WO2015198678A1

WO2015198678A1 - Power supply system and controller

Info

Publication number: WO2015198678A1
Application number: PCT/JP2015/060732
Authority: WO
Inventors: 浩一上山
Original assignee: シャープ株式会社
Priority date: 2014-06-26
Filing date: 2015-04-06
Publication date: 2015-12-30

Abstract

Provided is a power supply system in which power can be more effectively utilized by efficiently converting power. The power supply system (1100) is equipped with: an AC/DC converter (30) for converting the AC power supplied from a power system (60) to DC power; an electricity storage device (20) configured so that the DC power thereof can be charged and discharged; and a home controller (10) for controlling the AC/DC converter (30) and the electricity storage device (20). The home controller (10) monitors the power consumption (P) of a DC load group (80) receiving the DC power supplied from a DC bus (50), stores efficiency characteristic information indicating the relationship between input power to the AC/DC converter (30) and conversion efficiency, allows the AC/DC converter (30) to perform a power conversion so that the conversion efficiency becomes a reference threshold value or more, and controls the charging and discharging operation of the electricity storage device (20) according to the power consumption (P).

Description

Power supply system and controller

The present invention relates to a power supply system and a controller, and more particularly, to a technique for supplying power by controlling the operation of a power conversion device and a power storage device connected to a DC bus in the power supply system and controller.

In recent years, with increasing awareness of global environmental problems, a power supply system that combines a distributed power supply device such as a solar cell, a wind power generator, and a fuel cell and power storage by a storage battery has become widespread. In addition, a technique is known in which DC power is directly supplied to a DC load without converting DC power into AC power for a DC load (electrical device) such as an audio device, a television, or a personal computer.

In such a power supply system including a DC load, the DC power generated by the distributed power supply device is consumed by being supplied to the DC load, or sold by a reverse power flow to the commercial power system. Further, by charging the storage battery with the power generated by the distributed power supply device, stable power supply that is not affected by the weather is performed.

Regarding power supply, for example, JP 2012-249471 A (Patent Document 1) discloses a power distribution system. The power distribution system includes a load DC / DC converter and a power conditioner connected to an output terminal of a DC power supply unit, an AC / DC converter connected to an AC power system, and a control unit for controlling them. . The control unit individually controls the operation of each unit so that the power from the DC power supply unit is supplied to the load with priority over the AC power system. The DC power supply unit supplies power to a DC load via a load DC / DC converter, and supplies power to an AC load via a power conditioner. The AC power system supplies power to a DC load via an AC / DC converter, and supplies power directly to the AC load.

JP 2012-249471 A

According to the power distribution system disclosed in Patent Document 1, when operating a DC load when power is not supplied from the DC power supply unit, power is supplied from the AC power system to the DC load via an AC / DC converter. Will be. Here, when a converter such as an AC / DC converter performs a conversion operation, a fixed power loss that does not depend on the power to be converted occurs. For this reason, when the load power is relatively low, the influence of the fixed power loss on the converted power of the AC / DC converter becomes large, and the state where the power is not efficiently utilized continues. There is.

The present invention has been made in order to solve the above-described problems, and provides a power supply system and a controller capable of more effectively using power by performing efficient power conversion. The purpose is to do.

A power supply system according to an embodiment is provided between a power system and a DC bus, has a forward conversion function for converting AC power supplied from the power system into DC power, and DC power supplied from the DC bus. A power conversion device having at least one function of an inverse conversion function for converting to AC power, a power storage device connected to a DC bus and configured to charge and discharge DC power, and the power conversion device and the power storage device are controlled. Controller. The controller includes a power consumption monitoring unit that monitors power consumption of a load unit that is supplied with DC power from a DC bus, and a storage unit that stores efficiency characteristic information indicating a relationship between input power to the power converter and conversion efficiency; And a power control unit that controls the charge / discharge operation of the power storage device based on the power consumption while causing the power conversion device to perform power conversion so that the conversion efficiency is equal to or higher than the reference threshold.

According to the present invention, power can be used more effectively by performing efficient power conversion.

It is a figure which shows roughly the whole structure of the electric power supply system according to Embodiment 1. FIG. It is a figure which shows the relationship between input electric power and conversion efficiency. It is a schematic diagram which shows the hardware constitutions of the home controller 10 contained in the electric power supply system according to Embodiment 1. 3 is a functional block diagram of a home controller according to the first embodiment. FIG. 6 is a flowchart showing an example of a processing procedure executed by the home controller according to the first embodiment. It is a figure which shows roughly the whole structure of the electric power supply system according to Embodiment 2. FIG. FIG. 10 is a functional block diagram of a home controller according to a second embodiment. It is a flowchart which shows an example of the process sequence which the home controller according to Embodiment 2 performs. It is a figure which shows roughly the whole structure of the electric power supply system according to Embodiment 3. FIG. FIG. 11 is a functional block diagram of a home controller according to a third embodiment. 12 is a flowchart showing an example of a processing procedure executed by a home controller according to the third embodiment. It is a figure which shows roughly the whole structure of the electric power supply system according to Embodiment 4. FIG. FIG. 10 is a functional block diagram of a home controller according to a fourth embodiment. It is a flowchart which shows an example of the process sequence which the home controller according to Embodiment 4 performs. It is a figure which shows roughly the whole structure of the electric power supply system according to Embodiment 5. FIG. FIG. 16 is a functional block diagram of a home controller according to a fifth embodiment. It is a flowchart which shows an example of the process sequence which the home controller according to Embodiment 5 performs. It is a figure which shows roughly the whole structure of the electric power supply system according to Embodiment 6. FIG. FIG. 17 is a functional block diagram of a home controller according to a sixth embodiment. It is a flowchart which shows an example of the process sequence which the home controller according to Embodiment 6 performs.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[Embodiment 1]
<System overview>
(overall structure)
FIG. 1 schematically shows an overall configuration of power supply system 1100 according to the first embodiment. The power supply system 1100 is realized by, for example, a HEMS (Home Energy Management System). The same applies to the power supply systems in the following embodiments.

Referring to FIG. 1, power supply system 1100 includes home controller 10, power storage device 20, AC / DC converter 30, power measuring device 40, and DC bus 50. In addition, a DC load group 80 is connected to the DC bus 50, and a power system 60 is connected to the AC / DC converter 30.

The power system 60 is typically a single-phase three-wire commercial AC power system. In the single-phase three-wire commercial AC power system, the neutral wire is grounded via a resistor, and AC200V is supplied using two wires other than the neutral wire (R-phase wire RL and T-phase wire TL). To do.

The DC load group 80 includes a refrigerator 81, an air conditioner 82, a lighting fixture 83, and a television 84 as a DC load. The DC load group 80 is an electric device such as a washing machine or a personal computer used at home, an electric device such as a computer, a copying machine or a facsimile used in an office, or a showcase used in a store. Such electrical equipment may be included. In the present embodiment, the DC load group 80 includes a plurality of DC loads (electrical devices), but may be configured by a single electric device.

The power storage device 20 is connected to a DC bus 50 and configured to charge and discharge DC power. The power storage device 20 is a rechargeable power storage-dedicated device, a storage battery (not shown) such as a lithium ion battery or a nickel metal hydride battery, and a CPU (Central Control Unit) that controls the operation of the power storage device 20 in accordance with instructions from the home controller 10. Control unit (not shown) such as Processing Unit). For example, the storage battery is configured by connecting a plurality of battery cells in series.

The storage battery is “directly connected” to the DC bus 50, and it is preferable to exchange DC power with the DC bus 50. Here, “directly connected” means that a power converter such as a DC / DC converter is not interposed between the DC bus 50 and the storage battery. Therefore, when the storage battery and the DC bus 50 are “directly connected”, no loss due to power conversion occurs in the exchange of DC power between the power storage device 20 and the DC bus 50.

The AC / DC converter 30 is connected between the DC bus 50 and the power system 60. The AC / DC converter 30 converts the AC power into DC power and outputs (supplies) to the DC bus 50 when AC power is supplied (purchased) from the power system 60. Specifically, the AC / DC converter 30 performs power conversion in accordance with an instruction from the home controller 10 so that the conversion efficiency (ratio of output power to input power) is equal to or higher than a reference threshold value. This conversion efficiency changes according to the input power input to the AC / DC converter 30. Specifically, the conversion efficiency and the input power have a relationship as shown in FIG.

FIG. 2 is a diagram showing the relationship between input power and conversion efficiency. Referring to FIG. 2, it can be seen that the conversion efficiency increases as the input power increases. For example, the conversion efficiency when the input power is 1.5 kW is 0.95, and the conversion efficiency when the input power is 0.5 kW is 0.9. The reason why the input power and the conversion efficiency have such a relationship is that there is a fixed power loss due to the switching operation of the internal circuit that is not affected by the power value of the converted power during the power conversion operation by the AC / DC converter 30. Because. Therefore, in order to efficiently use power, it can be said that it is desirable to convert as much AC power (input power) as possible into DC power (output power) and supply it to the DC bus 50.

Referring again to FIG. 1, the power meter 40 measures the power consumption of the DC load group 80 and transmits the measurement information to the home controller 10 via the network 90. Thereby, the home controller 10 can always monitor the power consumption of the DC load group 80. For example, as the power measuring device 40, a power consumption measuring device that is disposed between the DC bus 50 and the plug of the DC load group 80 and measures power consumption is used.

The home controller 10 is configured to be able to communicate with the power storage device 20, the AC / DC converter 30, and the power measuring device 40 via a wired or wireless network 90. Home controller 10 monitors the power consumption measured by power meter 40 and controls the charge / discharge operation of DC power in power storage device 20 and the power conversion operation of AC / DC converter 30 based on the power consumption. .

