JP7484253B2 - Power control device and power control system - Google Patents

Description

The present invention relates to a power control device and a power control system.

Conventionally, there are distributed power supply systems that include a PV power conditioner that operates a PV (photovoltaic power generation) unit connected to the power grid, and a storage power conditioner that operates a storage battery unit connected to the power grid. In such distributed power supply systems, there is a need to retrofit a storage power conditioner to an existing PV power conditioner, or to retrofit a PV power conditioner to an existing storage power conditioner.

When a PV power conditioner and a storage power conditioner are installed together, the DC/AC inverter of the storage power conditioner and the DC/AC inverter of the PV power conditioner overlap, resulting in higher costs and a larger installation area. From this perspective, it has been proposed to connect a transformer that transforms the DC power generated by the PV unit to the PV unit, input the DC power output from this transformer to the storage power conditioner, convert it to AC power by the DC/AC inverter of the storage power conditioner, and connect the system to supply it to the power grid or load (see, for example, Patent Documents 1 and 2).

As mentioned above, when expanding or modifying a power control system such as a distributed power system by including an existing power control device such as a power conditioner, sufficient consideration has not been given to how to handle combinations of multiple types of devices, including distributed power sources.

JP 2019-103197 A JP 2019-103198 A

The present invention was made in consideration of the above problems, and aims to provide a technology that can improve the degree of freedom in the configuration of a system that includes a power control device.

To solve the above problems, the present invention provides:
an input unit to which DC power is input;
a first transformer unit that transforms a voltage of the DC power;
a first input/output unit that outputs the DC power transformed by the first transformer unit to a storage battery unit and receives the DC power from the storage battery unit;
A converter for converting DC power into AC power;
a second input/output unit that outputs the AC power converted by the conversion unit to a power system or a load and receives AC power from the power system;
A first control unit that controls the first transformer unit and the converter unit;
A first communication unit that communicates with the storage battery unit;
Equipped with
The first transformer receives the DC power input to the input unit and the DC power input to the second input/output unit and converted by the conversion unit,
A power control device in which the conversion unit receives the DC power output from the first transformer unit and the DC power input to the input unit,
The first control unit is
a connection candidate device information acquisition unit that is connected to the power control device and is capable of inputting and outputting power between the power control device and the connection candidate device information acquisition unit, the connection candidate device information being information related to a connection candidate device including the storage battery unit;
a control content determination unit that determines control content based on the connection candidate device information;
The present invention is characterized by having the following.

The power control device according to the present invention includes an input unit to which DC power is input, a first transformer unit to transform the voltage of the DC power, a first input/output unit to output the DC power transformed by the first transformer unit to a storage battery unit and to which the DC power is input from the storage battery unit, a conversion unit to convert the DC power to AC power, a second input/output unit to output the AC power converted by the conversion unit to a power system or a load and to which the AC power is input from the power system, a first control unit to control the first transformer unit and the conversion unit, and a first communication unit to communicate with the storage battery unit, and the first transformer unit receives the DC power input to the input unit and the DC power input to the second input/output unit and converted by the conversion unit, and the conversion unit receives the DC power output from the first transformer unit and the DC power input to the input unit.

A connection candidate device is a device that inputs and outputs at least one of power between this power control device, is a device that can be connected to the power control device, and is a candidate device for configuring a system including the power control device. Here, a storage battery unit is also included in the connection candidate device. A system including a power control device is configured by actually connecting a connection candidate device to the power control device and controlling it to input and output at least one of power between the power control device and the power control device. When configuring a system including a power control device, various combinations are possible as combinations of power control devices and connection candidate devices. It is not limited to actually connecting all connection candidate devices to the power control device, but any connection candidate device or a combination of multiple connection candidate devices can be connected to the power control device to configure a system. In addition, a system in which the connection candidate devices are selectively connected to the power control device, that is, only one of them is connected to the power control device. Furthermore, it is also possible to control the connection candidate devices not to operate when any of the connectable devices are operated while simultaneously connected to the power control device.

The connection candidate device information is information about the connection candidate device, and includes, for example, information on the presence or absence of a connection, such as whether the connection candidate device is connected or not, and information on characteristics such as the rated capacity of the connection candidate device. By including information on the characteristics of the connection candidate device in the connection candidate device information, when there are connection candidate devices of the same type but with different characteristics, it is possible to configure a system including not only the functions but also the characteristics. The connection candidate device information may be information set by equipment outside the power control device, such as an operation unit where a user inputs operation instructions, or it may be information obtained by transmitting and receiving signals to and from the connection candidate device, or by detecting state changes such as voltage changes in a specified area.

The first control unit of the power control device of the present invention has a connection candidate device information acquisition unit that acquires connection candidate device information, and a control content determination unit that controls the first transformer unit and the converter unit based on the connection candidate device information acquired by the connection candidate device information acquisition unit. This determines the control content of the first transformer unit and the converter unit, i.e., the power control device, based on the configuration of the system including the power control device specified by the connection candidate device information. Therefore, a system can be configured including various combinations of connection candidate devices and power control devices, improving the degree of freedom in the configuration of the system including the power control device.

In addition, in the present invention,
a system configuration basic information generation unit that generates system configuration basic information regarding a configuration of a system including the power control device and the connection candidate device connected to the power control device based on the connection candidate device information acquired by the connection candidate device information acquisition unit;
a control information derivation unit that derives control system configuration information including a control mode for at least one of the power control device and the connection candidate device connected to the power control device based on the system configuration basic information;
having
The control content determination unit may determine the control content based on the control system configuration information.

By generating basic system configuration information regarding the configuration of a system including a power control device and a connection candidate device connected to the power control device based on the connection candidate device information, basic information regarding the configuration of a system including the power control device can be managed as system configuration basic information. By storing the system configuration basic information in a storage means in a table-like format that associates connection candidate devices with information regarding the connection candidate devices, the system configuration basic information can be managed efficiently.

In addition, for a specific combination of a power control device and a connection candidate device included in the system configuration basic information, a control mode can be prepared as a pre-prepared control method. Therefore, by having the first control unit have a control information derivation unit that derives control system configuration information including a control mode for at least one of the power control device and the connection candidate device connected to the power control device based on the system configuration basic information, consistent control is possible between the power control device and the connection candidate device. The control system configuration information derived in this manner is transmitted to the connection candidate device as necessary and shared.

In addition, in the present invention,
The control system configuration information may be configured not to be changed while the power control device is running.

In this way, by preventing the control system configuration information from being changed while the power control device is running, it is possible to prevent the control system configuration from being dynamically changed while the power control device is running. Restarting the power control device, which allows changes to the control system configuration information, is not limited to re-powering on, but also includes resetting the first control unit.

