realized by the control circuit 32, and do not necessarily indicate a substantive configuration.

The determination unit 321 determines the droop characteristics of each of the plurality of power storage devices 4. Details of the function of the determination unit 321 will be described later.

The main circuit control unit 322 controls the operation of the main circuit 31. As a specific example, the main circuit control unit 322 controls PWM (Pulse Width Modulation) of one or more switching elements included in the main circuit 31. As a result, the main circuit control unit 322 controls the input / output of the main circuit 31. Further, as a result, the main circuit control unit 322 boosts or lowers the bus voltage.

The acquisition unit 33 acquires the information used by the control circuit 32 for control. The information acquired by the acquisition unit 33 includes, for example, information on the maximum input current, maximum output current, charge start voltage, discharge start voltage, remaining capacity, and maximum capacity of each of the plurality of power storage devices 4 (storage batteries 42). The maximum capacity is the capacity when the power storage device 4 (storage battery 42) is fully charged. The acquisition unit 33 acquires, for example, information on the rated capacity of the power storage device 4 (storage battery 42) as information on the maximum capacity. Further, the information acquired by the acquisition unit 33 includes, for example, a measured value of the bus voltage, an input / output current of each of the plurality of power storage devices 4, and a measured value of the input / output voltage.

(3) Power Storage Device Each of the plurality of power storage devices 4 has a DC / DC converter 41, a storage battery 42, and a connection portion 43.

The DC / DC converter 41 performs DC / DC conversion. More specifically, the DC / DC converter 41 performs bidirectional DC / DC conversion. That is, the DC / DC converter 41 is a bidirectional DC / DC converter. The first end (two first input / output terminals) of the DC / DC converter 41 is connected to the connection portion 43, and the second end (two second input / output terminals) is connected to the storage battery 42. There is. The DC / DC converter 41 converts the electric power input from one of the connection unit 43 and the storage battery 42 into a predetermined electric power and outputs the electric power to the other.

The storage battery 42 is, for example, a lithium ion battery. The storage battery 42 is charged and discharged according to the operation of the DC / DC converter 41. That is, the storage battery 42 is charged by the electric power input from the connection unit 43 to the DC / DC converter 41 and output from the DC / DC converter 41 through the DC / DC conversion. Further, the electric power discharged from the storage battery 42 is input to the DC / DC converter 41, and is output to the connection unit 43 through the DC / DC conversion.

The connection portion 43 is, for example, a connector. More specifically, the connecting portion 43 is an inlet. The connection portion 43 is detachably connected to the first DC connector 11 or the second DC connector 12 (connection target). The connection unit 43 conforms to a standard corresponding to the connection target. That is, the connection unit 43 has a structure that can be connected to the connection target. As an example, the connection 43 conforms to the CHAdeMO® standard.

(4) Electric Vehicle In the present embodiment, a case where the electric vehicle C1 is a four-wheeled vehicle will be described as an example. However, the electric vehicle C1 is not limited to the four-wheeled vehicle, and may be a two-wheeled vehicle, an electric bicycle, an electrically assisted bicycle, or the like. Further, in the present embodiment, the case where the electric vehicle C1 is a battery car (an electric vehicle using a loaded storage battery as a power source) will be described as an example. However, the electric vehicle C1 may be a fuel cell hybrid vehicle equipped with a fuel cell in addition to the storage battery, or a plug-in hybrid vehicle equipped with an internal combustion engine in addition to the storage battery.

The electric vehicle C1 includes a power storage device 4 and an ECU (Electronic Control Unit) 430.

The ECU 430 controls various operations related to the running of the electric vehicle C1 and the like. Further, the ECU 430 controls the operation of the DC / DC converter 41.

(5) Other Configurations The facility F1 of the present embodiment includes an AC bus ab1, a solar cell system 6, a connection unit 71, an interconnection switch 73, a load switch 74, a load 75, and a power failure detection unit. It has 76 and.

The AC bus ab1 has a node N2. The solar cell system 6, the connection portion 71, the interconnection switch 73, and the load switch 74 are connected to the node N2. The node N2 is connected to the power system 72 via the interconnection switch 73. Further, the node N2 is connected to the load 75 via the load switch 74. Although the load 75 is one in the present embodiment, the facility F1 may be provided with a plurality of loads 75.

The solar cell system 6 includes an AC / DC converter 61 and a solar cell 62.

The AC / DC converter 61 performs power conversion between DC power and AC power. More specifically, the AC / DC converter 61 performs an operation of converting DC power into AC power. The first end (two DC terminals) of the AC / DC converter 61 is a DC power input end and is connected to the solar cell 62. The second end (two AC terminals) of the AC / DC converter 61 is an output end of AC power and is connected to the node N2 of the AC bus ab1. The AC / DC converter 61 converts the DC power input from the solar cell 62 into a predetermined AC power and outputs the DC power to the AC bus ab1.

The connection portion 71 is, for example, a tip portion of an electric wire as an AC bus ab1. The connection unit 71 is connected to the AC connection unit 13 (connection target).

The AC terminal 35 of the AC / DC converter 3 is connected to the AC bus ab1 via the AC connection unit 13 and the connection unit 71. AC power is supplied to the AC bus ab1 from a power source (power system 72 and solar cell system 6). The AC terminal 35 of the AC / DC converter 3 can receive AC power from the power supply via the AC bus ab1, the connection unit 71, and the AC connection unit 13. That is, the AC / DC converter 3 has at least an AC terminal 35 that can be connected to a power source, and receives power supply from the power source.

The power failure detection unit 76 monitors the voltage supplied from the power system 72. When this voltage falls below the threshold value, the power failure detection unit 76 detects a power failure in the power system 72.

(6) Droop Control (6-1) Outline The charging / discharging system 1 can control the charging current (input current) and the discharging current (output current) of each of the plurality of power storage devices 4 by the droop control. More specifically, the charge / discharge system 1 includes a plurality of (two) DC / DC converters 2, and the plurality of DC / DC converters 2 have a one-to-one correspondence with the plurality of power storage devices 4. Specifically, the first DC / DC converter 201 corresponds to the first power storage device 401, and the second DC / DC converter 202 corresponds to the second power storage device 402. Each of the plurality of DC / DC converters 2 is connected between the corresponding power storage device 4 and the power line (DC bus db1). Each of the plurality of DC / DC converters 2 has a control unit 22, and the control unit 22 targets the corresponding power storage device 4 based on the droop characteristics determined by the determination unit 321 for charge control and discharge. Take control. Further, the observed amount used for the droop control is the bus voltage, and the main circuit control unit 322 of the AC / DC converter 3 changes the bus voltage. If the value of the bus voltage is known, the control unit 22 can uniquely determine the charge current or the discharge current based on the droop characteristic. Following the change in the bus voltage, the control unit 22 changes the charge current or the discharge current of each of the plurality of power storage devices 4 based on the droop characteristic.

Further, the charge control and the discharge control based on the droop characteristic by the control unit 22 are the control to make the sum of the charge currents and the sum of the discharge currents of the plurality of power storage devices 4 equal to each other, or bring the bus voltage close to a predetermined reference value. It is control.

The control that brings the bus voltage close to a predetermined reference value is as follows. That is, if the bus voltage is higher than the above reference value, the control unit 22 performs control based on the droop characteristic, so that the sum of the charge currents of the plurality of power storage devices 4 becomes larger than the sum of the discharge currents, and the bus voltage. Try to drop. However, the main circuit control unit 322 maintains the bus voltage. If the bus voltage is lower than the above reference value, the control unit 22 performs control based on the droop characteristic, so that the sum of the charging currents of the plurality of power storage devices 4 becomes smaller than the sum of the discharging currents, and the bus voltage rises. try to. However, the main circuit control unit 322 maintains the bus voltage. The reference value is a voltage corresponding to the origin O in FIG.

