JP7175580B2 - Charging/discharging device and power supply switching system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a charging/discharging device and a power switching system, and more particularly, to a charging/discharging device that switches power sources depending on the situation, and a power switching system that switches power sources depending on the situation.

With global warming and economic and industrial development progressing on a global scale, efforts aimed at reducing energy consumption are becoming more important. Against this background, distributed power supply systems typified by photovoltaic power generation systems are becoming popular (see Patent Documents 1 to 3, for example). Recently, interest in a distributed power supply system equipped with a storage battery as an emergency power supply in the event of a disaster is increasing.

JP 2011-172334 A JP-A-2001-8380 JP 2006-158084 A

In the power supply system described above, when power stored in the storage battery is supplied to the load, it is necessary to convert the power from direct current to alternating current. Normally, power conversion is performed by power supplied from the commercial power grid, but when the commercial power grid fails, it is necessary to take some action to convert the power.

In addition, with regard to distributed power supply systems installed in general households, excluding photovoltaic power generation systems, it is prohibited to flow stored or generated power to a commercial power system. Therefore, in order to use a distributed power supply during a power outage, it is necessary to take measures such as separating the commercial power system from the domestic power system.

SUMMARY OF THE INVENTION The present invention has been made under the circumstances described above, and it is an object of the present invention to disconnect the domestic power system from the commercial power system and to reliably supply the stored power to the load when the commercial power system fails. and

In order to achieve the above object, a charging/discharging device according to the present invention is provided between a load and a main battery unit of an electric vehicle, and converts power supplied from a power system to the main battery unit, or A charging/discharging device external to an electric vehicle, comprising: power conversion means for converting power supplied from a main battery unit to a load; and a control unit for controlling the operation of the power conversion means. A first switching means connected to the primary side and operated based on instructions from the control unit, and a battery consisting of a plurality of cells filled with electrolyte outside the charging and discharging device in the event of a power failure, a lithium ion battery , a general-purpose dry battery, a portable generator, a fuel cell, a solar battery, a wind power generator, and a terminal port for connecting by the user and supplying power to the control unit, the control unit comprising: notifying a vehicle control unit of the electric vehicle of a connection instruction for the main battery unit, and when the main battery unit is connected to the charging/discharging device, operating the power conversion means to supply power from the main battery unit to the load; The control unit controls to close the first opening/closing means before operating the power conversion means.

According to the present invention, it is possible to reliably supply the power of the main battery unit to the load.

1 is a power system diagram of a house according to Embodiment 1. FIG. It is a block diagram of a switchboard. 1 is a block diagram of a charging/discharging device; FIG. 1 is a block diagram showing a control system of an electric vehicle; FIG. 4 is a flowchart showing power switching processing; 4 is a flowchart showing power recovery processing; 2 is a power system diagram of a house according to Embodiment 2. FIG. It is a block diagram of a switchboard. It is a figure for demonstrating the modification of a charging/discharging apparatus. It is a figure for demonstrating the modification of a charging/discharging apparatus.

<<Embodiment 1>>
Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a power system diagram of a house 10. As shown in FIG. As shown in FIG. 1, a house 10 is connected to a power system of an electric power company (hereinafter referred to as a commercial power system). A domestic power system including a switchboard 30 and a load 40 connected to the switchboard 30 is connected to the commercial power system via the watt-hour meter 20 . In addition, a power storage unit 41 that operates as an emergency power source in the event of a power failure in the commercial power system is connected to the domestic power system.

The load 40 is an electrical appliance used in the house 10, such as an air conditioner, refrigerator, microwave oven, washing machine, television, personal computer, and other household appliances. Each load 40 is connected to the switchboard 30 .

FIG. 2 is a block diagram of the switchboard 30. As shown in FIG. As shown in FIG. 2 , the switchboard 30 includes a main breaker 31 , an earth leakage breaker 32 , a contactor 33 and a plurality of branch breakers 34 .

Main breaker 31 is a circuit breaker that separates the commercial power system from the domestic power system of house 10 . This main breaker 31 disconnects the domestic power system interconnected with the commercial power system from the commercial power system when an overcurrent flows from the commercial power system to the domestic power system. Note that the main breaker 31 may not be installed depending on the electric power company.

The earth leakage breaker 32 is provided on the secondary side (load side) of the main breaker 31 . This earth leakage breaker 32 is turned off when an electric leakage occurs on the secondary side of the earth leakage breaker 32 . By turning off the earth leakage breaker 32, the load 40 on the secondary side of the earth leakage breaker 32 is disconnected from the commercial power system.

The contactor 33 is provided on the secondary side of the earth leakage breaker 32 . The contactor 33 operates in response to an open/close command from the charging/discharging device 50, and connects and disconnects the commercial power system and the domestic power system.

