JP7186027B2 - Grid interconnection system and grid interconnection method - Google Patents

Description

The present invention relates to a grid interconnection system and a grid interconnection method.

The market is shifting from gasoline vehicles or hybrid vehicles to electric vehicles such as plug-in hybrid vehicles (PHEV) or electric vehicles (EV). Patent Literature 1 discloses a V2H (Vehicle to Home) device that connects such an electric vehicle to electrical equipment used in a home and supplies power to the electrical equipment in the home as an emergency power supply in the event of a disaster or the like. ing.

On the other hand, the power distribution service from automobiles to the power system is not limited to V2H, and is a general term for V2B (Vehicle to Building) or V2G (Vehicle to Grid), which is a service for general households and larger consumers and power grids. is expanding to V2X.

JP 2018-61432 A

A battery mounted on an electric vehicle has a large amount of electric power, and the average operating time of an electric vehicle per day is relatively short. For this reason, there are great expectations for supplying electric power from electric vehicles to loads such as electric power systems in the event of a disaster. However, when the electric vehicle is in operation at the time of a disaster, the power of the electric vehicle cannot be used and the required power cannot be supplied to the load.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a system interconnection system and a system interconnection method capable of supplying required power to a load.

A grid interconnection system according to the present invention is a grid interconnection system with a power system having a commercial power supply, and includes a storage battery installed in a parking lot, an AC/DC power converter for the storage battery, and a charge/discharge stand for an electric vehicle. , and an interconnection control device, wherein the interconnection control device supplies electric power to a first load from at least one of the charging/discharging station and the AC/DC power converter when the power system is in an emergency.

A system interconnection method according to the present invention is a system interconnection method with an electric power system, which includes a storage battery installed in a parking lot, an AC/DC power converter for the storage battery, a charge/discharge stand for an electric vehicle, and an interconnection A control device is provided, and power is supplied to a first load from at least one of the charging/discharging station and the AC/DC power converter in the event of an emergency in the power system.

According to the present invention, required power can be supplied to the load.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows an example of an external appearance structure of the grid connection system of this Embodiment. It is a top view which shows an example of installation of the grid connection system of this Embodiment. BRIEF DESCRIPTION OF THE DRAWINGS It is a front view which shows an example of installation of the grid connection system of this Embodiment. FIG. 2 is a schematic diagram showing an example of an electrical conduit buried underground; FIG. 4 is a plan view showing an arrangement example of decorative walls installed around the grid connection unit; 1 is a schematic diagram showing an example of a circuit configuration of a grid interconnection system according to an embodiment; FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing a first example of grid interconnection when a power system is normal by the grid interconnection system of the present embodiment; FIG. 4 is a schematic diagram showing a second example of grid interconnection when the power grid is normal by the grid interconnection system of the present embodiment; FIG. 2 is a schematic diagram showing an example of self-sustained operation in an emergency of the power system by the interconnection system of the present embodiment; FIG. 4 is a schematic diagram showing an example of operation switching when the power system is restored from an emergency to a normal state by the grid interconnection system of the present embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described based on the drawings showing its embodiments. FIG. 1 is a schematic diagram showing an example of an external configuration of a grid interconnection system 100 according to this embodiment. In the example of FIG. 1, the parking lot has five parking spaces. The grid interconnection system 100 includes charge/discharge stands 41, 42, 43, 44, and 45 for electric vehicles (51, 52, 53, 54, and 55) installed in parking lots, and grid interconnection stations installed in parking lots. equip the unit. The grid interconnection system 100 can be provided as equipment for business continuity planning (BCP). The system interconnection unit includes a storage battery board 10 that houses a storage battery (not shown), a power conversion board 20 that houses a storage battery PCS (Power Conditioning System) (not shown), and an interconnection control device that performs power interconnection with the power system. (not shown) is provided. Note that the number of charge/discharge stands is not limited to five.

Electric vehicles are plug-in hybrid vehicles (PHEV) or electric vehicles (EV), also referred to herein as PHEVs or EVs. The charging/discharging stands 41 to 45 can charge and discharge a battery (vehicle storage battery) mounted on an electric vehicle. The storage battery PCS (also referred to as an AC/DC power converter) housed in the power conversion board 20 can convert power in both directions, from alternating current to direct current and from direct current to alternating current. Also called a storage battery) can be charged and discharged. The interconnection control device accommodated in the interconnection board 30 performs system interconnection operation between the power system, the storage battery PCS, and the charging/discharging stands 41 to 45 when the power system is normal, and when the power system is abnormal (during a disaster). In this case, the storage battery PCS and the charging/discharging stands 41 to 45 can be operated independently.