The control cycle of the process in which the determination unit 321 of the control circuit 32 determines the droop characteristic and transmits the information of the droop characteristic to the control unit 22 of the DC / DC converter 2 is determined by the control unit 22 based on the droop characteristic. It is longer than the control cycle of the process that controls. That is, the control unit 22 uses the droop characteristic information acquired from the determination unit 321 until new droop characteristic information is transmitted from the determination unit 321. Therefore, the communication amount of the control circuit 32 can be reduced as compared with the case where the control circuit 32 directly controls the power storage device 4.

By using the charge / discharge system 1 of the present embodiment, it is possible to reduce the amount of communication as compared with the case of adopting the high-speed communication control method which is one of the control methods of the power storage device 4. In the high-speed communication control method, as in the present embodiment, a plurality of sets of DC / DC converters and power storage devices are provided, and each DC / DC converter is connected to one AC / DC converter. Then, in the high-speed communication control method, a plurality of power storage devices are controlled by issuing output commands from one AC / DC converter to a plurality of DC / DC converters via an optical fiber or the like. In the high-speed communication control method, since it is necessary to issue an output command in a relatively short control cycle, the amount of communication is relatively large.

(6-2) First Example Hereinafter, an example of droop control by the charge / discharge system 1 will be described with reference to FIG.

The determination unit 321 of the AC / DC converter 3 determines the droop characteristics of each of the plurality of power storage devices 4 individually corresponding to the plurality of power storage devices 4. FIG. 2 is a graph showing an example of droop characteristics determined corresponding to one of the plurality of power storage devices 4.

The horizontal axis represents the storage battery current of the power storage device 4. Here, it is defined that the storage battery current is X [A], and when X is a positive value, the storage battery current is a charging current, and when X is a negative value, the absolute value of the storage battery current is a discharge current. .. That is, the storage battery current is a charge current or a discharge current. The storage battery current at the origin O is 0 [A]. When the coordinates are to the right of the origin O, the power storage device 4 is charged, and when the coordinates are to the left of the origin O, the power storage device 4 is discharged.

The vertical axis represents the bus voltage (that is, the voltage of the DC bus db1). The value of the bus voltage at the origin O is a predetermined reference value of the bus voltage and is larger than 0 [V].

Vmax is the maximum value of the bus voltage. Vmin is the minimum value of the bus voltage. The maximum value Vmax and the minimum value Vmin are predetermined.

The determination unit 321 determines the droop characteristic at least between the maximum value Vmax and the minimum value Vmin of the bus voltage. That is, the determination unit 321 determines the change in the storage battery current when the bus voltage changes between the maximum value Vmax and the minimum value Vmin. The droop characteristic shown by the line segment L1 in FIG. 2 is such that the storage battery current increases as the bus voltage increases. More specifically, as the bus voltage increases, the battery current increases linearly. Here, it is possible to obtain the maximum value Imax and the minimum value Imin of the storage battery current when the bus voltage changes between the maximum value Vmax and the minimum value Vmin from the droop characteristic. Imax is the maximum value of the charging current, and Imin = (maximum value of the discharging current) × (-1).

When determining the droop characteristic, the determination unit 321 refers to the information of the maximum input current and the maximum output current of the power storage device 4 acquired by the acquisition unit 33. That is, the determination unit 321 determines the droop characteristic so that the maximum value Imax of the storage battery current is equal to or less than the maximum input current and the absolute value of the minimum value Imin is equal to or less than the maximum output current.

The acquisition unit 23 of each DC / DC converter 2 acquires the droop characteristic information from the determination unit 321. In each DC / DC converter 2, the control unit 22 controls the main circuit 21 based on the droop characteristics. As a result, the control unit 22 controls the storage battery current (charge current in charge control and discharge current in discharge control) of the power storage device 4.

That is, when the bus voltage is Va (0 ≦ Va ≦ Vmax), the storage battery current value Ia1 at the coordinates corresponding to Va in the graph of FIG. 2 showing the droop characteristic is a positive value, so that the power storage device 4 is charged. Will be done. The above value Ia1 is the target value of the charging current of the power storage device 4.

When the bus voltage is Vb (Vmin ≦ Vb ≦ 0), the storage battery current value Ib1 at the coordinates corresponding to Vb is a negative value, so that the power storage device 4 discharges. The absolute value of the above value Ib1 becomes the target value of the discharge current.

The control unit 22 determines the target value of the charge current (or discharge current) in this way, and controls the main circuit 21 so that the charge current (or discharge current) of the power storage device 4 approaches the target value.

Further, in this way, the control unit 22 determines whether to perform charge control or discharge control for each of the plurality of power storage devices 4 based on the droop characteristics. That is, the control unit 22 performs charge control if the value of the storage battery current of the corresponding power storage device 4 is a positive value, and discharge control if the value is a negative value. Charging control involves determining a target value for the charging current. Discharge control involves determining a target value for the discharge current.

When the power storage device 4 is fully charged, the control circuit 32 sets the charge current and the discharge current to 0 [A]. For example, the determination unit 321 of the control circuit 32 sets the charge current and the discharge current to 0 [A] by giving the control unit 22 a droop characteristic in which the storage battery current is 0 [A] with respect to an arbitrary bus voltage. .. Alternatively, the main circuit control unit 322 of the control circuit 32 sets the charge current and the discharge current to 0 [A] by making the bus voltage equal to the reference value.

Here, in the first DC / DC converter 201, the control unit 22 controls the charging current and the discharging current of the first power storage device 401 by controlling the main circuit 21. On the other hand, in the second DC / DC converter 202, the control unit 22 controls the charging current and the discharging current of the second power storage device 402 by controlling the main circuit 21.

The determination unit 321 can make the droop characteristic given to the control unit 22 of the first DC / DC converter 201 different from the droop characteristic given to the control unit 22 of the second DC / DC converter 202. This will be described with reference to FIGS. 3 to 5.

(6-3) Second Example In FIG. 3, the droop characteristic given to the control unit 22 of the first DC / DC converter 201 is represented by a line segment L1, and the droop characteristic given to the control unit 22 of the second DC / DC converter 202 is represented by a line segment L1. It is represented by a line segment L2. That is, the line segment L1 represents the droop characteristic corresponding to the first power storage device 401, and the line segment L2 represents the droop characteristic corresponding to the second power storage device 402.

When the bus voltage is Va (0 ≦ Va ≦ Vmax), the storage battery current value Ia1 corresponding to the first power storage device 401 and the storage battery current value Ia2 corresponding to the second power storage device 402 are positive values. Therefore, the first power storage device 401 and the second power storage device 402 are charged. The target value of the charging current of the first power storage device 401 is Ia1, and the target value of the charging current of the second power storage device 402 is Ia2.

When the bus voltage is Vb (Vmin ≦ Vb ≦ 0), the storage battery current value Ib1 corresponding to the first power storage device 401 and the storage battery current value Ib2 corresponding to the second power storage device 402 are negative values. Therefore, the first power storage device 401 and the second power storage device 402 are discharged. The target value of the discharge current of the first power storage device 401 is the absolute value of Ib1, and the target value of the discharge current of the second power storage device 402 is the absolute value of Ib2.

Further, the sum of the storage battery current of the first power storage device 401 and the storage battery current of the second power storage device 402 is represented by the line segment L12. When the bus voltage is Va (0 ≦ Va ≦ Vmax), the sum Ia12 of the storage battery current of the first power storage device 401 and the storage battery current of the second power storage device 402 becomes a positive value. Therefore, only Ia12 is supplied with current from the AC / DC converter 3 (see FIG. 1) to the DC bus db1 (see FIG. 1). This current is supplied to the plurality of power storage devices 4.

On the other hand, when the bus voltage is Vb (Vmin ≦ Vb ≦ 0), the sum Ib12 of the storage battery current of the first power storage device 401 and the storage battery current of the second power storage device 402 becomes a negative value. Therefore, only Ib12 is supplied with current from the plurality of power storage devices 4 to the AC / DC converter 3 via the DC bus db1.