Any network 90 can be used, but Ethernet (registered trademark), PLC (Power Line Communications), or the like can be used as long as it is a wired network. If the network 90 is a wireless network, for example, a wireless LAN (Local Area Network) compliant with IEEE (Institute of Electrical and Electronic Engineers) 802.11 standard, ZigBee (registered trademark), Bluetooth (registered trademark). Infrared communication method can be used. Further, a plurality of communication methods may be combined.

(Overview of operation)
With reference to FIG. 1, the operation | movement outline | summary of the electric power supply system 1100 is demonstrated. Here, in the initial state, it is assumed that power storage device 20 is in a charged state (for example, a fully charged state) in which power consumption P of DC load group 80 can be supplemented.

Referring to FIG. 1, the home controller 10 stops the AC / DC converter 30 (arrow X1). In addition, the home controller 10 discharges power for the power consumption P from the power storage device 20 to the DC load group 80 in order to supply power for the power consumption P (0.5 kW) to the DC load group 80 (arrow Z1). (Arrow Y1).

Next, when the power consumption P increases (0.5 kw → 2.5 kw) and becomes equal to or higher than the reference power (1.425 kw), the AC / DC converter 30 converts the conversion efficiency into a reference threshold value (in accordance with an instruction from the home controller 10). 0.95) Power conversion is executed with input power (for example, rated power: 3 kW) that is equal to or greater than that, and DC power (2.85 kW) is output to the DC bus 50 (arrow X2). The DC load group 80 is supplied with power (2.5 kW) corresponding to the power consumption P (arrow Z2), and the power storage device 20 uses the DC power (2.85 kw) to the power consumption P (2) according to the instruction of the home controller 10. .5 kw) is subtracted from the differential power (0.35 kw) (arrow Y2).

Thereafter, when the power consumption P decreases (2.5 kw → 0.5 kw) and becomes less than the reference power, the home controller 10 stops the AC / DC converter 30 (arrow X1), and power for the power consumption P Is discharged from the power storage device 20 (arrow Y1).

<Home controller 10>
(Hardware configuration)
FIG. 3 is a schematic diagram showing a hardware configuration of home controller 10 included in power supply system 1100 according to the first embodiment.

Referring to FIG. 3, home controller 10 includes at least CPU 101 and memory 110, and touch panel 102 including display 103 and tablet 104 as necessary, operation buttons 105, communication interface 106, output interface 107, and the like. The input interface 108, the speaker 111, and the clock 112 may be included.

The CPU 101 is a processing entity that controls the entire processing in the home controller 10, and provides various functions as described later by executing a program stored in advance in the memory 110 or the like. In response to a user operation input to the tablet 104 or the operation button 105, the CPU 101 executes processing instructed by the user operation.

The touch panel 102 is a device that provides a user interface, presents various information to the user according to instructions from the CPU 101, and outputs instructions input from the user to the CPU 101.

The display 103 includes, for example, an LCD (Liquid Crystal Display), an organic EL (Electro Luminescence) display, and the like, and displays an image on its display surface.

The tablet 104 detects a touch operation with a user's finger or the like, and outputs a coordinate value indicating a position where the touch operation is performed to the CPU 101. A tablet 104 is provided in association with the display surface of the display 103. However, the home controller 10 does not necessarily include a touch panel, and it is sufficient that various information can be presented to the user.

The operation button 105 is an input unit for accepting a user operation, and typically one or more are arranged on the surface of the home controller 10. When the operation button 105 receives a user operation, the operation button 105 outputs information indicating the user operation to the CPU 101.

The communication interface 106 performs data communication with the power storage device 20 and the AC / DC converter 30 according to a command from the CPU 101. More specifically, the communication interface 106 uses Ethernet (registered trademark), PLC, wireless LAN, ZigBee (registered trademark), Bluetooth (registered trademark), an infrared communication method, or the like.

The output interface 107 mediates exchange of internal commands between the CPU 101 and the display 103. The input interface 108 mediates exchange of internal commands between the tablet 104 and / or the operation buttons 105 and the CPU 101.

The memory 110 is realized by a RAM (Random Access Memory), a ROM (Read-Only Memory), a hard disk, or the like. The memory 110 stores various data and programs executed by the CPU 101.

The speaker 111 is an audio device, and outputs audio according to a command from the CPU 101. The clock 112 is a time measuring unit, and inputs the current date and time to the CPU 101 in accordance with a command from the CPU 101.

Note that the memory 110 may be realized using a storage medium connected via a communication interface. As such a storage medium, optical disk storage media such as flash memory, CD-ROM (Compact Disc-Read Only Memory) and DVD-ROM (Digital Versatile Disk-Read Only Memory) can be used.

Information processing as described in the following flowchart in the home controller 10 is realized by the CPU 101 executing a program in cooperation with peripheral hardware components. Generally, such a program is preinstalled in the memory 110 or the like.

Such a program can be provided by being stored and distributed in an arbitrary storage medium. Alternatively, such a program can be provided by downloading from a server device (or other device) connected to the Internet or the like. That is, the program stored in the storage medium is read out, or the program is acquired by downloading from the server device and temporarily stored in the memory 110 or the like. The CPU 101 expands the program stored in the memory 110 into an executable format and then executes the program.

The CPU 101 executes not only all the functions according to the present embodiment by executing a program, but also all or part of processing required by an OS (operating system) executed on the computer according to the program. By performing the above, the function according to the present embodiment may be realized.

(Functional configuration)
FIG. 4 is a functional block diagram of home controller 10 according to the first embodiment.

Referring to FIG. 4, home controller 10 includes a power consumption monitoring unit 150, a power control unit 152, and a storage unit 154 as its main functional configuration. The power consumption monitoring unit 150 and the power control unit 152 are basically realized by the CPU 101 of the home controller 10 executing a program stored in the memory 110 and giving a command to the components of the home controller 10. . The storage unit 154 is a functional configuration realized by the memory 110. Note that some or all of these functional configurations may be realized by hardware.

The storage unit 154 stores efficiency characteristic information indicating the relationship between AC power (input power) input from the power system 60 to the AC / DC converter 30 and conversion efficiency. Specifically, the efficiency characteristic information is the graph shown in FIG.

The power consumption monitoring unit 150 monitors the power consumption P of the DC load group 80. Specifically, the power consumption monitoring unit 150 receives measurement information from the power meter 40 and monitors the power consumption P of the DC load group 80. The power consumption P of the DC load group 80 is the sum of the power consumption of each DC load. When the power meter 40 is provided for each DC load, the power consumption monitoring unit 150 may monitor the power consumption of each DC load.

The power control unit 152 controls the AC / DC converter 30 and the power storage device 20 based on the efficiency characteristic information stored in the storage unit 154 and the power consumption P monitored by the power consumption monitoring unit 150.

Specifically, the power control unit 152 refers to the efficiency characteristic information stored in the storage unit 154 when the AC power is supplied (purchased) from the power system 60, and the conversion efficiency is equal to or higher than the reference threshold value. The AC / DC converter 30 is caused to perform power conversion so that For example, when the reference threshold is set to 0.95, the power controller 152 causes the AC / DC converter 30 to convert AC power of 1.5 kW or more into DC power from the relationship shown in FIG. To instruct. Typically, the power control unit 152 performs the conversion operation of the AC / DC converter 30 with the rated power (for example, 3 kW). For example, the reference threshold value is stored in the storage unit 154 and can be appropriately changed according to an instruction from the user via the touch panel 102.

Further, the power control unit 152 receives AC power from the power system 60 (purchases power) and outputs DC power to the DC bus 50 when the power consumption P is equal to or higher than the reference power. Instruct the converter 30. Specifically, when the DC power output from the AC / DC converter 30 to the DC bus 50 is equal to or higher than the power consumption P, the power control unit 152 stores the difference power obtained by subtracting the power consumption P from the DC power. Let 20 charge. When the DC power output from the AC / DC converter 30 to the DC bus 50 is less than the power consumption P, the power control unit 152 uses the power consumption P to subtract the DC power from the power storage device 20 to the DC bus 50. To discharge. The reference power is preferably equal to or higher than output power (1.425 kW) obtained by converting input power (1.5 kW) at which the conversion efficiency is equal to or higher than a reference threshold (for example, 0.95).

Further, when the power consumption P is less than the reference power, the power control unit 152 stops the AC / DC converter 30 and discharges the DC power corresponding to the power consumption P from the power storage device 20 to the DC bus 50.

<Processing procedure>
Next, a specific processing procedure executed by the home controller 10 will be described.

FIG. 5 is a flowchart showing an example of a processing procedure executed by the home controller 10 according to the first embodiment. This flow is mainly realized by the CPU 101 executing a control program or the like stored in the memory 110. The same applies to the flows in the following embodiments. Note that at the start of the flowchart of FIG. 5, AC / DC converter 30 is stopped, and power storage device 20 is in a charged state in which power consumption P of DC load group 80 can be supplemented (for example, a fully charged state). Suppose that

Referring to FIG. 5, home controller 10 discharges power corresponding to power consumption P of DC load group 80 from power storage device 20 to DC load group 80 (step S10).

The home controller 10 determines whether or not the power consumption P is greater than or equal to the reference power (step S12). If power consumption P is less than the reference power (NO in step S12), home controller 10 stops AC / DC converter 30 (step S22), and returns to the process of step S10 (return). If the power consumption P is greater than or equal to the reference power (YES in step S12), the home controller 10 purchases AC power from the power system 60 and outputs the DC power to the DC bus 50. 30 is instructed (step S14). Typically, the home controller 10 causes the AC / DC converter 30 to execute a power conversion operation with power at which the conversion efficiency is equal to or higher than a reference threshold.