A voltage detection transformer VT1 and a current transformer CT1 are provided between the earth leakage breaker 32 and the contactor 33 . The voltage detection transformer VT1 outputs a voltage signal V1 having a voltage proportional to the voltage of the commercial power system. Current transformer CT1 also outputs a current signal I1 having a value proportional to the current flowing between earth leakage breaker 32 and contactor 33 . Although FIG. 2 shows the case where there is one contactor 33, two contactors 33 may be connected in series. As a result, even if the contact of any contactor 33 is welded, the load 40 and the power storage unit 41 can be reliably disconnected from the commercial power system.

The branch breakers 34 are provided on the secondary side of the contactor 33 in parallel with each other. Each of these branch breakers 34 is provided for each load 40 and power storage unit 41 . By opening and closing the branch breaker, the load 40 and the power storage unit 41 can be separated from the power system.

Each of the main breaker 31, the earth leakage breaker 32, the contactor 33, and the branch breaker 34 described above is housed in a metal or resin housing.

The power storage unit 41 has a charge/discharge device 50 and an electric vehicle 80 connected to the charge/discharge device 50 via a connector 90 . FIG. 3 is a block diagram of charging/discharging device 50. As shown in FIG. As shown in FIG. 3, the charging/discharging device 50 includes a contactor 51, three AC/DC converters 53, 54, 55 connected in series, and drive units 61, 62 for driving the AC/DC converters 53, 54, 55. , 63, a control unit 66 for overall control of the above components, a power supply unit 64 for supplying power to the control unit 66, a battery unit 65 for storing starting power in the event of a power failure, and the like.

The contactor 51 is arranged on the secondary side of the branch breaker 34 housed in the switchboard 30 . This contactor 51 operates based on instructions from the control unit 66 . Charging/discharging device 50 is disconnected from load 40 when contactor 51 is off, and charging/discharging device 50 is connected to load 40 when contactor 51 is on.

The AC/DC converter 53 has a switching element such as a transistor and a diode connected in parallel to the transistor. This AC/DC converter 53 is connected to the secondary side of the contactor 51 via reactors 52A and 52B. The AC/DC converter 53 converts AC power supplied from the primary side (power system side) into DC power. Alternatively, it converts DC power supplied from the secondary side into AC power.

The AC/DC converter 54, like the AC/DC converter 53, has a switching element such as a transistor and a diode. The AC/DC converter 54 is connected to the secondary side of the AC/DC converter 53 . The AC/DC converter 54 converts DC power supplied from the primary side into AC power. Alternatively, AC power supplied from the secondary side is converted into DC power. A capacitor 57 is connected between the AC/DC converters 53 and 54 for stabilizing the voltage across the terminals of the AC/DC converters 53 and 54 .

The AC/DC converter 55, like the AC/DC converters 53 and 54, has a switching element such as a transistor and a diode. The AC/DC converter 55 is connected to the secondary side of the AC/DC converter 54 via an insulating transformer 58 . The AC/DC converter 55 converts AC power supplied from the primary side into DC power. Alternatively, it converts DC power supplied from the secondary side into AC power. A secondary side of the AC/DC converter 55 is connected with a capacitor 59 for stabilizing the voltage across the terminals of the AC/DC converter 55 .

The insulating transformer 58 is installed for the purpose of insulating the commercial power system and the storage unit 41 . By arranging the insulating transformer 58, using the AC/DC converters 54 and 55, for example, the output phase of the AC voltage on the secondary side of the AC/DC converter 54 and the AC voltage on the primary side of the AC/DC converter 55 can be adjusted. The voltage across capacitor 59 can be adjusted to be higher or lower than the voltage across capacitor 57 . Conversely, when electric power is supplied from the storage unit 41 , the voltage across the capacitor 57 can be made higher or lower than the voltage across the capacitor 59 .

In charging/discharging device 50 , AC/DC converters 53 to 55 work together to convert AC power from the commercial power system into DC power, which is supplied to electric vehicle 80 . Also, the DC power from the electric vehicle 80 is converted into AC power and supplied to the load 40 via the switchboard 30 .

Drive units 61 , 62 , 63 operate switching elements constituting AC/DC converters 53 , 54 , 55 , respectively, based on instructions from control unit 66 . The power used to control the drive units 61 - 63 is supplied from the control unit 66 .

Here, for convenience of explanation, the operation of the AC/DC converters 53 to 55 when power is supplied from the primary side to the secondary side of the charging/discharging device 50 is assumed to be charging operation, and the secondary side of the charging/discharging device 50 to the primary side The operation of the AC/DC converters 53 to 55 when power is supplied to is called a discharging operation.