That is, each of the plurality of power storage devices 4 is connected to the AC / DC converter 3 via the power line (DC bus db1), and supplies a current to the AC / DC converter 3 and the AC / DC converter. At least one of receiving the current from 3 (both in this embodiment). The current supplied to the AC / DC converter 3 is supplied to at least one of the load 75 and the power system 72.

The slopes of the line segments L1 and L2 correspond to the rate of change of the storage battery current with respect to the change of the bus voltage. The determination unit 321 determines the inclination of the line segments L1 and L2 as follows, for example. That is, the determination unit 321 reduces the inclination of the line segment as the maximum capacity of the power storage device 4 corresponding to the line segment (droop characteristic) increases. As a result, when the bus voltage has a certain value, the target value of the charge current or the discharge current of the power storage device 4 having a larger maximum capacity among the plurality of power storage devices 4 becomes larger. For example, in FIG. 3, the line segment L1 corresponds to the power storage device 4 having the largest capacity among the two power storage devices 4, and the line segment L2 corresponds to the other power storage device 4 of the two power storage devices 4. By determining the target value according to the maximum capacity of the power storage device 4, deterioration of the power storage device 4 can be suppressed. The magnitude of the inclination of the line segments L1 and L2 may be proportional to the maximum capacity of the power storage device 4.

(6-4) Third Example Next, FIG. 4 shows a droop characteristic (line segment L1) given to the control unit 22 of the first DC / DC converter 201 and a droop characteristic (line segment L1) given to the control unit 22 of the second DC / DC converter 202. Another example of the droop characteristic (line segment L2) is shown.

In FIG. 4, the line segment L1 has a positive slope, as in FIG. That is, in the power storage device 4 corresponding to the line segment L1, the storage battery current increases as the bus voltage increases. On the other hand, in FIG. 4, the line segment L2 has a negative slope. That is, in the power storage device 4 corresponding to the line segment L2, the storage battery current decreases as the bus voltage increases.

When the bus voltage is Va (0 ≦ Va ≦ Vmax), the storage battery current value Ia1 corresponding to the first power storage device 401 is a positive value, so that the first power storage device 401 is charged. The target value of the charging current of the first power storage device 401 is Ia1. On the other hand, since the storage battery current value Ia2 corresponding to the second power storage device 402 is a negative value, the second power storage device 402 discharges. The target value of the discharge current of the second power storage device 402 is the absolute value of Ia2.

When the bus voltage is Vb (Vmin ≦ Vb ≦ 0), the storage battery current value Ib1 corresponding to the first power storage device 401 is a negative value, so that the first power storage device 401 is discharged. The target value of the discharge current of the first power storage device 401 is the absolute value of Ib1. On the other hand, since the storage battery current value Ib2 corresponding to the second power storage device 402 is a positive value, the second power storage device 402 is charged. The target value of the charging current of the second power storage device 402 is Ib2.

Further, the sum of the storage battery current of the first power storage device 401 and the storage battery current of the second power storage device 402 is represented by the line segment L12. When the bus voltage is Va (0 ≦ Va ≦ Vmax), the sum Ia12 of the storage battery current of the first power storage device 401 and the storage battery current of the second power storage device 402 becomes a positive value. Therefore, only Ia12 is supplied with current from the AC / DC converter 3 (see FIG. 1) to the DC bus db1 (see FIG. 1). This current is supplied to the plurality of power storage devices 4.

On the other hand, when the bus voltage is Vb (Vmin ≦ Vb ≦ 0), the sum Ib12 of the storage battery current of the first power storage device 401 and the storage battery current of the second power storage device 402 becomes a negative value. Therefore, only Ib12 is supplied with current from the plurality of power storage devices 4 to the AC / DC converter 3 via the DC bus db1.

In short, as shown in FIGS. 3 and 4, when the bus voltage is a certain value and the sum of the storage battery currents of the plurality of power storage devices 4 is a positive value, the AC / DC converter 3 to the DC bus db1 A current is supplied to the plurality of power storage devices 4 via the above, and when the value is negative, a current is supplied from the plurality of power storage devices 4 to the AC / DC converter 3 via the DC bus db1.

(6-5) Fourth Example Further, the determination unit 321 has a function of determining a droop characteristic satisfying the following conditions. The above condition is that the sum of the charging currents of the plurality of power storage devices 4 and the sum of the discharge currents of the plurality of power storage devices 4 are equal. In other words, the above condition is a condition that the sum of the storage battery currents of the plurality of power storage devices 4 becomes 0 with respect to an arbitrary bus voltage. In other words, the above condition is a condition that the line segment L12 coincides with a part of the vertical axis as shown in FIG. Here, since the first power storage device 401 and the second power storage device 402 are the control targets as the power storage device 4, if the line segment L1 and the line segment L2 are line symmetric with the vertical axis as the axis of symmetry, the above condition is satisfied. It is filled. In other words, the above condition is satisfied if the storage battery current represented by the line segment L1 is (-1) times the storage battery current represented by the line segment L2 with respect to an arbitrary bus voltage.

By satisfying the above conditions, the range in which electric power is interchanged can be limited between the plurality of power storage devices 4. That is, the electric power supplied from the DC bus db1 to the AC bus ab1 and the electric power supplied from the AC bus ab1 to the DC bus db1 can be made equal (substantially zero). As a result, electric power can be efficiently exchanged between the plurality of power storage devices 4.

Further, the determination unit 321 has the following functions. The function is that the control unit 22 controls charging of a part of the power storage devices 4 among the plurality of power storage devices 4, and at the same time, the control unit 22 causes the control unit 22 to control charging of a part of the power storage devices 4. This is a function of controlling the discharge of the power storage device 4. For example, in FIGS. 4 and 5, the above functions are realized.

(7) Example of Use of Charge / Discharge System As shown in FIG. 1, the first DC connector 11 of the charge / discharge system 1 is connected to, for example, the power storage device 4 (first power storage device 401) of the electric vehicle C1. Further, the second DC connector 12 is connected to, for example, a stationary power storage device 4 (second power storage device 402). An example of using the charge / discharge system 1 in such a case will be described below.

In the present embodiment, the control circuit 32 has functions as a first control unit, a second control unit, and a third control unit, which will be described later, but as a first control unit, a second control unit, and a third control unit. The function may be realized by a configuration other than the control circuit 32. Further, the functions as the first control unit, the second control unit, and the third control unit may be distributed and provided in a plurality of configurations.

(7-1) Peak Cut Function The control circuit 32 (first control unit) controls the power supply from the second DC connector 12 to the first DC connector 11. The control circuit 32 has a peak cut function. The peak cut function referred to here is a function of controlling the power supplied from the second DC connector 12 to the first DC connector 11 so that the power supplied from the AC / DC converter 3 to the first DC connector 11 falls below the threshold value. be. The control circuit 32 uses the peak cut function when charging the first power storage device 401 of the electric vehicle C1. The control circuit 32 may have a function of switching between enabling and disabling the peak cut function. Switching between enabling and disabling the peak cut function may be performed by a user's operation, may be performed in response to an external signal input, or may be automatically performed according to a predetermined condition. The predetermined condition is, for example, a condition in which the first power storage device 401 is quickly charged. Rapid charging refers to charging in a state where the magnitude of the current supplied to the first power storage device 401 is equal to or greater than a predetermined value.

The threshold value may be determined in advance, or may be determined by the control circuit 32 or the like according to conditions related to the contract power of the facility F1 and the power consumption of the facility F1 when the peak cut function is executed.

For example, the first power storage device 401 is connected to the first DC connector 11, and the second power storage device 402 is connected to the second DC connector 12, for example. In this case, for example, the peak cut function can be realized by using the droop characteristic as shown in FIG. In FIG. 4, the droop characteristic represented by the line segment L1 corresponds to the first power storage device 401, and the droop characteristic represented by the line segment L2 corresponds to the second power storage device 402.

