Electric power system, charging station and vehicle-mounted charger

Abstract

This power system is provided with: a charging station which is electrically connected to a power network and which has a master station that transmits an accurate setting value; and an on-board charger connectable with the power network and having a sub-station that receives the correct setting value from the main station. As a result, provided are a power system, a charging station, and an on-board charger which are capable of ensuring integration of setting values even when the on-board charger is connected to a charging station having a different setting value.

Description

Technical Field

[0001] The present disclosure relates to a power system, a charging station and a vehicle charger. Background Art

[0002] Due to the introduction of renewable energy, the amount of power generation sometimes fluctuates due to weather conditions, leading to instability in the power grid. Therefore, the scheme of using the on-board charger mounted on the vehicle as a distributed power source and operating it as part of a virtual power plant (VPP) is attracting attention. Among the VPP methods, the V2G (Vehicle to Grid) method performs bidirectional control of charging from the power grid to the on-board charger and power supply from the on-board charger to the power grid.

[0003] When a distributed power source is connected to a power grid, in the event of over- or undervoltage, over- or underfrequency, or power grid failure, the distributed power source needs to be disconnected from the power grid to stop supplying power to the grid. The voltage and frequency thresholds used to determine when the supply is stopped, the time until disconnection, etc. are called setting values, and the setting values ​​vary depending on the power company and region. Distributed power sources connected to a power grid are required to set the correct setting values ​​required by the power company and operate according to the setting values ​​for the stability and safety of the power grid. There are multiple candidate values ​​for each item of the setting value set for the distributed power source, and the value indicated by the power company is set from these candidate values. Fig.10 This is a diagram showing an example of setting value items and candidate values. Fig.10 This is just an example and is not a requirement.

[0004] Patent document 1 discloses the following technology: in order to smoothly set and manage the setting value of the distributed power source, the setting value and disconnection instruction are sent to the protection relay of the power conditioner of the distributed power source connected to the power network. In patent document 1, the distributed power source is a private power source such as solar power generation and wind power generation, the power conditioner is a DCAC converter that converts the direct current generated by the distributed power source into alternating current, and the protection relay is a relay for disconnecting the distributed power source from the network. In addition, the distributed power source and the power conditioner are installed in the customer's home. Prior Art Literature Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-182904 Summary of the invention Problems to be solved by the invention

[0006] However, in V2G, the onboard charger may be connected to a V2G charging station with a different set value due to vehicle movement. As a result, the set value of the V2G charging station may differ from the set value set in the onboard charger, and consistency of the set value may not be ensured.

[0007] The present disclosure has been achieved in view of the above-mentioned contents, and an object thereof is to provide a power system, a charging station, and a vehicle charger that can ensure the integrity of the set values ​​even when the vehicle charger is connected to a charging station with a different set value. Means for solving problems

[0008] The power system involved in the present disclosure includes: a charging station electrically connected to a power network and having a main station for sending a correct set value; and an on-board charger capable of being connected to the power network and having a sub-station for receiving the correct set value from the main station.

[0009] The charging station involved in the present disclosure includes a main station, which is electrically connected to a power network and sends a correct setting value to a sub-station of a vehicle charger that can be connected to the power network.

[0010] The on-vehicle charger according to the present disclosure includes a sub-station that can be connected to an electric power network and receives a correct setting value from a main station included in a charging station electrically connected to the electric power network. Effects of the Invention

[0011] According to the present disclosure, it is possible to realize an electric power system, a charging station, and an on-board charger that can ensure the integrity of the set value even when the on-board charger is connected to a charging station with a different set value. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic configuration diagram showing an electric power system according to the first embodiment. Figure 2 This is a schematic diagram of the structure of a V2G charging station according to the first embodiment. Figure 3 This is a schematic configuration diagram of the vehicle charger according to the first embodiment. Figure 4 This is a flowchart showing an example of processing executed by the V2G charging station according to the first embodiment. Figure 5 This is a flowchart showing an example of processing executed by the vehicle charger according to the first embodiment. Figure 6 This is a diagram showing a state where the disconnecting relay performs disconnection. Figure 7 This is a schematic configuration diagram of an electric power system according to the third embodiment. Figure 8 This is a flowchart showing an example of processing executed by the vehicle charger according to the third embodiment. Fig. 9 This is a schematic configuration diagram of an electric power system according to Modification 1. Fig.10 This is a diagram showing an example of setting value items and candidate values. DETAILED DESCRIPTION