The power supply unit 64 is a unit for supplying power to the control unit 66 . A commercial power system is connected to the power supply unit 64 via a rectifier circuit 60 . Therefore, the DC voltage converted from the AC voltage by the rectifier circuit 60 is applied to the power supply unit 64 . In this state, the power supply unit 64 supplies power supplied through the rectifier circuit 60 to the control unit 66 . At the same time, the power supplied through the rectifier circuit 60 is also supplied to the battery unit 65 . As a result, the battery unit 65 is charged.

Also, the power supply unit 64 is connected to the primary side of the AC/DC converter 54 via a diode 56 . The power supply unit 64 controls the power supplied through the diode 56 when the DC voltage generated by the operation of the AC/DC converters 53 to 55 is higher than the DC voltage on the secondary side of the rectifier circuit 60. supply to unit 66;

A battery unit 65 is connected to the power supply unit 64 . Therefore, when the operation of the AC/DC converters 53 to 55 is temporarily stopped due to a power failure in the commercial power system, or when the operation of the AC/DC converters 53 to 55 has been stopped before the power failure occurs, the power The DC voltage of the battery unit 65 is applied to the supply unit 64 . In this state, the power supply unit 64 supplies power supplied from the battery unit 65 to the control unit 66 .

The battery unit 65 has a battery composed of a plurality of cells filled with electrolyte. The battery unit 65 is charged with electric power used for starting the AC/DC converters 53 to 55 when the commercial power system fails. Charging of the battery unit 65 is realized by supplying power through the rectifier circuit 60 when the commercial power system is healthy as described above.

The control unit 66 includes a computer having a CPU, a main memory, an auxiliary memory, and an interface. This control unit 66 monitors the voltage signal V1 from the voltage detection transformer VT1 and the current signal I1 from the current transformer CT1 to detect the power supply unit 64, the contactor 33 of the switchboard 30, and the contactor 51 of the charging/discharging device 50. to control. It also controls the AC/DC converters 53-55 via the drive units 61-63. The operation of control unit 66 will be described later.

FIG. 4 is a block diagram showing the control system of the electric vehicle 80. As shown in FIG. Electric vehicle 80 is detachably connected to charge/discharge device 50 via connector 90 . As shown in FIG. 4 , the electric vehicle 80 has an open/close switch 81 , a main battery unit 82 , a charging unit 83 , an auxiliary battery 84 , a drive unit 85 and a vehicle control unit 86 .

The open/close switch 81 is a contactor driven by the drive unit 85 . The open/close switch 81 connects and disconnects the domestic electric power system of the house 10 and the electric vehicle 80 .

The main battery unit 82 is connected to the secondary side of the open/close switch 81 . This main battery unit 82 is a unit for storing electric power used for driving the electric vehicle 80 . A plurality of lithium ion batteries are used as the batteries of the main battery unit 82 . In this embodiment, a battery with a terminal voltage of about 200V to 400V is configured by connecting lithium ion battery cells of 3V to 4V in series.

Main battery unit 82 is connected to charge/discharge device 50 by connecting connector 90 to electric vehicle 80 . Then, when the open/close switch 81 of the electric vehicle 80 is turned on, the electric vehicle 80 is connected to the charging/discharging device 50 , and the domestic power system of the house 10 becomes capable of charging and discharging electric power.

Auxiliary device battery 84 is a battery for storing electric power used for controlling vehicle control unit 86 . The auxiliary battery 84 has a terminal voltage of about 12 V or 24 V and is composed of a plurality of cells filled with an electrolytic solution.

The charging unit 83 is provided between the main battery unit 82 and the auxiliary battery 84 . The charging unit 83 steps down the voltage of the main battery unit 82 and applies it to the auxiliary battery 84 and the vehicle control unit 86 . As a result, the charging of the auxiliary battery 84 and the supply of electric power to the vehicle control unit 86 are realized.

Drive unit 85 drives open/close switch 81 based on an instruction from vehicle control unit 86 .

The vehicle control unit 86 includes a computer having a CPU, a main memory, an auxiliary memory, and an interface. This vehicle control unit 86 is connected to the control unit 66 via a connector 90 . Then, based on the instruction from the control unit 66, the drive unit 85 is operated. The vehicle control unit 86 also acquires information such as the amount of power stored in the main battery unit 82, and provides the information to the control unit 66 as necessary.

Next, the operation of the charging/discharging device 50 described above will be described with reference to FIGS. 5 and 6. FIG. 5 and 6 are flowcharts showing a series of processes executed by control unit 66 that constitutes charging/discharging device 50. FIG. First, the power switching process executed by the control unit 66 will be described with reference to FIG.

The power switching process is a process of switching the power source of the load 40 from the commercial power system to the main battery unit 82 when the commercial power system fails. This power switching process is executed when sufficient electric power is stored in the main battery unit 82 of the electric vehicle 80 .