The main circuit control unit 322 of the control circuit 32 sets the bus voltage to Va (0 <Va ≦ Vmax). As a result, the first power storage device 401 is charged, and the second power storage device 402 is discharged. Further, a current is supplied from the AC / DC converter 3 to the DC bus db1. That is, the first power storage device 401 is charged by the current supplied from the second power storage device 402 and the AC / DC converter 3. The current supplied from the AC / DC converter 3 is, traceably, the current supplied from the power system 72 or the solar cell system 6. The magnitude of the current supplied from the AC / DC converter 3 is equal to the sum Ia12 of the storage battery current of the first power storage device 401 and the storage battery current of the second power storage device 402. In other words, the magnitude of the current supplied from the AC / DC converter 3 is equal to the value obtained by subtracting the discharge current of the second power storage device 402 from the charge current of the first power storage device 401. That is, a current that cannot be covered by the discharge current of the second power storage device 402 is supplied from the AC / DC converter 3 to charge the first power storage device 401.

Compared with the case where the first power storage device 401 is charged only by the current supplied from the AC / DC converter 3, the current supplied from the AC / DC converter 3 can be reduced by using the peak cut function. .. As a result, the peak value of the power purchased from the power system 72 can be suppressed when the first power storage device 401 is charged. Therefore, it is possible to reduce the electric power charge according to the peak value of the purchased electric power. In addition, it is possible to reduce the possibility that it will be necessary to change the equipment such as a transformer required according to the peak value of the purchased power to equipment having a larger capacity. Further, conventionally, a power drop line for supplying power to a power storage device of an electric vehicle may be provided separately from a service line for supplying power to other equipment (load or the like). From such a configuration, when the configuration is changed so as to combine the drop lines into one, it is possible to reduce the possibility that the peak value of the power supplied from one drop line increases.

(7-2) VtoX power supply function The control circuit 32 (second control unit) controls the power supply from the first DC connector 11 to the second DC connector 12. The control circuit 32 has a VtoX (Vehicle to X) power feeding function. The VtoX power supply function referred to here is to supply power from the first DC connector 11 to the second DC connector 12 when the power storage device 4 (first power storage device 401) of the electric vehicle C1 is connected to the first DC connector 11. It is a function. The trigger for starting the VtoX power supply function may be a user operation or an external signal input, and the power storage device 4 of the electric vehicle C1 is connected to the first DC connector 11. It may be that a predetermined condition including is satisfied.

For example, a second power storage device 402 is connected to the second DC connector 12. In this case, for example, the VtoX power feeding function can be realized by using the droop characteristic as shown in FIG. In FIG. 5, the droop characteristic represented by the line segment L1 corresponds to the first power storage device 401, and the droop characteristic represented by the line segment L2 corresponds to the second power storage device 402.

The main circuit control unit 322 of the control circuit 32 sets the bus voltage to Vb (Vmin ≦ Vb <0). As a result, the first power storage device 401 is discharged, and the second power storage device 402 is charged. That is, the second power storage device 402 is charged by the current supplied from the first power storage device 401.

The user can use the VtoX power supply function in the event of a power failure of the power system 72 or the like. For example, the user drives the electric vehicle C1 to a facility for charging the power storage device of the electric vehicle. However, it is assumed that power is supplied to this equipment from the power system 72, or that the power storage device of the electric vehicle can be charged by the power of the power generation device or power storage device of this facility. The user charges the power storage device 4 of the electric vehicle C1 with this equipment, and then drives the electric vehicle C1 to the facility F1. After that, the VtoX power supply function is started to supply power from the power storage device 4 (first power storage device 401) of the electric vehicle C1 to the second power storage device 402.

For example, when the electric vehicle C1 is a fuel cell hybrid vehicle, hydrogen may be replenished and the second power storage device 402 may be supplied with the current generated by the fuel cell.

Further, when the VtoX power supply function is executed, a load may be connected to the second DC connector 12 instead of the second power storage device 402.

(7-3) Power failure backup function The control circuit 32 (third control unit) controls the power supply to the AC / DC converter 3 from at least one of the first DC connector 11 and the second DC connector 12. The control circuit 32 has a power failure backup function. The power failure backup function referred to here is a function of supplying power to the AC / DC converter 3 from at least one of the first DC connector 11 and the second DC connector 12 when a power failure occurs.

When the condition that the power failure detection unit 76 detects the power failure of the power system 72 is satisfied, the control circuit 32 starts the power failure backup function. As a result, a current can be supplied to the load 75. The conditions for starting the power failure backup function include user operation, external signal input, and connection of the power storage device 4 to at least one of the first DC connector 11 and the second DC connector 12. It may be further included.

For example, the first power storage device 401 is connected to the first DC connector 11, and the second power storage device 402 is connected to the second DC connector 12, for example. In this case, for example, the peak cut function can be realized by using the droop characteristic as shown in FIG. In FIG. 3, the droop characteristic represented by the line segment L1 corresponds to the first power storage device 401, and the droop characteristic represented by the line segment L2 corresponds to the second power storage device 402.

The main circuit control unit 322 of the control circuit 32 sets the bus voltage to Vb (Vmin ≦ Vb <0). As a result, the first power storage device 401 and the second power storage device 402 are discharged. The current corresponding to the sum Ib12 of the discharge powers of the first power storage device 401 and the second power storage device 402 is supplied to the load 75 via the DC bus db1, the AC / DC converter 3, and the AC bus ab1.

(Modified Example of Embodiment 1)
Hereinafter, modifications of the first embodiment will be listed. The following modifications may be realized in appropriate combinations.

The same function as the charge / discharge system 1 may be realized by a charge / discharge method, a (computer) program, a non-temporary recording medium on which the program is recorded, or the like.

The charging / discharging method according to one aspect is a method of controlling the charging current and the discharging current of each of the plurality of power storage devices 4. The plurality of power storage devices 4 are connected to each other via a power line (DC bus db1). The charging / discharging method includes a determination process and a control process. The determination process is a process for determining the droop characteristic. The droop characteristic is a characteristic that increases or decreases the charge current or the discharge current of each of the plurality of power storage devices 4 as the predetermined observation amount (bus voltage) increases. The control process is a process of performing charge control and discharge control based on the droop characteristics determined by the determination process. The charge control is a control for charging at least one of the plurality of power storage devices 4 by the current supplied from the power line. The discharge control is a control in which at least one of the plurality of power storage devices 4 is discharged to supply a current to the power line.

Specifically, as shown in FIG. 6, first, the determination unit 321 individually corresponds to the plurality of power storage devices 4 and determines the droop characteristics (step ST1: determination process). The control unit 22 acquires the droop characteristic information from the determination unit 321 via the acquisition unit 23 (step ST2). Further, the main circuit control unit 322 boosts or lowers the bus voltage (step ST3). The main circuit control unit 322 may perform a process of changing the bus voltage at an arbitrary timing. The control unit 22 monitors the magnitude of the bus voltage.

Here, as an example, when the droop characteristic is represented by the line segment L1 in FIG. 2, when the bus voltage is higher than the reference value (step ST4: YES), the control unit 22 performs charge control (step ST5). When the bus voltage is lower than the reference value (step ST4: NO, step ST6: NO), the control unit 22 performs discharge control (step ST7). When the bus voltage is equal to the reference value (step ST6: YES), the control unit 22 does not perform either charge control or discharge control.

In addition, the determination unit 321 newly determines the droop characteristic as appropriate. When the determination unit 321 newly determines the droop characteristic (step ST8: YES), the information of the new droop characteristic is acquired by the control unit 22, and the droop characteristic used by the control unit 22 is updated (step ST9).

The flowchart of FIG. 6 is merely an example of a charging / discharging method, and the processing may be omitted or added as appropriate, or the order of the processing may be changed as appropriate.

The program according to one aspect is a program for causing one or more processors to execute the above charging / discharging method.