Next, the home controller 10 determines whether or not the DC power output to the DC bus 50 is greater than or equal to the power consumption P (step S16). If the DC power is greater than or equal to power consumption P (YES in step S16), home controller 10 causes power storage device 20 to charge surplus power obtained by subtracting power consumption P from DC power (step S18), and step S12. Return to the process. If the DC power is less than power consumption P (NO in step S16), home controller 10 discharges insufficient power obtained by subtracting DC power from power consumption P from power storage device 20 (step S20), and step S12. Return to the process.

According to the first embodiment, when the power consumption P is less than the reference power, the DC load group 80 is operated by the power of the power storage device 20, and therefore no conversion loss is caused by the AC / DC converter 30. Also, when the power consumption P is greater than the reference power and it becomes difficult to operate the DC load group 80 with the power from the power storage device 20, the AC / DC converter 30 purchases AC power from the power system 60. The power conversion operation is performed with electric power having a conversion efficiency equal to or higher than a reference threshold. Thereafter, when the power consumption P becomes less than the reference power, the AC / DC converter 30 is stopped, and the DC load group 80 is operated again by the power from the power storage device 20 to return to a state where no conversion loss occurs.

Therefore, even when purchasing electricity while maximally using the power of the power storage device 20 that does not cause conversion loss, the conversion loss is suppressed by high-efficiency power conversion. can do.

[Embodiment 2]
<System overview>
(overall structure)
FIG. 6 is a diagram schematically showing an overall configuration of power supply system 1200 according to the second embodiment.

Referring to FIG. 6, power supply system 1200 includes home controller 10 A, power storage device 20, AC / DC converter 30, power meter 40, and DC bus 50. The home controller 10A corresponds to the home controller 10 of the first embodiment shown in FIG. 1, but for the sake of distinction from the other embodiments, an additional symbol “A” is attached for convenience. The same applies to the following embodiments. Since the configuration of power supply system 1200 other than home controller 10A is substantially the same as the configuration of power supply system 1100, detailed description thereof will not be repeated.

(Overview of operation)
Next, an outline of the operation of the power supply system 1200 will be described. In the second embodiment, the home controller 10A acquires the remaining battery charge Q of the power storage device 20 from the device. Note that the state of charge (SOC) (%) indicates the current remaining capacity as a percentage (0 to 100%) with respect to the full charge capacity.

Referring to FIG. 6, home controller 10A stops AC / DC converter 30 (arrow Xa1) when battery remaining amount Q is equal to or greater than reference remaining amount RQ1 (for example, SOC = 5%). Further, the home controller 10A supplies the DC load group 80 with DC power corresponding to the power consumption P (0.5 kW) (arrow Za), from the power storage device 20 to the DC load group 80. Discharge (arrow Ya1).

When the battery remaining amount Q becomes less than the reference remaining amount RQ1 due to the electric power of the power storage device 20 being discharged, the AC / DC converter 30 converts the conversion efficiency into the reference threshold (0) according to the instruction of the home controller 10A. .95) The power conversion is executed with the rated power (3 kW) that is equal to or higher than that, and the DC power (2.85 kW) is output to the DC bus 50 (arrow Xa2). The DC load group 80 is supplied with power corresponding to power consumption P (0.5 kW) (arrow Za), and the power storage device 20 subtracts the power consumption P from this DC power in accordance with an instruction from the home controller 10A ( 2.35 kW) is charged (arrow Ya2).

Thereafter, when the remaining battery level Q becomes greater than or equal to a reference remaining amount RQ2 (for example, SOC = 30%) larger than the reference remaining amount RQ1 due to the charging, the home controller 10A stops the AC / DC converter 30. (Arrow Xa1), the DC power corresponding to the power consumption P is discharged from the power storage device 20 to the DC load group 80 (arrow Ya1).

<Home controller 10A>
Since the hardware configuration of home controller 10A is the same as that of home controller 10 shown in FIG. 3, detailed description thereof will not be repeated.

(Functional configuration)
FIG. 7 is a functional block diagram of home controller 10A according to the second embodiment.

Referring to FIG. 7, home controller 10A includes a power consumption monitoring unit 150A, a power control unit 152A, a storage unit 154A, and a battery remaining amount monitoring unit 156A as its main functional configuration. The power consumption monitoring unit 150A and the storage unit 154A have substantially the same functions as the power consumption monitoring unit 150 and the storage unit 154 shown in FIG. 4, respectively.

Battery remaining amount monitoring unit 156A monitors battery remaining amount Q of power storage device 20. Specifically, the remaining battery level monitoring unit 156A receives the remaining battery level information transmitted from the power storage device 20 and monitors the remaining battery level Q. Specifically, the control unit of the power storage device 20 transmits the detected remaining battery level Q to the remaining battery level monitoring unit 156A via the network 90.

The power control unit 152A performs AC based on the efficiency characteristic information stored in the storage unit 154A, the power consumption P of the DC load group 80 monitored by the power consumption monitoring unit 150A, and the battery remaining amount Q of the power storage device 20. / DC converter 30 and power storage device 20 are controlled.

Specifically, power control unit 152A stops AC / DC converter 30 and performs direct current from power storage device 20 when battery remaining amount Q is equal to or greater than reference remaining amount RQ1 (eg, SOC = 5%). DC power is discharged to the bus 50. The power control unit 152A receives the AC power from the power system 60 and outputs the DC power to the DC bus 50 when the battery remaining amount Q is less than the reference remaining amount RQ1. To instruct. In addition, the power control unit 152A causes the power storage device 20 to be charged with the differential power obtained by subtracting the power consumption P from the DC power. Typically, the power control unit 152A causes the AC / DC converter 30 to perform a conversion operation at the rated power, and causes the DC bus 50 to output DC power that is greater than or equal to the power consumption P.

When the difference power is charged in power storage device 20, power control unit 152 A has battery remaining amount Q that is greater than reference remaining amount RQ 2 (for example, SOC = 30%) greater than reference remaining amount RQ 1. Then, the AC / DC converter 30 is stopped and the DC power is discharged from the power storage device 20 to the DC bus 50. The reference remaining amount RQ2 is set to a remaining amount that allows the DC load group 80 to be operated only by the electric power from the power storage device 20 for a predetermined time or more in consideration of the power consumption P. For example, the reference remaining amount RQ 1 and the reference remaining amount RQ 2 are stored in the storage unit 154 A and can be appropriately changed according to an instruction from the user via the touch panel 102.

<Processing procedure>
Next, a specific processing procedure executed by the home controller 10A will be described.

FIG. 8 is a flowchart showing an example of a processing procedure executed by the home controller 10A according to the second embodiment. Note that at the start of the flowchart of FIG. 8, the AC / DC converter 30 is stopped, and the remaining battery charge Q is equal to or higher than the reference remaining charge RQ1.

Referring to FIG. 8, home controller 10A discharges power corresponding to power consumption P of DC load group 80 from power storage device 20 to DC load group 80 (step S30).

The home controller 10A determines whether or not the remaining battery charge Q is less than the reference remaining charge RQ1 due to the discharge (step S32). If battery remaining amount Q is equal to or greater than reference remaining amount RQ1 (NO in step S32), home controller 10A repeats the processing from step S30.

When battery remaining amount Q becomes less than reference remaining amount RQ1 (YES in step S32), home controller 10A purchases AC power from power system 60 and outputs DC power to DC bus 50. / DC converter 30 is instructed (step S34). At this time, the home controller 10A causes the AC / DC converter 30 to execute the power conversion operation with the rated power at which the conversion efficiency is equal to or higher than the reference threshold and the power consumption P is equal to or higher.

Next, the home controller 10A charges the power storage device 20 with surplus power obtained by subtracting the power consumption P from the DC power output from the AC / DC converter 30 to the DC bus 50 (step S36). The home controller 10A determines whether or not the remaining battery charge Q has become equal to or greater than the reference remaining charge RQ2 due to the charging (step S38).

When the battery remaining amount Q is less than the reference remaining amount RQ2 (NO in step S38), the home controller 10A repeats the processing from step S36. If battery remaining amount Q is equal to or greater than reference remaining amount RQ2 (YES in step S38), home controller 10A stops AC / DC converter 30 to end the power purchase (step S40), and the process in step S30 Return to (Return). Specifically, home controller 10A operates DC load group 80 again by DC power from power storage device 20.

According to the second embodiment, when battery remaining capacity Q is equal to or greater than reference remaining capacity RQ1, DC load group 80 operates with power from power storage device 20 without purchasing AC power from power system 60. Therefore, conversion loss due to the AC / DC converter 30 does not occur. When the remaining battery level Q is less than the reference remaining level RQ1 and it is difficult to continue power supply from the power storage device 20 to the DC load group 80, the AC / DC converter 30 purchases power from the power system 60 and increases power consumption. Performs efficient power conversion. In addition, the power storage device 20 charges surplus power. Thereafter, when the remaining battery level Q becomes equal to or greater than the reference remaining level RQ2, the AC / DC converter 30 is stopped, and the DC load group 80 is operated again by the power from the power storage device 20 so that no conversion loss occurs. Return to.

Therefore, it becomes possible to suppress power conversion loss due to the AC / DC converter 30, and it is possible to use power more efficiently. In addition, when power is purchased, since a large amount of power near the rated power is supplied to the DC bus 50, the charging time of the power storage device 20 can be shortened, so that the power conversion operation time (power purchase time) can also be shortened. Also from this point, the power conversion loss by the AC / DC converter 30 can be suppressed.