By installing the charge/discharge stands 41 to 45, the storage battery board 10, the power conversion board 20, and the interconnection board 30 (system interconnection unit) in the parking lot, the electric vehicle is in operation during a disaster. Even if all or part of the automobile is not parked in the parking lot and the required power cannot be supplied from the charge/discharge stands 41 to 45 to the predetermined load (also referred to as the important load or the first load), the storage battery Since the power of the storage battery can be supplied to the load by the PCS, the required power can be supplied to the load as a whole.

FIG. 2 is a plan view showing an example of installation of the grid interconnection system 100 of this embodiment, and FIG. 3 is a front view showing an example of installation of the grid interconnection system 100 of this embodiment. In the illustrated example, among the five parking spaces 501 to 505, the electric vehicle parked in the parking space 501 is not parked. Reference numeral 6 is a collision prevention pole, and reference numeral 7 is a wheel chock.

As shown in FIG. 2, the storage battery board 10, the power conversion board 20, and the interconnection board 30 are arranged side by side along the vehicle length direction of the parking space (the direction indicated by symbol L in the figure). That is, the storage battery board 10, the power conversion board 20, and the interconnection board 30 can be arranged side by side along the vehicle length direction of the parking space. By arranging the storage battery board 10, the power conversion board 20, and the interconnection board 30 side by side along the vehicle length direction of the parking space arranged for each electric vehicle in the parking lot, for example, a parking space for about one electric vehicle. The system interconnection unit (storage battery board 10, power conversion board 20 and interconnection board 30) can be arranged, and the site area required for the parking lot including the system interconnection unit can be made compact. In addition, since the distance between the grid connection unit and the charging/discharging stands 41 to 45 can be shortened, the wiring work and burying work for the power lines and communication/control lines described later can be facilitated, and the cost required for the work can be reduced. can do.

The storage battery board 10 has opening/closing doors 121, 122, and 123 on the front surface on the parking space side. The power converter board 20 has an opening/closing door 211 on the front surface on the parking space side. The interconnection board 30 has open/close doors 311 and 312 on the front surface on the parking space side. That is, the storage battery board 10, the power conversion board 20, and the interconnection board 30 can be installed so that the opening/closing doors provided on each of the storage battery board 10, the power conversion board 20, and the interconnection board 30 face the parking space side. . Each opening/closing door can be opened by a worker for maintenance and inspection of the storage battery board 10, the power conversion board 20, and the interconnection board 30. FIG.

For example, as shown in FIG. 2, an electric vehicle parked in a parking space 501 adjacent to each opening/closing door of the storage battery board 10, the power conversion board 20, and the interconnection board 30 is moved from the parking space 501, and the parking space 501 is moved. By opening the parking space 501, it is possible to use the parking space 501 as a work space for maintenance and inspection of the grid-connected unit. As a result, it is not necessary to install the system interconnection unit in a state in which a work space for maintenance and inspection is secured in advance, and the occupied area including the work space can be reduced.

The storage battery board 10 has an intake/exhaust port 125 on the rear surface opposite to the parking space. The power conversion board 20 has an intake/exhaust port 215 on the rear surface opposite to the parking space. The storage battery board 10 accommodates a cooling device and a heater (not shown) for temperature control of the storage battery in addition to the storage battery. In addition to the storage battery PCS, the power conversion board 20 houses a cooling device (not shown) for heat dissipation of the storage battery PCS. By providing air intake/exhaust ports on the back side opposite to the parking space, it is possible to suppress hot air from hitting the users of the parking lot, thereby preventing the users from feeling uncomfortable. can.

The storage battery board 10, the power conversion board 20, and the interconnection board 30 can have a plate thickness of 2.3 mm or more. Usually, a cubicle-type high-voltage power receiving equipment (simply called a cubicle) uses a metal plate having a thickness of about 1.6 mm. In this case, according to the fire prevention ordinance, the cubicle must be installed at least 3m away from the building. By setting the board thickness to 2.3 mm or more, the restriction that the separation distance from the building is 3 m or more is eliminated. Therefore, even for parking lots adjacent to buildings, the layout of the grid-connected unit can be considered without considering the separation distance from the building, increasing the degree of freedom in installing the grid-connected unit. , resulting in easier installation.

As shown in FIG. 2, the bottom plate of the interconnection board 30 is formed with a high pressure lead-in port 301 and a high pressure lead-out port 302 on the rear side, and a low-pressure lead-out port 303 on the front side. The high-voltage lead-in 301 is wired through a wire tube (for example, a flexible hard polyethylene tube) buried in the ground, and is connected to a power line (high-voltage power line) from the commercial power supply side of the power system and communication/ The control line is pulled in to an appropriate length. A power line (high-voltage power line) from the load side and a communication/control line are drawn into the high-voltage outlet 302 through a conduit buried in the ground. The low-voltage outlet 303 is wired through a conduit buried in the ground, and a ground line, a power line (low-voltage power line) and a communication/control line between the charging/discharging stands 41 to 45 are drawn to an appropriate length.