In addition, in the present invention,
The connection candidate device includes a transformer device having a second transformer unit that transforms DC power generated by a power generation device, a second output unit that outputs the DC power output from the second transformer unit to the input unit, a second control unit that controls the second transformer unit, and a second communication unit that communicates with the power control device,
The first control unit has a control information output unit that outputs the control system configuration information,
the first communication unit communicates with the connection candidate device including the storage battery unit;
The second control unit may receive the control system configuration information transmitted from the first control unit via the first communication unit via the second communication unit, and control the second transformer unit based on the control system configuration information.

In this way, in the present invention, the second control unit of the transformer device receives, via the second communication unit, the control system configuration information transmitted from the control information output unit of the power control device via the first communication unit, and controls the second transformer device based on this control system configuration information. In this way, it is possible to control the system including the power control device and the transformer device connected to the power generation device in a consistent manner, thereby improving the degree of freedom in the configuration of the system including the power control device.

In addition, in the present invention,
the connection candidate device information acquisition unit transmits a command in which a response corresponding to a characteristic of the storage battery unit is defined to the storage battery unit via the first communication unit, and acquires the characteristic as the connection candidate device information based on the response of the storage battery unit to the command;
The control content determination unit may control an output of the first transformer unit or the converter unit based on the control system configuration information including the characteristics of the storage battery unit.

According to this, the first control unit of the power control device can recognize the characteristics of the storage battery unit by transmitting a command, in which a response corresponding to the characteristics of the storage battery unit is defined, to the storage battery unit via the first communication unit and receiving the response of the storage battery unit to the command. By controlling the output of the first transformer unit of the power control device according to the characteristics of the storage battery unit recognized in this manner, a system can be configured by connecting storage battery units having various characteristics to the power control device. Therefore, it is possible to improve the degree of freedom in the configuration of a system including the power control device.
Furthermore, the first control unit may be configured to determine that an abnormality has occurred when the first communication unit does not receive a response from the storage battery unit within a predetermined time for any command transmitted to the storage battery unit. According to this, when a storage battery unit not having preset characteristics is connected, the first control unit of the storage power conditioner determines that an abnormality has occurred, and thus it is possible to deal with storage battery units not having preset characteristics.

In addition, in the present invention,
The characteristic may be a rated capacity of the storage battery unit.

According to this, by controlling the output of the first transformer of the power control device according to the rated capacity of the recognized storage battery unit, it is possible to configure a system by connecting storage battery units having various rated capacities to the power control device. Therefore, it is possible to improve the degree of freedom in the configuration of a system including a power control device.

In addition, in the present invention,
the second input/output unit has a plurality of first output units for outputting AC power input to the second input/output unit to an outside of the power control device, and an output selection unit for selecting the first output unit to which the AC power input to the second input/output unit should be output,
the connection candidate device information acquisition unit detects the connection candidate device connected to the first output unit, and acquires the connection candidate device information regarding the connection candidate device;
The first control unit may control the output selection unit based on the control system configuration information derived from the connection candidate device information.

According to this, the second input/output unit is provided with a plurality of output units for outputting the AC power input to the second input/output unit to the outside of the device, so that a plurality of connection candidate devices can be connected to the plurality of output units. In addition, the second input/output unit is provided with an output selection unit for selecting an output unit to which the AC power input to the second input/output unit should be output. Then, the connection candidate device information acquisition unit acquires connection candidate device information related to the connection candidate device by detecting the connection candidate device connected to the first output unit. Furthermore, the first control unit controls the output selection unit by the control unit based on the control system configuration information derived from the connection candidate device information acquired in this manner, so that a system including the power control device can be configured by combining the connection candidate devices to which the AC power output from the power control device is supplied in various ways with the power control device, and the degree of freedom of the system configuration is improved.
In this case, the first control unit may control the output selection unit depending on whether the grid-connected operation is performed in a grid-connected state or whether the grid-independent operation is performed. In this way, the first control unit controls the output selection unit depending on whether the grid-connected operation is performed in a grid-connected state or whether the grid-independent operation is performed. As a result, a system including a power control device can be configured by combining a connection candidate device that outputs AC power when performing grid-connected operation and a connection candidate device that outputs AC power when performing grid-independent operation, improving the degree of freedom in system configuration.

In addition, in the present invention,
The first control unit may change a voltage of the AC power output from the conversion unit to the connection candidate device based on the connection candidate device information.

This allows a system including a power control device to be configured by combining connection candidate devices that output different AC power voltages with the power control device, improving the flexibility of system configuration.

In addition, in the present invention,
The connection candidate device may be a transformer unit that changes a voltage of output AC power and supplies the power to the load.

This allows a system including a power control device to be configured by combining a transformer unit that transforms the voltage according to the load and supplies AC power with the power control device, thereby improving the flexibility of system configuration.

In addition, in the present invention,
The first output section to which the transformer unit is connected may be connected to either the transformer unit or a specific load distribution board which is a connection candidate device for supplying AC power to a specific load identified in advance.

With this, either the transformer unit or the specific load device can be selectively connected to the output section to which the transformer unit is connected, which reduces costs and the size of the installation area when configuring a system that includes a power control device.

The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of:
The power control device;
the connection candidate device connected to the power control device;
The power control system is characterized by comprising:

In this way, the power control system is configured by the above-mentioned power control device and the connection candidate devices connected to the power control device, which improves the flexibility of the configuration of the power control system.

The present invention makes it possible to improve the degree of freedom in the configuration of a system that includes a power control device.

