Power Control Device

Abstract

To provide a power control device capable of supplying and managing power derived from renewable energy relative to a detachable load.SOLUTION: A power control device (10) includes: a first end unit (11) that is connected with a first load that is a load in facilities where the power control device is provided and a system; a second end unit (12) that is connected with a second load that is load separatable from the facilities where the power control device is provided; a switchgear (14) that switches connection and disconnection of a power path to the second end unit; and a control unit (13) that controls the switchgear based on power or an amount of power supplied at least from the power control device to the first end unit so that power based on renewable energy among the power supplied to the second load becomes a predetermined ratio.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a power control device. [Background technology]

[0002] In recent years, with the growing awareness of the use of renewable energy (hereinafter also referred to as "renewable energy"), there is a demand for technology that can distinguish and manage the electricity used based on whether it is derived from renewable energy or not. Renewable energy is non-fossil energy, and its energy source is, for example, solar, wind, hydroelectric, geothermal, etc. For example, Patent Document 1 discloses a power management method that uses blockchain to manage the charging rate of a power storage device that is charged from renewable energy. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-007988 Summary of the Invention [Problem to be solved by the invention]

[0004] While Patent Document 1 describes a system including a storage battery connected to both a device that uses renewable energy, such as a solar power generation device, and a commercial grid, it only supplies power to loads within consumer facilities. However, there is a demand for technology that can supply and manage renewable energy-derived power not only to loads within consumer facilities, but also to mobile devices that are separated from consumer facilities, such as electric vehicle batteries.

[0005] An object of the present disclosure is to provide a power control device that is capable of supplying and managing power derived from renewable energy to a separable load. [Means for solving the problem]

[0006] (1) A power control device according to an embodiment of the present disclosure includes: A power control device connected to a first distributed power source that supplies power based on renewable energy and a grid, and controlling power supply to a first load and a second load, a first end connected to the first load, which is a load within a facility where the power control device is installed, and the grid; a second end connected to the second load, which is a load that can be separated from the facility where the power control device is installed; a switch that switches between connection and disconnection of a power path to the second end; and a control unit that controls the switch based on at least the power or amount of power supplied from the power control device to the first end so that a predetermined proportion of the power supplied to the second load is power based on renewable energy.

[0007] (2) As one embodiment of the present disclosure, in (1), The predetermined percentage is 100%.

[0008] (3) As an embodiment of the present disclosure, in (1) or (2), The control unit controls the switch based on the amount of power supplied from the first distributed power source to the first end portion and the power consumption of the second load.

[0009] (4) As an embodiment of the present disclosure, in any one of (1) to (3), During stand-alone operation when disconnected from the grid, power from the first distributed power source is supplied to the second load.

[0010] (5) As an embodiment of the present disclosure, in any one of (1) to (4), connected to a second distributed power source that can receive power from the first distributed power source or the grid and supply power to at least one of the first load and the second load; The control unit manages the power that can be supplied from the second distributed power source to the second load.

[0011] (6) As an embodiment of the present disclosure, in any one of (1) to (5), The control unit displays information about the state of the switch and the renewable energy-based power supplied to the second load.

[0012] (7) As an embodiment of the present disclosure, in any one of (1) to (6), The control unit stores information about the power and amount of power based on renewable energy supplied to the second load. [Effects of the Invention]

[0013] According to an embodiment of the present disclosure, it is possible to provide a power control device that is capable of supplying and managing renewable energy-derived power to a separable load. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic configuration diagram of a power control device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram showing a display example when the switch is open. [Figure 3] FIG. 3 is a diagram for explaining the operation during the independent operation. [Figure 4] FIG. 4 is a diagram for explaining the determination by the control unit. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, a power control device according to an embodiment of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals. In the following description of the embodiment, the description of the same or corresponding parts will be omitted or simplified as appropriate. Also, the drawings are schematic.

[0016] 1 is a schematic configuration diagram of a power control device 10 according to an embodiment of the present disclosure. The power control device 10 is used in a grid-connected power generation system that is connected to a commercial grid (hereinafter simply referred to as "the grid") and is capable of supplying power based on renewable energy to a load. Renewable energy is non-fossil energy, and its energy source is, for example, solar, wind, hydroelectric, geothermal, or the like.