FIG. 4 is a schematic diagram showing an example of a conduit buried underground. In FIG. 4, the diagram on the left shows an example of excavation on the low pressure side, and the diagram on the right shows an example of excavation on the high pressure side. On the low voltage side, power lines (for example, CV cables: cross-linked polyethylene insulated vinyl sheath cables) are wired to each of the five conduits corresponding to the five charge/discharge stands, and 5 corresponding to the five charge/discharge stands. A communication/control line is wired to each conduit, and each conduit is buried at a required depth (for example, 60 cm or more) underground. On the high voltage side, power lines (e.g., CV cables) are wired in conduits, communication and control lines are wired in separate conduits, and each conduit is installed at a required depth (e.g., 60 cm or more) underground. Buried.

The grid interconnection system 100 of this embodiment can be installed as follows. That is, a storage battery board 10, a power conversion board 20, and an interconnection board 30 are installed side by side on a foundation 1 provided on the ground of a parking lot. By inserting the foundation bolts fixed to the foundation 1 into the bolt holes formed in the bottom plates (not shown) of the storage battery board 10, the power conversion board 20, and the interconnection board 30 and tightening the nuts, the storage battery board 10, the power conversion board 20 and the interconnection board 30 can be fixed to the foundation 1;

By separating the system interconnection unit into three equipment panels of the storage battery panel 10, the power conversion panel 20, and the interconnection panel 30, when the storage battery panel 10, the power conversion panel 20, and the interconnection panel 30 are brought into the installation site This eliminates the need for large transport vehicles. Moreover, when lifting the storage battery board 10, the power conversion board 20, and the interconnection board 30 at the installation site and moving them to the installation position, a large heavy machine becomes unnecessary. In particular, in installation in a parking lot such as a shopping mall where an unspecified number of users come and go, it is possible to prevent users from being inconvenienced or having a bad impression. In addition, it is possible to realize a compact equipment installation that makes effective use of the limited space in the parking lot.

Also, a cable from a commercial power supply is connected through the high voltage lead-in port 301 of the interconnection board 30, a cable to a predetermined load is connected through the high voltage outlet 302 of the interconnection board 30, and a low voltage outlet 303 of the interconnection board 30 is connected. Cables from charge/discharge stands 41 to 45 are connected through. Cables include power lines and communication and control lines. Since the wire lengths of the low-voltage side wiring and the communication/control line can be assumed by the package design of the system interconnection unit, it is possible to prepare wire-processed ones in advance.

With the above configuration, installation work of the grid-connected unit can be performed in a relatively short period of time, and construction costs can be reduced.

Also, a plurality of charging/discharging stands 41 to 45 can be arranged side by side on the foundation 1 provided on the ground of the parking lot. Since the grid-connected unit is installed adjacent to the parking space, the distance between the grid-connected unit and the charging/discharging stands 41 to 45 can be shortened. Construction work becomes easier and the cost required for construction work can be reduced.

FIG. 5 is a plan view showing an arrangement example of decorative walls 90 installed around the grid connection unit. As shown in FIG. 5, a decorative wall 90 is placed on the foundation 1 on which the storage battery board 10, the power conversion board 20 and the interconnection board 30 are installed so as to cover the periphery of the storage battery board 10, the power conversion board 20 and the interconnection board 30. can be installed in The decorative wall 90 can be a display board on which advertisements, art, etc. are displayed. The decorative wall 90 can have a height such that the storage battery board 10, the power conversion board 20, and the interconnection board 30 cannot be seen. In shopping malls and public places, the external appearance of the storage battery board 10, the power conversion board 20, and the interconnection board 30 is highly likely to give the user a slight sense of discomfort. Therefore, by covering the storage battery board 10, the power conversion board 20 and the interconnection board 30 with the decorative wall 90, it is possible to display information that arouses the interest of the user without making the user feel uncomfortable. .

Doorways 93 are provided on the front surface of the decorative wall 90 on the parking space side so as to correspond to the positions of the opening/closing doors 121 , 122 , and 123 of the storage battery board 10 . A doorway 92 is provided on the front face of the decorative wall 90 on the parking space side so as to correspond to the position of the opening/closing door 211 of the power conversion board 20 . In addition, an entrance 91 is provided on the front surface of the decorative wall 90 on the parking space side so as to correspond to the positions of the opening/closing doors 311 and 312 of the interconnection board 30 . The doorways 91 to 93 may be doors that can be opened and closed, or detachable wall plates. Thereby, even if the storage battery board 10, the power conversion board 20 and the interconnection board 30 are covered with the decorative wall 90, maintenance and inspection of the storage battery board 10, the power conversion board 20 and the interconnection board 30 can be performed.