In the first step S201, the control unit 66 determines whether or not a power failure has occurred in the commercial power system. When a power failure occurs in the commercial power system, the voltage of the commercial power system becomes zero, so the value of the voltage signal V1 from the voltage detection transformer VT1 becomes equal to or less than the predetermined threshold. Therefore, the control unit 66 monitors the value of the voltage signal V1, and determines that a power failure has occurred in the commercial power system when the value of the voltage signal V1 becomes equal to or less than a predetermined threshold (step S201: Yes). , the process proceeds to the next step S202.

In the next step S202, the control unit 66 notifies the power supply unit 64 of the power failure. If a power failure occurs in the commercial power system while the AC/DC converters 53-55 are performing the power receiving operation, the control unit 66 stops the AC/DC converters 53-55.

The power supply unit 64 supplies the power stored in the battery unit 65 to the control unit 66 when notified by the control unit 66 of the power failure. Thereby, the control unit 66 can continue to control the AC/DC converters 53 to 55 constituting the charging/discharging device 50 .

In the next step S<b>203 , the control unit 66 notifies the vehicle control unit 86 that configures the electric vehicle 80 of an instruction to disconnect the main battery unit 82 . Upon receiving the parallel-off instruction, the vehicle control unit 86 of the electric vehicle 80 drives the drive unit 85 to turn off the open/close switch 81 . As a result, the main battery unit 82 is disconnected from the commercial power system.

In the next step S204, control unit 66 turns off contactor 51 of charging/discharging device 50. FIG. As a result, charging/discharging device 50 is disconnected from the commercial power system. Note that if the AC/DC converters 53 to 55 are stopped when a power failure occurs, the open/close switch 81 and the contactor 51 are off (open). Therefore, there is no problem even if the processing of steps S203 and S204 is omitted.

In the next step S205, the control unit 66 waits for a power switching operation from the user living in the house 10. FIG. In this power switching operation, when the commercial power system is out of power for a long period of time due to a disaster or the like, or in the case of planned power outages with advance notice, the electric power used for running the electric vehicle 80 is switched to the house 10. This is the operation to supply the load installed in the In this embodiment, for example, the power supply switching operation is realized by operating an operation switch provided in the charging/discharging device 50 .

The control unit 66 repeats the processes of steps S201 to S205 until the resident performs a power switching operation (step S205: No). On the other hand, when the power supply switching operation is performed by the resident or the like (step S205: Yes), the control unit 66 proceeds to step S206.

In step S<b>206 , the control unit 66 turns off the contactor 33 housed in the switchboard 30 . As a result, the domestic power system can be disconnected from the commercial power system.

Through the processes from steps S203 to S206, the commercial power system and the domestic power system are completely disconnected. As a result, even if the power supply source for the domestic power system is switched from the commercial power system to the main battery unit 82 of the electric vehicle 80 at the time of a power failure, reverse power flow to the commercial power system is prevented, and maintenance at the time of the power failure is facilitated. It is possible to ensure the safety of the workers who do it.

In the next step S<b>207 , the control unit 66 notifies the vehicle control unit 86 configuring the electric vehicle 80 of an instruction to connect the main battery unit 82 . Upon receiving the interconnection instruction, the vehicle control unit 86 of the electric vehicle 80 drives the drive unit 85 to turn on the open/close switch 81 . Thereby, the main battery unit 82 is connected to the charging/discharging device 50 .

In the next step S208, control unit 66 turns on contactor 51 of charging/discharging device 50. FIG. As a result, charging/discharging device 50 is connected to the domestic power system.

In the next step S209, the control unit 66 instructs each of the drive units 61 to 63 to start the discharge operation. When each of the drive units 61 to 63 receives the discharge operation start instruction, it causes the AC/DC converters 53 to 55 to operate during discharge. This causes the AC/DC converters 53 to 55 to start discharging. Electric power stored in the electric vehicle 80 is supplied to the load 40 installed in the house 10 . Further, the power supply unit 64 outputs power from the AC/DC converter 54 to the control unit 66 and the battery unit 65 when the AC/DC converter 54 starts discharging operation. Thereby, the operation of the control unit 66 is maintained and charging of the battery unit 65 is started. There is no problem even if the operation of turning on the contactor 51 of the charging/discharging device 50 (step S208) is executed after the discharging operation is started. The control unit 66 ends the power switching process after the process of step S209 ends.

Next, with reference to FIG. 6, power restoration processing executed by the control unit 66 will be described. The power restoration process is a process for restoring the commercial power system as a power source by switching the power supply of the load 40 from the main battery unit 82 to the commercial power system when the commercial power system recovers from a power failure. This power restoration process can be executed when commercial power becomes healthy.