The charge / discharge system 1 in the present disclosure includes a computer system. The main configuration of a computer system is a processor and memory as hardware. When the processor executes the program recorded in the memory of the computer system, at least a part of the function as the charge / discharge system 1 in the present disclosure is realized. The program may be pre-recorded in the memory of the computer system, may be provided through a telecommunications line, and may be recorded on a non-temporary recording medium such as a memory card, optical disk, hard disk drive, etc. that can be read by the computer system. May be provided. A processor in a computer system is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or a large scale integrated circuit (LSI). The integrated circuit such as IC or LSI referred to here has a different name depending on the degree of integration, and includes an integrated circuit called a system LSI, VLSI (Very Large Scale Integration), or ULSI (Ultra Large Scale Integration). Further, an FPGA (Field-Programmable Gate Array) programmed after the LSI is manufactured, or a logical device capable of reconfiguring the junction relationship inside the LSI or reconfiguring the circuit partition inside the LSI should also be adopted as a processor. Can be done. A plurality of electronic circuits may be integrated on one chip, or may be distributed on a plurality of chips. The plurality of chips may be integrated in one device, or may be distributed in a plurality of devices. The computer system referred to here includes a microprocessor having one or more processors and one or more memories. Therefore, the microprocessor is also composed of one or a plurality of electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit.

Further, it is not an essential configuration for the charge / discharge system 1 that a plurality of functions in the charge / discharge system 1 are integrated in one housing, and the components of the charge / discharge system 1 are dispersed in a plurality of housings. It may be provided. Further, at least a part of the functions of the charge / discharge system 1, for example, a part of the functions of the control unit 22 or the control circuit 32 may be realized by the cloud (cloud computing) or the like.

On the contrary, in the first embodiment, a plurality of configurations distributed in a plurality of devices may be integrated in one housing.

The control circuit 32 is not limited to being provided in the AC / DC converter 3. For example, the charge / discharge system 1 may include a control device having at least a part of the functions of the control circuit 32. Further, at least a part of the functions of the control circuit 32 may be provided in, for example, the DC / DC converter 2 or the power storage device 4.

The control unit 22 is not limited to being provided in the DC / DC converter 2. For example, the control unit 22 may be provided in the control device, the AC / DC converter 3, or the power storage device 4. In the power storage device 4, the control unit 22 may be included in the DC / DC converter 41, or may be provided separately from the DC / DC converter 41.

Further, it is not essential that droop control is performed by a plurality of control units 22 dispersedly provided in a plurality of configurations (in the first embodiment, a plurality of DC / DC converters 2). For example, the control device, the AC / DC converter 3 or one DC / DC converter 2 may include one control unit 22, and droop control may be performed by the control unit 22.

Further, it is not essential that at least one control unit 22 and the control circuit 32 are distributed and provided in a plurality of configurations (DC / DC converter 2 and AC / DC converter 3 in the first embodiment).

Further, in the charge / discharge system 1, the plurality of DC / DC converters 2 are not indispensable configurations. When the charging / discharging system 1 does not include a plurality of DC / DC converters 2, in order to perform droop control of the plurality of power storage devices 4, a configuration different from that of the plurality of DC / DC converters 2 is used as a control unit. 22 may be provided. For example, each of the plurality of power storage devices 4 may include a control unit 22.

The power storage device 4 may be connected to the AC bus ab1. The charge current and discharge current of each of the plurality of power storage devices 4 connected to each other via the AC bus ab1 (power line) may be controlled by droop control.

The AC / DC converter 3 may be connected to the AC bus ab1 without going through the AC connection unit 13.

The AC / DC converter 3 may not be included in the configuration of the charge / discharge system 1. Further, the AC / DC converter 3 may be provided outside the housing 10. The charge / discharge system 1 may include a DC connection portion for connecting the DC bus db1 to the AC / DC converter 3. The DC connection is, for example, a connector.

Facility F1 may optionally include a power generation system such as a solar cell system 6 or a fuel cell system. The power generation system may be connected to the AC bus ab1 or may be connected to the first DC connector 11 or the second DC connector 12.

The first DC connector 11 and the second DC connector 12 may have different specifications such as a shape.

The specifications such as the shape may be different between the connection portion 43 of the first power storage device 401 of the electric vehicle C1 and the connection portion 43 of the second power storage device 402 of the facility F1.

The cable 15 may be retrofitted to the housing 10 of the charge / discharge system 1. In this case, the charge / discharge system 1 may include a first DC connector 11 and a second DC connector 12 to which the cable 15 can be connected. Further, in this case, the first DC connector 11 and the second DC connector 12 are not directly connected to the connection portion 43 of the power storage device 4 as in the first embodiment, but are connected via the cable 15.

The power storage device 4 may have a plurality of storage batteries 42.

The storage battery current is not limited to changing linearly with an increase in bus voltage, and may change non-linearly.

Observables monitored by droop control are not limited to bus voltage. The observed amount may be, for example, a value included in the signal transmitted to the control unit 22. The signal may be transmitted by, for example, the control circuit 32. Further, the signal may be transmitted by wired communication via a power line such as DC bus db1 or a signal line, or may be transmitted by wireless communication. Further, when a plurality of power storage devices 4 are connected to the AC bus ab1, the observed amount may be, for example, the frequency or the phase of the voltage or the current of the AC bus ab1.

(Embodiment 2)
Hereinafter, the charge / discharge system 1 according to the second embodiment will be described with reference to FIG. 7. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. In addition, the following embodiments may be realized in combination with each modification of the first embodiment as appropriate.

The determination unit 321 of the present embodiment has a function of setting the charge current and the discharge current of each of the plurality of power storage devices 4 to 0 [A] when the predetermined observation amount (here, the bus voltage) is within the predetermined range. Have.

More specifically, the first offset voltage _VO 1 and the second offset voltage _VO 2 are predetermined. The first offset voltage _VO 1 is a positive value, and the second offset voltage _VO 2 is a negative value. The first offset voltage _VO 1 is, for example, 0.1 [mV] to several [mV]. The second offset voltage _{V O} 2 example, a -0.1 [mV] ~ minus number [mV]. In this embodiment, _VO 1 = (-1) × _VO 2 is satisfied.

The determination unit 321 sets the droop characteristic so that the storage battery current of each power storage device 4 becomes 0 [A] in the range _{where the bus voltage is smaller than the first offset voltage VO} 1 and larger than the second offset voltage _{VO 2.} decide. As a result, when the bus voltage (measured value) fluctuates near 0 [V], the storage battery current becomes 0 [A]. That is, when the bus voltage is a value near 0 [V], neither charge control nor discharge control is performed on the power storage device 4. As a result, it is possible to reduce the possibility that the charge current and the discharge current fluctuate due to the fluctuation of the bus voltage. Further, when the bus voltage fluctuates in the vicinity of 0 [V], the possibility of frequent switching between charge control and discharge control can be reduced. That is, the possibility that a circulating current is generated can be reduced.

(Embodiment 3)
Hereinafter, the charge / discharge system 1A according to the third embodiment will be described with reference to FIGS. 8 and 9. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. In addition, the following embodiments may be realized in combination with the respective modifications of the first embodiment and the second embodiment as appropriate.

As shown in FIG. 8, the charge / discharge system 1A of the present embodiment is different from the charge / discharge system 1 of the first embodiment in that it includes a plurality (two) of second DC connectors 12.

Further, the charge / discharge system 1A includes a plurality (two) of second DC / DC converters 202. Further, the charge / discharge system 1A includes a cable 15 that holds each second DC connector 12. Each second DC connector 12 corresponds to one second DC / DC converter 202 and one cable 15. The first end of each second DC / DC converter 202 is connected to the corresponding second DC connector 12 via the corresponding cable 15, and the second end is connected to the node N1.

In FIG. 8, as an example, the power storage device 4 (second power storage device 402) is connected to each of the plurality of second DC connectors 12. In this case, a total of three power storage devices 4 (one first power storage device 401 and two second power storage devices 402) are connected to the charge / discharge system 1A. An example of droop control for the three power storage devices 4 in this case will be described with reference to FIG.