The rear surface of the decorative wall 90 on the opposite side of the parking space is provided with an opening 95 corresponding to the position of the intake/exhaust port 125 of the storage battery board 10 . Further, an opening 94 is provided on the rear surface of the decorative wall 90 on the opposite side of the parking space so as to correspond to the position of the intake/exhaust port 215 of the power conversion board 20 . The openings 94, 95 may be punched or slit or the like. By providing the openings 94 and 95, the storage battery board 10, the power conversion board 20 and the interconnection board 30 are cooled even when the decoration wall 90 covers the periphery of the storage battery board 10, the power conversion board 20 and the interconnection board 30. be able to.

In the example of FIG. 5 , the decorative wall 90 is configured to cover all four surfaces around the storage battery board 10 , the power conversion board 20 and the interconnection board 30 , but the present invention is not limited to this. For example, only two of the four surfaces may be covered. For example, when covering only two surfaces, it is possible to cover two surfaces, the storage battery board 10 side and the back side. The side of the storage battery board 10 is the most visible to the user, and the rear side can hide discrepancies in the sizes of the boards. Also, by using two surfaces, the cost can be reduced more than the case of four surfaces.

In the example of FIG. 2, the storage battery board 10, the power conversion board 20, and the interconnection board 30 are installed side by side at a position adjacent to the parking space 501 at the end of the five parking spaces 501 to 505. However, the installation is not limited to the example of FIG. For example, a section corresponding to approximately one parking space may be provided between the parking space 502 and the parking space 503, and the storage battery board 10, the power conversion board 20, and the interconnection board 30 may be arranged side by side in the section. .

FIG. 6 is a schematic diagram showing an example of the circuit configuration of the interconnection system 100 of this embodiment. The storage battery board 10 accommodates a storage battery (stationary storage battery) 11, a control device (not shown), a cooling device, a heater, and the like. The power conversion board 20 accommodates a storage battery PCS21, a control device and a cooling device (not shown), and the like. The interconnection board 30 includes a remote IO 31, a VCB 32 as a switching unit, a transformer 33, a UVR 34, a voltage transformer 35, and the like, in addition to the interconnection control device 36. FIG.

The interconnection board 30 includes terminal blocks 101, 102 and breakers 103, 104, 111-115. The terminal block 101 is provided on the electric line (high voltage power line) on the high voltage lead-in side. That is, the terminal block 101 is connected to a power line from the secondary side of the step-down transformer 85 of the power system and a power line from the primary side of the step-down transformer 86 connected to a general load (second load). Here, the general load includes, for example, electrical equipment that is relatively unaffected even if power is interrupted in the event of a disaster.

The terminal block 102 is provided on the electric line (high-voltage power line) on the high-voltage lead side. That is, the terminal block 102 is connected to the power line from the primary side of the step-down transformer 87 connected to the important load (first load). Here, the important load is an important load (important load) that needs to be continuously supplied with power even in the event of a disaster. Air conditioners, etc. are included.

One electrode of the VCB 32 , the UVR 34 and the potential transformer 35 are connected to the terminal block 101 via the disconnector 37 . The voltage transformer 35 will be described later. The VCB 32 is a vacuum circuit breaker in which electrodes are housed in a high-vacuum container, and the material that forms the arc discharge that occurs between the electrodes when the current is interrupted is diffused in the high-vacuum to extinguish the arc. It is a vessel.

The UVR 34 is an undervoltage relay and can detect abnormalities such as short circuits and power outages on the power system side. When the UVR 34 detects an abnormality, it outputs a control signal to the VCB 32 to cut off the electric circuit of the VCB 32 .

A power monitoring unit 80 that monitors power on the primary side of the step-down transformer 85 is provided in a building that uses a grid interconnection system to manage power demand. Note that the power monitoring unit 80 is not necessarily essential. Further, when the step-down transformer 85 is not installed, the locations monitored by the power monitoring unit 80 are appropriately set. Power monitoring unit 80 includes OVGR 81 , RPR/UPR 82 and power sensor 83 . The OVGR 81 is a ground fault overvoltage relay that continuously detects ground faults in the power system. The RPR/UPR 82 is a reverse power relay and underpower relay, and can detect abnormalities such as reverse power flow to the power system side and short-circuit accidents. Also when an abnormality is detected in the OVGR 81 and the RPR/UPR 82, the electrical circuit of the VCB 32 is cut off.

The remote IO 31 is an AD converter that converts the power (analog value) detected by the power sensor 83 into a digital value, and outputs the converted power (digital value) to the interconnection control device 36 .