[Embodiment 3]
<System overview>
(overall structure)
FIG. 9 schematically shows an overall configuration of power supply system 1300 according to the third embodiment.

Referring to FIG. 9, power supply system 1300 includes home controller 10 B, power storage device 20, bidirectional power conversion device 32,

power measuring devices

40 and 42, DC bus 50, and power generation device 70. . Since the configuration of the power supply system 1300 other than the home controller 10B, the bidirectional power conversion device 32, the power measuring device 42, and the power generation device 70 is substantially the same as the configuration of the power supply system 1100, a detailed description thereof will be given. Do not repeat.

The bidirectional power converter 32 has a forward conversion function that converts AC power supplied from the power system 60 into DC power, and an inverse conversion function that converts DC power supplied from the DC bus 50 into AC power. ing. Specifically, the bidirectional power converter 32 converts an AC power into a DC power when AC power is purchased from the power system 60 (for example, the above-described AC / DC converter 30). And a DC / AC converter that converts DC power to AC power when DC power is sold to the power system 60.

The bidirectional power converter 32 receives AC power from the power system 60 and converts it into DC power (purchased power) in accordance with an instruction from the home controller 10B, and receives DC power from the DC bus 50 and converts it into AC power. In either case (power sale), power conversion is performed so that the conversion efficiency is equal to or higher than a reference threshold. Specifically, with reference to FIG. 2, the bidirectional power conversion device 32 has a conversion efficiency of 1.5 kW or more that makes the conversion efficiency equal to or higher than the reference threshold (0.95) when purchasing power from the power system 60. Converts AC power (input power) to DC power. In addition, when the bi-directional power conversion device 32 sells power to the power system 60, the DC power (input power) of 1.5 kW or higher that makes the conversion efficiency equal to or higher than the reference threshold (0.95) is converted into AC power. Convert.

The power generation device 70 includes a solar cell 72 and a DC / DC converter 74. The solar cell 72 is composed of a crystalline solar cell, a polycrystalline solar cell, a thin film solar cell, or the like. The DC / DC converter 74 is connected between the solar cell 72 and the DC bus 50, converts the DC power received from the solar cell 72 into a voltage, and supplies it to the DC bus 50. The DC / DC converter 74 performs control (so-called maximum power point tracking control) such that maximum power can be acquired from the solar cell 72. The power generation device 70 may be a power generation method other than solar power generation, and may include a fuel cell, a wind power generation device, a plasma power generation device, or the like instead of the solar cell 72.

The power meter 42 measures the generated power Pg generated by the power generator 70 and transmits the measurement information to the home controller 10B via the network 90. Thereby, the home controller 10B can always monitor the generated power Pg of the power generator 70.

(Overview of operation)
Further, an outline of the operation of the power supply system 1300 will be described with reference to FIG. Here, the operation in the case where DC power from the DC bus 50 is converted into AC power and sold to the power system 60 will be described. Therefore, the generated power Pg of the power generator 70 is assumed to be larger than the power consumption of the DC load group 80.

Referring to FIG. 9, the power generation device 70 supplies the generated power Pg (2.5 kW) to the DC bus 50 (arrow Wb). When the battery remaining amount Q of the power storage device 20 is less than the reference remaining amount RQ3 (SOC = 95%), the home controller 10B stops the bidirectional power conversion device 32 (arrow Xb1). Further, the home controller 10B causes the DC load group 80 to supply power corresponding to the power consumption P (0.5 kW) (arrow Zb) and also generates DC power (2.0 kW) obtained by subtracting the power consumption P from the generated power Pg. The power storage device 20 is charged (arrow Yb1).

When the remaining battery level Q becomes equal to or higher than the reference remaining level RQ3 due to the charging, the bidirectional power conversion device 32 receives the input power whose conversion efficiency is equal to or higher than the reference threshold (0.95) according to the instruction of the home controller 10B. (Rated power: 3 kW) is converted into AC power, and AC power (2.85 kW) is output to the power system 60 (arrow Xb2). At this time, the home controller 10B generates the generated power Pg from the sum (3.5 kW) of the power consumption P (0.5 kW) and the rated power supplied to the DC load group 80 so that the input power becomes the rated power. The DC power (1 kW) obtained by subtracting (2.5 kW) is discharged from the power storage device 20 (arrow Yb2).

Thereafter, when the remaining battery level Q becomes less than the reference remaining amount RQ4 (for example, SOC = 90%) smaller than the reference remaining amount RQ3, the home controller 10B stops the bidirectional power converter 32 (arrow) Xb1), the power storage device 20 is charged with surplus power (arrow Yb1).

<Home controller 10B>
Since the hardware configuration of home controller 10B is the same as that of home controller 10 shown in FIG. 3, detailed description thereof will not be repeated.

(Functional configuration)
FIG. 10 is a functional block diagram of home controller 10B according to the third embodiment.

Referring to FIG. 10, home controller 10B has, as its main functional configuration, power consumption monitoring unit 150B, power control unit 152B, storage unit 154B, battery remaining amount monitoring unit 156B, and generated power monitoring unit 158B. including. The power consumption monitoring unit 150A and the storage unit 154A have substantially the same functions as the power consumption monitoring unit 150 and the storage unit 154 shown in FIG. 4, respectively. Further, the remaining battery level monitoring unit 156B has substantially the same function as the remaining battery level monitoring unit 156A shown in FIG.

The generated power monitoring unit 158B monitors the generated power Pg of the power generation device 70. Specifically, the generated power monitoring unit 158B receives the measurement information from the power measuring instrument 42 and monitors the generated power Pg.

The power control unit 152B includes the efficiency characteristic information stored in the storage unit 154B, the power consumption P of the DC load group 80 monitored by the power consumption monitoring unit 150B, and the power storage device 20 monitored by the battery remaining amount monitoring unit 156B. The bidirectional power conversion device 32 and the power storage device 20 are controlled based on the remaining battery charge Q and the generated power Pg of the power generation device 70 monitored by the generated power monitoring unit 158B.

Specifically, the power control unit 152B stops the bidirectional power conversion device 32 and generates generated power Pg when the battery remaining amount Q of the power storage device 20 is less than the reference remaining amount RQ3 (SOC = 95%). The power storage device 20 is charged with the differential power obtained by subtracting the power consumption P from. When the remaining battery capacity Q is equal to or greater than the reference remaining capacity RQ3, the power control unit 152B receives supply of DC power from the DC bus 50 to the bidirectional power conversion device 32 and supplies AC power to the power system 60. Instruct to output.

Further, the power control unit 152B adjusts the power discharged from the power storage device 20 to the DC bus 50 based on the generated power Pg and the consumed power P, so that the conversion efficiency becomes equal to or higher than the reference threshold value. 32 is caused to perform power conversion. Specifically, the power control unit 152B is configured so that the input power corresponding to the conversion efficiency equal to or higher than the reference threshold is input from the DC bus 50 to the bidirectional power conversion device 32 based on the efficiency characteristic information (see FIG. 2). The discharge power of the power storage device 20 is adjusted.

Further, when direct current is discharged from the power storage device 20 to the direct current bus 50, the battery remaining amount Q becomes less than the reference remaining amount RQ4 (SOC = 90%) which is smaller than the reference remaining amount RQ3. Unit 152B stops bidirectional power conversion device 32 and causes power storage device 20 to be charged with differential power obtained by subtracting power consumption P from generated power Pg.

<Processing procedure>
Next, a specific processing procedure executed by the home controller 10B will be described.

FIG. 11 is a flowchart illustrating an example of a processing procedure executed by the home controller 10B according to the third embodiment. Note that at the start of the flowchart of FIG. 11, it is assumed that bidirectional power conversion device 32 is stopped and battery remaining amount Q of power storage device 20 is less than reference remaining amount RQ3.

Referring to FIG. 11, home controller 10B operates DC load group 80 with generated power Pg of power generation device 70 and charges power storage device 20 with surplus power obtained by subtracting power consumption P from generated power Pg (step). S50).

The home controller 10B determines whether or not the battery remaining amount Q of the power storage device 20 has become equal to or greater than the reference remaining amount RQ3 (SOC = 95%) due to the charging (step S52). When battery remaining amount Q is less than reference remaining amount RQ3 (NO in step S52), home controller 10B repeats the processing from step S50.

When the remaining battery level Q is equal to or greater than the reference remaining level RQ3 (YES in step S52), the home controller 10B sets the input power to the bidirectional power converter 32 to the rated power (the input power value is the rated power value). The discharge power of the power storage device 20 is adjusted so as to become (step S54). Specifically, home controller 10 B discharges power difference from power storage device 20 by subtracting generated power Pg from the sum of rated power and power consumption P.

Then, the home controller 10B instructs the bidirectional power converter 32 to sell DC power (step S56). Specifically, the home controller 10B causes the bidirectional power converter 32 to convert DC power (input power) received from the DC bus 50 into AC power and output the AC power to the power system 60.

Next, the home controller 10B determines whether or not the battery remaining amount Q is less than the reference remaining amount RQ4 (SOC = 90%) by the discharging operation of the power storage device 20 (step S58). If battery remaining amount Q is equal to or greater than reference remaining amount RQ4 (NO in step S58), home controller 10B repeats the processing from step S54. If battery remaining amount Q is less than reference remaining amount RQ4 (YES in step S58), home controller 10B stops bidirectional power conversion device 32 to end the power sale (step S60), and the process of step S50 Return to (Return). Specifically, home controller 10 B operates DC load group 80 again with generated power Pg of power generation device 70 and charges power storage device 20 with surplus power.