[0017] The power control device 10 is connected to a first distributed power source that supplies power based on renewable energy and to a grid, and controls the power supply to a first load and a second load. The power control device 10 is also called a power conditioner. In this embodiment, the power control device 10 is also connected to a second distributed power source that can receive power from the first distributed power source or the grid and supply power to at least one of the first load and the second load.

[0018] In this embodiment, the first distributed power source is a solar cell (photovoltaic power generation device), but is not limited to a solar cell and may be another type of renewable energy power source. In this embodiment, the second distributed power source is a storage battery, but is not limited to a storage battery and may be another type of power source. The first load is a load within the facility where the power control device 10 is installed. The first load is a load that cannot be separated from the facility, such as lighting or air conditioners within the facility. The second load is a load that can be separated from the facility where the power control device is installed. The second load may be, for example, a personal computer or an air purifier. Furthermore, the second load may be charged with power supplied by the power control device 10 and then used after leaving the facility. The second load may be, for example, a battery for an electric vehicle or a mobile battery. However, the first load and the second load are not limited to the above specific examples.

[0019] Here, with the growing awareness of the use of renewable energy, there is a demand for supplying and managing renewable energy-derived power to mobile equipment that is away from consumer facilities. As will be described below, the power control device 10 according to this embodiment can supply and manage renewable energy-derived power to the second load.

[0020] The power control device 10 includes a first end 11 connected to a first load and a power grid, and a second end 12 connected to a second load. The power control device 10 also includes a switch 14 that switches between connecting (closing) and disconnecting (opening) a power path to the second end 12. The switch 14 is a switch, and specifically, may be a relay. As shown in FIG. 1 , the power control device 10 includes a DC / DC converter that increases or decreases the voltage of DC power from the first distributed power source. The power control device 10 also includes a DC / DC converter that increases or decreases the voltage of DC power from the second distributed power source. The DC / DC converter is indicated as "D / D" in FIG. 1. In this embodiment, the outputs (DC power) of the two DC / DC converters are combined and converted into AC power by an inverter. The inverter is indicated as "D / A" in FIG. 1. The converted AC power can be supplied to the first load via the first end 11. Furthermore, if the switch 14 is in a connected (closed) state, the converted AC power can be supplied to a second load via the second end 12.

[0021] Furthermore, in the power control device 10, the second distributed power source, which is a storage battery, is charged with power from the first distributed power source or the grid. For example, the power from the first distributed power source is boosted or lowered in voltage by a DC / DC converter and then used to charge the second distributed power source. For example, power from the grid is converted to DC power by an inverter, and the voltage of the converted DC power is boosted or lowered by a DC / DC converter and used to charge the second distributed power source.

[0022] The control unit 13 controls and manages each functional unit of the power control device 10 and the entire power control device 10. The control unit 13 may be configured to include at least one processor. The processor includes one or more circuits or units configured to execute one or more data calculation procedures or processes. For example, the processor may be configured to include one or more microprocessors, microcontrollers, application specific integrated circuits (ASICs), digital signal processing devices, programmable logic devices, or combinations thereof.

[0023] In this embodiment, the control unit 13 controls the switch 14 based on at least the power or amount of power supplied from the power control device 10 to the first end 11 so that the power based on renewable energy is a predetermined percentage of the power supplied to the second load. Here, the power or amount of power supplied from the power control device 10 to the first end 11 includes negative values, i.e., power or amount of power drawn from the grid. The predetermined percentage is not limited to 100%, but unless otherwise specified, the following description will be given assuming the predetermined percentage is 100%. The control unit 13 may further control the switch 14 based on the power consumption of the second load. The control unit 13 may further control the switch 14 based on the power or amount of power supplied to the second load. As shown in FIG. 1 , the power control device 10 may include a power measurement unit 15 and a power measurement unit 16. The power measurement unit 15 and the power measurement unit 16 are devices that measure power and may include, for example, a current sensor. The power or amount of power supplied from the power control device 10 to the first end 11 is measured by the power measurement unit 15 and output to the control unit 13. The power or amount of power supplied to the second load is measured by the power measuring unit 16 and output to the control unit 13.