A transformer 33 (more specifically, a first winding 331) is connected to the other electrode of the VCB 32 via an electric circuit. Transformer 33 has a first winding 331, a second winding 332 connected to breaker 103 via an electric circuit, and a third winding 333 connected to breakers 111-115 via an electric circuit.

That is, the transformer 33 can be a three-phase, three-winding transformer. The voltage and power (apparent power) on the first winding 331 side can be, for example, 6600 V and 50 kVA, and the voltage and power on the second winding 332 side can be, for example, 300 V and 50 kVA, The voltage and power on the side of the third winding 333 can be, for example, 210 V and 50 kVA, but the voltage and power are not limited to these values. By using a three-winding transformer as the transformer 33, space saving and weight reduction can be achieved as compared with the case where two transformers are provided.

A storage battery PCS21 is connected to the breaker 103 . The storage battery PCS21 is capable of bi-directionally converting power from alternating current to direct current and from direct current to alternating current, and is capable of charging and discharging the storage battery 11 .

A circuit of one of the three phases of the third winding 333 is connected to the breaker 104. For example, a voltage of 105 V to 210 V is supplied as a power source for the control device and the cooling device in the power conversion board 20. It is supplied as a power source for the controller, cooling device and heater in the storage battery board 10 .

Power lines from charging/discharging stands 41-45 are connected to the breakers 111-115, respectively. The charging/discharging stands 41-45 are equipped with conversion circuits capable of bi-directionally converting power from alternating current to direct current and from direct current to alternating current, and can charge and discharge the batteries mounted on the electric vehicles 51 to 55. .

The charging/discharging stands 41-45 include notification units (not shown) for notifying information regarding charging/discharging of the batteries of the electric vehicles 51-54. The notification unit may be, for example, a display panel or an indicator lamp, or may notify a terminal device used by a user or an administrator via wireless communication. Information related to charging and discharging includes, for example, operating states such as preparing for charging and discharging, preparation completed, charging and discharging, and charging and discharging completed, battery state of charge (SOC), time required for full charge, and full charge. It can include information such as remaining time until discharge, dischargeable amount, charge for charge/discharge, and the like. Accordingly, it is possible to timely grasp information on charging and discharging of the electric vehicle.

Next, a grid interconnection method by the grid interconnection system 100 of the present embodiment will be described.

FIG. 7 is a schematic diagram showing a first example of grid interconnection by the grid interconnection system 100 of the present embodiment when the power system is normal. The interconnection control device 36 can charge the electric vehicles 51 to 55 using the charging/discharging stands 41 to 45 when the power system is normal and the charging mode is set. As a result, the grid interconnection system 100 can be used as a rapid charging/discharging stand for an electric vehicle.

Also, although not shown, when the power system is normal, power is supplied from the commercial power source to the important load. Also, when the power system is normal, power is supplied from the commercial power source to the general load.

By dividing the load into two systems, a general load and a critical load, the power to be supplied in the event of a disaster, which will be described later, is minimized, and power is continuously supplied to the critical load, and the time during which power can be supplied to the critical load. can be lengthened.

FIG. 8 is a schematic diagram showing a second example of grid interconnection by the grid interconnection system 100 of the present embodiment when the power system is normal. When the power system is normal and the energy management mode (energy management mode) is set, the interconnection control device 36 detects, for example, the power sensor 83 when the power of the power receiving point at a predetermined location is equal to or higher than the threshold. When the power is equal to or higher than the threshold, power is supplied from the charging/discharging stations 41 to 45 to the important loads and general loads, or the power is supplied from the storage battery PCS21 to the important loads and general loads so as to be equal to or lower than the threshold. This enables power peak cut operation. When the power at the receiving point at a predetermined location is equal to or less than the threshold, power can be supplied from the power system to the charging/discharging stations 41 to 45 or the storage battery PCS21 within a range not exceeding the threshold.

FIG. 9 is a schematic diagram showing an example of self-sustained operation in an emergency of the power system by the grid interconnection system 100 of the present embodiment. The interconnection control device 36 opens the electrodes of the VCB 32 to disconnect the commercial power supply from the important load when the power system is in an emergency. By supplying electric power from the charging/discharging stands 41 to 45 or the storage battery PCS21 in this state, the grid connection control device 36 can enable self-sustained operation.

The interconnection control device 36 can supply power to important loads from at least one of the charging/discharging stations 41 to 45 or the storage battery PCS21 when the power system is in an emergency.

When the interconnection control device 36 performs self-sustained operation, the storage battery PCS21 performs voltage control and operates as a voltage source. The current required to obtain the required power is realized by connecting the charging/discharging stands 41 to 45 to the storage battery PCS21 operating as a voltage source and operating as a current source.