[0013] The power system, charging station and on-board charger according to the embodiments of the present disclosure are described with reference to the drawings. In addition, the components in the following embodiments include components that can be easily replaced by those skilled in the art, or components that are substantially the same.

[0014] [Implementation method 1] (Power System) Figure 1 1 is a schematic diagram of the configuration of an electric power system according to Embodiment 1. The electric power system 1 includes a V2G charging station 3 electrically connected to an electric power network 2 and an on-vehicle charger 4 connectable to the electric power network 2 .

[0015] (V2G Charging Station) Figure 2 : is a schematic diagram of the V2G charging station involved in Embodiment 1. The V2G charging station 3 includes a main station 31, a storage unit 32, a paralleling relay 33, a V2H relay 34, a metering unit 35, a network connection unit 36, a vehicle connection unit 37, a home load connection unit 38, and a sub-station connection unit 39. The V2G charging station 3 is connected to the power network 2 of a single-phase three-wire, for example, but may also be connected to the power network 2 of a three-phase three-wire.

[0016] The master site 31 sends the correct set value to the sub-site 41. In addition, the master site 31 obtains the set set value set by the on-board charger 4 from the sub-site 41, and when the correct set value and the set set value are equal, sends a permission signal to the sub-site 41 to grant permission to connect to the power network 2.

[0017] The storage unit 32 is implemented by a storage medium such as an EPROM (Erasable Programmable ROM), a hard disk drive (HDD), or a removable medium. Examples of the removable medium include a USB (Universal Serial Bus) memory, a CD (Compact Disc), a DVD (Digital Versatile Disc), and a BD (Blu-ray (registered trademark) Disc).

[0018] The storage unit 32 can store an operating system (OS), various programs, various tables, various databases, etc. The storage unit 32 stores different correct setting values ​​for each power company and region.

[0019] The disconnect relay 33 disconnects the electrical connection between the on-board charger 4 and the power network 2 .

[0020] When power is not supplied from power grid 2 to the home during a power outage, V2H relay 34 discharges power from onboard charger 4 to the home via V2G charging station 3 installed in the home. As a result, power stored in battery 45 of onboard charger 4 can be supplied to the loads in the home.

[0021] The metering unit 35 can measure the power supplied from the power grid 2 to the onboard charger 4, and charge the electricity fee according to the measured power. In addition, the metering unit 35 can measure the power supplied from the onboard charger 4 to the power grid 2, and pay the user according to the measured power. The metering unit 35 can also be provided in the onboard charger 4.

[0022] The network connection unit 36 ​​is electrically connected to the single-phase three-wire power network 2 .

[0023] The vehicle connection unit 37 is electrically connected to the vehicle charger 4 .

[0024] The household load connection unit 38 is electrically connected to the household load.

[0025] The sub-site connection unit 39 can communicate with the sub-site 41 by wire or wirelessly, and can send and receive various signals.

[0026] (Car Charger) Figure 3: This is a schematic diagram of the on-board charger according to Embodiment 1. The on-board charger 4 includes a sub-station 41, a control unit 42, a DCAC converter 43, an insulated DCDC converter 44, a battery 45, a V2G charging station connection unit 46, and a main station connection unit 47. In addition, the on-board charger 4 may also include an AC filter for removing noise, a metering unit for measuring power, or a disconnect relay for disconnecting the electrical connection between the on-board charger 4 and the power grid 2 in the subsequent stage of the DCAC converter 43 as viewed from the battery 45 side.

[0027] The slave station 41 receives the correct set value from the master station 31. When the slave station 41 detects an abnormality based on the correct set value, it transmits an abnormality signal to the master station 31.