1 is an overall configuration diagram illustrating an example of a power storage system according to a first embodiment of the present invention; 1 is a diagram showing a schematic configuration of a power storage system according to a first embodiment of the present invention; FIG. 2 is a functional block diagram of a control unit according to the first embodiment of the present invention. 11 is a flowchart of a processing procedure related to a system configuration table according to the first embodiment of the present invention. FIG. 4 is a diagram illustrating an example of a system configuration table according to the first embodiment of the present invention. 4A and 4B are diagrams illustrating an example of a system configuration table and a control mode explanatory diagram according to the first embodiment of the present invention. 1 is a diagram illustrating a configuration example of a power storage system according to a first embodiment of the present invention. 1 is a diagram illustrating a configuration example of a power storage system according to a first embodiment of the present invention. 1 is a diagram illustrating a configuration example of a power storage system according to a first embodiment of the present invention. FIG. 11 is a block diagram showing a schematic configuration of a power storage system according to a second embodiment of the present invention. FIG. 11 is a diagram showing an overall configuration of a power storage system according to a second embodiment of the present invention. 10 is a flowchart showing a procedure of a recognition process of a rated capacity according to a second embodiment of the present invention. FIG. 11 is a diagram illustrating an example of a system configuration table according to the second embodiment of the present invention. 10 is a flowchart showing a procedure of charge/discharge control according to a second embodiment of the present invention. FIG. 11 is a block diagram showing a schematic configuration of a power storage system according to a third embodiment of the present invention. FIG. 11 is a diagram showing an overall configuration of a power storage system according to a third embodiment of the present invention. FIG. 11 is a diagram illustrating an example of a system configuration table according to the third embodiment of the present invention. FIG. 11 is a block diagram showing a schematic configuration of a power storage system having another configuration according to the third embodiment of the present invention. FIG. 11 is a diagram showing an overall configuration of a power storage system having another configuration according to the third embodiment of the present invention. 13 is a flowchart showing a procedure of a process for changing an independent output according to a third embodiment of the present invention.

[Application example]
Hereinafter, application examples of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing the overall configuration of a power storage system 1, which is an example of a power control system of the present invention. The power storage system 1 includes a power generation device 2, a transformer device 3, a power storage power conditioner 4, a storage battery unit 5, an operation unit 8, a display unit 9, a communication unit 10, a specific load distribution board 11, a specific load 71, a transformer unit 12, a full load switching distribution board 13, an independent input solar cell (PV) power conditioner 16, and an independent input PV 17. The power storage power conditioner 4 is an example of a power control device of the present invention. In addition, the transformer device 3, the storage battery unit 5, the specific load distribution board 11, the specific load 71, the transformer unit 12, and the independent input PV power conditioner 16 are examples of connection candidate devices of the present invention. The connection candidate devices of the present invention may include a power generation device 2 connected to the transformer device 3, a full load switching distribution board 13 connected to the transformer unit 12, and an independent input PV 17 connected to the independent input PV power conditioner 16.

The energy storage system 1 shown in FIG. 1 is an example of devices that can be connected to the energy storage power conditioner 4, but the energy storage system 1 does not necessarily include all of these devices, and the devices that make up the energy storage system 1 are not limited to these.

Figure 2 shows the schematic configuration of the energy storage system 1. In Figure 2, the energy storage power conditioner 4 is connected to the storage battery unit 5, the power generation device 2, and the transformer device 3.

The storage power conditioner 4 has an input unit 41, a transformer unit 42, an input/output unit 43, a converter unit 44, an input/output unit 45, a control unit 46, and a communication unit 47. The DC power output from the output unit 33 of the transformer device 3 is input to the input unit 41. The transformer unit 42 transforms the DC power input to the input unit 41. The input/output unit 43 inputs the transformed DC power to the storage battery unit 5. In addition, the DC power output from the storage battery unit 5 is input to the input/output unit 43. The transformer unit 42 transforms the voltage of the DC power input to the input/output unit 43 and outputs it. The converter unit 44 converts the DC power output from the transformer unit 42 into AC power. The control unit 46 controls the transformer unit 42, the converter unit 44, and the input/output unit 45. The communication unit 47 communicates, via wire or wirelessly, with the storage battery unit 5, the transformer device 3, and the independent input PV power conditioner 16. The input unit 41, the transformer unit 42, the input/output unit 43, the conversion unit 44, the input/output unit 45, the control unit 46, and the communication unit 47 are examples of the input unit, first transformer unit, first input/output unit, conversion unit, second input/output unit, first control unit, and first communication unit, respectively, of the present invention.

The power generation device 2 is a device capable of generating power, and outputs the generated DC power to the transformer device 3. The transformer device 3 has an input unit 31, a transformer unit 32, an output unit 33, a control unit 34, and a communication unit 35. The DC power output from the power generation device 2 is input to the input unit 31. The DC power input to the input unit 31 is transformed by the transformer unit 32. The transformed DC power is output from the output unit 33 to the storage power conditioner 4. The control unit 34 controls the transformer unit 32. The communication unit 35 communicates with the storage power conditioner 4 via a wired or wireless connection. The transformer unit 32, the output unit 33, the control unit 34, and the communication unit 35 are examples of the second transformer unit, the second output unit, the second control unit, and the second communication unit of the present invention.

Figure 3 is a functional block diagram of the control unit 46 of the storage power conditioner 4. Here, the control unit 46 includes a first control unit 461 and a second control unit 462, but is not limited to this configuration. The first control unit 461 includes a setting acquisition unit 4611, a system configuration table management unit 4612, a system configuration table conversion unit 4614, and a control table output unit 4615, and the second control unit 462 includes a control table acquisition unit 4621 and a control content determination unit 4622.

FIG. 4 is a flow chart showing a procedure for determining the control contents based on the control system configuration table obtained from the acquired system configuration information.
The system configuration table management unit 4612 reads out the system configuration table T from the system configuration table storage unit 4613 (step S1). An example of the data configuration of the system configuration table T is shown in FIG. 5A. The system configuration table T includes whether or not the storage battery unit 5 is connected, whether or not the transformer device 3 is connected, and whether or not the transformer unit 12 is connected. Here, whether or not the transformer device 3 is connected includes whether or not the power generation device 2 connected to the transformer device 3 is connected, and whether or not the transformer unit 12 is connected includes whether or not the full load switching distribution board 13 and the load 7 connected to the transformer unit 12 are connected. Here, whether or not to perform degenerated operation when the storage battery unit 5 fails is also set as part of the system configuration. It is assumed that an initial value is set in each item of the system configuration table T read out from the system configuration table storage unit 4613 shown in FIG. 5A.

Next, the setting acquisition unit 4611 of the first control unit 461 acquires system configuration information (step S2). The system configuration information is information including each item of the above-mentioned system configuration table and the value of the item, and the setting acquisition unit 4611 acquires information set by the user or construction company using the operation unit 8 via the communication unit 47. In addition, the system configuration information may be acquired by the setting acquisition unit 4611 detecting the presence or absence of a connection of a specific device by transmitting and receiving signals between the device connected to the storage power conditioner 4 or detecting a state change such as a voltage change in a specific part. The system configuration information is an example of connection candidate device information of the present invention, and the setting acquisition unit 4611 is an example of a connection candidate device information acquisition unit of the present invention.