With the above-described configuration, even when the charging/discharging stands 41 to 45 cannot supply the required power to the important loads in the event of a disaster because the electric vehicle is in operation, the power can be supplied from the storage battery PCS21 to the important loads. Therefore, the required power can be supplied to the important loads of the power system as a whole.

More specifically, when the power system is in an emergency and the power that can be supplied from the charging/discharging stands 41 to 45 exceeds the capacity of the important load, the interconnection control device 36 removes the storage battery PCS21 from the charging/discharging stands 41 to 45. supply surplus power to As a result, when the electric vehicle is parked in the parking space and is not in operation, the electric power of the electric vehicle can be effectively used.

In addition, when the power system is in an emergency and the power that can be supplied from the charging/discharging stands 41 to 45 is less than the capacity of the important load, the interconnection control device 36 controls both the charging/discharging stands 41 to 45 and the storage battery PCS21. Power the load. For example, if the capacity of the important load is 50 kVA and a total of 30 kVA of power can be supplied from the charging/discharging stands 41 to 45, 20 kVA of power is supplied from the storage battery PCS21, and the high voltage side of the transformer 33 50 kVA of power can be supplied to critical loads. If the capacity of the critical load changes, only power suitable for the capacity of the critical load can be supplied. As a result, when all or part of the required number of electric vehicles are not parked in the parking space and are in operation, the shortage of power can be supplied from the storage battery PCS21, and the important load of the power system can be supplied. It can supply the required power.

FIG. 10 is a schematic diagram showing an example of operation switching when the power system is restored from an emergency to a normal state by the grid interconnection system 100 of the present embodiment. When the power system recovers, the interconnection control device 36 switches the power supplied from at least one of the charging/discharging stations 41 to 45 or the storage battery PCS21 to the commercial power source without interruption. The uninterrupted switching, for example, detects the phase of the commercial power supply by the voltage transformer 35, and closes the electrodes of the VCB 32 at the timing when the phase of the storage battery PCS21 is synchronized with the phase of the commercial power supply, thereby switching the power from the commercial power supply. Supply critical loads.

After the commercial power supply is reconnected to the important load without interruption, the interconnection control device 36 stops the operation of the charging/discharging stands 41 to 45 and the storage battery PCS21, and terminates the self-sustained operation. Since the storage battery PCS21 performs voltage control, uninterrupted switching is possible. After that, the interconnection control device 36 can restart the charging/discharging stands 41 to 45 and the storage battery PCS 21 for system interconnection. As a result, by synchronizing the phases and switching without interruption, stable power can be supplied to the important load.

In the above-described embodiment, the power system is interconnected at a high voltage of 6600 V, but the present invention is not limited to this, and may be interconnected at a low voltage. If the voltage is low, it must be less than 50 kVA, so the voltage and power (apparent power) on the first winding 331 side of the transformer 33 can be, for example, 210 V and 49 kVA, and the second winding The voltage and power (apparent power) on the 332 side can be, for example, 300 V and 49 kVA, and the voltage and power (apparent power) on the third winding 333 side can be, for example, 210 V and 49 kVA. Also, the transformer is not limited to a three-winding transformer, and may be configured to include two two-winding transformers.

The grid interconnection system of the present embodiment is a grid interconnection system with a power system having a commercial power supply, and includes a storage battery installed in a parking lot, an AC/DC power converter for the storage battery, and a charge/discharge for an electric vehicle. A stand and an interconnection control device are provided, and the interconnection control device supplies power to a first load from at least one of the charging/discharging stand and the AC/DC power converter when the power system is in an emergency.

A system interconnection method according to the present embodiment is a method for system interconnection with an electric power system, and includes a storage battery installed in a parking lot, an AC/DC power converter for the storage battery, a charging/discharging stand for an electric A system control device is provided, and power is supplied to a first load from at least one of the charging/discharging station and the AC/DC power converter in the event of an emergency in the power system.

The grid interconnection system includes a storage battery installed in a parking lot, an AC/DC power converter for the storage battery, a charge/discharge stand for electric vehicles, and a grid connection control device. An AC/DC power converter can convert power in both directions, from AC to DC and from DC to AC, and can charge and discharge a storage battery (also referred to as a stationary storage battery). The charge/discharge stand can charge and discharge a battery (vehicle storage battery) mounted on an electric vehicle (PHEV or EV). When the power system is normal, the interconnection control device performs grid-interconnected operation between the power system, the AC/DC power converter, and the charging/discharging station. Self-sustained operation by discharge stand.

That is, the grid interconnection system supplies power from the commercial power source to the first load when the power grid is normal. Also, power can be supplied to the first load from a charging/discharging stand or an AC/DC power converter. The interconnection control device supplies power to the first load from at least one of the charging/discharging station and the AC/DC power converter in an emergency in the power system. The first load is an important load (important load) that needs to be continuously supplied with power even in the event of a disaster. and so on.