[0028] The control unit 42 controls each unit of the vehicle charger 4. The control unit 42 sends a gate signal to a switching element of the DCAC converter 43 and the isolated DCDC converter 44 to control the operation of the DCAC converter 43 and the isolated DCDC converter 44.

[0029] The DCAC converter 43 converts alternating current and direct current of a frequency corresponding to the power grid 2. The DCAC converter 43 has a configuration capable of bidirectional power conversion by using upper and lower arms as switching elements.

[0030] The isolated DCDC converter 44 converts a DC voltage. The isolated DCDC converter 44 is a dual active bridge (DAB) circuit, and is configured to be capable of bidirectional power conversion. In addition, the isolated DCDC converter 44 disconnects the electrical connection between the battery 45 and the V2G charging station 3 .

[0031] The battery 45 stores or discharges electricity under the control of the control unit 42 .

[0032] The V2G charging station connection portion 46 is electrically connected to the V2G charging station 3 .

[0033] The master station connection unit 47 can communicate with the master station 31 by wire or wirelessly, and can send and receive various signals.

[0034] (Processing performed by V2G charging station) Next, refer to Figure 4 An example of a processing procedure executed by the V2G charging station according to the first embodiment will be described. Figure 4 This is a flowchart showing an example of processing executed by the V2G charging station according to the first embodiment.

[0035] like Figure 4 As shown, the master site 31 acquires accurate setting values ​​that differ for each power company and region from the storage unit 32 (step S1 ).

[0036] Next, the master station 31 obtains the set setting value set by the vehicle charger 4 from the slave station 41 (step S2 ).

[0037] Then, the master station 31 determines whether the correct set value and the set set value are equal (step S3).

[0038] When the master station 31 determines that the correct set value and the set set value are different (step S3: No), the master station 31 sends the correct set value to the slave station 41 (step S4). Then, the process returns to step S1 and repeats the process until the correct set value and the set set value are determined to be equal.

[0039] On the other hand, when the master site 31 determines that the correct set value is equal to the set set value (step S3: Yes), the master site 31 sends a permission signal to the slave site 41 to grant permission to connect to the power grid 2 (step S5), and ends a series of processing.

[0040] Through the above actions, the V2G charging station 3 sets the correct setting value for the substation 41 of the on-board charger 4 .

[0041] (Processing performed by the on-board charger) Next, refer to Figure 5 An example of a processing procedure executed by the vehicle charger according to the first embodiment will be described. Figure 5 This is a flowchart showing an example of processing executed by the vehicle charger according to the first embodiment.

[0042] like Figure 5 As shown, the sub-site 41 determines whether a permission signal giving permission to connect to the electric power network 2 is received from the master site 31 (step S11 ).

[0043] When the slave station 41 determines that the permission signal has not been received (step S11 : No), the slave station 41 determines whether a correct setting value has been received from the master station 31 (step S12 ).

[0044] When the slave station 41 determines that a correct set value has been received from the master station 31 (step S12 : Yes), the slave station 41 sets the received correct set value as the set set value of the vehicle charger 4 (step S13 ).

[0045] In step S11 , when the slave station 41 determines that the permission signal has been received (step S11 : Yes), the vehicle charger 4 starts connecting to the power network 2 (step S14 ), charges or discharges the battery 45 , and then ends a series of processes.

[0046] In step S12 , when the slave station 41 determines that the correct setting value has not been received from the master station 31 (step S12 : No), a series of processing ends.

[0047] The above process allows the correct setting value to be set in the onboard charger 4. Furthermore, since connection to the power grid 2 is started only when a permission signal is received from the master station 31, that is, when the onboard charger 4 has set the correct setting value, safety can be ensured.

[0048] According to the first embodiment described above, even when the onboard charger 4 is connected to the V2G charging station 3 with different set values, the consistency of the set values ​​can be ensured. In addition, since the V2G charging station 3 does not have a DCAC converter, the V2G charging station 3 can be miniaturized.