Next, the system configuration table management unit 4612 of the first control unit 461 sets or updates the system configuration table T based on the system configuration information acquired in step S2 (step S3). FIG. 5 (B) shows an example of the set system configuration table T. The set or updated system configuration table T is stored in the system configuration table storage unit 4613 by the system configuration table management unit 4612. The system configuration table T is an example of the system configuration basic information of the present invention, and the system configuration table management unit 4612 is an example of the system configuration basic information generation unit of the present invention. Furthermore, the setting or updating of the system configuration table T by the system configuration table management unit 4612 is an example of the generation of the system configuration basic information of the present invention.

Next, the system configuration table conversion unit 4614 of the first control unit 461 converts the system configuration table T set or updated in step S3 into a control system configuration table (hereinafter referred to as the "control table") Tc (step S4). The control table Tc converted from the system configuration table T shown in FIG. 5(B) is shown in FIG. 6(A). As shown in FIG. 6(A), the control table Tc includes the operation mode of the storage power conditioner 4 in addition to the presence or absence of the connection of the storage battery unit 5. That is, the system configuration table conversion unit 4614 derives the operation mode of the storage power conditioner 4 based on the presence or absence of the device connected to the storage power conditioner 4 and/or the presence or absence of the degenerate operation included in the system configuration table set or updated by the system configuration table management unit 4612. FIG. 6(B) is a table showing the correspondence between the presence or absence of the connection of the transformer device 3 and the presence or absence of the degenerate operation when the storage battery unit 5 fails, and the operation mode of the storage power conditioner 4. The control table Tc is an example of the control system configuration information of the present invention, the system configuration table conversion unit 4614 is an example of the control information derivation unit of the present invention, and the operation mode is an example of the control mode of the present invention.

Next, the control table output unit 4615 of the first control unit 461 outputs the control table Tc obtained in step S4 to the second control unit 462 included in the same control unit 46 and to devices such as the transformer device 3 connected to the storage power conditioner 4 (step S5). The control table output unit 4615 is an example of a control information output unit of the present invention.

The control table Tc output from the first control unit 461 is received by the control table acquisition unit 4621 of the second control unit 462 and stored in a predetermined area of the memory (step S11). Then, in the second control unit 462, the control content determination unit 4622 refers to the control table Tc and determines the control content of the transformer 42, the converter 44, and the input/output unit 45 based on the information contained therein (step S12). Similarly, in the transformer device 3, the control unit 34 receives the control table Tc via the communication unit 35, acquires it, and stores it in a predetermined area of the memory (step S11), and the control unit 34 refers to the control table Tc and determines the control content of the transformer 32 based on the information contained therein (step S12). The control content determination unit 4622 is an example of the control content determination unit of the present invention.

In this way, the control unit 46 of the storage power conditioner 4 has a setting acquisition unit 4611 and a control content determination unit 4622 that controls the transformer unit 42 and the converter unit 44 based on the system configuration information acquired by the setting acquisition unit 4611. With this, the control content of the storage power conditioner 4 is determined based on the configuration of the system including the storage power conditioner 4, which is specified by the system configuration information. Therefore, a system can be configured including the storage power conditioner 4 and various devices such as the storage battery unit 5, the power generation device 2, and the transformer device 3, thereby improving the degree of freedom in the configuration of the system including the storage power conditioner 4.

Example 1
Hereinafter, a power storage system 1 according to a first embodiment of the present invention will be described in more detail with reference to the drawings. However, the configurations of the devices and systems described in this embodiment should be appropriately modified depending on various conditions. In other words, it is not intended that the scope of the present invention be limited to the following embodiment.

<System Configuration>
Fig. 1 shows the overall configuration of a power storage system 1 according to Example 1. In Fig. 1, devices that can be connected to a power storage power conditioner 4 are illustrated as examples of the power storage system 1, but the power storage system 1 does not necessarily include all of these devices, and the devices that configure the power storage system 1 are not limited to these.

The energy storage system 1 includes a power generation device 2, a transformer device 3, an energy storage power conditioner 4, a storage battery unit 5, an operation unit 8, a display unit 9, a communication unit 10, a specific load distribution board 11, a specific load 71, a transformer unit 12, a full load switching distribution board 13, an independent input PV power conditioner 16, and an independent input PV 17.

The power generation device 2 is a device capable of generating electricity, such as a PV unit, a fuel cell (FC) unit, or a wind power generation unit. The power generation device 2 inputs the generated DC power to the transformer device 3. The transformer device 3 transforms the DC power input from the power generation device 2 into DC power of a first predetermined voltage and outputs it to the storage power conditioner 4.

The storage power conditioner 4 transforms the DC power of the first predetermined voltage input from the transformer 3 and/or the DC power converted from the AC power input from the power grid 6 to a second predetermined voltage and inputs it to the storage battery unit 5. In addition, the storage power conditioner 4 converts the DC power output from the storage battery unit 5 and transformed to a third predetermined voltage and/or the DC power input from the transformer 3 into AC power, which is supplied to the power grid 6 or the load 7, and is supplied to the specific load 71 via the specific load distribution board 11, or to the load 7 via the transformer unit 12 and the full load switching distribution board 13. In addition, AC power is input to the storage power conditioner 4 from the independent input PV power conditioner 16 to which the independent input PV 17 is connected.

The storage battery unit 5 is a chargeable and dischargeable secondary battery, and for example, a lithium ion battery or various other types of secondary batteries can be used. The first and third specified voltages are voltages suitable for outputting AC power to the power grid 6 or the load 7. The second specified voltage is a voltage suitable for inputting DC power to the storage battery unit 5. The first and second specified voltages are different values. The first and third specified voltages may be the same value or different values.

The operation unit 8 is a remote controller that inputs an instruction signal to the storage power conditioner 4 and operates the storage power conditioner 4. The operation unit 8 may be configured with input devices such as a keyboard, a mouse, a keyboard and an operation button. The operation unit 8 may have a Home Energy Management System (HEMS) controller or a Virtual Power Plant (VPP) controller. The HEMS is a system that manages the power consumption of a home. The VPP is a system that collectively manages multiple small-scale power generation facilities through a network. The display unit 9 displays various information. The display unit 9 is, for example, a Cathode Ray Tube (CRT) display, a liquid crystal display, a plasma display, an organic EL (Electro Luminescence) display, or the like. The communication unit 10 is an interface that communicates with a server 15 connected to the network 14. The communication unit 10 includes, for example, a router and a modem. The network 14 includes, for example, a public network such as the Internet and a LAN (Local Area Network).

The specific load distribution board 11 is a distribution board to which specific loads 71 that are specified as loads to be operated in an autonomous operation independent of the power grid 6 when the power supply from the power grid 6 is stopped due to a power outage or the like are connected, and is connected to the autonomous output terminal of the storage power conditioner 4.

