JP7587940B2 - Power Supply System - Google Patents

Description

The present invention relates to technology for a power supply system capable of supplying power to a load.

Technology for power supply systems capable of supplying power to a load has been publicly known. For example, see Patent Document 1.

Patent Document 1 describes a power supply system that includes multiple power storage systems having a storage battery (first storage battery) and a solar power generation unit, and that can supply the discharged power of the first storage battery and the generated power of the solar power generation unit to multiple loads (houses). In the power supply system, the multiple power storage systems are provided on a distribution line (first distribution line) that connects a system power source and the multiple loads.

However, in the power supply system, although the power output from the multiple storage systems to the first distribution line can be supplied to multiple loads provided on the opposite side (downstream side) of the grid power source based on the multiple storage systems, it is not envisaged that the power will be supplied to, for example, another load connected from the middle of the first distribution line via another distribution line (second distribution line), or to a storage battery (second storage battery) provided on the second distribution line together with the other load. Therefore, there is a demand for technology that can effectively utilize the second storage battery provided on the second distribution line in accordance with the power output from the storage systems to the first distribution line.

JP 2019-165561 A

The present invention was made in consideration of the above-mentioned circumstances, and the problem it aims to solve is to provide a power supply system that can effectively utilize a second storage battery installed on a second distribution line according to the power flow state of the first distribution line.

The problem that the present invention aims to solve is as described above, and the means for solving this problem will be explained next.

That is, in claim 1, the present invention provides a power supply system including a first distribution line connecting a system power source and a first power load, a second distribution line connecting a middle portion of the first distribution line and a second power load, a first power generating unit provided between the middle portion of the first distribution line and the first power load, capable of generating power using natural energy and outputting the generated power to the first distribution line, a first power sensor provided closer to the system power source than the middle portion of the first distribution line and capable of detecting power, and a second power sensor provided between the middle portion of the first distribution line and the first power load, for charging and discharging the generated power of the first power generating unit. the first storage battery capable of being charged with electricity and outputting power based on the detection result of the first power sensor to the first distribution line; a second storage battery provided on the second distribution line toward the midway side of the second power load and capable of charging and discharging power; and a control unit that controls the second storage battery according to at least the flow state of power on the first distribution line, wherein when there is power flowing upstream on the first distribution line and the first storage battery is not discharging, the control unit issues a charge instruction to the second storage battery based on the power flowing upstream on the first distribution line .

In claim 2, the present invention relates to a power generation system including a first distribution line connecting a system power source and a first power load, a second distribution line connecting a midway portion of the first distribution line and a second power load, a first power generation unit provided between the midway portion of the first distribution line and the first power load, capable of generating power using natural energy and outputting the generated power to the first distribution line, a first power sensor provided closer to the system power source than the midway portion of the first distribution line and capable of detecting power, and a second power sensor provided between the midway portion of the first distribution line and the first power load, the first power generation unit being configured to generate power by using natural energy and outputting the generated power to the first distribution line. the first storage battery capable of charging and discharging the generated power of a power load unit and outputting power to the first distribution line based on the detection result of the first power sensor; a second storage battery provided on the second distribution line closer to the midway point than the second power load and capable of charging and discharging power; and a control unit that controls the second storage battery according to at least the flow state of power on the first distribution line, wherein the control unit instructs the second storage battery to stop charging when power is flowing upstream on the first distribution line and the first storage battery is discharging .

In claim 3, the present invention relates to a power supply system including a first distribution line connecting a system power source and a first power load, a second distribution line connecting a midway portion of the first distribution line and a second power load, a first power generation unit provided between the midway portion of the first distribution line and the first power load, capable of generating power using natural energy and outputting the generated power to the first distribution line, a first power sensor provided closer to the system power source than the midway portion of the first distribution line and capable of detecting power, a first storage battery provided between the midway portion of the first distribution line and the first power load, capable of charging and discharging the power generated by the first power generation unit and capable of outputting power based on a detection result of the first power sensor to the first distribution line, and a second power sensor provided between the midway portion of the first distribution line and the first power load, capable of charging and discharging the power generated by the first power generation unit and capable of outputting power based on a detection result of the first power sensor to the first distribution line, and The system comprises a second storage battery that is located on the midway side of the load and is capable of charging and discharging electric power; a control unit that controls the second storage battery according to at least the flow state of electric power on the first distribution line; and a second power generation unit that is located on the midway side of the second power load on the second distribution line and is capable of generating electric power using natural energy and outputting the generated electric power to the second distribution line, wherein the second storage battery is capable of charging and discharging the electric power generated by the second power generation unit, and the control unit issues a charging instruction to the second storage battery based on the electric power flowing upstream through the first distribution line and the second distribution line when there is electric power flowing upstream through the first distribution line and the second distribution line and the first storage battery is not discharging .

In claim 4, the present invention relates to a power supply system including a first distribution line connecting a system power source and a first power load, a second distribution line connecting a midway portion of the first distribution line and a second power load, a first power generation unit provided between the midway portion of the first distribution line and the first power load, capable of generating power using natural energy and outputting the generated power to the first distribution line, a first power sensor provided closer to the system power source than the midway portion of the first distribution line and capable of detecting power, a first storage battery provided between the midway portion of the first distribution line and the first power load, capable of charging and discharging the power generated by the first power generation unit and capable of outputting power based on a detection result of the first power sensor to the first distribution line, and a storage battery provided between the midway portion of the first distribution line and the first power load, capable of charging and discharging the power generated by the first power generation unit and capable of outputting power to the first distribution line based on a detection result of the first power sensor. The system comprises a second storage battery that is located on the midway side of the second power load and is capable of charging and discharging power; a control unit that controls the second storage battery according to at least the power flow state of the first distribution line; and a second power generation unit that is located on the midway side of the second power load of the second distribution line and is capable of generating power using natural energy and outputting the generated power to the second distribution line, wherein the second storage battery is capable of charging and discharging the power generated by the second power generation unit, and the control unit issues a charging instruction to the second storage battery based on the power flowing upstream of the second distribution line when there is no power flowing upstream of the first distribution line and there is power flowing upstream of the second distribution line .

In a fifth aspect of the present invention, the control unit issues a discharge instruction to the second storage battery when power from a system power supply is flowing through the first distribution line to the first power load side .

The effects of the present invention are as follows:

In the present invention, the second storage battery installed on the second distribution line can be effectively utilized according to the power flow state of the first distribution line.

1 is a block diagram showing a configuration of a power supply system according to an embodiment of the present invention; FIG. 4 is a diagram showing the connection relationship of a control unit. 4 is a flowchart showing a first power storage system operation control. 5 is a flowchart showing second power storage system operation control. FIG. 4 is a diagram showing an example of a power distribution mode when a first power storage system operation control is executed. FIG. 6 is a continuation of FIG. 5 . FIG. 4 is a diagram showing a first example of a power distribution mode when a second power storage system operation control is executed. FIG. 8 is a continuation of FIG. 7 . FIG. 11 is a diagram showing a second example of a power distribution mode when a second power storage system operation control is executed. FIG. 10 is a continuation of FIG. 9 . FIG. 11 is a diagram showing a third example of a power distribution mode when the second power storage system operation control is executed. FIG. 12 is a continuation of FIG. 11 . FIG. 11 is a diagram showing a fourth example of a power distribution mode when the second power storage system operation control is executed. FIG. 14 is a continuation of FIG. 13 . FIG. 11 is a diagram showing a fifth example of a power distribution mode when the second power storage system operation control is executed. FIG. 16 is a continuation of FIG. 15 .

The following describes a power supply system 1 according to one embodiment of the present invention.

The power supply system 1 shown in FIG. 1 is applied to a specified area (hereinafter referred to as "bulk receiving area A") where energy management is performed by a specified business operator (aggregator). The aggregator performs bulk receiving of high-voltage power and supplies the received power to various consumers in the bulk receiving area A, thereby performing bulk energy management. In the bulk receiving area A, a commercial facility S and a residential block A1 are provided as examples of such consumers.