[0049] (Function of the de-energizing relay) Figure 6 3 is a diagram showing the state of disconnection by the disconnection relay. When the sub-site 41 detects an abnormality based on the correct setting value, it sends an abnormality signal to the main site 31. Then, when the main site 31 receives the abnormality signal from the sub-site 41, it disconnects the electrical connection between the vehicle charger 4 and the power grid 2 through the disconnection relay 33. By disconnecting by the disconnection relay 33 of the V2G charging station 3, it is possible to prevent the power grid 2 and the vehicle charger 4 from being connected in a state where the integrity of the setting value is not achieved.

[0050] In addition, the master site 31 or the sub-site 41 may also disconnect the electrical connection between the on-board charger 4 and the power grid 2 through the disconnect relay 33 when the communication between the V2G charging station 3 and the on-board charger 4 is not established for more than a predetermined time. As a result, the safety when the communication between the V2G charging station 3 and the on-board charger 4 is not established can be improved.

[0051] [Implementation method 2] The power system involved in the second embodiment can have the same configuration as that of the first embodiment, so the description is omitted. In the second embodiment, the master site 31 obtains the voltage or frequency from the sub-site 41. Then, when the master site 31 detects an abnormality in the obtained voltage or frequency based on the correct setting value, the electrical connection between the vehicle charger 4 and the power network 2 is cut off by the disconnection relay 33. In this way, it is also possible to determine whether to disconnect the electrical connection between the vehicle charger 4 and the power network 2 by the disconnection relay 33 on the V2G charging station 3 side.

[0052] [Implementation method 3] Figure 71 is a schematic diagram of the configuration of an electric power system according to Embodiment 3. The onboard charger 4A of the electric power system 1A includes a parallel-off relay 48A. On the other hand, the V2G charging station 3A does not include a parallel-off relay.

[0053] (Processing performed by the on-board charger) Next, refer to Figure 8 An example of a processing procedure executed by the vehicle charger according to the third embodiment will be described. Figure 8 This is a flowchart showing an example of processing executed by the vehicle charger according to the third embodiment.

[0054] like Figure 8 As shown, the sub-site 41A obtains accurate setting values ​​that differ for each power company and region from the master site 31 (step S21 ).

[0055] Furthermore, the slave station 41A acquires the set setting value set by the vehicle charger 4 from the control unit 42 (step S22 ).

[0056] Then, the substation 41A determines whether the correct set value and the set set value are equal (step S23).

[0057] When the sub-station 41A determines that the correct set value and the set set value are different (step S23: No), the sub-station 41A sets the received correct set value as the set set value of the vehicle charger 4A (step S24). Then, the process returns to step S22 and repeats the process until the correct set value and the set set value are determined to be equal.

[0058] On the other hand, when the subsite 41A determines that the correct setting value is equal to the set setting value (step S23: Yes), the vehicle charger 4A starts to connect to the power network 2 (step S25), charges or discharges the battery 45, and then ends a series of processing.

[0059] According to the third embodiment described above, even when the onboard charger 4A is connected to the V2G charging station 3A with different setting values, the consistency of the setting values ​​can be ensured. In addition, since the V2G charging station 3A is configured without a DCAC converter, the V2G charging station 3A can be miniaturized.

[0060] (Function of the de-energizing relay) When the substation 41A detects an abnormality based on the correct set value, the disconnect relay 48A disconnects the electrical connection between the vehicle charger 4A and the power grid 2. By disconnecting the vehicle charger 4A through the disconnect relay 48A, it is possible to prevent the power grid 2 and the vehicle charger 4A from being connected in a state where the integrity of the set value is not achieved. In this way, the vehicle charger 4A may be provided with the disconnect relay 48A, and the vehicle charger 4A side may determine whether to disconnect the electrical connection between the vehicle charger 4A and the power grid 2 through the disconnect relay 48A.