In the first step S301, the control unit 66 determines whether the voltage has been restored. When the commercial power system is restored, the voltage of the commercial power system becomes the rated voltage, so the value of the voltage signal V1 from the voltage detection transformer VT1 becomes equal to or higher than the predetermined threshold. Therefore, the control unit 66 monitors the value of the voltage signal V1, and determines that the voltage of the commercial power system has been restored when the value of the voltage signal V1 exceeds a predetermined threshold (step S301: Yes). , the process proceeds to the next step S302.

In the next step S302, the control unit 66 waits for a power restoration operation from the user living in the house 10. FIG. This power restoration operation is an operation for switching the power source of the load 40 to the commercial power system when the commercial power system recovers from a power failure. In this embodiment, for example, the power restoration operation is realized by operating an operation switch provided in the charging/discharging device.

If there is no power restoration operation (step S302: No), the control unit 66 repeats the processes of steps S301 and S302. Further, when the power restoration operation is performed (step S302: Yes), the control unit 66 proceeds to step S303.

In step S303, the control unit 66 instructs each of the drive units 61 to 63 to stop the discharge operation. Each of the drive units 61-63 stops the operation of the AC/DC converters 53-55 upon receiving the discharge operation stop instruction. This stops the operation of the AC/DC converters 53-55.

When the AC/DC converters 53 to 55 stop operating, the power supply unit 64 supplies power stored in the battery unit 65 to the control unit 66 . This keeps the control unit 66 operational.

In the next step S304, the control unit 66 turns on the contactor 33 accommodated in the switchboard 30, thereby connecting the domestic power system to the commercial power system.

In the next step S305, the control unit 66 instructs each of the drive units 61 to 63 to start the charging operation. Each drive unit 61 to 63, upon receiving the charge operation start instruction, causes the AC/DC converters 53 to 55 to operate during charging. This causes the AC/DC converters 53 to 55 to start the charging operation. Electric power from the commercial power system is supplied to the load 40 installed in the house 10 . Further, the power supply unit 64 outputs power from the commercial power system to the control unit 66 and the battery unit 65 when the interconnection between the commercial power system and the domestic power system is completed. Thereby, the operation of the control unit 66 is maintained and charging of the battery unit 65 is started. The control unit 66 ends the power restoration process after the process of step S305 ends. In this embodiment, the charging operation of the main battery unit 82 is quickly executed in the power restoration process, but the charging operation does not necessarily have to be executed quickly. For example, a start time may be reserved and the charging operation may be started from the reserved time.

As described above, in the present embodiment, power of the battery unit 65 constituting the charging/discharging device 50 is supplied to the control unit 66 when the commercial power system fails. Then, the control unit 66 uses the power supplied from the battery unit 65 to turn off the contactor 33 of the switchboard 30 to disconnect the domestic power system from the commercial power system. Next, the control unit 66 operates the AC/DC converters 53 to 55 to supply the electric power stored in the main battery unit 82 of the electric vehicle 80 to the load 40 of the house 10 .

Therefore, even if the supply of power used for control from the commercial power system is stopped due to a power failure in the commercial power system, the power stored in the battery unit 65 ensures that the load 40 installed in the house 10 is maintained. The electric power stored in the electric vehicle 80 is supplied to . As a result, power can be quickly supplied to the load in the event of a power outage in the commercial power system.

Further, even if the supply of power used for control from the commercial power system stops, the electric power stored in the battery unit 65 causes the domestic power system to be disconnected from the commercial power system. Therefore, it is possible to reliably avoid reverse flow of electric power stored when the commercial power system is sound to the commercial power system.

<<Embodiment 2>>
Next, Embodiment 2 of the present invention will be described with reference to the drawings. In addition, about the structure same as that of Embodiment 1, or equivalent, while using equivalent code|symbol, the description is abbreviate|omitted or simplified. FIG. 7 is a power system diagram of the house 10 according to this embodiment. As shown in FIG. 7, this embodiment differs from Embodiment 1 in that a photovoltaic power generation unit 70 is connected to the domestic power system.

As shown in FIG. 7, the photovoltaic power generation unit 70 has a solar cell panel 72 arranged on the roof of the house 10, for example, and an inverter 71 that converts the voltage of the solar cell panel 72 from AC to DC.

As shown in FIG. 8 , in this embodiment, the photovoltaic power generation unit 70 is connected to the wiring branched from between the contactor 33 and the branch breaker 34 via the branch breaker 35 .

In general, when the photovoltaic power generation unit 70 is installed, the power generated by the photovoltaic power generation unit 70 is allowed to reversely flow into the commercial power system, but it is not stored in the power storage means such as the power storage unit 41. It is not permitted to reverse power flow to the commercial power grid. Therefore, the photovoltaic power generation unit 70 is connected to the secondary side of the contactor 33 and the primary side of the current transformer CT2 so that power can be supplied to the load 40 of the house 10 in the event of a power failure.