The commercial facility S is a facility for commercial purposes. Tenants in the commercial facility S include, for example, supermarkets and drugstores. As described below, the commercial facility S is equipped with various electrical devices. The electricity used by the commercial facility S is sold by an aggregator. In addition, surplus electricity in the commercial facility S can also be sold to the aggregator.

The residential block A1 is a collection of multiple houses H that can share energy (e.g., electricity and heat) with each other. Various electrical appliances are provided in the residential block A1, as described below. In the residential block A1, the electricity used is sold from an aggregator to each house H. Also, surplus electricity in the residential block A1 can be sold to the aggregator. In this embodiment, it is assumed that four houses H are provided in the residential block A1. In the following, the four houses H may be referred to as the first house H1, the second house H2, the third house H3, and the fourth house H4, respectively.

As shown in Figures 1 and 2, the power supply system 1 includes electrical equipment in the commercial facility S (facility-side distribution board 10 and facility-side energy storage system 20), an inlet distribution board 30, electrical equipment in the residential block A1 (residential-side distribution board 40 and residential-side energy storage system 50), multiple power meters, a control unit 70, and the like. In the following description, "upstream side" and "downstream side" refer to the direction of power supply from the system power source K.

The electrical equipment of the commercial facility S includes a facility-side distribution board 10 and a facility-side power storage system 20.

The facility-side distribution board 10 distributes power supplied from a specified supply source to tenants in the commercial facility S. The facility-side distribution board 10 is connected to a power load consumed by the tenant (i.e., the commercial facility S) (not shown). For convenience, the facility-side distribution board 10 may be referred to as the power load of the commercial facility S below. The facility-side distribution board 10 is connected to a system power source K via a first distribution line L1 and a second distribution line L2. The upstream end of the first distribution line L1 is connected to the system power source K, and the downstream end is connected to a second connection point P2, which will be described later. The upstream end of the second distribution line L2 is connected to the second connection point P2, and the downstream end is connected to the facility-side distribution board 10 (power load).

In this embodiment, the power load of the commercial facility S is much larger than, for example, the power load of the residential block A1 described below. The power load of the commercial facility S is also much larger than the power that can be output by the facility-side power storage system 20 described below (the maximum discharge power of the facility-side storage battery 22 and the maximum output power of the facility-side power generation unit 21). Specifically, for example, when the commercial facility S is open for business, even if the facility-side storage battery 22 discharges at its maximum discharge power and the facility-side power generation unit 21 generates at its maximum output power, the power load is so large that it cannot be covered.

The facility-side power storage system 20 is capable of generating power using solar light and charging and discharging power. The facility-side power storage system 20 is connected to a midway point of the second distribution line L2. Specifically, the facility-side power storage system 20 is connected to the upstream side of the facility-side distribution board 10 on the second distribution line L2. The facility-side power storage system 20 includes a facility-side power generation unit 21, a facility-side storage battery 22, a facility-side sensor 23, and a facility-side power conditioner 24.

The facility-side power generation unit 21 is a device that generates electricity using sunlight. The facility-side power generation unit 21 is composed of a solar panel or the like. The facility-side power generation unit 21 is installed in a sunny location, such as the rooftop of the commercial facility S.

The facility-side storage battery 22 is configured to be able to charge and discharge power. The facility-side storage battery 22 is configured, for example, by a lithium-ion battery. In this embodiment, the maximum discharge power of the facility-side storage battery 22 is 2000 W. The maximum charge power of the facility-side storage battery 22 is 2000 W. The facility-side storage battery 22 can perform load-following operation to adjust the magnitude of charge and discharge power based on the detection results of the facility-side sensor 23 described below. The facility-side storage battery 22 performs a predetermined operation such as charging and discharging by executing one of multiple operating modes set in advance. The multiple operating modes include a discharge mode, a charge mode, a standby mode, and a charge and discharge mode. A detailed explanation of these modes will be given later.

The facility-side sensor 23 detects the power flowing through the location where it is installed. The facility-side sensor 23 is provided in the middle of the first distribution line L1. Specifically, the facility-side sensor 23 is installed on the first distribution line L1 between the system power source K and a second connection point P2, which will be described later. The facility-side sensor 23 is connected to the facility-side power conditioner 24, which will be described later.

The facility-side power conditioner 24 is a hybrid power conditioner capable of converting power appropriately. The facility-side power conditioner 24 is provided between the facility-side power generation unit 21 and the facility-side storage battery 22, and is connected to the facility-side power generation unit 21 and the facility-side storage battery 22. The facility-side power conditioner 24 can convert the DC power of the facility-side power generation unit 21 and the facility-side storage battery 22 into AC power. The facility-side power conditioner 24 is connected to the upstream side of the facility-side distribution board 10 on the second distribution line L2. In this way, the facility-side power conditioner 24 connects the facility-side storage system 20 to the second distribution line L2. In the following, the connection point of the second distribution line L2 with the facility-side power conditioner 24 (facility-side storage system 20) is referred to as the "first connection point P1".

In this way, the facility-side power conditioner 24 can output the power generated by the facility-side power generation unit 21 to the second distribution line L2. The facility-side power conditioner 24 can also charge the facility-side storage battery 22 with the power generated by the facility-side power generation unit 21 and the power flowing through the second distribution line L2. The facility-side power conditioner 24 can also output the discharged power of the facility-side storage battery 22 to the second distribution line L2. The facility-side power conditioner 24 can also control the operation of the facility-side storage battery 22.

The facility-side power conditioner 24 is also configured to be able to send and receive signals to and from the facility-side power generation unit 21, and can obtain information about the power generated by the facility-side power generation unit 21 based on the signals. The facility-side power conditioner 24 is also configured to be able to send and receive signals to and from the facility-side storage battery 22, and can obtain information about the remaining charge of the facility-side storage battery 22 and the currently running operating mode based on the signals. The facility-side power conditioner 24 is also configured to be able to receive signals from the facility-side sensor 23, and can obtain information about the detection results of the facility-side sensor 23.

In this way, in the commercial facility S, the power generated by the facility-side power generation unit 21 of the facility-side power storage system 20 and the discharged power of the facility-side storage battery 22 can be supplied to the power load of the commercial facility S. However, as described above, in this embodiment, since the power load of the commercial facility S is very large, the power generated by the facility-side power generation unit 21 and the discharged power of the facility-side storage battery 22 are basically insufficient to meet the required power (except for exceptions such as when the commercial facility S is not open, including at night). For this reason, the commercial facility S often purchases a relatively large amount of power from the system power source K.

The incoming distribution board 30 distributes the power supplied from a specified source as appropriate. The incoming distribution board 30 is provided in the middle of the third distribution line L3. The upstream end of the third distribution line L3 is connected to the connection point between the first distribution line L1 and the second distribution line L2 (hereinafter referred to as the "second connection point P2"). The downstream end of the third distribution line L3 branches into four, and each of the branches is connected to a later-described house-side distribution board 40 of the four houses H.

The electrical equipment in residential block A1 includes the electrical equipment in each home H. The electrical equipment in each home H also includes a home distribution board 40 and a home energy storage system 50.

The configurations of the home distribution board 40 and home energy storage system 50 of each home H are identical to each other, except for their arrangement. Therefore, unless otherwise specified, the following will use the first home H1 of the four homes H as an example and explain the home distribution board 40 and home energy storage system 50 of the first home H1.

The residential distribution board 40 distributes power supplied from a specified source to the electrical appliances (not shown) of the first residence H1 connected to the residential distribution board 40. In the following, the residential distribution board 40 may also be referred to as the power load of the first residence H1. The power load of the first residence H1 is very small compared to the power load of the commercial facility S. For example, in many cases, the total power load of all the residences H is smaller than the power load of the commercial facility S. The residential distribution board 40 is connected to the downstream end of the branched third distribution line L3. Thus, the residential distribution board 40 is provided downstream of the incoming distribution board 30 on the third distribution line L3.

The home side power storage system 50 is capable of generating electricity using solar power and charging and discharging electricity. The home side power storage system 50 is connected to the inlet distribution board 30. That is, the home side distribution board 40 is connected to the third distribution line L3 via the inlet distribution board 30. The home side power storage system 50 includes a home side power generation unit 51, a home side storage battery 52, a home side sensor 53, and a home side power conditioner 54.