With the above-described configuration, even if the required power cannot be supplied from the charging/discharging station to the first load due to the operation of the electric vehicle in the event of a disaster, power is supplied from the AC/DC power converter to the first load. Therefore, the required power can be supplied to the load as a whole.

The grid interconnection system of the present embodiment includes an opening/closing unit for opening and closing an electric circuit between the commercial power supply and the first load, and when the power system is in an emergency, the opening/closing unit is opened to switch the commercial power supply and the first load. disconnect from the first load;

The grid interconnection system includes an opening/closing unit that opens/closes an electric circuit between the commercial power supply and the first load. The switching part can be, for example, a vacuum circuit breaker (VCB), the electrodes of the switching part are housed in a high-vacuum container, and the material that constitutes the arc discharge that occurs between the electrodes when the current is interrupted. A circuit breaker that extinguishes an arc by diffusing it in a high vacuum.

The grid interconnection system opens the electrode of the switching unit to disconnect the commercial power supply and the first load in the event of an emergency in the power system. Thereby, it is possible to enable self-sustained operation by the interconnection control device.

The grid interconnection system of the present embodiment supplies power from the commercial power supply to the first load and a second load different from the first load when the power system is normal.

The grid interconnection system supplies power from a commercial power supply to a first load and a second load different from the first load when the power system is normal. While the first load is a critical load, the second load is a general load and includes electrical equipment that is relatively unaffected even if power is interrupted in the event of a disaster. By dividing the load into two systems, the first load and the second load, the power to be supplied in the event of a disaster is minimized, the power is continuously supplied to the important loads, and the time during which the power can be supplied is extended. can be done.

The grid interconnection system of the present embodiment includes a first winding connected to the commercial power supply side, a second winding connected to the AC/DC power converter side, and a charging/discharging stand side. an interconnection board having a three-winding transformer with a third winding;

The interconnection board has three windings, including a first winding connected to the commercial power supply side, a second winding connected to the AC/DC power converter side, and a third winding connected to the charging/discharging stand side. It has a line transformer. The first winding is a high-voltage side winding, and for example, a voltage of 6600V is applied or output, but the voltage is not limited to 6600V. The second winding is a winding on the low voltage side, and for example, a voltage of 300V is applied or output, but the voltage is not limited to 300V. The third winding is a winding on the low voltage side, and for example, a voltage of 210V is applied or output, but the voltage is not limited to 210V. By providing the 3-winding transformer, it is possible to save space and reduce the weight as compared with the case where two transformers are provided.

In the grid interconnection system of the present embodiment, the interconnection control device controls the charge/discharge when the power that can be supplied from the charge/discharge stand exceeds the capacity of the first load in the event of an emergency in the power system. Surplus power is supplied from the stand to the AC/DC power converter.

The interconnection control device supplies surplus power from the charging/discharging stand to the AC/DC power converter when the power that can be supplied from the charging/discharging stand exceeds the capacity of the first load in the event of an emergency in the power system. As a result, when the electric vehicle is parked in the parking space and is not in operation, the electric power of the electric vehicle can be effectively used.

In the grid interconnection system of the present embodiment, the interconnection control device controls the charge/discharge when the power that can be supplied from the charge/discharge stand is less than the capacity of the first load in the event of an emergency in the power system. Power is supplied to the first load from both the stand and the AC/DC power converter.

The interconnection control device supplies power to the first load from both the charging/discharging stand and the AC/DC power converter when the power that can be supplied from the charging/discharging stand is less than the capacity of the first load in the event of an emergency in the power system. do. As a result, when all or part of the required number of electric vehicles are not parked in the parking space and are in operation, the power required for the shortage can be supplied from the AC/DC power converter, and the required power is supplied to the load. Power can be supplied.

The grid interconnection system of the present embodiment includes a notification unit that notifies information about charging/discharging of the battery of the electric vehicle by the charging/discharging stand.

The notification unit notifies information about charging/discharging of the battery of the electric vehicle by the charging/discharging stand. The notification unit may be provided in, for example, a charging/discharging stand, may be a display panel or indicator lamp, or may notify a terminal device used by a user or an administrator via wireless communication. Accordingly, it is possible to timely grasp information on charging and discharging of the electric vehicle.

In the grid interconnection system of the present embodiment, the grid interconnection control device charges the electric vehicle from the charging/discharging stand when the power grid is normal and the charging mode is set.

The interconnection control device charges the electric vehicle with the charging/discharging station when the power system is normal and the charging mode is set. As a result, it can be used as a rapid charging/discharging stand for an electric vehicle.

In the grid interconnection system of the present embodiment, when the power system is normal and the energy management mode is set, the power receiving point power at a predetermined location is equal to or higher than the threshold, the Power is supplied from the charging/discharging station to the first load and the second load, or power is supplied from the AC/DC power converter to the first load and the second load.