In FIG. 9, the droop characteristics represented by the line segments L1, L2, and L3 correspond one-to-one with the three power storage devices 4. The control method of the individual power storage device 4 is the same as that of the first embodiment. That is, the charge current or discharge current of each power storage device 4 is controlled to be the charge current or discharge current corresponding to the bus voltage.

Further, the sum of the storage battery currents of the three power storage devices 4 is represented by the line segment L123. When the bus voltage is a certain value, whether the current is supplied from the AC / DC converter 3 to the DC bus db1 or the current is supplied from the DC bus db1 to the AC / DC converter 3 corresponds to the bus voltage. It is determined by the sum of the storage battery currents of the three power storage devices 4 in terms of coordinates. That is, when the sum of the storage battery currents of the three power storage devices 4 is a positive value, the current is supplied from the AC / DC converter 3 to the DC bus db1, and when the sum is a negative value, the current is supplied from the DC bus db1 to the AC / DC. A current is supplied to the converter 3.

That is, regardless of the number of power storage devices 4, when the bus voltage is a certain value, the current is supplied from the AC / DC converter 3 to the DC bus db1, or the current is supplied from the DC bus db1 to the AC / DC converter 3. Whether it is supplied or not is determined by the sum of the storage battery currents of one or a plurality of power storage devices 4 at the coordinates corresponding to the bus voltage.

The number of the second DC connectors 12 is not limited to two, and may be three or more. Further, the charging / discharging system 1A may include a plurality of first DC connectors 11. That is, the charge / discharge system 1A may include one or more first DC connectors 11 and one or more second DC connectors 12.

Further, two or more power storage devices 4 may be connected to one DC / DC converter 2. The DC / DC converter 2 may perform common control or different controls for the two or more power storage devices 4.

(Embodiment 4)
Hereinafter, the charge / discharge system 1B according to the fourth embodiment will be described with reference to FIG. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. In addition, the following embodiments may be realized in combination with the above-described embodiments (including modifications) as appropriate.

The charge / discharge system 1B of the present embodiment includes a plurality (two) of second DC / DC converters 202, similarly to the charge / discharge system 1A of the third embodiment. Each second DC / DC converter 202 is connected to, for example, a second power storage device 402, a solar cell 62, or the like. In FIG. 10, one second DC / DC converter 202 is connected to the second power storage device 402 via the second DC connector 12. In FIG. 10, the other second DC / DC converter 202 is connected to the solar cell 62 without going through the second DC connector 12. The second DC / DC converter 202 may be connected to the solar cell 62 via the second DC connector 12 and the adapter connected to the second DC connector 12.

Further, the charging / discharging system 1B of the present embodiment includes a first housing 20 in addition to the housing 10 (second housing). The first housing 20 houses the first DC / DC converter 201. The first housing 20 is installed in a parking lot, for example. The housing 10 (second housing) houses two second DC / DC converters 202 and an AC / DC converter 3. The housing 10 (second housing) is installed in, for example, a building attached to a parking lot or in the vicinity of the building.

That is, the charge / discharge system 1B includes a second device 100B including the housing 10 (second housing) and its internal configuration, and a first device 200 including the first housing 20 and its internal configuration. ing.

The first DC / DC converter 201 is connected to the node N1. The connection method between the first DC / DC converter 201 and the node N1 may be different from the connection method of the first DC connector 11 (CHAdeMO (registered trademark)).

The first DC connector 11 is connected to the first DC / DC converter 201 via a cable 15. As a result, the first DC connector 11 is connected to the node N1 via the cable 15 and the first DC / DC converter 201. Therefore, when the first DC connector 11 is connected to the first power storage device 401 of the electric vehicle C1, electric power can be interchanged between the node N1 and the first power storage device 401.

According to the charging / discharging system 1B of the present embodiment, the first housing 20 containing the first DC / DC converter 201 and the housing 10 containing the two second DC / DC converters 202 are installed at different positions from each other. can. Therefore, the housing 10 can be miniaturized and the space occupied by the housing 10 can be reduced.

A plurality of first DC / DC converters 201 may be connected to the node N1.

(Embodiment 5)
Hereinafter, the charge / discharge system 1C according to the fifth embodiment will be described with reference to FIG. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. In addition, the following embodiments may be realized in combination with the above-described embodiments (including modifications) as appropriate.

In the present embodiment, the adapter 51 is provided as an external configuration of the charge / discharge system 1C. The adapter 51 includes a first connection portion 511, a second connection portion 512, and a wiring 513. The first connection portion 511 is connected to the second DC connector 12. The second connection unit 512 is connected to the second power storage device 402. The first connection portion 511 and the second connection portion 512 are connected via the wiring 513.

The first connection portion 511 has a structure that can be directly connected to the second DC connector 12. As an example, the structure of the first connection 511 conforms to the CHAdeMO® standard. The structure of the second connection portion 512 is different from the structure of the first connection portion 511.

The charge / discharge system 1C includes a plurality of (three in FIG. 11) second power storage devices 402. That is, the charge / discharge system 1C includes a second device 100 including the housing 10 and its internal configuration, and a plurality of second power storage devices 402.

Each second power storage device 402 includes a DC / DC converter 41, a storage battery 42, and a node N3.

Further, at least one of the plurality of second power storage devices 402 has a first terminal 44 connected to the second DC connector 12. Each of the plurality of second power storage devices 402 has a second terminal 45 connected to another second power storage device 402 among the plurality of second power storage devices 402. In the present embodiment, each of the plurality of second power storage devices 402 has a first terminal 44 and a plurality of (two in FIG. 11) second terminals 45.

The first end of the DC / DC converter 41 is connected to the node N3, and the second end is connected to the storage battery 42. The first terminal 44 and the two second terminals 45 are connected to the node N3.

The first terminal 44 can be connected to the second connection portion 512 of the adapter 51. Therefore, the first terminal 44 is connected to the second DC connector 12 via the adapter 51.

The plurality of second power storage devices 402 can be connected to each other. More specifically, by connecting at least one of the two second terminals 45 of the second power storage device 402 to the second terminal 45 of another second power storage device 402, a plurality of second power storage devices can be connected. 402s can be connected to each other. In the present embodiment, a plurality of second power storage devices 402 can be connected to each other via the connection cable 18. The connection cable 18 has two connection portions 181 and wiring 182. The two connecting portions 181 are provided at both ends of the wiring 182. The two connecting portions 181 can be connected to the second terminal 45 of the second power storage device 402.

In FIG. 11, the second connection portion 512 of the adapter 51 is connected to the first terminal 44 of one of the three second power storage devices 402.

Further, in FIG. 11, three second power storage devices 402 are connected to each other via a connection cable 18. As a result, the three second power storage devices 402 are connected in parallel. That is, a DC line connecting the nodes N3 of each second power storage device 402 is formed. The output power of the storage battery 42 is supplied to the DC line. Further, the electric power supplied from the second DC / DC converter 202 to the DC line via the adapter 51 is input to the storage battery 42 of each second power storage device 402.

In the present embodiment, the number of parallels of the second power storage device 402 can be increased or decreased by attaching / detaching the connection cable 18 and the second terminal 45. Further, the droop control of the plurality of second power storage devices 402 connected in parallel is performed by the second DC / DC converter 202. That is, the droop control is performed by regarding the plurality of second power storage devices 402 connected in parallel as one second power storage device 402 having the capacity of a plurality of units. Therefore, even when the number of parallel second power storage devices 402 is increased, the charging / discharging of each second power storage device 402 can be controlled without newly providing a communication line or the like for droop control.

At least one of the plurality of second power storage devices 402 may have a connection portion 43 (see FIG. 1) for directly connecting to the second DC connector 12 instead of the first terminal 44. ..