[0024] In this embodiment, the power control device 10 manages the power that can be supplied from the second distributed power source to the second load. The management of the power that can be supplied to the second load includes determining whether the power is based on renewable energy. The power control device 10 also manages the source of the power used to charge the second distributed power source.

[0025] The control unit 13 also has a communication function and can output information to an external device of the power control device 10 via a network for display. The network is, for example, the Internet, but may also be a local area network (LAN). The external device may include, for example, a display device 21 of the grid-connected power generation system. The display device 21 may be installed in a customer facility to display the power generation status and other information to a user. In this embodiment, the control unit 13 causes the display device 21 to display information about the state of the switch 14 and the renewable energy-based power supplied to the second load. The external device may also include a server 22 that manages the grid-connected power generation system. In this embodiment, the control unit 13 stores information about the renewable energy-based power and the amount of power supplied to the second load. Based on the information stored in the server 22, the user's renewable energy usage rate and other information can be calculated. Based on the calculated usage rate, measures such as preferential purchase prices for renewable energy can be implemented for the user. The external device may include, for example, an electronic device 23 owned by the user. The electronic device 23 may be, for example, a mobile terminal such as a smartphone or a tablet terminal. The control unit 13 may display information about the state of the switch 14 and the power based on renewable energy supplied to the second load on the display of the electronic device 23 together with or instead of the display device 21. Compared to a case where information is displayed only on the display device 21, this increases the likelihood that the user will be able to quickly grasp the state of the switch 14, etc.

[0026] The power control performed by the control unit 13 of the power control device 10 having the above configuration will be specifically described as Cases 1 to 11. The present disclosure is not limited to the contents of the following cases. The control unit 13 can perform a combination of the power controls in Cases 1 to 11, except when the execution conditions are clearly incompatible, and such combinations are also included in the contents of the present disclosure.

[0027] (Case 1) When the grid-tied power generation system is in grid-connected operation, the control unit 13 of the power control device 10 may connect (close) the switch 14 when the power output from the power control device 10 to the first end 11 is equal to or greater than a threshold value. The threshold value is zero or a positive value, but is not limited to a specific value. In other words, the control unit 13 may connect (close) the switch 14 when it is known that power will not be drawn from the grid. Furthermore, there does not need to be one threshold value. For example, the control unit 13 may close the switch 14 when the power measured by the power measuring unit 15 is equal to or greater than a first threshold value, which is a non-zero positive value. The control unit 13 may open the switch 14 when the power measured by the power measuring unit 15 is equal to or less than a second threshold value. Here, the second threshold value is a value smaller than the first threshold value.

[0028] (Case 2) Even when the grid-tied power generation system is in grid-connected operation, the control unit 13 of the power control device 10 may charge the second distributed power source, which is a storage battery, using only power from the first distributed power source. Since the second distributed power source is charged only with power based on renewable energy, all power from the second distributed power source comes from renewable energy. The control unit 13 may supplement power from the second distributed power source when, for example, the power from the first distributed power source is less than the power consumption of the second load. The control unit 13 may open the switch 14 when, for example, the power based on renewable energy is less than the power consumption of the second load even after supplementing power from the second distributed power source.

[0029] Here, when the switch 14 is opened even though power can be supplied from the first distributed power source, the control unit 13 preferably notifies the user that the power based on renewable energy is less than the power consumption of the second load, even when supplemented with power from the second distributed power source. FIG. 2 is a diagram showing an example of a display on the display device 21 when the switch 14 is open. The example in FIG. 2 shows a state in which the power control device 10 is outputting 100% renewable energy to the second end 12 (upper right diagram). However, for example, the first distributed power source decreases, causing the second load to become overloaded, and the output from the power control device 10 to the second end 12 is turned off (lower right diagram). When the power based on renewable energy (renewable energy power) that can be supplied from the first and second distributed power sources is less than the power consumption of the second load, the switch 14 is opened, and the output from the power control device 10 to the second end 12 is turned off (lower right diagram in FIG. 2). By viewing the display as shown in FIG. 2, the user can understand that the switch 14 has been disconnected (opened) and that the power supply to the second load has been stopped. In other words, the user can understand that the grid-connected power generation system is not malfunctioning but is operating normally. The control unit 13 may further display a message suggesting a course of action to resume the power supply to the second load, as in the example of FIG. 2. The message may, for example, suggest the user to reduce the second load.