The transformer unit 12 is connected to the independent output terminal of the storage power conditioner 4 and transforms the AC power output from the independent output terminal. The AC power transformed by the transformer unit 12 is supplied to the load 7 via the full-load switching distribution board 13. Here, for example, single-phase two-wire 200V AC power is output from the independent output terminal of the storage power conditioner 4, and the transformer unit 12 transforms this single-phase two-wire 200V AC power into single-phase three-wire 200V AC power and outputs it to the full-load switching distribution board 13.

The independent input PV power conditioner 16 is connected to the independent input terminal of the storage power conditioner 4, converts the DC power generated by the independent input PV 17 into AC power, and outputs it to the storage power conditioner 4.

A specific configuration of the power storage system 1 centered around the power storage power conditioner 4 will be described with reference to FIG.
As described above, the power generation device 2 is a device capable of generating power, such as a PV unit, and outputs the generated DC power to the transformer device 3. The transformer device 3 has an input unit 31, a transformer unit 32, an output unit 33, a control unit 34, and a communication unit 35. The DC power output from the power generation device 2 is input to the input unit 31. The transformer unit 32 is, for example, a non-insulated DC/DC converter or an insulated DC/DC converter. The output unit 33 inputs the DC power transformed to a first predetermined voltage to the storage power conditioner 4. The control unit 34 controls the transformer unit 32. The control unit 34 has a processor such as a CPU or an MPU, and a memory such as a RAM or a ROM. The control unit 34 may be configured with one CPU or MPU, or may be configured with a combination of multiple CPUs or multiple MPUs. The CPU or MPU is not limited to a single processor, and may be configured with a multiprocessor configuration. The control unit 34 executes various processes according to a program executablely deployed in the memory. The communication unit 35 communicates with the storage power conditioner 4 via a wired or wireless connection. The storage system 1 may include a plurality of power generation devices 2. The transformer device 3 may have a plurality of input units 31 connected to the plurality of power generation devices 2, a plurality of transformer units 32, and a plurality of output units 33.

The storage power conditioner 4 has an input unit 41, a transformer unit 42, an input/output unit 43, a conversion unit 44, an input/output unit 45, a control unit 46, and a communication unit 47. The DC power of the first predetermined voltage output from the output unit 33 of the transformer device 3 is input to the input unit 41. The transformer unit 42 transforms the first predetermined voltage of the DC power input to the input unit 41 to a second predetermined voltage. The transformer unit 42 is, for example, a non-insulated DC/DC converter or an insulated DC/DC converter. The input/output unit 43 inputs the DC power transformed to the second predetermined voltage to the storage battery unit 5. In addition, the DC power output from the storage battery unit 5 is input to the input/output unit 43. The transformer unit 42 transforms the voltage of the DC power input to the input/output unit 43 to the first predetermined voltage and outputs the DC power. The conversion unit 44 is, for example, a DC/AC inverter. The conversion unit 44 converts the DC power output from the input unit 41 or the transformer unit 42 into AC power.

The conversion unit 44 converts the AC power input to the input/output unit 45 into DC power and outputs the DC power. The transformer unit 42 transforms the voltage of the DC power output from the conversion unit 44 into a second predetermined voltage. The control unit 46 controls the transformer unit 42, the conversion unit 44, and the input/output unit 45. The control unit 46 has a processor such as a CPU or an MPU and a memory such as a RAM or a ROM. The control unit 46 may be configured with one CPU or MPU, or may be configured with a combination of multiple CPUs or multiple MPUs. The CPU or MPU is not limited to a single processor, and may be configured as a multiprocessor. The control unit 46 executes various processes according to a program that is executable and deployed in the memory. The communication unit 47 communicates with the storage battery unit 5, the transformer device 3, and the independent input PV power conditioner 16 via wired or wireless communication. Information received from the storage battery unit 5, the transformer device 3, and the independent input PV power conditioner 16 is transmitted to the control unit 46.

3 shows a functional block diagram of the control unit 46. Here, the control unit 46 includes a first control unit 461 and a second control unit 462. The first control unit 461 and the second control unit 462 can each be configured, for example, by an MCU (Micro Controller Unit). The first control unit 461 includes a setting acquisition unit 4611, a system configuration table management unit 4612, a system configuration table storage unit 4613, a system configuration table conversion unit 4614, and a control table output unit 4615. The second control unit 462 includes a control table acquisition unit 4621 and a control content determination unit 4622. The functions of each unit of the control unit 46 will be described later.

FIG. 4 is a flowchart illustrating the procedure of the control content determination process based on the system configuration table.
First, the system configuration table management unit 4612 of the first control unit 461 reads the system configuration table T from the system configuration table storage unit 4613 (step S1). The system configuration table storage unit 4613 can be configured, for example, by an EEPROM, but is not limited to this. An example of the data configuration of the system configuration table T is shown in FIG. 5 (A). The system configuration table T includes whether or not the storage battery unit 5 is connected, whether or not the transformer device 3 is connected, and whether or not the transformer unit 12 is connected. Here, whether or not the transformer device 3 is connected includes whether or not the power generation device 2 connected to the transformer device 3 is connected, and whether or not the transformer unit 12 is connected includes whether or not the full load switching distribution board 13 and the load 7 connected to the transformer unit 12 are connected. In the operation of the power storage system 1, when at least one of the storage battery unit 5, the transformer device 3 (including the power generation device 2), and the transformer unit 12 connected to the power storage power conditioner 4 has a failure and does not operate normally, the power storage system 1 can be operated (also called degenerate operation) by other devices that are connected to the power storage power conditioner 4 and operate normally and the power storage power conditioner 4. Here, whether or not to perform degenerate operation in the event of a failure of the storage battery unit 5 is also set as part of the system configuration. It is assumed that initial values are set in each item of the system configuration table T read from the system configuration table storage unit 4613 shown in Fig. 5(A). When updating the system configuration table T, the system configuration table T previously set is stored in the system configuration table storage unit 4613, so in step S1, the system configuration table T including the previous setting values is read.