(Embodiment 6)
Hereinafter, the charge / discharge system 1D according to the sixth embodiment will be described with reference to FIG. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. In addition, the following embodiments may be realized in combination with the above-described embodiments (including modifications) as appropriate.

The charge / discharge system 1D includes a second device 100 including a housing 10 and its internal configuration, and a distribution device 8.

The distribution device 8 includes a housing 80, a control system CS1, a connection unit 83, a plurality of (three in FIG. 12) first DC connectors 84, and a plurality of (three in FIG. 12) holding units 85. It is provided with cables 86 (three in FIG. 12). The control system CS1 includes a plurality of devices 81 (three in FIG. 12) and a supply control circuit 82.

The connection unit 83 has a structure that can be directly connected to the first DC connector 11. As an example, the structure of the connection 83 conforms to the CHAdeMO® standard.

Each first DC connector 84 has a structure that can be directly connected to the connection portion 43 (inlet) of the electric vehicle C1. As an example, the structure of the first DC connector 84 conforms to the CHAdeMO® standard. In FIG. 12, a plurality (three) electric vehicles C1 are illustrated. The plurality of first DC connectors 84 correspond one-to-one with the plurality of electric vehicles C1. In FIG. 12, each first DC connector 84 is connected to the connection portion 43 of the corresponding electric vehicle C1.

The housing 80 houses a plurality of devices 81 and a supply control circuit 82. The first end of each of the plurality of cables 86 is held in the housing 80. A holding portion 85 is provided at the second end of each of the plurality of cables 86. The holding portion 85 holds the first DC connector 84.

Each of the plurality of devices 81 is, for example, a DC / DC converter. That is, as an example, the control system CS1 includes a DC / DC converter. The plurality of devices 81 correspond one-to-one with the plurality of first DC connectors 84. Each device 81 is connected to the connection portion 43 of the electric vehicle C1 via the corresponding first DC connector 84.

The supply control circuit 82 transmits a control signal to each of the plurality of devices 81. The supply control circuit 82 controls the operation of each of the plurality of devices 81 by the control signal. As a result, the control system CS1 (supply control circuit 82) controls the power supply via the plurality of first DC connectors 84 for each one first DC connector 84. That is, the supply control circuit 82 receives the electric power supplied from the first DC / DC converter 201 to the electric vehicle C1 via the connection unit 83 and each device 81, and the electric vehicle C1 via each device 81 and the connection unit 83. Controls the power supplied to the first DC / DC converter 201. The control of each device 81 (DC / DC converter) by the supply control circuit 82 includes adjusting the magnitude of the output power.

The supply control circuit 82 controls each device 81 according to the remaining capacity of the power storage device 4 of each electric vehicle C1, for example. Specifically, in the supply control circuit 82, the smaller the remaining capacity of the power storage device 4, the larger the power supplied to the power storage device 4, and the smaller the remaining capacity of the power storage device 4, the larger the power output from the power storage device 4. Each device 81 is controlled so that

Further, the supply control circuit 82 controls each device 81 according to the connection order of the plurality of electric vehicles C1 and the plurality of first DC connectors 84, for example. Specifically, the supply control circuit 82 controls each device 81 so that the electric power supplied to the power storage device 4 becomes larger as the electric vehicle C1 connected to the first DC connector 84 first.

Further, the supply control circuit 82 controls each device 81 so that, for example, the magnitude ratio of the power supplied to the power storage device 4 of the plurality of electric vehicles C1 is a preset ratio. Further, the supply control circuit 82 controls each device 81 so that, for example, the magnitude ratio of the electric power output from the power storage devices 4 of the plurality of electric vehicles C1 becomes a preset ratio. Further, the charge / discharge system 1D may include a user interface for setting the above ratio.

According to the present embodiment, when a plurality of electric vehicles C1 and a plurality of first DC connectors 84 are connected, the power supply to the electric vehicle C1 or the power supply from the electric vehicle C1 can be controlled for each electric vehicle C1. ..

In this embodiment, a plurality of devices 81 and the supply control circuit 82 may be housed in the housing 10.

(Modified Example of Embodiment 6)
The device 81 is not limited to the DC / DC converter. At least one of the plurality of devices 81 may be a switch. That is, as an example, the control system CS1 includes a switch. The switch is, for example, a semiconductor switching element. The supply control circuit 82 opens and closes each of the plurality of semiconductor switching elements by transmitting a control signal to each of the semiconductor switching elements.

In the following description, it is assumed that each of the plurality of devices 81 is a switch. Further, in the following description, the supply control circuit 82 opens and closes a plurality of switches so that the number of closed switches among the plurality of switches is always one or less.

The supply control circuit 82 controls each device 81 according to the connection order of the plurality of electric vehicles C1 and the plurality of first DC connectors 84, for example. Specifically, the supply control circuit 82 charges the power storage device 4 in order from the electric vehicle C1 connected to the first DC connector 84 first.

Further, the supply control circuit 82 opens and closes, for example, two or more switches connected to the electric vehicle C1 among the plurality of switches according to a preset schedule. Further, the charge / discharge system 1D may include a user interface for setting the schedule.

Further, the supply control circuit 82 closes, for example, two or more switches connected to the electric vehicle C1 among the plurality of switches in a preset order. When a predetermined condition is satisfied, the closed switch is opened and the next switch is closed. The predetermined condition is, for example, that a predetermined time elapses or that the charge amount of the power storage device 4 changes over a predetermined threshold value. Further, the charge / discharge system 1D may include a user interface for setting the closing order and the predetermined conditions.

(summary)
From the embodiments described above, the following aspects are disclosed.

The charge / discharge system (1, 1A, 1B, 1C, 1D) according to the first aspect includes a DC bus (db1), a first DC connector (11, 84), and a second DC connector (12). The DC bus (db1) has a node (N1) connected to the DC terminal (34) of the AC / DC converter (3). The first DC connector (11, 84) is connected to the node (N1). The first DC connector (11, 84) can be connected to at least the power storage device (4) of the electric vehicle (C1). The second DC connector (12) is connected to the node (N1). The second DC connector (12) supplies power to the first DC connector (11, 84) and receives power supplied from the first DC connector (11, 84) via the DC bus (db1). To do.

According to the above configuration, electric power is generated between the power storage device (4) of the electric vehicle (C1) and the configuration (for example, the power storage device (4) or the fuel cell system) connected to the second DC connector (12). Can be accommodated. Moreover, since the power storage device (4) and the configuration connected to the second DC connector (12) are connected to each other via the connector, the connection is easier than when the electric wires are directly connected. In that respect, convenience can be improved.

Further, the charge / discharge system (1, 1A, 1B, 1C, 1D) according to the second aspect has the first DC / DC converter (201) and the second DC / DC converter (202) in the first aspect. And at least one of them is further provided. The first DC / DC converter (201) is connected between the node (N1) and the first DC connector (11, 84). The second DC / DC converter (202) is connected between the node (N1) and the second DC connector (12).

According to the above configuration, the convenience can be further improved in that the electric power can be converted by the first DC / DC converter (201) and / or the second DC / DC converter (202).

Further, the charging / discharging system (1B) according to the third aspect further includes a first housing (20) and a second housing (housing 10) in the second aspect. The first housing (20) houses the first DC / DC converter (201). The second housing houses the second DC / DC converter (202).

According to the above configuration, the first housing (20) and the second housing (housing 10) can be installed at different positions from each other.

Further, in the charge / discharge system (1, 1A, 1B, 1C, 1D) according to the fourth aspect, in any one of the first to third aspects, the first DC connector (11, 84) and the second DC connector (1, 84) At least one of 12) complies with predetermined standards for at least one of connector connection and communication.

According to the above configuration, the versatility of the charge / discharge system (1, 1A, 1B, 1C, 1D) can be enhanced.