The home-side power generating unit 51 is a device that generates power using sunlight. The home-side power generating unit 51 is composed of a solar panel or the like. The home-side power generating unit 51 is installed in a sunny location, such as the roof of the first house H1. In this embodiment, the maximum output power of the home-side power generating unit 51 is 5,500 W.

The residential storage battery 52 is configured to be able to charge and discharge power. The residential storage battery 52 is configured, for example, with a lithium ion battery. In this embodiment, the maximum discharge power of the residential storage battery 52 is 2000 W. The residential storage battery 52 can perform load following operation to adjust the magnitude of charge and discharge power based on the detection results of the residential sensor 53 described below. The residential storage battery 52 performs a predetermined operation such as charging and discharging by executing one of multiple preset operation modes. The multiple operation modes include a discharge mode similar to that of the facility storage battery 22 of the commercial facility S.

The home sensor 53 detects the power flowing through the location where it is installed. The home sensor 53 is provided in the middle of the first distribution line L1. Specifically, the home sensor 53 is provided on the first distribution line L1, upstream of the facility sensor 23. The home sensor 53 is connected to the home power conditioner 54, which will be described later.

The house side sensors 53 of the four houses H are installed on the first distribution line L1 in order from the upstream side to the downstream side. In this embodiment, of the four house side sensors 53, the house side sensor 53 of the first house H1 is installed first (furthest upstream) when viewed from the upstream side, the house side sensor 53 of the second house H2 is installed second, the house side sensor 53 of the third house H3 is installed third, and the house side sensor 53 of the fourth house H4 is installed fourth (furthest downstream).

The residential power conditioner 54 is a hybrid power conditioner capable of converting power as appropriate. The residential power conditioner 54 is provided between the residential power generation unit 51 and the residential storage battery 52, and is connected to the residential power generation unit 51 and the residential storage battery 52. The residential power conditioner 54 can convert the DC power of the residential power generation unit 51 and the residential storage battery 52 into AC power. The residential power conditioner 54 is also connected to the inlet distribution board 30. In this way, the residential power conditioner 54 connects the residential energy storage system 50 to the inlet distribution board 30.

The home-side inverters 54 of the four homes H are connected to the inlet distribution board 30 in order from the upstream side to the downstream side. In this embodiment, the home-side inverters 54 of the first home H1, the second home H2, the third home H3, and the fourth home H4 are connected in order from the upstream side to the downstream side. That is, in the four home-side storage systems 50, the home-side storage system 50 of the first home H1 is connected to the inlet distribution board 30 first (most upstream) from the upstream side through the four home-side inverters 54, the home-side storage system 50 of the second home H2 is connected second, the home-side storage system 50 of the third home H3 is connected third, and the home-side storage system 50 of the fourth home H4 is connected fourth (most downstream).

In this way, the home side power conditioner 54 can output the power generated by the home side power generation unit 51 to the inlet distribution board 30. The home side power conditioner 54 can also charge the home side storage battery 52 with the power generated by the home side power generation unit 51 and the power from the inlet distribution board 30. The home side power conditioner 54 can also output the discharged power of the home side storage battery 52 to the inlet distribution board 30. The home side power conditioner 54 can also control the operation of the home side storage battery 52.

The home side power conditioner 54 is also configured to be able to send and receive signals to and from the home side power generation unit 51, and can obtain information about the power generated by the home side power generation unit 51 based on the signals. The home side power conditioner 54 is also configured to be able to send and receive signals to and from the home side storage battery 52, and can obtain information about the remaining charge of the home side storage battery 52 and the operating mode currently being performed based on the signals. The home side power conditioner 54 is also configured to be able to receive signals from the home side sensor 53, and can obtain information about the detection results of the home side sensor 53.

The multiple power meters detect the electricity flowing through the locations where they are installed. The multiple power meters include a power purchase meter 61, a first power purchase meter 62, a second power purchase meter 63, and a third power purchase meter 64.

The power purchase meter 61 is provided midway along the third distribution line L3. Specifically, the power purchase meter 61 is installed between the branch point at the downstream end of the third distribution line L3 and the inlet distribution board 30. The power purchase meter 61 can obtain the power flowing from the inlet distribution board 30 to the residential distribution boards 40 (power loads) of the four homes H. In other words, the power purchase meter 61 can obtain the total power load of the residential block A1.

The first electricity buying and selling meter 62 is provided in the middle of the first distribution line L1. Specifically, the first electricity buying and selling meter 62 is provided between the facility side sensor 23 and the second connection point P2 on the first distribution line L1. The first electricity buying and selling meter 62 can acquire the electricity that flows from the system power source K to the collective power receiving area A (electricity purchased from the system power source K). The first electricity buying and selling meter 62 can also acquire the electricity that flows backward from the collective power receiving area A to the system power source K (electricity sold to the system power source K).

The second electricity buying and selling meter 63 is provided in the middle of the second distribution line L2. Specifically, the first electricity buying and selling meter 62 is provided between the second connection point P2 and the first connection point P1 on the second distribution line L2. The second electricity buying and selling meter 63 can acquire electricity (electricity purchased by the commercial facility S) flowing from a specified source to the commercial facility S's electrical equipment (facility side distribution board 10 and facility side energy storage system 20). The second electricity buying and selling meter 63 can also acquire electricity (electricity sold by the commercial facility S) flowing backward from the commercial facility S's facility side energy storage system 20 to the upstream side.

The third electricity buying and selling meter 64 is provided in the middle of the third distribution line L3. Specifically, the third electricity buying and selling meter 64 is installed between the upstream end (second connection point P2) of the third distribution line L3 and the inlet distribution board 30. The third electricity buying and selling meter 64 can obtain electricity (electricity purchased by the residential block A1) that flows from a specified source to the electrical equipment in the residential block A1 (the residential distribution boards 40 and the residential energy storage systems 50 of the four homes H). The third electricity buying and selling meter 64 can also obtain electricity that flows backward from the residential block A1 to the upstream side (electricity sold by the residential block A1).

The control unit 70 shown in FIG. 2 is an energy management system that manages the operation of the power supply system 1. The control unit 70 can set the power supply mode in the collective power receiving area A. The control unit 70 is equipped with an arithmetic processing unit such as a CPU, a storage unit such as a RAM or ROM, and an input/output unit such as a touch panel, and can perform predetermined arithmetic processing and storage processing. The control unit 70 stores various information and programs used when controlling the operation of the power supply system 1 in advance. The control unit 70 is connected to the facility side power conditioner 24 of the facility side power storage system 20, the home side power conditioners 54 of the four home side power storage systems 50, and multiple power meters (power purchase meter 61, first power purchase meter 62, second power purchase meter 63, and third power purchase meter 64).

The control unit 70 can control the operation of the facility-side power storage system 20 of the commercial facility S. Specifically, the control unit 70 can control the operation (operation mode) of the facility-side storage battery 22 via the facility-side power conditioner 24 of the facility-side power storage system 20. The control unit 70 can also control the operation of the home-side power storage systems 50 of the four homes H. Specifically, the control unit 70 can control the operation (operation mode) of the home-side storage battery 52 via the home-side power conditioner 54 of each home-side power storage system 50.

The control unit 70 can also acquire information about the facility-side power storage system 20. Specifically, the control unit 70 can acquire the generated power of the facility-side power generation unit 21, the remaining charge of the facility-side storage battery 22, the currently running operating mode, and the like, via the facility-side power conditioner 24 of the facility-side power storage system 20.

The control unit 70 can also obtain information about the four home-side energy storage systems 50. Specifically, the control unit 70 can obtain the generated power of the home-side power generation unit 51, the remaining charge of the home-side storage battery 52, the current operating mode (operating status), and the like, via the home-side power conditioner 54 of each home-side energy storage system 50. Based on the obtained information, the control unit 70 can also calculate the cumulative discharge amount, which is the sum of the amount of power discharged from the installation of each home-side storage battery 52 to the present.