Next, the setting acquisition unit 4611 of the first control unit 461 acquires the system configuration information (step S2). The system configuration information is information including each item of the above-mentioned system configuration table and the value of the item, and the setting acquisition unit 4611 acquires the information set by the user or the construction company using the operation unit 8 via the communication unit 47. For example, "whether or not the transformer device 3 is connected" is an item, and "yes" or "no" is a value of the item. The system configuration information acquired from the operation unit 8 may be received by the operation unit 8 from the server 15 via the network 14 and the communication unit 10. The system configuration information is not limited to being set from or via the operation unit 8 as described above, but may be acquired by the setting acquisition unit 4611 detecting the presence or absence of connection of a predetermined device by transmitting and receiving signals between the device connected to the storage power conditioner 4 or detecting a state change such as a voltage change in a predetermined part. The system configuration information set from or via the operation unit 8 is referred to as set system configuration information, and the system configuration information detected by the setting acquisition unit 4611 is referred to as detected system configuration information. The system configuration information is classified into at least one of set system configuration information and detected system configuration information. That is, the system configuration information may be acquired by only one of setting from or via the operation unit 8, or detection by the setting acquisition unit 4611, or may be acquired by both. Regarding a specific item of the system configuration information, the processing when both the set system configuration information and the detected system configuration information are acquired is not particularly limited, but it may be judged as an abnormality and notified by displaying a message to that effect on the display unit 9, or one of them may be prioritized and adopted as the system configuration information. Here, it is assumed that the system configuration information acquired is information that the storage battery unit 5 is connected "with", the degenerate operation at the time of failure of the storage battery unit 5 is "with", the transformer device 3 is "with", the transformer unit 12 is "without", and the PV power conditioner 16 for independent input is "without". The order of steps S1 and S2 is not limited to that described above, and after acquiring system configuration information from the setting acquisition unit 4611, the system configuration table management unit 4612 may read the system configuration table T from the system configuration table memory unit 4613.

Next, the system configuration table management unit 4612 of the first control unit 461 sets or updates the system configuration table T based on the system configuration information acquired in step S2 (step S3). FIG. 5(B) shows an example of the set system configuration table T. The set or updated system configuration table T is stored in the system configuration table storage unit 4613 by the system configuration table management unit 4612.

Next, the system configuration table conversion unit 4614 of the first control unit 461 converts the system configuration table T set or updated in step S3 into a control system configuration table (hereinafter referred to as a "control table") Tc (step S4). The control table Tc converted from the system configuration table T shown in FIG. 5(B) is shown in FIG. 6(A). As shown in FIG. 6(A), the control table Tc includes the operation mode of the storage power conditioner 4 in addition to the presence or absence of the connection of the storage battery unit 5, the presence or absence of the connection of the transformer device 3, the presence or absence of the connection of the transformer unit 12, and the presence or absence of the connection of the independent input PV power conditioner 16. In the storage power conditioner 4, a plurality of operation modes are possible depending on the presence or absence of a device connected to the storage power conditioner 4 and/or the presence or absence of degenerate operation. For this reason, the system configuration table conversion unit 4614 derives the operation mode of the storage power conditioner 4 based on the presence or absence of a device connected to the storage power conditioner 4 and/or the presence or absence of degenerate operation included in the system configuration table set or updated by the system configuration table management unit 4612. The above-mentioned conversion refers to a process of obtaining a control table Tc from the set or updated system configuration table T. Fig. 6(B) is a table showing the correspondence between the presence or absence of connection of the transformer device 3 and the presence or absence of degenerate operation when the storage battery unit 5 fails, and the operation mode of the storage power conditioner 4. In the system configuration table T shown in Fig. 5(B), the transformer device 3 is "present" and the degenerate operation when the storage battery unit 5 fails is "not present", so by converting this system configuration table T, a control table Tc in which the operation mode is "hybrid mode" is obtained.
In addition, in order to prevent the information in the control table from changing dynamically during operation of the energy storage system 1, the conversion from the system configuration table T read from the system configuration table memory unit 4613 to the control table Tc is performed only once when the energy storage power conditioner 4 is started up.

Next, the control table output unit 4615 of the first control unit 461 outputs the control table Tc obtained in step S4 to the second control unit 462 included in the same control unit 46 and to devices such as the transformer device 3 connected to the storage power conditioner 4 (step S5).

The control table Tc output from the first control unit 461 is
The control table Tc is received by the control table acquisition unit 4621 of the second control unit 462 and stored in a predetermined area of the memory (step S11). Then, in the second control unit 462, the control content determination unit 4622 refers to the control table Tc and determines the control content of the transformer 42, the converter 44, and the input/output unit 46 based on the information contained therein (step S12). Similarly, in the transformer device 3, the control unit 34 receives the control table Tc via the communication unit 35, acquires it, and stores it in a predetermined area of the memory (step S11), and the control unit 34 refers to the control table Tc and determines the control content of the transformer 32 based on the information contained therein (step S12).

In this way, the control unit 46 of the storage power conditioner 4 has a setting acquisition unit 4611 and a control content determination unit 4622 that controls the transformer unit 42 and the converter unit 44 based on the system configuration information acquired by the setting acquisition unit 4611. With this, the control content of the storage power conditioner 4 is determined based on the configuration of the system including the storage power conditioner 4, which is specified by the system configuration information. Therefore, a system can be configured including the storage power conditioner 4 and various devices such as the storage battery unit 5, the power generation device 2, and the transformer device 3, thereby improving the degree of freedom in the configuration of the system including the storage power conditioner 4.

Here, each operation mode of the above-mentioned storage power conditioner 4 will be described.
The storage power conditioner 4 operates in the storage-only mode when the transformer device 3 is not connected and the degenerate operation is not performed when the storage battery unit 5 fails. There are three system configurations shown in Fig. 7(A), Fig. 7(B), and Fig. 7(C) as the storage system 1 when operating in the storage-only mode. In Fig. 7(A), a specific load distribution board 11 to which a specific load 71 is connected is connected to the independent output terminal of the storage power conditioner 4 to which the storage battery unit 5, the power system 6, and the load 7 are connected. Here, the main distribution board 18, which is omitted in Fig. 2, is clearly shown (the same applies below). In Fig. 7(B), in addition to the system configuration of Fig. (A), an independent input PV power conditioner 16 to which an independent input PV 17 is connected is connected to the independent input terminal of the storage power conditioner 4. In Fig. 7(C), a transformer unit 12 is connected to the independent output terminal of the storage power conditioner 4 to which the storage battery unit 5, the power system 6, and the load 7 are connected. The power system 6 and the transformer unit 12 are connected to the main distribution board 18 and the load 7 via a full-load switching distribution board 13. The full-load switching distribution board is a distribution board that switches between the supply of AC power from the power system 6 to the load 7 via the storage power conditioner 4 and the main distribution board 18, and the supply of AC power output from an independent output terminal of the storage power conditioner 4 and transformed by the transformer unit 12 to the load 7 via the main distribution board 18.
In the power storage dedicated mode, since there is no input of DC power from the transformer device 3 to the power storage power conditioner 4, the control unit 46 controls the transformer unit 42, the conversion unit 44, and the input/output unit 45 independently of the transformer device 3.