Further, the charge / discharge system (1, 1A, 1B, 1C, 1D) according to the fifth aspect further includes an AC / DC converter (3) in any one of the first to fourth aspects. The AC / DC converter (3) has an AC terminal (35). The AC terminal (35) can be connected to at least a power source (for example, the power system 72 or the solar cell system 6). The AC / DC converter (3) receives power from a power source.

According to the above configuration, power can be supplied from the power supply to the first DC connector (11, 84) and the second DC connector (12).

Further, the charge / discharge system (1A) according to the sixth aspect includes a plurality of second DC connectors (12) in any one of the first to fifth aspects.

According to the above configuration, the convenience of the charge / discharge system (1A) can be improved as compared with the case where the charge / discharge system (1A) includes only one second DC connector (12).

Further, the charge / discharge system (1, 1A, 1B, 1C, 1D) according to the seventh aspect further includes a first control unit (control circuit 32) in any one of the first to sixth aspects. The first control unit controls the power supply from the second DC connector (12) to the first DC connector (11, 84). The first control unit moves from the second DC connector (12) to the first DC connector (11, 84) so that the power supplied from the AC / DC converter (3) to the first DC connector (11, 84) falls below the threshold value. It has a peak cut function that controls the supplied power.

According to the above configuration, it is possible to suppress the peak power consumption of the consumer (facility F1) using the charge / discharge system (1, 1A, 1B, 1C, 1D).

Further, the charge / discharge system (1, 1A, 1B, 1C, 1D) according to the eighth aspect further includes a second control unit (control circuit 32) in any one of the first to seventh aspects. The second control unit controls the power supply from the first DC connector (11, 84) to the second DC connector (12). The second control unit moves from the first DC connector (11, 84) to the second DC connector (12) when the power storage device (4) of the electric vehicle (C1) is connected to the first DC connector (11, 84). Power is supplied.

According to the above configuration, in the event of a power failure or the like, the electric power of the power storage device (4) of the electric vehicle (C1) is connected to the second DC connector (12) (stationary power storage device 4 or load). Etc.) can be supplied.

Further, the charge / discharge system (1, 1A, 1B, 1C, 1D) according to the ninth aspect further includes a third control unit (control circuit 32) in any one of the first to eighth aspects. The third control unit controls the power supply to the AC / DC converter (3) from at least one of the first DC connector (11, 84) and the second DC connector (12). When a power failure occurs, the third control unit supplies power to the AC / DC converter (3) from at least one of the first DC connector (11, 84) and the second DC connector (12).

According to the above configuration, in the event of a power failure, power is supplied to the load (75) or the like from at least one of the first DC connector (11, 84) and the second DC connector (12) via the AC / DC converter (3). Can be supplied.

Further, the charge / discharge system (1, 1A, 1C, 1D) according to the tenth aspect has the DC bus (db1), the first DC connector (11, 84) and the first DC connector (11, 84) in any one of the first to ninth aspects. A single housing (10) for holding the second DC connector (12) is further provided.

According to the above configuration, the DC bus (db1), the first DC connector (11, 84) and the second DC connector (12) are integrated into a single housing (10), so that the facility (F1) is filled. Discharge systems (1, 1A, 1C, 1D) can be easily installed.

Further, the charge / discharge system (1C) according to the eleventh aspect further includes a plurality of power storage devices (4) in any one of the first to tenth aspects. At least one of the plurality of power storage devices (4) has a first terminal (44). The first terminal (44) is connected to the second DC connector (12). Each of the plurality of power storage devices (4) has a second terminal (45) connected to another power storage device (4) among the plurality of power storage devices (4).

According to the above configuration, the number of parallel storage devices (4) can be increased or decreased.

Further, the charge / discharge system (1D) according to the twelfth aspect includes a plurality of first DC connectors (84) in any one of the first to eleventh aspects. The charge / discharge system (1D) further includes a control system (CS1). The control system (CS1) controls the power supply through the plurality of first DC connectors (84) for each one first DC connector (84).

According to the above configuration, the power supply to the configuration (here, the power storage device 4) connected to the first DC connector (84) or the power supply from the power storage device (4) is supplied for each power storage device (4). Can be controlled.

Further, in the charge / discharge system (1D) according to the thirteenth aspect, in the twelfth aspect, the control system (CS1) includes a switch (equipment 81).

According to the above configuration, it is possible to switch whether or not power is supplied to (or from) the configuration connected to each first DC connector (84).

Further, in the charge / discharge system (1D) according to the fourteenth aspect, in the twelfth or thirteenth aspect, the control system (CS1) includes a DC / DC converter (equipment 81).

According to the above configuration, the amount of power supplied to (or from) the configuration connected to each first DC connector (84) can be controlled.

The configuration other than the first aspect is not an essential configuration for the charge / discharge system (1, 1A, 1B, 1C, 1D) and can be omitted as appropriate.

1, 1A, 1B, 1C, 1D Charging / discharging system 11, 84 1st DC connector 12 2nd DC connector 201 1st DC / DC converter 202 2nd DC / DC converter 3 AC / DC converter 32 Control circuit (1st control unit) , 2nd control unit, 3rd control unit)
34 DC terminal 35 AC terminal 4 Power storage device 44 1st terminal 45 2nd terminal 81 Equipment (switch, DC / DC converter)
10 housing (second housing)
20 First chassis C1 Electric vehicle CS1 Control system db1 DC bus N1 Node

Claims (14)

A DC bus with a node connected to the DC terminal of the AC / DC converter,
A first DC connector that is connected to the node and can be connected to at least a power storage device of an electric vehicle.
The node is connected to the node, and includes a second DC connector that supplies power to the first DC connector and receives power from the first DC connector at least one of them via the DC bus.
Charge / discharge system. A first DC / DC converter connected between the node and the first DC connector,
Further comprising at least one of a second DC / DC converter connected between the node and the second DC connector.
The charging / discharging system according to claim 1. A first housing containing the first DC / DC converter and
A second housing containing the second DC / DC converter is further provided.
The charging / discharging system according to claim 2. At least one of the first DC connector and the second DC connector complies with a predetermined standard for at least one of connector connection and communication.
The charging / discharging system according to any one of claims 1 to 3. Further equipped with the AC / DC converter
The AC / DC converter has at least an AC terminal that can be connected to a power source and receives power supply from the power source.
The charging / discharging system according to any one of claims 1 to 4. A plurality of the second DC connectors are provided.
The charging / discharging system according to any one of claims 1 to 5. Further, a first control unit for controlling the power supply from the second DC connector to the first DC connector is provided.
The first control unit has a peak cut function that controls the power supplied from the second DC connector to the first DC connector so that the power supplied from the AC / DC converter to the first DC connector falls below the threshold value. Have,
The charging / discharging system according to any one of claims 1 to 6. A second control unit that controls the power supply from the first DC connector to the second DC connector is further provided.
The second control unit causes the first DC connector to supply electric power to the second DC connector when the power storage device of the electric vehicle is connected to the first DC connector.
The charging / discharging system according to any one of claims 1 to 7. Further, a third control unit for controlling the power supply to the AC / DC converter from at least one of the first DC connector and the second DC connector is provided.
When a power failure occurs, the third control unit supplies power to the AC / DC converter from at least one of the first DC connector and the second DC connector.
The charging / discharging system according to any one of claims 1 to 8. Further comprising a single housing for holding the DC bus, the first DC connector and the second DC connector.
The charging / discharging system according to any one of claims 1 to 9. Equipped with multiple power storage devices
At least one of the plurality of power storage devices has a first terminal connected to the second DC connector.
Each of the plurality of power storage devices has a second terminal connected to another power storage device among the plurality of power storage devices.
The charging / discharging system according to any one of claims 1 to 10. A plurality of the first DC connectors are provided.
A control system for controlling the power supply via the plurality of first DC connectors for each first DC connector is further provided.
The charging / discharging system according to any one of claims 1 to 11. The control system includes a switch.
The charging / discharging system according to claim 12. The control system includes a DC / DC converter.
The charging / discharging system according to claim 12 or 13.

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