The control unit 70 can also acquire the detection results of multiple power meters (power purchase meter 61, first power purchase meter 62, second power purchase meter 63, and third power purchase meter 64).

The control unit 70 can also obtain (calculate) the total power generated by all of the home-side power generating units 51 (for the entire residential block A1) (hereinafter referred to as "total PV power generation") based on the power generated by the home-side power generating units 51 of each home H obtained via the home-side power conditioner 54. The control unit 70 can also obtain (calculate) the total power load of all of the homes H (hereinafter referred to as "total home load") based on the detection results obtained from the power purchase meter 61.

The following describes the operating modes (discharge mode, charge mode, standby mode, and charge/discharge mode) of the facility-side storage battery 22 of the facility-side energy storage system 20 and the home-side storage battery 52 of the home-side energy storage system 50.

The operation modes of the facility-side storage battery 22 and the home-side storage battery 52 are identical to each other, except for the sensors used when performing load following operation. Therefore, unless otherwise specified, the operation modes will be explained below using the facility-side storage battery 22 as an example.

The discharge mode of the facility-side storage battery 22 is a mode in which discharging is performed. When the discharge mode is executed, the facility-side storage battery 22 discharges based on the detection result of the facility-side sensor 23 by load following operation. Specifically, when the discharge mode is executed, if the facility-side sensor 23 detects power flowing downstream, the facility-side storage battery 22 discharges power of a magnitude corresponding to the detected power. Note that if the remaining battery level of the facility-side storage battery 22 is not sufficient to discharge (for example, if the remaining battery level is at the lower limit or minimum remaining level), the facility-side storage battery 22 does not discharge (enters a standby state) even if the facility-side sensor 23 detects power flowing downstream.

The charging mode of the facility-side storage battery 22 is a mode in which charging is performed. When the charging mode is executed, the facility-side storage battery 22 is charged with the power generated by the facility-side power generation unit 21. In addition, when the facility-side power generation unit 21 is not generating power or when the power generated by the facility-side power generation unit 21 is smaller than the maximum charging power of the facility-side storage battery 22, the facility-side storage battery 22 also charges with power supplied from the upstream side of the facility-side power storage system 20 (for example, power purchased from the system power source K). Note that even when the charging mode is executed, if the power generated by the facility-side power generation unit 21 is greater than the charging power of the facility-side storage battery 22, the surplus power of the generated power is output to the second distribution line L2. In addition, when the facility-side storage battery 22 is fully charged, the facility-side storage battery 22 does not charge (is in a standby state) even when the charging mode is executed.

The standby mode of the facility-side storage battery 22 is a mode in which the battery is on standby. In other words, when the standby mode is executed, the facility-side storage battery 22 remains in operation but does not charge or discharge (it is in a standby state). In the following, the standby state may also be referred to as "stopped."

The charge/discharge mode of the facility-side storage battery 22 is a mode in which charging and discharging are performed. When the charge/discharge mode is executed, the facility-side storage battery 22 performs charging and discharging based on the detection results of the facility-side sensor 23 through load following operation.

Specifically, when the charge/discharge mode is executed, the facility-side storage battery 22 discharges power of a magnitude corresponding to the detected power when the facility-side sensor 23 detects power flowing downstream, similar to the discharge mode. Note that even when the facility-side sensor 23 detects power flowing downstream, if the facility-side storage battery 22 does not have a remaining battery charge that allows discharge, the facility-side storage battery 22 does not discharge (enters a standby state).

In addition, when the charge/discharge mode is executed, if the facility-side sensor 23 detects power flowing upstream, the facility-side storage battery 22 charges with power of a magnitude corresponding to the detected power. Note that even if the facility-side sensor 23 detects power flowing upstream, the facility-side storage battery 22 does not charge (enters a standby state) if the facility-side sensor 23 detects power flowing upstream, for example, if the facility-side storage battery 22 is fully charged.

The operation mode of the facility-side storage battery 22 is switched by instructions from the control unit 70 via the facility-side power conditioner 24. In the following, instructions from the control unit 70 to execute (switch) the discharge mode, charge mode, standby mode, and charge/discharge mode of the facility-side storage battery 22 may be referred to as a discharge instruction, a charge instruction, a standby (stop) instruction, and a charge/discharge instruction, respectively.

Although the facility-side storage battery 22 has been described as an example as above, the operation modes of the home-side storage battery 52 are also the same. Specifically, the home-side storage battery 52 executes a discharge mode or a charge/discharge mode based on the detection result of the home-side sensor 53 corresponding to the home-side storage battery 52. Note that the home-side sensor 53 corresponding to the home-side storage battery 52 refers to the relationship between the home-side storage battery 52 and the home-side sensor 53 in the same home-side storage system 50 among the four home-side power storage systems 50.

In the power supply system 1 configured as described above, the power distribution mode is determined by the control of the residential block A1 and the commercial facility S by the control unit 70. In the control of the residential block A1 and the commercial facility S by the control unit 70, the operation modes of the residential side storage battery 52 in the residential block A1 and the facility side storage battery 22 in the commercial facility S are switched.

In the following, the control by the control unit 70 over the residential block A1, i.e., the control of switching the operation mode of the residential storage battery 52, is referred to as "first power storage system operation control." Also, the control by the control unit 70 over the commercial facility S, i.e., the control of switching the operation mode of the facility storage battery 22, is referred to as "second power storage system operation control." The first power storage system operation control and the second power storage system operation control by the control unit 70 are repeatedly executed at predetermined timing (e.g., every 5 minutes).

The following describes the operation control of the first power storage system by the control unit 70 (control of switching the operation mode of the home storage battery 52) with reference to FIG. 3.

In step S101, the control unit 70 acquires information regarding the current total residential load and total PV power generation. As described above, the total residential load is the total power consumption of the residential loads of all (four) homes H. As described above, the total PV power generation is the total power generation of all (four) home-side power generation units 51. After executing the process of step S101, the control unit 70 executes the process of step S102.

In step S102, the control unit 70 determines whether the total residential load is equal to or greater than the total PV power generation. If the control unit 70 determines that the total residential load is equal to or greater than the total PV power generation (step S102: YES), it executes the process of step S105. On the other hand, if the control unit 70 determines that the total residential load is less than the total PV power generation (step S102: NO), it executes the process of step S103.

In step S103, the control unit 70 calculates the number of home storage batteries 52 that will be in charging mode.

When the processing of step S103 is executed, the total residential load is smaller than the total PV power generation, so the power generated by the four residential power generation units 51 is in excess of the power load of the four homes H.

Therefore, the control unit 70 calculates how many home-side storage batteries 52 should be charged with the surplus power using formula (1) "Number of storage batteries to be charged = (Total PV power generation - Total home load) / Maximum storage battery charging power". Note that if the number calculated using formula (1) contains a decimal point, the decimal point is rounded down. After executing the process of step S103, the control unit 70 executes the process of step S104.

In step S104, the control unit 70 issues a charge instruction to the number of home storage batteries 52 calculated in step S103. At this time, the control unit 70 obtains the remaining battery power from all home storage batteries 52 (or home storage batteries 52 for which a charge instruction can be issued), and issues a charge instruction to the number of home storage batteries 52 in order starting from the home storage battery 52 with the least remaining battery power (executes a charge mode). In addition, the control unit 70 issues a standby instruction to home storage batteries 52 other than the home storage battery 52 for which a charge instruction was issued (executes a standby mode). After executing the process of step S104, the control unit 70 temporarily ends the first power storage system operation control.

In addition, in step S105, which is reached when it is determined in step S102 that the total residential load is equal to or greater than the total PV power generation, the control unit 70 calculates the number of residential storage batteries 52 that will be in the discharge mode.

When the processing of step S105 is executed, the total residential load is equal to or greater than the total PV power generation, so the power generated by the four residential power generation units 51 alone is insufficient to meet the power load of the four homes H.

Therefore, the control unit 70 calculates how many home-side storage batteries 52 need to be discharged to cover the power shortage using formula (2) "Number of storage batteries to be discharged = (total home load - total PV power generation) / maximum discharge power of storage batteries." Note that if the number calculated using formula (2) contains a decimal point, the decimal point is rounded up. After executing the process of step S105, the control unit 70 executes the process of step S106.

