Power supply system

Abstract

To automatically switch between power supply from system power to a specific load and power supply from an electric motor vehicle, and to simplify a device.SOLUTION: In a power supply system including a system breaker connected to system power, a specific breaker attached between the system breaker and a specific load, and a power supply device connected to a battery mounted on an electric motor vehicle, a system-side switch is attached between the system breaker and the specific load, and a vehicle-side switch is attached between the power supply device and the specific load. Then, on the basis of the power information, switching control of the system-side switch and the vehicle-side switch is performed so that power supply from the system power to the specific load is stopped and power supply from the power supply device to the specific load is performed, or power supply from the power supply device to the specific load is stopped and power supply from the system power to the specific load is performed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a power supply system, and more particularly to a power supply system connected to a grid power supply and a power supply device connected to a battery mounted on an electric vehicle. [Background technology]

[0002] A conventional power supply system of this type includes a power conditioner and a charging / discharging device that charges and discharges the drive battery of an electric vehicle (see, for example, Patent Document 1). In this system, if communication with the power conditioner is normal, the charging / discharging device sends a notification to the power conditioner that it has received a startup command and continues to operate in accordance with the operation command. If the power conditioner is not energized, the charging / discharging device supplies power discharged from the drive battery to the power conditioner regardless of the operation command. This makes it possible to utilize the power stored in the electric vehicle during a power outage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-071721 Summary of the Invention [Problem to be solved by the invention]

[0004] In a power supply system capable of supplying power from the battery of an electric vehicle to a load, it is generally necessary to switch between the power supply from the grid to a specific load and the power supply from the electric vehicle, which requires switches and leakage prevention measures, making the equipment configuration complex.

[0005] The main object of the power supply system of the present disclosure is to automatically switch between the power supply from the grid power and the power supply from the electric vehicle to a specific load, and to simplify the device. [Means for solving the problem]

[0006] The power supply system of the present disclosure employs the following measures to achieve the above-mentioned main object.

[0007] The power supply system of the present disclosure is a power supply system including a system breaker connected to a system power grid, a specific breaker installed between the system breaker and a specific load, and a power supply device connected to a battery mounted on an electric vehicle, and is characterized by including a system-side switch installed between the system breaker and the specific load, a vehicle-side switch installed between the power supply device and the specific load, and a control device that switches and controls the system-side switch and the vehicle-side switch based on power information so as to stop the power supply from the system power to the specific load and supply power from the power supply device to the specific load, or to stop the power supply from the power supply device to the specific load and supply power from the system power to the specific load.

[0008] The power supply system disclosed herein includes a grid breaker connected to a grid power system, a specific breaker installed between the grid breaker and a specific load, and a power supply device connected to a battery mounted on an electric vehicle. A grid-side switch is installed between the grid breaker and the specific load, and a vehicle-side switch is installed between the power supply device and the specific load. A control device controls switching between the grid-side switch and the vehicle-side switch based on power information, such that the system stops supplying power from the grid power to the specific load and supplies power from the power supply device to the specific load, or stops supplying power from the power supply device to the specific load and supplies power from the grid power to the specific load. This allows automatic switching between power supply from the grid power to the specific load and power supply from the electric vehicle, while simplifying the system. Here, the grid breaker corresponds to a ground fault circuit interrupter or an overcurrent circuit interrupter. The specific breaker corresponds to an overcurrent circuit interrupter connected to the specific load. The specific load corresponds to a general 100V load.

[0009] In the power supply system of the present disclosure, the grid-side switch may be installed between the grid breaker and the specific breaker, and the vehicle-side switch may be installed on a power line connected from the power supply device between the grid-side switch and the specific breaker. Alternatively, the grid-side switch may be installed between the specific breaker and a specific load, and the vehicle-side switch may be installed on a power line connected from the power supply device between the grid-side switch and the specific load.