According to the third embodiment, when the battery remaining amount Q of the power storage device 20 is less than the reference remaining amount RQ3, power conversion loss due to power purchase occurs because the DC load group 80 is operated using the generated power Pg. do not do. In addition, since excess power is charged in the power storage device 20, power is not wasted. Further, when the remaining battery level of the power storage device 20 is equal to or greater than the reference remaining level RQ3, power is sold because there is a possibility that the battery may approach the fully charged state and cannot be charged. When selling power, the bidirectional power converter 32 is caused to execute a highly efficient power conversion operation. Thereafter, when the remaining battery level becomes less than the reference remaining level RQ4, the bidirectional power converter 32 is stopped, and the DC load group 80 is operated again by the generated power Pg to return to a state where no power conversion loss occurs. Can do.

Therefore, it is possible to suppress the power conversion loss by the bidirectional power conversion device 32 even when selling power while maximally using the generated power Pg and the power of the power storage device 20 without generating conversion loss. Electric power can be used more efficiently.

[Embodiment 4]
<System overview>
(overall structure)
FIG. 12 schematically shows an overall configuration of power supply system 1400 according to the fourth embodiment.

Referring to FIG. 12, power supply system 1400 includes home controller 10 C, power storage device 20, bidirectional power conversion device 32,

power measuring devices

40 and 42, DC bus 50, and power generation device 70. . Since the configuration of power supply system 1400 other than home controller 10C is substantially the same as the configuration of power supply system 1300, detailed description thereof will not be repeated.

(Overview of operation)
An outline of the operation of the power supply system 1400 will be described. Here, in particular, an operation in the case where the home controller 10C purchases power from the power system 60 as necessary using time zone information received from an electric power company or the like will be described. The time zone information includes, for example, information (demand response (DR) signal) indicating power demand by time zone received from an electric power company or the like, power rate information by time zone, and the like. By receiving the time zone information, the home controller 10C can grasp in which time zone the power demand increases (or decreases) or in which time zone the power rate is high (or low). . Further, it is assumed that the generated power Pg of the power generation device 70 is smaller than the power consumption of the DC load group 80.

Referring to FIG. 12, the power generation device 70 supplies the generated power Pg (1.5 kW) to the DC bus 50 (arrow Wc). The bidirectional power converter 32 stops operating in accordance with an instruction from the home controller 10C (arrow Xc1). The home controller 10C stores insufficient power (0.5 kW) obtained by subtracting the generated power Pg from the power consumption P in order to supply the DC load group 80 with power corresponding to the power consumption P (2.0 kW) (arrow Zc). The device 20 is discharged (arrow Yc1).

Home controller 10C does not purchase AC power from power system 60 during a peak time period (for example, a time period when demand power increases), and uses DC power from power storage device 20 and generated power Pg to set DC load group 80. A target battery remaining amount (for example, SOC = 50%) of power storage device 20 required for operation is predicted. Then, the home controller 10C starts purchasing AC power from the power system 60 so that the remaining battery level Q reaches the target remaining battery level by the start time of the peak time period. Specifically, the bidirectional power converter 32 performs power conversion at a rated power (3 kW) at which the conversion efficiency is equal to or higher than the reference threshold (0.95) in accordance with an instruction from the home controller 10 C, and directs the DC bus 50 Electric power (2.85 kW) is output (arrow Xc2).

The power storage device 20 has a difference power (2.35 kW) obtained by subtracting the power consumption P (2.0 kW) from the sum of the DC power (2.85 kW) and the generated power Pg (1.5 kW) in accordance with an instruction from the home controller 10C. Is charged (arrow Yc2). Note that the peak time zone may be a time zone during which the demand power increases or a time zone during which the power charge increases.

When the remaining battery level Q of the power storage device 20 reaches the target remaining battery level due to the charging, the home controller 10C stops the bidirectional power conversion device 32 (arrow Xc1) and supplies the insufficient power to the power storage device 20. To discharge (arrow Yc1).

<Home controller 10C>
Since the hardware configuration of home controller 10C is the same as that of home controller 10 shown in FIG. 3, detailed description thereof will not be repeated.

(Functional configuration)
FIG. 13 is a functional block diagram of home controller 10C according to the fourth embodiment.

Referring to FIG. 13, home controller 10C has, as its main functional configuration, power consumption monitoring unit 150C, power control unit 152C, storage unit 154C, battery remaining amount monitoring unit 156C, and generated power monitoring unit 158C. , And an input unit 160C. The power consumption monitoring unit 150C and the storage unit 154C have substantially the same functions as the power consumption monitoring unit 150 and the storage unit 154 shown in FIG. 4, respectively. Further, the remaining battery level monitoring unit 156C has substantially the same function as the remaining battery level monitoring unit 156A shown in FIG. The generated power monitoring unit 158C has substantially the same function as the generated power monitoring unit 158B shown in FIG.

The input unit 160C receives (receives) time zone information input from an external device (such as a power company management server) via the communication interface 106. Specifically, the input unit 160C receives input of time zone information. Note that the input unit 160 C may accept input of time zone information via the touch panel 102.

Based on the generated power Pg, the consumed power P, and the time zone information, the power control unit 152C does not receive the AC power supply from the power system 60 in the peak time zone, and discharge power and power generation discharged from the power storage device 20 The target battery remaining amount of the power storage device 20 necessary for operating the DC load group 80 by the electric power Pg is predicted.

Specifically, the power control unit 152C calculates the power consumption (kwh) of the DC load group 80 in the peak time zone from the current power consumption and the number of hours in the peak time zone, and calculates the current generated power Pg and the time. The amount of power generated during peak hours is calculated from the number. Here, the difference power amount obtained by subtracting the generated power amount from the power consumption amount is the power amount that the power storage device 20 needs to supplement during the peak time period.

Therefore, the power control unit 152C predicts the target battery remaining amount so that the power storage device 20 can discharge the power amount equal to or greater than the difference power amount in the peak time period. The power control unit 152C may calculate the amount of generated power Pg in the peak time period by acquiring weather information acquired from the outside, or consider the operation schedule of the DC load group 80 in the peak time period. The power consumption may be calculated. In addition, past performance data (power generation amount and power consumption amount) in the peak time period is stored in the storage unit 154C, and the power control unit 152C determines the generated power Pg amount and the power consumption amount based on the result data. It may be calculated.

Further, the power control unit 152C, based on the charging power charged in the power storage device 20 when AC power is supplied from the power system 60, the remaining battery level Q of the power storage device 20 by the start time of the peak time zone. Causes the bidirectional power conversion device 32 to start receiving AC power from the power grid 60 so that the battery reaches the target remaining battery level. Specifically, the power control unit 152C starts the receipt at the timing described below. The charging power is a difference obtained by subtracting the power consumption P from the sum of the DC power and the generated power Pg output from the bidirectional power converter 32 to the DC bus 50 when AC power is supplied from the power system 60. Electric power.

The power control unit 152C calculates a time T1 until the remaining battery level Q reaches the target remaining battery level based on the differential power. Specifically, the power control unit 152C calculates the difference battery remaining amount obtained by subtracting the current battery remaining amount from the target battery remaining amount, and the time required to satisfy the power amount corresponding to the difference battery remaining amount by the difference power. T1 is calculated.

The power control unit 152C then sends the bidirectional power conversion device 32 from the power system 60 at the timing immediately before the time T2 from the current time measured by the clock 112 to the start time of the peak time period becomes less than the time T1. Start receiving AC power. The immediately preceding timing is the timing at which the time T2 from the current time to the start time of the peak time zone coincides with the time T1, or the time T2 is slightly longer than the time T1 (for example, time T2−time T1> 1 minute). It is timing.

Further, the power control unit 152 C stops the bidirectional power conversion device 32 and stores the power storage device 20 when the remaining power Q reaches the target battery remaining amount by charging the power storage device 20 with the differential power. DC power is discharged to the DC bus 50.

<Processing procedure>
Next, a specific processing procedure executed by the home controller 10C will be described.

FIG. 14 is a flowchart showing an example of a processing procedure executed by the home controller 10C according to the fourth embodiment. Note that at the start of the flowchart of FIG. 14, the bidirectional power converter 32 is stopped, and the power consumption P of the DC load group 80 is greater than the generated power Pg of the power generator 70.

Referring to FIG. 14, home controller 10C receives time zone information (step S70). The home controller 10C discharges the insufficient power obtained by subtracting the generated power Pg of the power generation device 70 from the power consumption of the DC load group 80 from the power storage device 20 (step S72).

The home controller 10C predicts the target remaining battery level of the power storage device 20 based on the generated power Pg of the power generation device 70, the power consumption of the DC load group 80, and the time zone information (step S74). Next, for example, the home controller 10 C generates AC power from the power grid 60 in order to reach the target battery remaining amount of the power storage device 20 by the start time of the peak time period in which the demand power increases most. It is determined whether or not it is time to start power purchase (step S76).

If the timing has not arrived (NO in step S76), the process of step S76 is repeated. When the timing has arrived (YES in step S76), home controller 10C causes bidirectional power converter 32 to start receiving AC power (purchasing power) from power system 60 (step S78). At this time, the home controller 10C causes the bidirectional power conversion device 32 to execute a power conversion operation with the rated power at which the conversion efficiency is equal to or higher than the reference threshold.