In step S106, the control unit 70 issues a discharge command to the number of home storage batteries 52 calculated in step S105, starting with the storage system with the highest discharge priority. The control unit 70 also issues a standby command to the home storage batteries 52 other than the storage battery 52 to which the discharge command was issued. After executing the process of step S106, the control unit 70 temporarily ends the first storage system operation control.

The discharge priority order is a criterion for determining which of the multiple home storage batteries 52 should be given priority for discharge over the other home storage batteries 52. To determine the discharge priority order, the control unit 70 first acquires the accumulated discharge amount of all home storage batteries 52. Specifically, the control unit 70 acquires the total amount of power discharged from the time of installation to the present for each home storage battery 52. The control unit 70 then sets the discharge priority order (in this embodiment, first, second, and third) for all home storage batteries 52 in order of least accumulated discharge amount.

By controlling the operation of the first power storage system in this manner, if there is surplus power in the residential block A1 (step S102: NO), the power generated by the residential power generation unit 51 can be charged to an appropriate number of residential storage batteries 52 (steps S103 and S104). This makes it possible to improve the self-consumption rate of the power generated by the residential power generation unit 51 in the residential block A1.

Furthermore, if there is a power shortage in the residential block A1 (step S102: YES), an appropriate number of home storage batteries 52 can be discharged (steps S105, S106). This allows the power loads of the four homes H to be treated as a single power load, and allows the discharged power from the home storage batteries 52 of the four homes H to be supplied (accommodated). In this way, it is possible to minimize the power shortage in the residential block A1 being covered by power supplied from outside the residential block A1 (for example, power purchased from the power grid K).

When the residential storage battery 52 is in the discharge mode, it performs load following operation based on the detection results of the corresponding residential sensor 53. Here, the first distribution line L1 on which the residential sensor 53 is installed carries a relatively large amount of power from the system power source K to cover the relatively large power load of the commercial facility S as described above. Therefore, in many cases, the residential storage battery 52 in the discharge mode will discharge at the maximum discharge power (2000 W) based on the relatively large power detected by the corresponding residential sensor 53.

Thus, in this embodiment, when the discharge mode is executed for any home storage battery 52, in most cases, discharge can be performed at the maximum discharge power. In other words, regardless of the upstream or downstream placement of the home storage system 50 and home sensor 53, or the magnitude of the power shortage relative to the total home load, it is possible to prevent the discharge power of the home storage battery 52 from becoming small (the discharge efficiency from decreasing).

As described above, when calculating how many home-side batteries 52 are to be charged with the surplus power of the four home-side power generating units 51, if the number calculated by formula (1) contains a decimal point, the decimal point is rounded down (step S103). That is, not all of the surplus power is charged to the home-side batteries 52, and some of the power flows upstream through the third distribution line L3. Also, as described above, when calculating how many home-side batteries 52 are discharged to cover the power shortage of the four home-side power generating units 51, if the number calculated by formula (2) contains a decimal point, the decimal point is rounded up (step S105). That is, not all of the discharged power of the home-side batteries 52 (which is the maximum discharged power as described above) is supplied to the home load (because some of the discharged power of the home-side batteries 52 is surplus), and some of the power flows upstream through the third distribution line L3.

Here, Figures 5 and 6 are diagrams showing an example of the distribution of electricity when the first power storage system operation control is executed.

In the state shown in FIG. 5, the total power load (total power usage) of residential block A1 is 7,000 W. The total power generated by the residential power generation unit 51 in residential block A1 is 0 W. The total power load (total power usage) of commercial facility S is 10,000 W. The power from system power source K (total purchased power) is 17,000 W.

In this case, since the total residential load is equal to or greater than the total PV power generation, the number of residential storage batteries 52 that will execute the discharge mode is calculated (step S102: YES, step S105). In the state shown in FIG. 5, the number of residential storage batteries 52 that will execute the discharge mode is calculated as 4. That is, a discharge command is issued to all residential storage batteries 52 in residential block A1.

As a result, as shown in FIG. 6, the sum of the discharged power (total discharged power) of all the residential storage batteries 52 in the residential block A1 is 8000 W. Of the 8000 W, 7000 W is supplied to the power load in the residential block A1. The remaining 1000 W flows upstream through the third distribution line L3 and is supplied (transferred) to the power load of the commercial facility S via the second distribution line L2. The power from the system power source K (total purchased power) is reduced to 9000 W. In this way, by executing the first storage system operation control, a portion of the generated power in the residential block A1 can be transferred to the commercial facility S.

In the following, in order to clarify the technical significance of the second power storage system operation control described later, we will first explain the state of power distribution in the commercial facility S when the control unit 70 does not control switching of the operation mode of the facility-side storage battery 22 (specifically, when the charge/discharge mode is continuously executed as the operation mode of the facility-side storage battery 22).

When the facility-side storage battery 22 executes the charge/discharge mode, it charges and discharges based on the detection results of the facility-side sensor 23 through load following operation as described above.

As described above, in many cases, the power generated by the facility-side power generation unit 21 alone is insufficient to cover the power load of the commercial facility S, so a relatively large amount of power is purchased from the system power source K. That is, in the first distribution line L1 on which the facility-side sensor 23 is installed, a relatively large amount of power flows (downstream) from the system power source K to cover the relatively large power load of the commercial facility S. Therefore, the facility-side storage battery 22, which is executing the charge/discharge mode, continues to discharge at the maximum discharge power (2000 W) based on the relatively large amount of power detected by the facility-side sensor 23.

In this way, if the charge/discharge mode is continuously executed, the facility-side storage battery 22 continues to discharge, and therefore has no opportunity to charge with power from the grid power source K or the power generated by the facility-side power generation unit 21. Even if the facility-side storage battery 22 does have an opportunity to charge, the facility-side storage battery 22 will quickly discharge because the amount of power used at the commercial facility S is very large. In other words, the facility-side storage battery 22 is almost never in a state where it has a remaining battery capacity (more than the amount that can be discharged). Thus, if the operation mode of the facility-side storage battery 22 is not switched, for example, in the event of a power outage, the discharged power cannot be used, and it is difficult to say that the facility-side storage battery 22 is being used effectively.

Therefore, in the power supply system 1, second power storage system operation control is executed to effectively utilize the facility-side storage battery 22.

The following describes the second power storage system operation control (operation mode switching control of the facility-side storage battery 22) by the control unit 70 using Figure 4.

When the second power storage system operation control starts, the operation mode of the facility-side storage battery 22 is not particularly limited.

In step S201, the control unit 70 determines whether electricity is being purchased in the residential block A1. The control unit 70 makes this determination based on the detection result of the third electricity purchase and sale meter 64. If the control unit 70 determines that electricity is being purchased in the residential block A1 (electricity is flowing to the residential block A1 side) (step S201: YES), it executes the process of step S202. On the other hand, if the control unit 70 determines that electricity is not being purchased in the residential block A1 (electricity is not flowing to the residential block A1 side) (step S201: NO), it executes the process of step S203.

In step S202, the control unit 70 issues a discharge command to the facility-side storage battery 22 of the commercial facility S. That is, the control unit 70 switches the operation mode of the facility-side storage battery 22 to a discharge mode (or maintains that mode if it is already in the discharge mode). In this way, the facility-side storage battery 22 discharges by load following operation based on the detection result of the facility-side sensor 23. After executing the process of step S202, the control unit 70 temporarily ends the second storage system operation control.

In step S203, the control unit 70 determines whether there is reverse power flow from the residential block A1. The control unit 70 makes this determination based on the detection result of the third electricity buying and selling meter 64. If the control unit 70 determines that there is reverse power flow from the residential block A1 (step S203: YES), it executes the process of step S204. On the other hand, if the control unit 70 determines that there is no reverse power flow from the residential block A1 (step S203: NO), it executes the process of step S208.