In this embodiment, the control unit 66 measures the current through the contactor 33 using a current transformer CT1. Also, the total current flowing through each branch breaker 34 is measured using the current transformer CT2. Then, the current passing through the branch breaker 35 of the photovoltaic power generation unit 70 is measured using the current transformer CT3.

Therefore, from the current signal I1 from the current transformer CT1, the control unit 66 measures the power P1 exchanged between the commercial power system and the domestic power system, and from the current signal I2 from the current transformer CT2, , the power P2 reverse-flowed to the commercial power system can be measured, and the power P3 generated by the photovoltaic power generation unit 70 can be measured from the current signal I3 from the current transformer CT3.

Therefore, by monitoring the power P2, the control unit 66 can detect a reverse power flow from the power storage unit 41 and promptly perform control to prevent the reverse power flow. As this control, it is conceivable to stop the operation of the AC/DC converters 53 to 55, reduce the amount of discharge, or the like.

The control unit 66 can also detect erroneous connection or disconnection of the current transformer by utilizing the fact that the power P1 and the power P2 are equal when the photovoltaic power generation unit 70 is not operating. When the photovoltaic power generation unit 70 is operating, it is possible to detect erroneous connection, disconnection, or the like of the current transformer CT3 from the sign of P3.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, in the above embodiment, when a power failure occurs in the commercial power system, the power switching process is completed when the user performs a power switching operation (step S206: Yes). Without being limited to this, when the commercial power system fails, the domestic power system may be automatically disconnected from the commercial power system and the stored power may be supplied to the load 40 of the house 10 .

In the above embodiment, the case where the power stored in the electric vehicle 80 is supplied to the load 40 during a power failure in the commercial power system has been described. The power storage unit 41 is not limited to this, and instead of the electric vehicle 80, the power storage unit 41 may include power storage means having a dedicated battery. Alternatively, the power storage unit 41 may be a power storage unit or the like that includes a wind turbine generator and a battery.

In the charging/discharging device 50 of the above embodiment, the primary side and the secondary side of the charging/discharging device 50 are insulated by the isolation transformer 58 arranged between the AC/DC converters 54 and 55 . Alternatively, for example, as shown in FIG. 9, the primary side and secondary side of the charge/discharge device 50 may be insulated by arranging an isolation transformer 58 on the primary side of the contactor 51 . In this case, AC power and DC power can be converted by the AC/DC converter 53 and the voltage converter 67 having the switching element and the reactor 52C.

In the example of FIG. 9, since an isolation transformer 58 corresponding to the voltage on the commercial power supply side is required, the size of the isolation transformer 58 is increased. However, since the conversion circuit composed of the three AC/DC converters 53 to 55 is composed of the AC/DC converter 53 and the voltage converter 67, the configuration of the device is simplified. Therefore, it may be possible to reduce the manufacturing cost of the device depending on the application to which it is applied.

In addition, in the example of FIG. 9, since the number of switching elements constituting the conversion circuit is reduced, the loss in the switching elements is reduced and the reliability of the device is improved. Furthermore, since the potential of the AC/DC converter 53 and the voltage converter 67 can be shared, the driving power supply for the switching elements can be shared. As a result, the responsiveness of power conversion can be improved.

In the above embodiment, as shown in FIG. 3, the case where the charging/discharging device 50 has the single-phase AC/DC converters 54 and 55 has been described. This is just an example, and the charging/discharging device 50 may have three-phase AC/DC converters 54 and 55 as shown in FIG. 10, for example. In this case, as the isolation transformer 58, a YY connection isolation transformer, a Y-Δ connection isolation transformer, or a Δ-Δ connection transformer can be used.

In the above embodiment, as shown in FIGS. 3 and 10, the case where the single-phase AC/DC converter 53 constituting the charging/discharging device 50 is connected to the domestic power system has been described. The AC/DC converter 53 may be a three-phase AC/DC converter (not shown). If the AC/DC converter 53 is a three-phase AC/DC converter, it can supply power to a three-phase load installed in the house 10 . In addition, it becomes easy to deal with a single-phase three-wire domestic power system.

In the above embodiment, as shown in FIG. 3, the case where one capacitor 57 is connected between the terminals of the AC/DC converters 53 and 54 has been described. Alternatively, a capacitor other than the capacitor 57 may be connected in series between the terminals of the AC/DC converter 53 . Thereby, a groundable neutral point can be provided between the capacitors connected in series. As a result, it is possible to deal with single-phase three-wire output.