The storage power conditioner 4 operates in the hybrid mode when the storage battery unit 5 and the transformer device 3 are connected and the degenerated operation is not performed when the storage battery unit 5 fails. There are two system configurations shown in Fig. 8 (A) and Fig. 8 (B) as the storage system 1 when operating in the hybrid mode. In Fig. 8 (A), a specific load distribution board 11 to which a specific load 71 is connected is connected to an independent output terminal of the storage power conditioner 4 to which the storage battery unit 5, the power generation device 2, the transformer device 3, the power grid 6, and the load 7 are connected. In Fig. 8 (B), a transformer unit 12 is connected to an independent output terminal of the storage power conditioner 4 to which the storage battery unit 5, the power generation device 2, the transformer device 3, the power grid 6, and the load 7 are connected.
In the hybrid mode, the transformer unit 42 , the converter unit 44 and the input/output unit 45 are controlled in accordance with the DC power input to the input unit 41 .

The storage power conditioner 4 operates in the power generation device dedicated mode when the transformer 3 is connected and the storage battery unit 5 fails and performs degenerate operation. There are three system configurations of the storage system 1 when operating in such a power generation device dedicated mode, as shown in Fig. 9 (A), Fig. 9 (B), and Fig. 9 (C). In Fig. 9 (A), a specific load distribution board 11 to which a specific load 71 is connected is connected to an independent output terminal of the storage power conditioner 4 to which the power generation device 2, the transformer 3, the power grid 6, and the load 7 are connected. Here, the failed storage battery unit 5 and the cable connecting thereto are removed, and therefore are indicated by dotted lines. In Fig. 9 (B), the power generation device 2, the transformer 3, the power grid 6, and the load 7 are connected to the storage power conditioner 4. Here, the failed storage battery unit 5, the transformer unit 12, and the cable connecting thereto are removed, and therefore are indicated by dotted lines. In FIG. 9C , a transformer unit 12 is connected to an isolated output terminal of a power storage power conditioner 4 to which a power generation device 2, a transformer device 3, a power grid 6, and a load 7 are connected.
In the power generation device dedicated mode, the storage power conditioner 4 operates like a power conditioner connected to the power generation device 2, together with the transformer device 3 that transforms the DC power generated by the power generation device 2. That is, the DC power generated by the power generation device 2 is transformed by the transformer device 3 and the storage power conditioner 4, converted into AC power, and supplied to the power grid 6 or the load 7.

Example 2
Second Embodiment A power storage system 1 according to a second embodiment of the present invention will be described in detail below with reference to the drawings. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

<System Configuration>
10 is a block diagram showing a schematic configuration of a power storage system 1 including a power storage power conditioner according to a second embodiment of the present invention. The power storage system 1 includes a power generation device 2, a transformer device 3, a power storage power conditioner 4, and a storage battery unit 5. In the second embodiment, the power storage power conditioner 4 acquires not only the presence or absence of connection of the storage battery unit 5 to the power storage power conditioner 4, but also the rated capacity of the storage battery unit 5, among the system configuration information, without relying on settings via the operation unit 8. That is, in the second embodiment, the setting acquisition unit 4611 acquires the presence or absence of the storage battery unit 5 and its rated capacity as the detected system configuration information.

Figure 11 is a diagram showing the overall configuration of the energy storage system 1 according to the second embodiment. The energy storage system 1 includes a power generation device 2, a transformer device 3, a power storage power conditioner 4, a storage battery unit 5, an operation unit 8, a display unit 9, a communication unit 10, a specific load distribution board 11, and a specific load 71. The power generation device 2 and the transformer device 3 are connected to each other by a cable or the like. The transformer device 3 and the power storage power conditioner 4 are connected to each other by a cable or the like. The transformer device 3 is detachable from the power storage power conditioner 4. Even if the transformer device 3 is not attached to the power storage power conditioner 4, the power storage power conditioner 4 can operate independently. In the example of Figure 11, the number of transformers 3 is one, but this is not limited thereto, and the number of transformers 3 may be multiple, and the number of transformers 3 can be increased or decreased.

The storage power conditioner 4 is connected to a specific load distribution board 11, and when the supply of AC power from the power grid 6 is stopped due to a power outage or the like, it can switch to independent operation and supply power from at least one of the power generation device 2 and the storage battery unit 5 to the specific load 71 connected to the specific load distribution board 11.

<Recognition process of rated capacity of storage battery unit>
Hereinafter, a process in which the control unit 46 recognizes the rated capacity, which is a characteristic of the storage battery unit 5, will be described with reference to FIG.

Here, it is assumed that storage battery units with three types of rated capacity, 6.5 kWh, 9.8 kWh, and 16.4 kWh, are preset as candidates for storage battery units 5 connectable to the storage power conditioner 4. The candidates for storage battery units 5 connectable to the storage power conditioner 4 are not limited to those having these rated capacities, and can be set as appropriate. The rated capacities of the storage battery units 5 connectable to such storage power conditioner 4 are set by the operation unit 8 or by an external device via a network as part of the system configuration, and are stored in a predetermined area of the memory included in the control unit 46.

In this embodiment, the control unit 46 recognizes the rated capacity of the storage battery unit 5 by transmitting an Initialize command to the storage battery unit 5 via the communication unit 47. The Initialize command includes identification information called a Fixed Number that is assigned to each type of storage battery unit 5. For example, the Fixed Numbers 0, 1, and 2 correspond to 6.5 kWh, 9.8 kWh, and 16.4 kWh storage battery units 5, respectively. When the storage battery unit 5 receives its own Fixed Number from the storage power conditioner 4 via the Initialize command, it returns a normal response as a response, and when it receives a Fixed Number different from its own Fixed Number, it returns an abnormal response or does not return a response.

First, the control unit 46 transmits an Initialize command including a Fixed Number of 6.5 kWh to the storage battery unit 5 via the communication unit 47 (step S21).
In response to this, the control unit 46 determines whether the response received by the communication unit 47 from the storage battery unit 5 is a normal response, an abnormal response, or no response (step S22).

If the communication unit 47 receives a normal response, the control unit 46 determines that the rated capacity of the connected storage battery unit 5 is 6.5 kWh, and stores this in a specified area of the memory (EEPROM) as information about the storage battery unit 5 connected to the storage power conditioner 4 (step S23).
When the communication unit 47 receives the abnormal response, the control unit 46 transmits an Initialize command including a Fixed Number of 9.8 kWh to the storage battery unit 5 via the communication unit 47 (step S24).
If the communication unit 47 does not receive a response from the storage battery unit 5, it determines whether or not a predetermined time has elapsed (step S25), and if the predetermined time has not elapsed, the process returns to step S22. If the predetermined time has elapsed without receiving a response from the storage battery unit 5, the process proceeds to step S24.