In step S204, the control unit 70 determines whether the residential storage battery 52 in the residential block A1 is discharging. More specifically, the control unit 70 determines whether at least one of the four (all) residential storage batteries 52 in the residential block A1 is discharging. The control unit 70 makes the determination based on the operating status of the residential storage batteries 52 acquired through each residential power conditioner 54 in the residential block A1. If the control unit 70 determines that the residential storage batteries 52 in the residential block A1 are not discharging (none of the residential storage batteries 52 are discharging) (step S204: NO), it executes the process of step S205. On the other hand, if the control unit 70 determines that the residential storage batteries 52 in the residential block A1 are discharging (at least one of the residential storage batteries 52 is discharging) (step S204: YES), it executes the process of step S210.

In step S205, the control unit 70 determines whether there is reverse power flow from the commercial facility S. The control unit 70 makes this determination based on the detection result of the second electricity purchase and sale meter 63. If the control unit 70 determines that there is no reverse power flow from the commercial facility S (step S205: NO), it executes the process of step S206. On the other hand, if the control unit 70 determines that there is reverse power flow from the commercial facility S (step S205: YES), it executes the process of step S207.

In step S206, the control unit 70 instructs the facility-side storage battery 22 of the commercial facility S to charge the reverse flow of power from the residential block A1. That is, the control unit 70 switches the operation mode of the facility-side storage battery 22 to charging mode (or maintains that mode if it is already in charging mode), and instructs the facility-side storage battery 22 to charge the same amount of power as the detection result of the third electricity buying and selling meter 64. In this way, the facility-side storage battery 22 can charge the reverse flow of power from the residential block A1. After executing the process of step S206, the control unit 70 temporarily terminates the second storage system operation control.

In addition, in step S207, the control unit 70 instructs the facility-side storage battery 22 of the commercial facility S to charge the total amount of reverse power flow (i.e., the sum of the reverse power flow from the commercial facility S and the residential block A1). That is, the control unit 70 switches the operation mode of the facility-side storage battery 22 to the charging mode (or maintains the charging mode if it is already in the charging mode), and instructs the facility-side storage battery 22 to charge the same amount of power as the sum of the detection results of the second electricity buying and selling meter 63 and the third electricity buying and selling meter 64. In this way, the facility-side storage battery 22 can charge the total amount of reverse power flow from the commercial facility S and the residential block A1. After executing the process of step S207, the control unit 70 temporarily ends the second storage system operation control.

Furthermore, in step S208, which is performed when it is determined that there is no reverse power flow from the residential block A1 as described above (step S203: NO), the control unit 70 determines whether there is a reverse power flow from the commercial facility S. The control unit 70 makes this determination based on the detection result of the second electricity buying and selling meter 63. If the control unit 70 determines that there is a reverse power flow from the commercial facility S (step S208: YES), it executes the processing of step S209. On the other hand, if the control unit 70 determines that there is no reverse power flow from the commercial facility S (step S208: NO), it temporarily terminates the second power storage system operation control.

In step S209, the control unit 70 instructs the facility-side storage battery 22 of the commercial facility S to charge the reverse flow of power from the commercial facility S. That is, the control unit 70 switches the operation mode of the facility-side storage battery 22 to charging mode (or maintains that mode if it is already in charging mode), and instructs the facility-side storage battery 22 to charge the same amount of power as the detection result of the second electricity buying and selling meter 63. In this way, the facility-side storage battery 22 can charge the reverse flow of power from the facility-side storage battery 22. After executing the process of step S209, the control unit 70 temporarily terminates the second power storage system operation control.

As described above, if it is determined that the home storage battery 52 in residential block A1 is discharging (step S204: YES), the control unit 70 issues a standby (stop) instruction to the facility storage battery 22 in step S210. That is, the control unit 70 switches the operation mode of the facility storage battery 22 to standby mode (or maintains that mode if it is already in standby mode). In this way, the facility storage battery 22 can be stopped even if charging or discharging is desired. After executing the process of step S210, the control unit 70 temporarily ends the second power storage system operation control.

The following describes an example of the power flow pattern when the second power storage system operation control described above is executed.

First, Figures 7 and 8 are diagrams showing a first example of the power distribution state when the second power storage system operation control is executed.

In the state shown in FIG. 7, the total power load (total power usage) of the residential block A1 is 7000W. The total power generated by the residential power generation unit 51 of the residential block A1 (total power generation) is 8000W. Of the 8000W, 7000W is supplied to the power load of the residential block A1, and the remaining 1000W flows upstream and is supplied (accommodated) to the power load of the commercial facility S. The total power load (total power usage) of the commercial facility S is 10000W. The power generated (photovoltaic power generation) by the facility-side power generation unit 21 of the commercial facility S is 8000W. The power from the system power source K (total purchased power) is 1000W.

In this case, since there is a reverse power flow from the residential block A1, the residential battery 52 in the residential block A1 is not discharging, and there is no reverse power flow from the commercial facility S (step S203: YES, step S204: NO, step S205: NO), the facility battery 22 charges with the power equivalent to the reverse power flow from the residential block A1 (step S206).

As a result, as shown in FIG. 8, of the power generated by the home-side power generation unit 51 in the residential block A1, 1000 W of power that flows upstream is charged to the facility-side storage battery 22. In this way, although the power from the system power source K (total purchased power) increases to 2000 W, the facility-side storage battery 22 can be charged with surplus power from the residential block A1.

Next, Figures 9 and 10 show a second example of the power distribution mode when the second power storage system operation control is executed.

In the state shown in FIG. 9, the total power load (total power usage) of the residential block A1 is 7000W. The total discharged power (total discharged power) of the residential side storage batteries 52 in the residential block A1 is 8000W. Of the 8000W, 7000W is supplied to the power load of the residential block A1, and the remaining 1000W flows upstream and is supplied (accommodated) to the power load of the commercial facility S. The total power load (total power usage) of the commercial facility S is 10000W. The generated power (photovoltaic power generation) of the facility side power generation unit 21 of the commercial facility S is 0W. The power (total purchased power) from the system power source K is 9000W.

In this case, because there is a reverse power flow from residential block A1 and the home-side storage battery 52 in residential block A1 is discharging (step S203: YES, step S204: YES), the facility-side storage battery 22 is shut down (step S210).

As a result, as shown in FIG. 10, of the power generated by the residential power generating unit 51 in residential block A1, 1000 W of power that flows upstream is directly supplied (interchanged) to the power load of the commercial facility S. Thus, unlike the case shown in FIG. 8, when there is power flowing upstream from residential block A1, the facility storage battery 22 does not charge if that power is discharging power from the residential storage battery 52. In this way, it is possible to avoid the inefficient operation of charging another storage battery (residential storage battery 52) with power that has once been charged, again into a different storage battery (facility storage battery 22).

Next, Figures 11 and 12 are diagrams showing a third example of the power distribution mode when the second power storage system operation control is executed.

In the state shown in FIG. 11, the total power load (total power usage) of the residential block A1 is 4000W. The total power generated by the residential power generating unit 51 of the residential block A1 (total power generation) is 4000W. The total power load (total power usage) of the commercial facility S is 1000W. The power generated (photovoltaic power generation) of the facility-side power generating unit 21 of the commercial facility S is 5000W. Of the 5000W, 1000W is supplied to the power load of the commercial facility S, and the remaining 4000W flows upstream and is sold to the system power source K. Note that this state (a state in which the power generated by the facility-side power generating unit 21 is in excess of the power load of the commercial facility S) is assumed to be when the commercial facility S is not open (it is a regular holiday).

In this case, since there is no reverse power flow from the residential block A1 and there is a reverse power flow from the commercial facility S (step S203: NO, step S208: YES), the facility-side storage battery 22 is charged with the power equivalent to the reverse power flow from the commercial facility S (step S209).

As a result, as shown in FIG. 12, the facility-side storage battery 22 is charged with 4000 W of power generated by the facility-side power generation unit 21 of the commercial facility S that was flowing upstream. Note that the maximum charging power of the facility-side storage battery 22 is 2000 W, so in the state shown in FIG. 12, 2000 W of power is charged instead of 4000 W. In this way, although the amount of power sold to the system power source K is reduced, the facility-side storage battery 22 can be charged with surplus power from the facility-side power generation unit 21 (power generated by the facility-side power generation unit 21 that is in excess of the power load of the commercial facility S).