[0030] (Case 3) When the control unit 13 of the power control device 10 controls the switch 14 so that the power supplied to the second load is renewable energy, the control unit 13 may store the power or the amount of power in the server 22. In other words, the control unit 13 may store the power or the amount of power supplied to the second load measured by the power measurement unit 16 in the server 22 as information about the power based on renewable energy supplied to the second load. This enables tracking of renewable energy (visualization of its value).

[0031] (Case 4) The control unit 13 of the power control device 10 may control the switch 14 so that the proportion of power based on renewable energy in the supplied power (renewable energy rate) is 100%, using the amount of power supplied to the second load measured by the power measurement unit 16. The control unit 13 may open the switch 14, for example, when power is drawn from the grid and supplied to the second load, and the renewable energy rate of the second load does not reach 100%.

[0032] (Case 5) The control unit 13 of the power control device 10 may supply power from the first distributed power source to the second load during isolated operation when the power control device is disconnected from the grid. FIG. 3 is a diagram for explaining the operation during isolated operation. For example, during a power outage, the grid-connection relay is disconnected (opened), and the power control device 10 is not connected to the grid or the first load. The grid-connection relay is disposed, for example, outside the first end 11. The power control device 10 can supply power to the second load without changing the connection, whether the grid-tied power generation system is in grid-connected operation or in isolated operation.

[0033] (Case 6) The control unit 13 of the power control device 10 may control the display device 21 to display the message described in the above-mentioned Case 2 even when the renewable energy rate is 100%. Here, when all the power supplied to the second load is renewable energy power, the control unit 13 may not display the message, or may display a message indicating that "the renewable energy rate is 100%".

[0034] (Case 7) When the second distributed power source (storage battery) is charged with grid power and renewable energy-derived power, the control unit 13 of the power control device 10 may discharge (supply power to) the first load in excess of the amount of charge derived from the grid, and then supply power from the second distributed power source to the second load. In other words, when the storage battery is not charged only with renewable energy-derived power, the control unit 13 first discharges an amount equivalent to the amount of charge derived from the grid to the first load. With this control, the amount of charge in the storage battery thereafter will all be equivalent to the amount derived from renewable energy.

[0035] (Case 8) The control unit 13 of the power control device 10 may control the switch 14 based on the comparison of the power. As shown in FIG. 4, the power control device 10 may include a power measurement unit 17 that measures the total output power. The determination by the control unit 13 will be described below, with the powers measured by the power measurement units 15, 16, and 17 designated as P1, P2, and P0, respectively. First, the control unit 13 may connect (close) the switch 14 when P1 is greater than zero or when P0 is equal to or greater than a threshold value. Here, the threshold value compared with P0 may be different from that in Case 1. When the switch 14 is connected (closed), P2 (i.e., the power consumption of the second load) is measured. Next, the control unit 13 may disconnect (open) the switch 14 when P0 is likely to be less than P2. Here, the power control device 10 may have multiple second terminals 12 to accommodate multiple second loads. Assume that the power consumption of multiple second loads connected to multiple (n) second ends 12 is P2-1, P2-2, ..., P2-n, where n is an integer equal to or greater than 2. When all of the switches 14 connected to the multiple second ends 12 are connected (closed), the total power P2 is obtained as (P2-1) + (P2-2) + ... + (P2-n). When P0 is likely to be less than P2, the control unit 13 may open some of the switches 14 connected to the multiple second ends 12. By opening some of the switches 14, the control unit 13 can reduce the total power P2 and continue to supply power based on renewable energy to some of the second loads.

[0036] (Case 9) In the above-described cases 1 to 3 and 5 to 8, the control unit 13 of the power control device 10 may control the switch 14 so that the power based on renewable energy of the power supplied to the second load is a predetermined percentage less than 100%. The control unit 13 may receive information indicating the state of power supply and demand from, for example, a computer that manages power in the area where the consumer facility is located, and may switch the predetermined percentage from 100% to a value less than 100% based on the information indicating the state of power supply and demand. For example, when the predetermined percentage is 70%, the control unit 13 adjusts the power supplied from the inverter to the second load via the second end 12 to be 70% of the power consumed by the second load. The control unit 13 also adjusts the power supplied from the grid to the second load via the second end 12 to be the remaining power consumed by the second load (30%).