Next, the home controller 10C charges the power storage device 20 with surplus power obtained by subtracting the power consumption P from the DC power output from the bidirectional power conversion device 32 to the DC bus 50 (step S80). Home controller 10C determines whether or not the remaining battery level of power storage device 20 has reached the target remaining battery level due to the charging (step S82). If the remaining battery level has not reached the target remaining battery level (NO in step S82), the processing from step S78 is repeated. When the remaining battery level reaches the target remaining battery level (YES in step S82), home controller 10C stops bidirectional power converter 32 (step S84) and returns to the process in step S70 (return).

According to the fourth embodiment, the power storage device 20 is charged in advance with the power necessary for operating the DC load group 80 during the peak time period, so that power is not purchased during the peak time period. be able to. Thereby, it can contribute to the reduction of an electricity bill and the power saving of the whole area at the time of electric power demand pressure.

In addition, since the power storage device 20 is charged by the power necessary for the peak time period, it is possible to keep the required minimum power purchase and to suppress power conversion loss due to power purchase. Furthermore, since the bidirectional power converter 32 performs a highly efficient power conversion operation at the time of power purchase, power conversion loss can be suppressed also from this point.

[Embodiment 5]
<System overview>
(overall structure)
FIG. 15 schematically shows an overall configuration of power supply system 1500 according to the fifth embodiment.

Referring to FIG. 15, power supply system 1500 includes home controller 10 D, power storage device 20, AC / DC converter 30, power meter 40, and DC bus 50. In the present embodiment, a DC load group 80A is connected to the DC bus 50.

The DC load group 80A is obtained by adding a water heater 85 (DC load) having a peak shift mode for suppressing power use during peak hours to the DC load group 80. The water heater 85 is configured to be able to communicate with the home controller 10D via the network 90, and receives an instruction from the home controller 10D.

Note that a DC load having a peak shift mode is a DC load having a mode in which a time zone in which power consumption is maximum can be shifted from a peak time zone in which power demand is tight to a slow time zone. For example, the water heater 85 stops the heating operation to boil hot water with high power consumption during peak hours, performs the heating operation at low power demand, for example, at night (off-peak hours), and boils and stores hot water. I can leave.

(Overview of operation)
An outline of the operation of the power supply system 1500 will be described. Here, a case will be described in which home controller 10D controls the operation of water heater 85 using time zone information. Here, in the initial state, it is assumed that power is supplied from power storage device 20 to DC load group 80 in a time zone other than the off-peak time zone.

Referring to Fig. 15, home controller 10D stops AC / DC converter 30 and water heater 85 (arrow Xd1). In addition, the home controller 10D uses the power consumption P (0.5 kW) from the power storage device 20 to the DC load group 80A in order to supply the DC load group 80 with power corresponding to the power consumption P (0.5 kW) (arrow Zd1). The power of the minute is discharged (arrow Yd1).

When the start time of the off-peak time zone arrives, the AC / DC converter 30 receives supply of AC power from the power system 60 and outputs DC power to the DC bus 50 (arrow Xd2). Specifically, the AC / DC converter 30 performs power conversion at a rated power (3 kW) at which the conversion efficiency is equal to or higher than the reference threshold (0.95) according to an instruction from the home controller 10D, and directs the direct current to the direct current bus 50. Output power (2.85 kW). Moreover, since the water heater 85 starts operating according to the instruction of the home controller 10D and consumes 1.5 kW of power, the DC load group 80A is supplied with power equivalent to the power consumption P (2.0 kW) ( Arrow Zd2). At this time, the power storage device 20 charges the surplus power (0.85 kW) obtained by subtracting the power consumption P (2.0 kW) from the DC power (2.85 kW) according to the instruction of the home controller 10D (arrow Yd2).

When the end time of the off-peak time zone comes, the home controller 10D stops the AC / DC converter 30 and the hot water heater 85 (arrow Xd1), and discharges electric power necessary for the DC load group 80A from the power storage device 20 ( Arrow Yd1).

<Configuration of home controller 10D>
Since the hardware configuration of home controller 10D is the same as that of home controller 10 shown in FIG. 3, detailed description thereof will not be repeated.

(Functional configuration)
FIG. 16 is a functional block diagram of home controller 10D according to the fifth embodiment.

Referring to FIG. 16, home controller 10D includes a power consumption monitoring unit 150D, a power control unit 152D, a storage unit 154D, an input unit 160D, and a device control unit 162D as its main functional configuration. The power consumption monitoring unit 150D and the storage unit 154D have substantially the same functions as the power consumption monitoring unit 150 and the storage unit 154 shown in FIG. The input unit 160D has substantially the same function as the input unit 160C shown in FIG.

Based on the time zone information, device control unit 162D operates water heater 85 in the off-peak time zone and stops water heater 85 in a time zone other than the off-peak time zone (for example, the peak time zone) as described above. Such control is performed.

The power control unit 152D instructs the AC / DC converter 30 to receive the AC power from the power system 60 and output the DC power to the DC bus 50 during the off-peak time period. In addition, the power control unit 152D charges the power storage device 20 with the differential power obtained by subtracting the power consumption of the DC load group 80A from the DC power. Power control unit 152D stops AC / DC converter 30 in a time zone other than the off-peak time zone (for example, a peak time zone) and discharges DC power from power storage device 20 to DC bus 50.

<Processing procedure>
Next, a specific processing procedure executed by the home controller 10D will be described.

FIG. 17 is a flowchart illustrating an example of a processing procedure executed by the home controller 10D according to the fifth embodiment. Note that at the start of the flowchart of FIG. 17, it is assumed that AC / DC converter 30 and water heater 85 are stopped in a time zone other than the off-peak time zone. Further, it is assumed that the power storage device 20 is in a charged state capable of supplementing the power consumption of the DC load group 80A.

Referring to FIG. 17, home controller 10D receives time zone information from the power company (step S90). The home controller 10D discharges the insufficient power obtained by subtracting the generated power Pg of the power generation device 70 from the power consumption of the DC load group 80 from the power storage device 20 (step S92).

The home controller 10D determines whether or not the start time of the off-peak time period has arrived (step S94). If the start time has not arrived (NO in step S94), home controller 10D repeats the process in step S94. When the start time has arrived (YES in step S94), home controller 10D causes AC / DC converter 30 to start receiving (purchasing) AC power from power system 60 and operate water heater 85 (step). S96). At this time, the home controller 10D causes the AC / DC converter 30 to execute the power conversion operation with the rated power at which the conversion efficiency is equal to or higher than the reference threshold.

Next, the home controller 10D charges the power storage device 20 with surplus power obtained by subtracting the power consumption P from the DC power output from the AC / DC converter 30 to the DC bus 50 (step S98). Home controller 10D determines whether or not the end time of the off-peak time zone has arrived (step S100). If the end time has not come (NO in step S100), home controller 10D repeats the process of step S100. When the end time has arrived (YES in step S100), home controller 10D stops AC / DC converter 30 to end power purchase, and also stops water heater 85 (step S102). Return to processing (return).

According to the fifth embodiment, it is not necessary to purchase power because the AC / DC converter 30 is stopped and the DC load group 80 is operated by electric power from the power storage device 20 in a time zone other than the off-peak time zone. In addition, the water heater 85 that can use the peak shift mode stops in a time zone other than the off-peak time zone and operates in the off-peak time zone. Therefore, the power consumption of the DC load group 80A in a time zone other than the off-peak time zone can be reduced. This can contribute to the reduction of electricity charges and the avoidance of large-scale power outages and planned power outages when power demand is under pressure. Furthermore, since power conversion operation with high efficiency is executed by the AC / DC converter 30 during power purchase, power conversion loss can be suppressed.

[Embodiment 6]
<System overview>
(overall structure)
FIG. 18 schematically shows an overall configuration of power supply system 1600 according to the sixth embodiment.

Referring to FIG. 18, power supply system 1600 includes home controller 10E, power storage device 20, bidirectional power conversion device 32,

power measuring devices

40 and 42, DC bus 50, and power generation device 70. . Since the configuration other than home controller 10E is substantially the same as the configuration of power supply system 1300, detailed description thereof will not be repeated. However, in the sixth embodiment, the home controller 10E is configured to be communicable with the DC load group 80 via the network 90.

(Overview of operation)
An outline of the operation of the power supply system 1600 will be described. Here, an operation of stopping a part of the DC load group 80 when selling power to the power system 60 using time zone information received by the home controller 10E from an electric power company or the like will be described. Further, it is assumed that the generated power Pg of the power generation device 70 is larger than the power consumption of the DC load group 80. Here, in the initial state, power is supplied from power generation device 70 to power storage device 20 and DC load group 80 in a time zone other than the peak time zone.

Referring to FIG. 18, the power generation device 70 supplies the generated power Pg (2.5 kW) to the DC bus 50 (arrow We). The home controller 10E stops the bidirectional power conversion device 32 until the start time of the peak time zone arrives (arrow Xe1). Power corresponding to power consumption P (1.5 kW) is supplied to the DC load group 80 (arrow Ze1). The power storage device 20 charges the power storage device 20 with DC power (1.0 kW) obtained by subtracting the power consumption P of the DC load group 80 from the generated power Pg (arrow Ye1).

When the start time of the peak time period arrives, the home controller 10E stops at least one DC load in the DC load group 80. At this time, for example, the power consumption P of the DC load group 80 decreases from 1.5 kW to 0.5 kW (arrow Ze2). Further, the bidirectional power converter 32 converts the input power (rated power: 3 kW) whose conversion efficiency is equal to or higher than the reference threshold (0.95) into AC power according to the instruction of the home controller 10E, and supplies the AC power to the power system 60. Electric power (2.85 kW) is output (arrow Xe2). At this time, the home controller 10E subtracts the generated power Pg (2.5 kW) from the sum (3.5 kW) of the rated power and the power consumption P of the DC load group 80 so that the input power becomes the rated power. The direct current power (1 kW) thus discharged is discharged from the power storage device 20 (arrow Ye2).