Next, Figures 13 and 14 are diagrams showing a fourth example of the power distribution mode when the second power storage system operation control is executed.

In the state shown in FIG. 13, the total power load (total power usage) of the residential block A1 is 4000W. The total power generated by the residential power generation unit 51 of the residential block A1 (total power generation) is 5000W. Of the 5000W, 4000W is supplied to the power load of the residential block A1, and the remaining 1000W flows upstream and is sold to the system power source K. The total power load (total power usage) of the commercial facility S is 1000W. The power generated (photovoltaic power generation) of the facility power generation unit 21 of the commercial facility S is 5000W. Of the 5000W, 1000W is supplied to the power load of the commercial facility S, and the remaining 4000W flows upstream and is sold to the system power source K. The power (total reverse flow) of the power sold to the system power source K is 5000W.

In this case, since there is a reverse power flow from the residential block A1, the residential side storage battery 52 in the residential block A1 is not discharging, and there is a reverse power flow from the commercial facility S (step S203: YES, step S204: NO, step S205: YES), the facility side storage battery 22 charges with the combined power of the reverse power flow from the commercial facility S and the residential block A1 (step S207).

As a result, as shown in FIG. 14, the facility-side storage battery 22 is charged with the total power of 4000 W of the power generated by the facility-side power generation unit 21 of the commercial facility S that flows upstream, and 1000 W of the power generated by the home-side power generation unit 51 of the residential block A1 that flows upstream. Note that the maximum charging power of the facility-side storage battery 22 is 2000 W, so in the state shown in FIG. 14, 2000 W of power is charged, not 5000 W. In this way, although the power sold to the system power source K is reduced, the surplus power of the facility-side power generation unit 21 and the home-side power generation unit 51 can be charged to the facility-side storage battery 22.

Next, Figures 15 and 16 are diagrams showing a fifth example of the power distribution mode when the second power storage system operation control is executed.

In the state shown in FIG. 15, the total power load (total power usage) of residential block A1 is 10,000 W. The total discharged power (total discharged power) of the residential storage batteries 52 in residential block A1 is 8,000 W. Since the discharged power of the residential storage batteries 52 in residential block A1 is insufficient for the power load of residential block A1, the power (purchased power) from system power source K is 2,000 W. The total power load (total power usage) of commercial facility S is 10,000 W. The power (total purchased power) from system power source K is 12,000 W.

In this case, since electricity is purchased in the residential block A1 (step S201: YES), the facility-side storage battery 22 discharges electricity through load following operation based on the detection results of the facility-side sensor 23 (step S202).

As a result, as shown in FIG. 16, the detection result of the facility-side sensor 23 is 10,000 W, and the facility-side storage battery 22 discharges at a maximum discharge power of 2,000 W. The discharged power of the facility-side storage battery 22 is supplied to the power load of the commercial facility S. In other words, part of the power load of the commercial facility S can be covered by the discharged power of the facility-side storage battery 22. In this way, the power from the system power source K (total purchased power) can be reduced.

As described above, in the power supply system 1 according to this embodiment,
a first distribution line (a first distribution line L1 and a third distribution line L3) that connects the system power source K and a house-side distribution board 40 (a first power load);
A second distribution line (second distribution line L2) that connects a second connection point P2 (midway) of the first distribution line (first distribution line L1 and third distribution line L3) and a facility-side distribution board 10 (second power load);
a home-side power generating unit 51 (first power generating unit) that is provided between the second connection point P2 (midway) of the first distribution line (first distribution line L1 and third distribution line L3) and the home-side distribution board 40 (first power load), and that is capable of generating power using natural energy and outputting the generated power to the first distribution line (first distribution line L1 and third distribution line L3);
A home side sensor 53 (first power sensor) that is provided on the side of the system power source K from the second connection point P2 (midway portion) of the first distribution line (first distribution line L1 and third distribution line L3) and is capable of detecting power;
a home-side storage battery 52 (first storage battery) that is provided between the second connection point P2 (midway) of the first distribution line (first distribution line L1 and third distribution line L3) and the home-side distribution board 40 (first power load), that is capable of charging and discharging the power generated by the home-side power generation unit 51 (first power generation unit) and that is capable of outputting power to the first distribution line (first distribution line L1 and third distribution line L3) based on a detection result of the home-side sensor 53 (first power sensor);
a facility-side storage battery 22 (second storage battery) that is provided on the second distribution line (second distribution line L2) closer to the second connection point P2 (midway) than the facility-side distribution board 10 (second power load) and is capable of charging and discharging power;
A control unit 70 that controls the facility-side storage battery 22 (second storage battery) in accordance with a distribution state of power of at least the first distribution line (first distribution line L1 and third distribution line L3);
It is equipped with the following.

With this configuration, it is possible to effectively utilize the facility-side storage battery 22 in accordance with the power flow state of the first distribution line (the first distribution line L1 and the third distribution line L3).
Specifically, the facility-side storage battery 22 can be charged and discharged depending on the power flow pattern of the first distribution line (first distribution line L1 and third distribution line L3), i.e., depending on whether the power output from the home-side storage system 50 (home-side power generation unit 51 and home-side storage battery 52) to the first distribution line (first distribution line L1 and third distribution line L3) is flowing upstream, so that the facility-side storage battery 22 can be utilized effectively.

In addition, in the power supply system 1,
The control unit 70
When there is power flowing upstream through the first distribution line (first distribution line L1 and third distribution line L3) and the home side storage battery 52 (first storage battery) is not discharging,
A charging instruction is given to the facility-side storage battery 22 (second storage battery) based on the power flowing upstream through the first distribution line (first distribution line L1 and third distribution line L3) (step S203: YES, step S204: NO, step S206).

With this configuration, as in this embodiment, when the power load of the commercial facility S is very large compared to the power that the facility-side power storage system 20 can output, the facility-side storage battery 22 can be charged based on the power flowing upstream from the residential block A1. In this way, the facility-side storage battery 22 can discharge the charged power as appropriate, so that the facility-side storage battery 22 can be used effectively.

In addition, in the power supply system 1,
The control unit 70
When there is power flowing upstream through the first distribution line (first distribution line L1 and third distribution line L3) and the home side storage battery 52 (first storage battery) is discharging,
An instruction to stop charging is issued to the facility-side storage battery 22 (second storage battery) (step S203: YES, step S204: YES, step S210).

With this configuration, even if there is power flowing upstream from the residential block A1, the facility-side storage battery 22 will not charge if that power is discharging power from the home-side storage battery 52. In this way, the facility-side storage battery 22 can avoid the inefficient operation of recharging power that was once charged in another storage battery (the home-side storage battery 52), and the facility-side storage battery 22 can be used effectively.

In addition, in the power supply system 1,
a facility-side power generating unit 21 (second power generating unit) that is provided on the second distribution line (second distribution line L2) closer to the second connection point P2 (midway) than the facility-side distribution board 10 (second power load), capable of generating power using natural energy and outputting the generated power to the second distribution line (second distribution line L2);
The facility-side storage battery 22 (second storage battery) is
The facility-side power generation unit 21 (second power generation unit) is capable of charging and discharging the generated power,
The control unit 70
When there is electric power flowing upstream through the first distribution line (first distribution line L1 and third distribution line L3) and the second distribution line (second distribution line L2), and the home side storage battery 52 (first storage battery) is not discharging,
A charging instruction is given to the facility-side storage battery 22 (second storage battery) based on the power flowing upstream through the first distribution line (first distribution line L1 and third distribution line L3) and the second distribution line (second distribution line L2) (step S203: YES, step S204: NO, step S206, step S207).

With this configuration, the facility-side storage battery 22 can be charged based on the surplus power of the facility-side power generation unit 21 and the home-side power generation unit 51. In this way, the facility-side storage battery 22 can be effectively utilized.