In the above embodiment, the battery unit 65 is composed of a plurality of cells filled with electrolyte. Not limited to this, the battery unit 65 may have a lithium ion battery cell or the like. In addition, since the battery unit 65 only needs to store electric power used for control, it is possible to use, for example, an alkaline dry battery. In addition, by preparing a terminal port instead of always installing the battery unit 65, the battery unit 65 can be connected to the control unit 66 only in the event of a power failure, or when the battery unit 65 is insufficiently charged. , a general-purpose dry battery may be connected to supply power to the control unit 66 . Also, instead of the battery unit 65, a portable power generator, a fuel cell, a solar battery, or a wind power generator may be used.

The above-mentioned portable power generator may be one that generates power using propane gas, gasoline, or light oil, or one composed of a Peltier element that uses heat energy stored in a water heater to generate power, and there is no problem. In this case also, the same effects as those of the battery unit 65 can be achieved.

In the above-described embodiment, the main battery unit 82 that constitutes the electric vehicle 80 is provided with a battery that is configured by connecting lithium-ion battery cells in series. Not limited to this, the main battery unit 82 may include a battery made up of battery cells other than lithium battery cells. Also, the voltage across the terminals of the main battery unit 82 is not limited to 200V to 400V.

In the above embodiment, the vehicle control unit 86 acquires information such as the amount of electric power stored in the main battery unit 82, and provides the acquired information to the user of the electric vehicle 80 as necessary. Information about the main battery unit 82 includes battery voltage, charging current, discharging current, battery capacity, charging state, temperature of each cell, and the like. The control unit 66 forming the charging/discharging device 50 may control the operations of the AC/DC converters 53 to 55 based on the above information.

In the above embodiment, as shown in FIG. 2, the earth leakage breaker 32 is installed on the secondary side of the master breaker 31 . Aside from this earth leakage breaker 32, an earth leakage breaker may be installed in series with each branch breaker 34, respectively.

In the above embodiment, as shown in FIG. 2, the case where the main breaker 31, the earth leakage breaker 32, the contactor 33, and the plurality of branch breakers 34 are housed in the switchboard 30 has been described. The example shown in FIG. 2 is an example, and the present invention is not limited to this. For example, the main breaker 31 , the earth leakage breaker 32 , and the contactor 33 may be housed in a switchboard different from the switchboard 30 .

In the above embodiment, in the power switching process, the main battery unit 82 is disconnected from the commercial power system by the open/close switch 81 of the electric vehicle 80, the contactor 51 of the charging/discharging device 50, and the contactor 33 housed in the switchboard 30. In this way, parallel-connection is performed by a plurality of devices connected in series, so that the main battery unit 82 can be reliably disconnected from the commercial power system even if one of the devices malfunctions. can be done. As a result, reverse power flow to the commercial power system can be reliably prevented.

Further, it is desirable to use a device that does not normally turn off as a device for disconnecting the power system and the home power system, for example, a device such as the contactor 33 shown in FIG. By using equipment that does not normally turn off, it is possible to avoid unnecessary disconnection during short-term power outages.

The present invention is capable of various embodiments and modifications without departing from the broader spirit and scope of the invention. Moreover, the above-described embodiments are for explaining the present invention, and do not limit the scope of the present invention. In other words, the scope of the present invention is indicated by the claims rather than the embodiments. Various modifications made within the scope of the claims and within the meaning of equivalent inventions are considered to be within the scope of the present invention.

INDUSTRIAL APPLICABILITY The charging/discharging device and power switching system of the present invention are suitable for switching between a commercial power source and a power source installed in a house.

10 house, 20 electricity meter, 30 switchboard, 31 master breaker, 32 earth leakage breaker, 33 contactor, 34 branch breaker, 35 branch breaker, 40 load, 41 power storage unit, 50 charging and discharging device, 51 contactor, 52A to 52C reactor, 53 to 55 AC/DC converter, 56 diode, 57 capacitor, 58 isolation transformer, 59 capacitor, 60 rectifier circuit, 61 to 63 drive unit, 64 power supply unit, 65 battery unit, 66 control unit, 67 voltage converter, 70 sun Photovoltaic unit, 71 inverter, 72 solar panel, 80 electric vehicle, 81 open/close switch, 82 main battery unit, 83 charging unit, 84 auxiliary battery, 85 drive unit, 86 vehicle control unit, 90 connector, CT1 to CT3 Current Transformer, VT1 Voltage Sensing Transformer.