When the power system is normal and the energy management mode is set, the grid connection control device supplies power from the charge/discharge station to the first load and the second load when the power at the receiving point at a predetermined location is equal to or higher than the threshold. Alternatively, power is supplied from the AC/DC power converter to the first load and the second load. This enables power peak cut operation.

In the grid interconnection system of the present embodiment, when the power system is restored, the interconnection control device reduces the power supplied from at least one of the charging/discharging station or the AC/DC power converter to the first load. , to switch to power from the commercial power source without interruption.

When the power system recovers, the interconnection control device switches the power supplied from at least one of the charging/discharging stand or the AC/DC power converter to the first load without interruption to the power from the commercial power supply. For example, when the phase of the AC output by the AC/DC power converter is synchronized with the phase of the commercial power supply, turning on the commercial power supply allows the first load to recover from the disaster. stable power supply.

The grid interconnection system of this embodiment is used for business continuity planning.

This makes it possible to provide the grid interconnection system as equipment for business continuity planning (BCP).

At least part of the above-described embodiments can be combined arbitrarily.

REFERENCE SIGNS LIST 1 foundation 10 storage battery board 11 storage battery 20 power conversion board 21 storage battery PCS
30 interconnection board 32 VCB
33 transformer 36 interconnection control device 41, 42, 43, 44, 45 charge/discharge stand 51, 52, 53, 54, 55 electric vehicle 90 decorative wall 91, 92, 93 doorway 94, 95 opening 101, 102 terminal block 125 , 215 intake/exhaust port 311, 312 opening/closing door

Claims (12)

A system interconnection system with a power system having a commercial power supply,
A storage battery installed in a parking lot, an AC/DC power converter for the storage battery, a charging/discharging stand for an electric vehicle, a transformer, and an interconnection control device,
The AC/DC power converter and the charge/discharge stand are connectable to a first load connected to a power line on the secondary side of a step-down transformer of a power system via the transformer,
The interconnection control device is
A system interconnection system that supplies power to the first load from at least one of the charging/discharging station and the AC/DC power converter in an emergency of the power system. comprising an opening and closing unit for opening and closing an electric circuit between the commercial power supply and the first load;
2. The system interconnection system according to claim 1, wherein, in the event of an emergency in the power system, the switch is opened to disconnect the commercial power supply from the first load. 3. The grid interconnection system according to claim 1, wherein, when said power system is normal, power is supplied from said commercial power supply to said first load and to a second load different from said first load. Three windings having a first winding connected to the commercial power supply side, a second winding connected to the AC/DC power converter side, and a third winding connected to the charging /discharging stand side The system interconnection system according to any one of claims 1 to 3, comprising an interconnection board having the transformer. The interconnection control device is
When the power system is in an emergency and the power that can be supplied from the charging/discharging station exceeds the capacity of the first load, surplus power is supplied from the charging/discharging stand to the AC/DC power converter. Item 5. The grid interconnection system according to any one of items 4. The interconnection control device is
When the power system is in an emergency and the power that can be supplied from the charging/discharging stand is less than the capacity of the first load, power is supplied from both the charging/discharging stand and the AC/DC power converter to the first load. The interconnection system according to any one of claims 1 to 5. The grid interconnection system according to any one of claims 1 to 6, further comprising a notification unit that notifies information about charging/discharging of a battery of an electric vehicle by the charging/discharging stand. The interconnection control device is
The grid interconnection system according to any one of claims 1 to 7, wherein the electric vehicle is charged by the charge/discharge stand when the power system is normal and the charging mode is set. The interconnection control device is
When the power system is normal and the energy management mode is set, and the power receiving point power at a predetermined location is equal to or higher than a threshold, power is supplied from the charging/discharging stand to the first load and the second load, Alternatively, the grid interconnection system according to any one of claims 1 to 7, wherein power is supplied from the AC/DC power converter to the first load and the second load. The interconnection control device is
When the power system recovers, the power supplied from at least one of the charging/discharging station or the AC/DC power converter to the first load is switched to power from the commercial power source without interruption. Item 10. The grid interconnection system according to any one of items 9. The grid interconnection system according to any one of claims 1 to 10, which is used for business continuity planning. A system interconnection method with a power system,
A storage battery installed in a parking lot, an AC/DC power converter for the storage battery, a charging/discharging stand for an electric vehicle, a transformer, and an interconnection control device,
making it possible to connect the AC/DC power converter and the charge/discharge stand to a first load connected to a power line on the secondary side of a step-down transformer of a power system via the transformer;
A system interconnection method for supplying power to the first load from at least one of the charging/discharging stand and the AC/DC power converter in an emergency of the power system.

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