[0061] In addition, it is also possible to determine whether to disconnect the electrical connection between the vehicle charger 4A and the power network 2 by the disconnection relay 48A on the V2G charging station 3A side. Specifically, the main site 31 obtains voltage or frequency from the sub-site 41A. Then, when the main site 31 determines that the acquired voltage or frequency is abnormal based on the correct setting value, it sends an abnormal signal to the sub-site 41A. Then, when the sub-site 41A receives the abnormal signal from the main site 31, it disconnects the electrical connection between the vehicle charger 4A and the power network 2 by the disconnection relay 33.

[0062] In addition, the master site 31 or the sub-site 41 may also disconnect the electrical connection between the on-board charger 4A and the power grid 2 by means of the disconnect relay 48A when the communication between the V2G charging station 3A and the on-board charger 4A is not established for a predetermined time or longer. As a result, the safety can be improved when the communication between the V2G charging station 3A and the on-board charger 4A is not established.

[0063] (Variant 1) Fig. 9 : is a schematic diagram of the power system involved in Modification Example 1. Fig. 9 As shown, a plurality of on-board chargers 4 are connected to the V2G charging station 3 of the electric power system 1B. In this case, the V2G charging station 3 communicates with each on-board charger 4 to set the correct setting value. As a result, the correct setting value can be set for all on-board chargers 4.

[0064] Those skilled in the art can easily derive more effects and variations. Thus, more aspects of the present invention are not limited by the specific details and representative embodiments described and recorded above. Therefore, various changes can be made without departing from the spirit or scope of the general concept of the invention defined by the attached claims and their equivalents. Description of the label

[0065] 1.1A, 1B: Power system 2: Power network 3.3A: V2G charging station 4. 4A: Car charger 31: Main site 32: Storage 33, 48A: De-energizing relay 34: V2H relay 35: Metrology Department 36: Network connection department 37: Vehicle connection 38: Home load connection 39: Subsite connection 41, 41A: Subsite 42: Control Department 43: DCAC converter 44: Insulated DCDC Converter 45: Battery 46: V2G charging station connection 47: Main site connection unit.

Claims

1. A power system comprising: A charging station, electrically connected to the electricity network and having a master station that sends the correct setpoints; and An on-board charger is connectable to the power network and has a sub-station for receiving the correct setting value from the main station.

2. The power system according to claim 1, wherein: The main site obtains the set value set by the vehicle charger from the sub-site, In the case where the correct set value and the set set value are equal, a permission signal for granting permission to connect to the power network is sent to the substation.

3. The power system according to claim 1, wherein: The charging station or the on-board charger is provided with a disconnect relay that disconnects the electrical connection between the on-board charger and the power network.

4. The power system according to claim 3, wherein: If the charging station and the on-vehicle charger fail to establish communication for more than a predetermined period of time, The main site or the sub-site cuts off the electrical connection between the on-board charger and the power network through the disconnect relay.

5. The power system according to claim 3, wherein: The master station has the de-load relay, When the sub-station detects an abnormality based on the correct setting value, the sub-station sends an abnormality signal to the main station. When receiving the abnormal signal, the master site cuts off the electrical connection between the on-board charger and the power network through the disconnect relay.

6. The power system according to claim 3, wherein: The master station has the de-load relay, When the master station detects an abnormality based on the correct set value, the master station cuts off the electrical connection between the on-board charger and the power network through the disconnect relay.

7. The power system according to claim 3, wherein: The sub-station has the de-load relay, When the substation detects an abnormality based on the correct set value, the substation cuts off the electrical connection between the on-board charger and the power network through the disconnect relay.

8. The power system according to claim 1, wherein: The charging station includes a storage unit for storing the correct setting value.

9. The power system according to claim 1, wherein: The on-vehicle charger includes a DCAC converter for converting alternating current into direct current.

10. A charging station having a main station, The master site is electrically connected to the power network and sends correct setting values ​​to the sub-sites of the on-board chargers that can be connected to the power network.

11. The charging station according to claim 10, comprising a storage unit for storing the correct setting value.

12. A vehicle charger having a sub-station, The sub-station is connectable to the power network and receives correct setting values ​​from a main station provided by a charging station electrically connected to the power network. 13 . The vehicle-mounted charger according to claim 12 , comprising a DCAC converter for converting alternating current into direct current.

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