[0010] In the power supply system of the present disclosure, when the electricity rate of the grid power is equal to or higher than the average daily rate, the grid-side switch and the vehicle-side switch may be switched to stop the supply of power from the grid power to the specific load and supply power from the power supply device to the specific load, and when the electricity rate of the grid power is less than the average daily rate, the grid-side switch and the vehicle-side switch may be switched to charge a battery mounted on the electric vehicle via the power supply device and supply power from the grid power to the specific load. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing an outline of the configuration of a power supply system 20 according to an embodiment of the present disclosure. [Figure 2] 6 is a flowchart showing an example of a process executed by the energy management device 50 when an electric vehicle is connected. [Figure 3] FIG. 10 is a diagram showing an outline of the configuration of a power supply system 20B according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Next, a mode (embodiment) for carrying out the present disclosure will be described. Fig. 1 is a configuration diagram showing an outline of the configuration of a power supply system 20 according to one embodiment of the present disclosure. The power supply system 20 of the embodiment is configured as a system connected to, for example, a grid power 12 and an electric vehicle 10, and supplies power from the grid power 12 and the electric vehicle 10 to loads 62, 64a to 64n in each room of an ordinary home and a specific load 65. The power supply system 20 includes a breaker 22 connected to the grid power 12, a room-by-room breaker device 24 of a high-voltage system (200V system), a room-by-room breaker device 34 of a low-voltage system (100V system), a vehicle external power supply device 40 connected to a battery (not shown) mounted on the electric vehicle 10, and an energy management device (hereinafter referred to as "energy management device") 50.

[0013] The breaker 22 is configured as a leakage current breaker and an overcurrent breaker, and distributes three-phase AC power from the system power 12 to each room breaker device 24 of the high voltage system (200V system) and each room breaker device 34 of the low voltage system (100V system).

[0014] The high-voltage (200V) individual room breaker device 24 distributes the supply power to each room, and has a plurality of overcurrent breakers (not shown) for each room, and supplies power to the loads 62 in each room.

[0015] The low-voltage (100V) room breaker device 34 distributes the supply power to each room and has multiple overcurrent breakers 36a-36n, 37 for each room. The specific load 65 is a general load like the room loads 64a-64n, but is named differently from the room loads 64a-64n because it is a load that can switch between power supply from the grid power 12 and power supply from the electric vehicle 10. The room breaker device 34 has a breaker-side switch 38 between the breaker 22 of the power system of the specific load 65 and the overcurrent breaker 37. The breaker-side switch 38 is configured as an electromagnetic switch or a semiconductor switch.

[0016] The vehicle-external power supply device 40 is configured as a power conversion device having an inverter and a DC / DC converter that converts DC power from a battery (not shown) mounted on the electric vehicle 10 into AC power of a low voltage system (100 V system) and supplies the AC power to the specific load 65, or converts AC power of a low voltage system (100 V system) from the grid power 12 into DC power and charges the battery of the electric vehicle 10. The vehicle-external power supply device 40 is connected between a breaker-side switch 38 and an overcurrent breaker 37 of the power system of the specific load 65 via a vehicle-side switch 42. Like the breaker-side switch 38, the vehicle-side switch 42 is also configured as an electromagnetic switch or a semiconductor switch.

[0017] The energy management device 50 is composed of a microcomputer. The energy management device 50 communicates with an external power trading information center 14 and acquires power trading information. The power trading information includes the average daily trading amount per 1 kW of the grid power 12 and the current trading amount per 1 kW of the grid power 12. The energy management device 50 outputs a drive control signal (on / off signal) to the breaker-side switch 38 and the vehicle-side switch 42. The energy management device 50 communicates with the vehicle-external power supply device 40.

[0018] Next, the operation of the power supply system 20 configured as described above will be described, particularly the operation when power is supplied to the specific load 65 when connected to the electric vehicle 10. Fig. 2 is a flowchart showing an example of an electric vehicle connection process executed by the energy management device 50. This process is executed when the vehicle external power supply device 40 is connected to the electric vehicle.

[0019] When the electric vehicle connection process is executed, the energy management device 50 first turns on the breaker-side switch 38 (step S100) and acquires power trading information from the power trading information center 14 via communication (step S110). Next, based on the acquired power trading information, it determines whether the current trading price per kW of the grid power 12 is equal to or greater than the average daily trading price per kW of the grid power 12 (step S120).