Thereafter, when the end time of the peak time period comes, the home controller 10E operates the stopped DC load, stops the bidirectional power conversion device 32 (arrow Xe1), and supplies the surplus power to the power storage device 20. Is charged (arrow Ye1).

<Configuration of home controller 10E>
Since the hardware configuration of home controller 10E is the same as that of home controller 10 shown in FIG. 3, detailed description thereof will not be repeated.

(Functional configuration)
FIG. 19 is a functional block diagram of home controller 10E according to the sixth embodiment.

Referring to FIG. 19, home controller 10E has, as its main functional configuration, power consumption monitoring unit 150E, power control unit 152E, storage unit 154E, generated power monitoring unit 158E, input unit 160E, and device control. Part 162E. The power consumption monitoring unit 150A and the storage unit 154A have substantially the same functions as the power consumption monitoring unit 150 and the storage unit 154 shown in FIG. 4, respectively. Moreover, the generated power monitoring unit 158E has substantially the same function as the generated power monitoring unit 158B shown in FIG. The input unit 160E has substantially the same function as the input unit 160C shown in FIG.

The device control unit 162E operates a plurality of DC loads included in the DC load group 80 in a time zone other than the peak time zone (for example, off-peak time zone) based on the time zone information, and the DC load group in the peak time zone. At least one predetermined DC load out of 80 is stopped. In the sixth embodiment, device control unit 162E stops air conditioner 82, for example. As the DC load to be stopped, an electric device having a power saving mode or an electric device having a low priority order is selected.

The power control unit 152E stops the bidirectional power conversion device 32 in a time zone other than the peak time zone and charges the power storage device 20 with the differential power obtained by subtracting the power consumption from the generated power Pg. The power control unit 152E instructs the bidirectional power conversion device 32 to receive supply of DC power from the DC bus 50 and output AC power to the power system 60 during the peak time period.

Further, the power control unit 152E adjusts the power discharged from the power storage device 20 to the DC bus 50 based on the generated power Pg and the power consumption P, so that the conversion efficiency becomes equal to or higher than the reference threshold value. 32 is caused to perform power conversion.

<Processing procedure>
Next, a specific processing procedure executed by the home controller 10E will be described.

FIG. 20 is a flowchart showing an example of a processing procedure executed by home controller 10E according to the sixth embodiment. Note that at the start of the flowchart of FIG. 20, it is assumed that it is a time zone other than the peak time zone and the bidirectional power converter 32 is stopped.

Referring to FIG. 20, home controller 10E operates DC load group 80 with generated power Pg of power generation device 70 and charges power storage device 20 with surplus power obtained by subtracting power consumption P from generated power Pg (step). S110).

The home controller 10E determines whether or not the start time of the peak time period has arrived (step S112). If the start time has not arrived (NO in step S112), home controller 10E repeats the process of step S112. When the start time has arrived (YES in step S112), home controller 10E stops air conditioner 82 set in advance so as to stop the operation in the peak time zone (step S114).

The home controller 10B adjusts the discharge power of the power storage device 20 so that the input power to the bidirectional power conversion device 32 becomes the rated power (step S116). Specifically, home controller 10 B discharges power difference from power storage device 20 by subtracting generated power Pg from the sum of rated power and power consumption P. Then, the home controller 10B instructs the bidirectional power conversion device 32 to receive the supply of DC power from the DC bus 50 and supply (sell) AC power to the power system 60 (step S118).

The home controller 10E determines whether or not the end time of the peak time period has arrived (step S120). If the end time has not arrived (NO in step S120), home controller 10E repeats the process of step S120. When the end time has arrived (YES in step S120), home controller 10E stops bidirectional power conversion device 32 to end power sale and operates air conditioner 82 (step S122). Return to processing (return).

According to the sixth embodiment, in the time zone other than the peak time zone, it is not necessary to purchase power because the DC load group 80 is operated by the generated power Pg of the power generation device 70, so that the power conversion loss by the bidirectional power conversion device 32 occurs. Does not occur. Further, the power storage device 20 can be charged with surplus power. Further, since the air conditioner 82 is stopped during the peak time period, the power consumption of the DC load group 80 during the peak time period can be reduced accordingly. Thereby, it becomes possible to sell more power in the peak time zone. Power selling at a high price becomes possible, and power sales cooperation when power demand is tight can contribute to stable power demand in the entire region.

[Summary]
Embodiments of the present invention can be summarized as follows.

(1) The power supply system 1100 is provided between the power system 60 and the DC bus 50, and includes an AC / DC converter 30 that converts AC power supplied from the power system 60 into DC power, and a DC bus 50. The power storage device 20 is connected and configured to be able to charge and discharge DC power, and the home controller 10 that controls the AC / DC converter 30 and the power storage device 20 is provided. The home controller 10 monitors the power consumption P of the DC load group 80 that receives DC power supplied from the DC bus 50, and the relationship between the input power to the AC / DC converter 30 and the conversion efficiency. Storage unit 154 for storing the efficiency characteristic information to be shown, and causing AC / DC converter 30 to perform power conversion so that the conversion efficiency is equal to or higher than a reference threshold, and charging / discharging operation of power storage device 20 based on power consumption P And a power control unit 152 to be controlled.

According to the above configuration, even when purchasing power, it is possible to efficiently use power by suppressing conversion loss by high-efficiency power conversion.

(2) When the power consumption P is greater than or equal to the reference power, the power control unit 152 receives the AC power from the power system 60 and outputs the DC power to the DC bus 50 to the AC / DC converter 30. Instruct. When the power consumption P is less than the reference power, the power control unit 152 stops the AC / DC converter 30 and discharges DC power from the power storage device 20 to the DC bus 50.

According to the above configuration, since the power is purchased only when it is difficult to operate the DC load group 80 with the power from the power storage device 20, the power of the power storage device 20 in which no conversion loss occurs can be used to the maximum.

(3) When the DC power output from the AC / DC converter 30 to the DC bus 50 is equal to or greater than the power consumption P, the power control unit 152 supplies the power storage device 20 with the differential power obtained by subtracting the power consumption P from the DC power. Let it charge.

According to the above configuration, since excess power is charged in the power storage device 20, there is no waste of power.
(4) When the DC power output from the AC / DC converter 30 to the DC bus 50 is less than the power consumption P, the power control unit 152 uses the power storage device 20 to calculate the difference power obtained by subtracting the DC power from the power consumption P. The DC bus 50 is discharged.

According to the above configuration, since the insufficient power is discharged from the power storage device 20, the DC load group 80 can be operated.

(5) The home controller 10A further includes a remaining battery level monitoring unit 156A that monitors the remaining battery level Q of the power storage device 20. When battery remaining amount Q is equal to or greater than reference remaining amount RQ1, power control unit 152A stops AC / DC converter 30 and discharges DC power from power storage device 20 to DC bus 50. When the remaining battery level Q is less than the reference remaining level RQ1, the power control unit 152A receives an AC power supply from the power system 60 and outputs the DC power to the DC bus 50 to the AC / DC converter 30. The power storage device 20 is charged with the difference power obtained by subtracting the power consumption P from the DC power.

According to the above configuration, power is purchased by the AC / DC converter 30 because power is purchased only when the remaining battery capacity Q is not sufficient and it is difficult to continue power supply from the power storage device 20 to the DC load group 80. Loss can be minimized.

(6) The power control unit 152A determines that the AC / DC converter is used when the battery remaining amount Q becomes equal to or larger than the reference remaining amount RQ2 larger than the reference remaining amount RQ1 due to the difference power being charged into the power storage device 20. 30 is stopped and DC power is discharged from the power storage device 20 to the DC bus 50.

According to the above configuration, the AC / DC converter 30 is stopped when the remaining battery capacity Q is in a sufficient state and power supply from the power storage device 20 to the DC load group 80 becomes possible. It is possible to return to a state where no loss occurs.

(7) The power supply system 1300 further includes a power generator 70 that supplies the generated power Pg to the DC bus 50 as DC power. Home controller 10B further includes a battery remaining amount monitoring unit 156B that monitors battery remaining amount Q of power storage device 20, and a generated power monitoring unit 158B that monitors generated power Pg of power generation device 70. When the battery remaining amount Q is less than the reference remaining amount RQ3, the power control unit 152B stops the bidirectional power conversion device 32 and charges the power storage device 20 with the difference power obtained by subtracting the power consumption P from the generated power Pg. Let When the remaining battery level Q is greater than or equal to the reference remaining level RQ3, the power control unit 152B receives the DC power from the DC bus 50 and outputs AC power to the power system 60 to the bidirectional power converter 32. Instruct.

According to the above configuration, it is possible to make more efficient use of power by making maximum use of the generated power Pg that does not cause conversion loss and the power of the power storage device 20.

(8) The power control unit 152B adjusts the power discharged from the power storage device 20 to the DC bus 50 based on the generated power Pg and the consumed power P, so that the bidirectional power is set so that the conversion efficiency is equal to or higher than the reference threshold. The conversion device 32 is caused to perform power conversion.

According to the above configuration, since it is possible to cause the bidirectional power conversion device 32 to perform highly efficient power conversion, it is possible to suppress power conversion loss.