[0037] (Case 10) The control unit 13 of the power control device 10 may control the switch 14 based on the amount of power, rather than the amount of power. Using the amount of power makes it possible to manage a predetermined proportion of the power based on renewable energy among the power supplied to the second load for a predetermined period (e.g., one hour, one day, etc.). For example, a case will be described where the unit period is 30 minutes and the predetermined period is one hour. Suppose that the control unit 13 supplied 3 kW of renewable energy-derived power and 1 kW of grid-derived power to the second load in the first 30 minutes, but the proportion of renewable energy-derived power ends up being slightly higher than requested. In this case, the control unit 13 can adjust the proportion of renewable energy-derived power to be as requested over the predetermined period by limiting the supply of renewable energy-derived power to, for example, 2 kW for the next 30 minutes.

[0038] (Case 11) The control unit 13 of the power control device 10 may control the switch 14 based on the amount of power supplied from the first distributed power source to the first end 11 and the power consumption of the second load to adjust the power drawn from the grid. As in Example 10, using the amount of power makes it possible to manage a predetermined proportion of the power supplied to the second load that is derived from renewable energy over a predetermined period. For example, a case will be described in which the unit period is 30 minutes, the predetermined period is 1 hour, the predetermined proportion is 70%, and the power consumption of the second load is 10 kW. The control unit 13 can supply 6 kW of renewable energy-derived power and 4 kW of grid-derived power to the second load over the first 30 minutes, and then supply 8 kW of renewable energy-derived power and 2 kW of grid-derived power to the second load over the next 30 minutes. By managing the predetermined proportion of renewable energy-derived power over a predetermined period, the control unit 13 can flexibly adjust the supply depending on, for example, the state of power supply and demand while still meeting the required renewable energy-derived power supply.

[0039] As described above, the power control device 10 according to this embodiment, with the above-described configuration, is capable of supplying and managing power derived from renewable energy to a separable load.

[0040] Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art could make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications or alterations are included in the scope of the present disclosure. For example, the functions included in each component can be rearranged so as not to cause logical inconsistencies, and multiple components can be combined or divided into one.

[0041] In this disclosure, descriptions such as "first" and "second" are identifiers for distinguishing the configurations. Configurations distinguished by descriptions such as "first" and "second" in this disclosure may have their numbers exchanged. The exchange of identifiers is performed simultaneously. The identifiers may be deleted. The descriptions of identifiers such as "first" and "second" in this disclosure should not be used as a basis for interpreting the order of the configurations. [Explanation of symbols]

[0042] 10 Power control device 11 First end 12 Second end 13 Control Unit 14 Switchgear 15 Power measurement section 16 Power measurement section 17 Power measurement section 21 Display device 22 servers 23 Electronic equipment

Claims

1. A power control device connected to a first distributed power source that supplies power based on renewable energy and a grid, and configured to control power supply to a first load and a second load, a first end connected to the first load, which is a load within a facility where the power control device is installed, and the grid; a second end connected to the second load, which is a load that can be separated from a facility where the power control device is installed; a switch that switches between connection and disconnection of a power path to the second end; a control unit that controls the switch based on at least the power or amount of power supplied from the power control device to the first end so that a predetermined proportion of the power supplied to the second load is power based on renewable energy.

2. The power control device according to claim 1 , wherein the predetermined percentage is 100%.

3. 3 . The power control device according to claim 1 , wherein the control unit controls the switch based on an amount of power supplied from the first distributed power source to the first end and power consumption of the second load.

4. The power control device according to claim 1 or 2, wherein, during an isolated operation in which the power control device is disconnected from the grid, the power from the first distributed power source is supplied to the second load.

5. a second distributed power source that is capable of receiving power from the first distributed power source or the grid and supplying power to at least one of the first load and the second load; The power control device according to claim 1 , wherein the control unit manages the power that can be supplied from the second distributed power source to the second load.

6. The power control device according to claim 1 or 2, wherein the control unit displays information about a state of the switch and information about the power based on renewable energy supplied to the second load.

7. The power control device according to claim 1 or 2, wherein the control unit stores information about the power and the amount of power based on renewable energy supplied to the second load.

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