[0020] If it is determined in step S120 that the current transaction amount per kW of grid power 12 is equal to or greater than the average daily transaction amount per kW of grid power 12, the power storage ratio SOC of the battery mounted on electric vehicle 10 is acquired (step S130), and it is determined whether the acquired power storage ratio SOC exceeds the power storage ratio SOC required for the planned travel of electric vehicle 10 on the next day (step S140). The power storage ratio SOC required for the planned travel of electric vehicle 10 on the next day can be obtained, for example, by determining the power storage ratio SOC required for the travel of electric vehicle 10 for each day of the week based on the travel history for each day of the week, and creating a map; when the next day of the week is given, the power storage ratio SOC required for the corresponding travel of electric vehicle 10 can be derived from the map.

[0021] If it is determined in step S140 that the power storage ratio SOC exceeds the power storage ratio SOC required for the electric vehicle 10 to travel the next day as planned, the vehicle-side switch 42 is turned on (step S150), and the breaker-side switch 38 is turned off (step S160), and power is supplied from the electric vehicle 10 to the specific load 65 (step S170). Then, it is determined whether or not power supply has ended (step S180), and if it is determined that power supply has not ended, the process returns to step S130, in which the power storage ratio SOC of the battery mounted on the electric vehicle 10 is acquired. On the other hand, if it is determined in step S140 that the power storage ratio SOC does not exceed the power storage ratio SOC required for the electric vehicle 10 to travel the next day as planned, the vehicle-side switch 42 is turned off (step S190), and the process returns to step S100, in which the breaker-side switch 38 is turned on. Therefore, when it is determined in step S120 that the current transaction amount per kW of the grid power 12 is equal to or greater than the average daily transaction amount per kW of the grid power 12, and when it is determined in step S140 that the power storage ratio SOC exceeds the power storage ratio SOC required for the electric vehicle 10 to travel as planned for the next day, power supply from the electric vehicle 10 to the specific load 65 continues until the power storage ratio SOC no longer exceeds the power storage ratio SOC required for the electric vehicle 10 to travel as planned for the next day.

[0022] If it is determined in step S120 that the current transaction price per kW of the grid power 12 is less than the average daily transaction price per kW of the grid power 12, the vehicle-side switch 42 is turned on (step S200), and the battery mounted on the electric vehicle 10 is charged with power from the grid power 12 (step S210). At this time, power from the grid power 12 is supplied to the specific load 65. Then, it is determined whether charging of the battery mounted on the electric vehicle 10 has been completed (step S220), and if it is determined that charging of the battery mounted on the electric vehicle 10 has not been completed, the process returns to step S110, in which electricity trading information is acquired from the energy trading information center 14. Therefore, as long as the current transaction price per kW of the grid power 12 is less than the average daily transaction price per kW of the grid power 12, charging of the battery mounted on the electric vehicle 10 continues until charging is completed. If it is determined in step S220 that charging of the battery mounted on the electric vehicle 10 has been completed, the process returns to step S100 where the breaker-side switch 38 is turned on.

[0023] In the power supply system 20 of the embodiment described above, a breaker-side switch 38 configured with an electromagnetic switch or a semiconductor switch is provided between the breaker 22 of the power system of the specific load 65 and the overcurrent breaker 37, and the vehicle-external power supply device 40 is connected between the breaker-side switch 38 of the power system of the specific load 65 and the overcurrent breaker 37 via a vehicle-side switch 42 configured as an electromagnetic switch or a semiconductor switch. The energy management device 50 turns on and off the breaker-side switch 38 and the vehicle-side switch 42 based on power trading information obtained from the energy trading information center 14 to supply power from the grid power 12 to the specific load 65 or to supply power from the electric vehicle 10 to the specific load 65. This makes it possible to automatically switch between the power supply from the grid power 12 to the specific load 65 and the power supply from the electric vehicle 10, and to simplify the power supply system 20. Furthermore, when the current transaction amount per kW of grid power 12 is less than the average daily transaction amount per kW of grid power 12, the battery mounted on electric vehicle 10 is charged with power from grid power 12, so that the battery can be charged inexpensively.