(9) When the DC power is discharged from the power storage device 20 to the DC bus 50, the power control unit 152B has both the battery remaining amount Q less than the reference remaining amount RQ4 smaller than the reference remaining amount RQ3. The power conversion device 32 is stopped, and the power storage device 20 is charged with the differential power obtained by subtracting the power consumption P from the generated power Pg.

According to the above configuration, the AC / DC converter 30 is stopped when the remaining battery capacity Q is reduced and the power storage device 20 is sufficiently charged with power, so that the power conversion loss is restored again. Can do.

(10) The power supply system 1400 further includes a power generator 70 that supplies the generated power Pg to the DC bus 50 as DC power. The home controller 10C includes an input unit 160C that receives input of time zone information, a remaining battery level monitoring unit 156C that monitors the remaining battery level Q of the power storage device 20, and a generated power monitoring unit that monitors the generated power Pg of the power generation device 70. 158C and a clock 112 that keeps the current time. Based on generated power Pg, consumed power P, and time zone information, power control unit 152C is discharged from power storage device 20 to DC bus 50 without receiving supply of AC power from power system 60 in a peak time zone. The target battery remaining amount of the power storage device 20 necessary for operating the DC load group 80 is predicted by the DC power and the generated power Pg. Based on the charging power charged in the power storage device 20 when AC power is supplied from the power system 60, the power control unit 152C sets the remaining battery level Q to the target remaining battery level by the start time of the peak time period. The bidirectional power conversion device 32 is made to start receiving AC power from the power system 60 so as to reach.

According to the above configuration, since it is not necessary to purchase power during peak hours, it is possible to contribute to the reduction of electricity charges and the power saving of the entire region when power demand is compressed.

(11) The charging power is a difference obtained by subtracting the power consumption P from the sum of the DC power and the generated power Pg output from the bidirectional power converter 32 to the DC bus 50 when AC power is supplied from the power system 60. Including power. The power control unit 152C calculates a time T1 until the remaining battery level Q reaches the target remaining battery level based on the differential power. The power control unit 152C starts receiving the AC power from the power system 60 to the bidirectional power conversion device 32 at a timing immediately before the time T2 from the current time to the start time of the peak time period becomes less than the calculated time T1. Let

According to the above configuration, it is possible to charge the power storage device 20 by the amount of electric power necessary for the peak time period without using unnecessary power purchase time.

(12) The power control unit 152C stops the bidirectional power conversion device 32 and stores the power storage device 20 when the remaining power Q reaches the target battery remaining amount due to the difference power being charged in the power storage device 20. DC power is discharged to the DC bus 50.

According to the said structure, the power conversion loss by power purchase can be suppressed.
(13) In the power supply system 1500, the DC load group 80A includes a water heater 85 having a peak shift mode for suppressing power use in a peak time zone in which power demand increases. The home controller 10D has an input unit 160D that accepts input of time zone information, and device control that controls the hot water heater 85 to operate during a time zone other than the peak time zone and to stop the hot water heater 85 during the peak time zone. Part 162D. The power control unit 152D instructs the AC / DC converter 30 to receive AC power from the power system 60 and output DC power to the DC bus 50 in a time zone other than the peak time zone. The power control unit 152D stops the AC / DC converter 30 during the peak time period.

According to the above configuration, power conversion loss does not occur because power is not purchased during peak hours, and it can contribute to reduction of electricity charges and avoidance of large-scale blackouts and planned blackouts when power demand is compressed. Moreover, since the power consumption of the water heater 85 in the peak time zone can be reduced, the time during which power can be supplied from the power storage device 20 to the DC load group 80A can be extended.

(14) The power supply system 1600 further includes a power generator 70 that supplies the generated power Pg to the DC bus 50 as DC power. The DC load group 80 includes a plurality of electric devices. Home controller 10E further includes an input unit 160E that receives input of time zone information, a generated power monitoring unit 158E that monitors the generated power Pg of the power generation apparatus 70, and a device control unit 162E that controls the operation of a plurality of electrical devices. The device control unit 162E includes a plurality of electrical devices that operate in a time zone other than the peak time zone, and stops at least one predetermined electrical device among the plurality of electrical devices in the peak time zone. The power control unit 152E stops the bidirectional power conversion device 32 and charges the power storage device 20 with differential power obtained by subtracting the power consumption P from the generated power Pg during a time zone other than the peak time zone. The power control unit 152E instructs the bidirectional power conversion device 32 to receive supply of DC power from the DC bus 50 and output AC power to the power system 60 during the peak time period.

According to the above configuration, since the air conditioner 82 in the DC load group 80 is stopped during the peak time period, the power consumption of the DC load group 80 during the peak time period can be reduced accordingly. Thereby, more electric power can be sold by a peak time slot | zone. As a result, it is possible to sell power at a high price, and contribute to stable power demand in the entire region through power sale cooperation when power demand is tight.

(15) The home controller 10 is provided between the power system 60 and the DC bus 50, and is connected to the DC bus 50 and the AC / DC converter 30 that converts AC power supplied from the power system 60 into DC power. The power storage device 20 configured to be able to charge and discharge DC power is controlled. The home controller 10 monitors the power consumption P of the DC load group 80 that receives DC power supplied from the DC bus 50, and the relationship between the input power to the AC / DC converter 30 and the conversion efficiency. Storage unit 154 for storing the efficiency characteristic information to be shown, and causing AC / DC converter 30 to perform power conversion so that the conversion efficiency is equal to or higher than a reference threshold, and charging / discharging operation of power storage device 20 based on power consumption P And a power control unit 152 to be controlled.

The configuration illustrated as the above-described embodiment is an example of the configuration of the present invention, and can be combined with another known technique, and a part of the configuration is omitted without departing from the gist of the present invention. It is also possible to change the configuration.

Further, in the above-described embodiment, the processing and configuration described in the other embodiments may be adopted as appropriate.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

10, 10A, 10B, 10C, 10D, 10E Home controller, 20 power storage device, 30 AC / DC converter, 32 bidirectional power converter, 40, 42 power meter, 50 DC bus, 60 power system, 70 power generator 72 solar cell, 74 converter, 80, 80A DC load group, 81 refrigerator, 82 air conditioner, 83 lighting fixture, 84 TV, 85 water heater, 90 network, 101 CPU, 102 touch panel, 103 display, 104 tablet, 105 operation Button, 106 Communication interface, 107 Output interface, 108 Input interface, 110 Memory, 111 Speaker, 112 Clock, 150, 150A, 150B, 150C, 150D, 150E Power

consumption monitoring unit

152, 152A, 152B, 152C, 152D, 152E power control unit, 154, 154A, 154B, 154C, 154D, 154E storage unit, 156A, 156B, 156C remaining battery power monitoring unit, 158B, 158C, 158E power generation power monitoring unit, 160C, 160D, 160E input unit, 162D, 162E device control unit, 1100, 1200, 1300, 1400, 1500, 1600 power supply system.

Claims

A forward conversion function that is provided between the power system and the DC bus and converts AC power supplied from the power system into DC power, and an inverse conversion function that converts DC power supplied from the DC bus into AC power A power conversion device having at least one of the functions of
A power storage device connected to the DC bus and configured to charge and discharge DC power; and
A controller for controlling the power conversion device and the power storage device,
The controller is
A power consumption monitoring unit that monitors power consumption of a load unit that receives supply of DC power from the DC bus;
A storage unit for storing efficiency characteristic information indicating a relationship between input power to the power conversion device and conversion efficiency;
A power supply system including: a power control unit configured to cause the power conversion device to perform power conversion so that the conversion efficiency is equal to or higher than a reference threshold, and to control a charge / discharge operation of the power storage device based on the power consumption.
The power control unit
If the power consumption is greater than or equal to a reference power, the power converter is instructed to receive the supply of AC power from the power system and output DC power to the DC bus,
2. The power supply system according to claim 1, wherein when the power consumption is less than the reference power, the power converter is stopped and DC power is discharged from the power storage device to the DC bus.
The controller is
A battery remaining amount monitoring unit for monitoring a remaining battery amount of the power storage device;
The power control unit
When the battery remaining amount is equal to or greater than a first reference remaining amount, the power conversion device is stopped and DC power is discharged from the power storage device to the DC bus,
When the battery remaining amount is less than the first reference remaining amount, the power conversion device is instructed to receive the supply of AC power from the power system and output DC power to the DC bus, and The power supply system according to claim 1, wherein the power storage device is charged with differential power obtained by subtracting the power consumption from DC power.
A power generator for supplying the DC bus with generated power as DC power;
The controller is
A battery level monitor for monitoring the battery level of the power storage device;
A generated power monitoring unit that monitors the generated power of the power generation device,
The power control unit
When the battery remaining amount is less than the first reference remaining amount, the power conversion device is stopped, and the power storage device is charged with differential power obtained by subtracting the power consumption from the generated power,
The power converter is instructed to receive supply of DC power from the DC bus and output AC power to the power system when the remaining battery level is equal to or greater than the first reference remaining capacity. The power supply system according to 1.
A forward conversion function that is provided between the power system and the DC bus and converts AC power supplied from the power system into DC power, and an inverse conversion function that converts DC power supplied from the DC bus into AC power A controller for controlling a power conversion device having at least one of the functions and a power storage device connected to the DC bus and configured to charge and discharge DC power,
The controller is
A power consumption monitoring unit that monitors power consumption of a load unit that receives supply of DC power from the DC bus;
A storage unit for storing efficiency characteristic information indicating a relationship between input power to the power conversion device and conversion efficiency;
A controller including: a power control unit configured to cause the power conversion device to perform power conversion so that the conversion efficiency is equal to or higher than a reference threshold; and to control a charge / discharge operation of the power storage device based on the power consumption.