In addition, in the power supply system 1,
a facility-side power generating unit 21 (second power generating unit) that is provided on the second distribution line (second distribution line L2) closer to the second connection point P2 (midway) than the facility-side distribution board 10 (second power load), capable of generating power using natural energy and outputting the generated power to the second distribution line (second distribution line L2);
The facility-side storage battery 22 (second storage battery) is
The facility-side power generation unit 21 (second power generation unit) is capable of charging and discharging the generated power,
The control unit 70
When there is no power flowing through the first distribution line (first distribution line L1 and third distribution line L3) to the second connection point P2 (midway portion) and there is power flowing through the second distribution line (second distribution line L2) to the upstream side,
A charge instruction is issued to the facility-side storage battery 22 (second storage battery) based on the power flowing upstream through the second distribution line (second distribution line L2) (step S203: NO, step S208: YES, step S209).

With this configuration, the facility-side storage battery 22 can be charged based on the surplus power of the facility-side power generation unit 21. In this way, the facility-side storage battery 22 can be effectively utilized.

In addition, in the power supply system 1,
The control unit 70
When power from the system power source K flows through the first distribution line (the first distribution line L1 and the third distribution line L3) to the house side distribution board 40 (first power load),
An instruction to discharge is issued to the facility-side storage battery 22 (second storage battery) (step S201: YES, step S202).

With this configuration, for example, the facility-side storage battery 22 can be discharged at a different timing than when power from residential block A1 flows upstream (i.e., when power from residential block A1 is lent to the power load of commercial facility S). In this way, the discharged power of the facility-side storage battery 22 can be supplied to the power load of commercial facility S as much as possible, and the facility-side storage battery 22 can be used effectively.

Although an embodiment of the present invention has been described above, the present invention is not limited to the above configuration, and various modifications are possible within the scope of the invention described in the claims.

For example, in this embodiment, the facility-side storage battery 22 and the home-side storage battery 52 generate electricity using solar power, but they may also generate electricity using other natural energy sources (e.g., hydropower or wind power).

In addition, in this embodiment, the total amount of electricity discharged from the time the home storage battery 52 was installed to the present is taken as the accumulated discharge amount, but this is not limited to this. That is, for example, the total amount of electricity discharged during a predetermined period (for example, the most recent 24 hours) may be taken as the accumulated discharge amount. In addition, in this embodiment, the discharge priority is determined based on the accumulated discharge amount, but the criteria for determining the discharge priority are not limited to this, and may be determined based on, for example, the charge state of the home storage battery 52 (the ratio of the remaining battery power stored to the rated capacity at which power can be stored) or the number of times it is charged.

In addition, in this embodiment, the number of homes H and home-side power storage systems 50 is four, but this is not limited to four. In other words, the number of homes H and home-side power storage systems 50 can be any number. Similarly, the number of commercial facilities S and facility-side power storage systems 20 can also be any number.

The placement of the various power meters is not limited to that described in this embodiment. In other words, the placement of the power meters can be set arbitrarily as long as the control unit 70 can obtain the desired information.

The residential energy storage system 50 and the facility energy storage system 20 can be provided with fuel cells, such as polymer electrolyte fuel cells (PEFCs) and solid oxide fuel cells (SOFCs). The residential storage battery 52 and the facility storage battery 22 can also charge and discharge the power generated by the fuel cells.

REFERENCE SIGNS LIST 1 Power supply system 10 Facility-side distribution board 22 Facility-side storage battery 40 Residential-side distribution board 51 Residential-side power generation unit 52 Residential-side storage battery 53 Residential-side sensor 70 Control unit K System power supply L1 First distribution line L2 Second distribution line P2 Connection point

Claims (5)

a first distribution line connecting a system power source and a first power load;
a second distribution line connecting a middle portion of the first distribution line and a second power load;
a first power generation unit that is provided between the midway portion of the first distribution line and the first power load, the first power generation unit being capable of generating power using natural energy and outputting the generated power to the first distribution line;
a first power sensor that is provided closer to a power system than the midway portion of the first distribution line and is capable of detecting power;
a first storage battery that is provided between the midway portion of the first distribution line and the first power load, the first storage battery being capable of charging and discharging the power generated by the first power generation unit and outputting power based on a detection result of the first power sensor to the first distribution line;
a second storage battery that is provided on the second distribution line closer to the midway point than the second power load and is capable of charging and discharging power;
a control unit that controls the second storage battery in accordance with at least a distribution state of electric power of the first distribution line;
Equipped with
The control unit is
When there is power flowing upstream through the first distribution line and the first storage battery is not discharging,
issuing a charge instruction to the second storage battery based on the electric power flowing upstream through the first distribution line;
Power supply system. a first distribution line connecting a system power source and a first power load;
a second distribution line connecting a middle portion of the first distribution line and a second power load;
a first power generation unit that is provided between the midway portion of the first distribution line and the first power load, the first power generation unit being capable of generating power using natural energy and outputting the generated power to the first distribution line;
a first power sensor that is provided closer to a power system than the midway portion of the first distribution line and is capable of detecting power;
a first storage battery that is provided between the midway portion of the first distribution line and the first power load, the first storage battery being capable of charging and discharging the power generated by the first power generation unit and outputting power based on a detection result of the first power sensor to the first distribution line;
a second storage battery that is provided on the second distribution line closer to the midway point than the second power load and is capable of charging and discharging power;
a control unit that controls the second storage battery in accordance with at least a distribution state of electric power of the first distribution line;
Equipped with
The control unit is
When there is power flowing upstream through the first distribution line and the first storage battery is discharging,
issuing an instruction to stop charging the second storage battery;
Power supply system. a first distribution line connecting a system power source and a first power load;
a second distribution line connecting a middle portion of the first distribution line and a second power load;
a first power generation unit that is provided between the midway portion of the first distribution line and the first power load, the first power generation unit being capable of generating power using natural energy and outputting the generated power to the first distribution line;
a first power sensor that is provided closer to a power system than the midway portion of the first distribution line and is capable of detecting power;
a first storage battery that is provided between the midway portion of the first distribution line and the first power load, the first storage battery being capable of charging and discharging the power generated by the first power generation unit and outputting power based on a detection result of the first power sensor to the first distribution line;
a second storage battery that is provided on the second distribution line closer to the midway point than the second power load and is capable of charging and discharging power;
a control unit that controls the second storage battery in accordance with at least a distribution state of electric power of the first distribution line;
a second power generation unit that is provided on the second distribution line closer to the midway point than the second power load, capable of generating power using natural energy and outputting the generated power to the second distribution line;
Equipped with
The second storage battery is
The second power generation unit is capable of charging and discharging the generated power,
The control unit is
When there is electric power flowing upstream through the first distribution line and the second distribution line and the first storage battery is not being discharged,
issuing a charge instruction to the second storage battery based on electric power flowing upstream through the first distribution line and the second distribution line;
Power supply system. a first distribution line connecting a system power source and a first power load;
a second distribution line connecting a middle portion of the first distribution line and a second power load;
a first power generation unit that is provided between the midway portion of the first distribution line and the first power load, the first power generation unit being capable of generating power using natural energy and outputting the generated power to the first distribution line;
a first power sensor that is provided closer to a power system than the midway portion of the first distribution line and is capable of detecting power;
a first storage battery that is provided between the midway portion of the first distribution line and the first power load, the first storage battery being capable of charging and discharging the power generated by the first power generation unit and outputting power based on a detection result of the first power sensor to the first distribution line;
a second storage battery that is provided on the second distribution line closer to the midway point than the second power load and is capable of charging and discharging power;
a control unit that controls the second storage battery in accordance with at least a distribution state of electric power of the first distribution line;
a second power generation unit that is provided on the second distribution line closer to the midway point than the second power load, capable of generating power using natural energy and outputting the generated power to the second distribution line;
Equipped with
The second storage battery is
The second power generation unit is capable of charging and discharging the generated power,
The control unit is
When there is no power flowing upstream through the first distribution line and there is power flowing midway through the second distribution line,
issuing a charge instruction to the second storage battery based on the electric power flowing upstream through the second distribution line;
Power supply system. The control unit is
When power from a system power source flows through the first distribution line to the first power load,
issuing a discharge instruction to the second storage battery;
The power supply system according to any one of claims 1 to 4.

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