[0024] In the power supply system 20 of the embodiment, the breaker-side switch 38 is provided between the breaker 22 of the power system of the specific load 65 and the overcurrent breaker 37, and the vehicle-external power supply device 40 is connected between the breaker-side switch 38 of the power system of the specific load 65 and the overcurrent breaker 37 via the vehicle-side switch 42. However, it is also possible to provide a breaker-side switch between the specific load 65 and the overcurrent breaker 37 of the power system of the specific load 65, and to connect the vehicle-external power supply device 40 between the specific load 65 and the breaker-side switch of the power system of the specific load 65 via the vehicle-side switch.

[0025] In the embodiment, the power supply system 20 receives power from the grid power 12 and power from the electric vehicle 10. However, the power supply system 20 may also receive power from a solar power generation device in addition to the power supply from the grid power 12 and the power supply from the electric vehicle 10. FIG. 3 is a diagram showing an example of the configuration of a modified power supply system 20B that also receives power from a solar power generation device. As shown in the figure, the solar power generation device 16 is connected to a breaker 22 via a power conversion device (PCS) 54. As a result, power generated by the solar power generation device 16 is supplied to each room load 62 via each room breaker device 24 of the high-voltage system (200V system) and to each room load 64a-64n and a specific load 65 via each room breaker device 34 of the low-voltage system (100V system). The power conversion device 54 is also connected to the vehicle external power supply device 40 via a solar power generation side switch 56. As a result, by turning on the solar power generation side switch 56, the battery mounted on the electric vehicle 10 can be charged with power generated by the solar power generation device 16. In this modified power supply system 20B, a breaker-side switch 38 is provided between the breaker 22 of the power system of the specific load 65 and the overcurrent breaker 37, and a vehicle external power supply device 40 is connected between the breaker-side switch 38 of the power system of the specific load 65 and the overcurrent breaker 37 via a vehicle-side switch 42, so that the same effects as those of the power supply system 20 of the embodiment can be achieved.

[0026] The correspondence between the main elements of the embodiment and the main elements of the invention described in the "Means for Solving the Problem" section will be described below. In the embodiment, the breaker 22 corresponds to the "system breaker," the specific load 65 corresponds to the "specific load," the overcurrent breaker 37 corresponds to the "specific breaker," the electric vehicle 10 corresponds to the "electric vehicle," the vehicle external power supply device 40 corresponds to the "power supply device," the breaker-side switch 38 corresponds to the "system-side switch," the vehicle-side switch 42 corresponds to the "vehicle-side switch," and the energy management device 50 corresponds to the "control device."

[0027] The correspondence between the main elements of the embodiments and the main elements of the invention described in the "Means for Solving the Problem" section does not limit the elements of the invention described in the "Means for Solving the Problem" section, since the embodiments are examples for specifically explaining the mode for implementing the invention described in the "Means for Solving the Problem" section. In other words, the interpretation of the invention described in the "Means for Solving the Problem" section should be based on the description in that section, and the embodiments are merely specific examples of the invention described in the "Means for Solving the Problem" section.

[0028] The present disclosure has been described above using embodiments, but the present disclosure is not limited to these embodiments in any way, and it goes without saying that the present disclosure can be embodied in various forms within the scope that does not deviate from the gist of the present disclosure. [Industrial Applicability]

[0029] The present disclosure is applicable to the power supply system manufacturing industry and the like. [Explanation of symbols]

[0030] 10 Electric vehicle, 12 Power grid, 14 Electricity trading information center, 16 Solar power generation equipment, 20 Power supply system, 22 Breaker, 24 Room breaker device for high voltage system (200V system), 34 Room breaker device for low voltage system (100V system), 36a to 36n, 37 Overcurrent breaker, 38 Breaker side switch, 40 Vehicle external power supply device, 42 Vehicle side switch, 50 Energy management device, 54 Power conversion device, 62 Load, 64a to 64n Load, 65 Specific load.

Claims

[Claim 1] A power supply system including a system breaker connected to a system power supply, a specific breaker installed between the system breaker and a specific load, and a power supply device connected to a battery mounted on an electric vehicle, a system-side switch attached between the system breaker and the specific load; a vehicle-side switch attached between the power supply device and the specific load; a control device that controls switching between the grid-side switch and the vehicle-side switch based on power information so as to stop power supply from the grid power to the specific load and supply power from the power supply device to the specific load, or to stop power supply from the power supply device to the specific load and supply power from the grid power to the specific load; A power supply system comprising:

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