Claims (9)

Power provided between a load and a main battery unit of an electric vehicle to convert power supplied from a power system to the main battery unit or power supplied from the main battery unit to the load. a conversion means;
A control unit that controls the operation of the power conversion means, and a charging and discharging device external to the electric vehicle ,
a first opening/closing means connected to the primary side of the power conversion means and operated based on an instruction from the control unit;
In the event of a power outage, any of a battery consisting of a plurality of cells filled with an electrolytic solution, a lithium ion battery, a general-purpose dry battery, a portable power generator, a fuel cell, a solar battery, and a wind power generator outside the charging/discharging device a terminal port connected by a user for supplying power to the control unit ;
with
The control unit notifies a vehicle control unit of the electric vehicle of an instruction to connect the main battery unit, and when the main battery unit is connected to the charging/discharging device, operates the power conversion means to supplying power from the main battery unit to the load;
The charging/discharging device, wherein the control unit controls to close the first opening/closing means before operating the power conversion means. Power provided between a load and a main battery unit of an electric vehicle to convert power supplied from a power system to the main battery unit or power supplied from the main battery unit to the load. a conversion means;
A control unit that controls the operation of the power conversion means, and a charging and discharging device external to the electric vehicle ,
a first opening/closing means connected to the primary side of the power conversion means and operated based on an instruction from the control unit;
In the event of a power outage, any of a battery consisting of a plurality of cells filled with an electrolytic solution, a lithium ion battery, a general-purpose dry battery, a portable power generator, a fuel cell, a solar battery, and a wind power generator outside the charging/discharging device a terminal port connected by a user for supplying power to the control unit ;
with
The control unit notifies a vehicle control unit of the electric vehicle of an instruction to connect the main battery unit, and when the main battery unit is connected to the charging/discharging device, operates the power conversion means to supplying power from the main battery unit to the load;
The charging/discharging device, wherein the control unit controls the power converting means to be in a stopped state when the first opening/closing means is closed. wherein the control unit notifies the second opening/closing means provided on the primary side of the first opening/closing means of an opening instruction, and then notifies the vehicle control unit of an interconnection instruction for the main battery unit. 3. The charging/discharging device according to 1 or 2. The charge/discharge device according to any one of claims 1 to 3, further comprising a rectifier circuit that converts power from the power system and supplies the power to the control unit. 5. The charging/discharging device according to claim 4, wherein the rectifying circuit is connected to the primary side of the first opening/closing means. The power supplied to the terminal port is supplied to the control unit via a power supply unit.
The charge/discharge device according to any one of claims 1 to 5. Power is supplied to the terminal port during a power outage in the power system,
The charge/discharge device according to any one of claims 1 to 6. a main battery unit that accumulates power from a power system and supplies the accumulated power to a load;
an open/close switch connected to the main battery unit;
a vehicle control unit that controls the open/close switch;
an electric vehicle having
A charging and discharging device,
A power converter provided between the main battery unit and the load for converting power supplied from the power system to the main battery unit or converting power supplied from the main battery unit to the load means and
a control unit for controlling the operation of the power conversion means;
In the event of a power outage, any of a battery consisting of a plurality of cells filled with an electrolytic solution, a lithium ion battery, a general-purpose dry battery, a portable power generator, a fuel cell, a solar battery, and a wind power generator outside the charging/discharging device a terminal port connected by a user for supplying power to the control unit ;
a charging and discharging device external to the electric vehicle ,
The charging/discharging device comprises opening/closing means connected to the primary side of the power conversion means and operated based on instructions from the control unit,
The control unit notifies the vehicle control unit of an instruction to connect the main battery unit,
When the vehicle control unit receives the interconnection instruction, the vehicle control unit controls the opening/closing switch to connect the main battery unit to the charging/discharging device,
when the main battery unit is connected to the charging/discharging device, the control unit operates the power conversion means to supply power from the main battery unit to the load;
The power switching system, wherein the control unit controls to close the opening/closing means before operating the power conversion means. a main battery unit that accumulates power from a power system and supplies the accumulated power to a load;
an open/close switch connected to the main battery unit;
a vehicle control unit that controls the open/close switch;
an electric vehicle having
A charging and discharging device,
A power converter provided between the main battery unit and the load for converting power supplied from the power system to the main battery unit or converting power supplied from the main battery unit to the load means and
a control unit for controlling the operation of the power conversion means;
In the event of a power outage, any of a battery consisting of a plurality of cells filled with an electrolytic solution, a lithium ion battery, a general-purpose dry battery, a portable power generator, a fuel cell, a solar battery, and a wind power generator outside the charging/discharging device a terminal port connected by a user for supplying power to the control unit ;
a charging and discharging device external to the electric vehicle ,
The charging/discharging device comprises opening/closing means connected to the primary side of the power conversion means and operated based on instructions from the control unit,
The control unit notifies the vehicle control unit of an instruction to connect the main battery unit,
When the vehicle control unit receives the interconnection instruction, the vehicle control unit controls the opening/closing switch to connect the main battery unit to the charging/discharging device,
when the main battery unit is connected to the charging/discharging device, the control unit operates the power conversion means to supply power from the main battery unit to the load;
The power supply switching system, wherein the control unit controls the power conversion means to be in a stopped state when the opening/closing means is closed.

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