Following step S24, the control unit 46 determines whether the response from the storage battery unit 5 received by the communication unit 47 is a normal response, an abnormal response, or no response (step S26).

If the communication unit 47 receives a normal response, the control unit 46 determines that the rated capacity of the connected storage battery unit 5 is 9.8 kWh and stores this in a specified area of the memory as information about the storage battery unit 5 connected to the storage power conditioner 4 (step S27).
When the communication unit 47 receives the abnormal response, the control unit 46 transmits an Initialize command including a Fixed Number of 16.4 kWh to the storage battery unit 5 via the communication unit 47 (step S28).
If the communication unit 47 does not receive a response from the storage battery unit 5, it determines whether or not a predetermined time has elapsed (step S29), and if the predetermined time has not elapsed, the process returns to step S26. If the predetermined time has elapsed without receiving a response from the storage battery unit 5, the process proceeds to step S28.

Following step S28, the control unit 46 determines whether the response from the storage battery unit 5 received by the communication unit 47 is a normal response, an abnormal response, or no response (step S30).

If the communication unit 47 receives a normal response, the control unit 46 determines that the rated capacity of the connected storage battery unit 5 is 16.4 kWh and stores this in a specified area of memory as information about the storage battery unit 5 connected to the storage power conditioner 4 (step S31).
When the communication unit 47 receives the abnormality response, the control unit 46 determines that there is an abnormality in the storage battery connection (step S32), and ends the process.
If the communication unit 47 does not receive a response from the storage battery unit 5, it determines whether or not a predetermined time has elapsed (step S33), and if the predetermined time has not elapsed, it returns to step S30. If the predetermined time has elapsed without receiving a response from the storage battery unit 5, it proceeds to step S32.

Which Initialize command containing which Fixed Number is sent first is not limited to the order described above, but since the rated capacity of the connected storage battery unit 5 is stored in memory, if the storage power conditioner 4 is reset or the power is turned off, the Initialize command containing the Fixed Number corresponding to the rated capacity stored in memory may be sent first.

Through the above-described processing, the storage power conditioner 4 can recognize the rated capacity of the connected storage battery unit 5 .
13 shows an example of a system configuration table T that is set based on the thus recognized rated capacity of the storage battery unit 5. In this example, the rated capacity of the storage battery unit 5 is recognized as 9.8 kWh.
By controlling the output of the transformer unit 42 according to the rated capacity recognized in this manner, it is possible to perform appropriate charge/discharge control without damaging the storage battery units 5. In other words, storage battery units 5 having a plurality of types of rated capacities can be connected to the storage power conditioner 4, enabling operation according to different rated capacities, and improving the degree of freedom in the configuration of the storage system 1 including the storage power conditioner 4 and the storage battery units 5.

<Charge/discharge control during stand-alone operation>
Hereinafter, the charge/discharge control of the power storage system 1 during independent operation will be described with reference to Fig. 14. Fig. 14 is a flowchart showing the procedure of the charge/discharge control of the power storage system 1 during independent operation. The charge/discharge control described here is an example of the control content determined by referring to the control table in the second control unit 462 of the power storage power conditioner 4 and the control unit 34 of the transformer device 3 that have received the control table Tc converted from the system configuration table T including the rated capacity of the storage battery unit 5 acquired in the above-mentioned automatic recognition process of the rated capacity.

The energy storage system 1 is connected to a power grid 6 to operate the storage battery unit 5 and the power generation device 2, but in the event of a power outage or other interruption in the power supply from the power grid 6, the energy storage system 1 is disconnected from the power grid 6 and operates independently of the power grid 6.
During independent operation, DC power input to the input unit 41 from the power generation device 2 and/or DC power output from the storage battery unit 5 and transformed by the transformer unit 42 is converted to AC power by the converter unit 44 and output from the input/output unit 45 to be supplied to the specific load 71 connected to the specific load distribution board 11. At this time, single-phase two-wire 100V AC power is output from the input/output unit 45.
During the independent operation, the load 7 may be connected to the storage power conditioner 4 via a transformer unit and a full load switching distribution board. Here, the load 7 is also called a general load in contrast to a specific load, is connected to a main distribution board, and is a load to which AC power is supplied from the power grid 6 during grid-connected operation. The full load switching distribution board and the load 7 can be connected in various ways. AC power can be supplied to the load 7 connected to an outlet for independent output provided in the storage power conditioner 4. In addition, the input/output unit 45 is connected to the specific load distribution board via the main distribution board or directly, and can supply AC power to a load (specific load) 71 connected to this specific load distribution board. At this time, single-phase two-wire 100V AC power is output from the input/output unit 45.

First, the control unit 46 acquires the output power value P1 of the transformer device 3 (step S41). As described above, the control unit 34 of the transformer device 3 has an output power measurement unit 341 that measures the power value P1 of the DC power output to the input unit 41 from the current value of the DC power output from the output unit 33 and the output voltage value of the transformer unit 32 measured by the CT 3411. The power value P1 measured by the output power measurement unit 341 is transmitted from the control unit 34 to the control unit 46 of the storage power conditioner 4 by communication between the communication unit 35 and the communication unit 47. The control unit 46 is an example of a first power value acquisition unit of the present invention.

Next, the control unit 46 acquires the output current value P2 of the AC power output to the load (load or specific load) 7 from the input/output unit 45 (step S42). The input/output unit 45 is provided with an output power measurement unit 451 that measures the power value of the AC power output from the conversion unit 44 and output to the outside of the storage power conditioner 4 via the input/output unit 45. The control unit 46 acquires the output power value P2 from this output power measurement unit 451. The control unit 46 may calculate the power value after acquiring the current value and voltage value measured by the CT and voltmeter provided in the input/output unit 45.

The control unit 46 compares the power value P1 with the power value P2 to determine whether or not P1>P2 (step S43).
If it is determined in step S43 that the answer is Yes, i.e., that P1>P2, the DC power input to the input unit 41 is supplied to the load 7 and charges the storage battery unit 5 (step S44). That is, a part of the DC power input to the input unit 41 is transformed by the transformer unit 42, and the DC power output from the transformer unit 42 is output to the storage battery unit 5 via the input/output unit 43.
Then, the control unit 46 determines whether or not the remaining battery charge of the storage battery unit 5 is equal to or greater than a predetermined upper limit value according to the rated capacity (step S45).
In step S45, if it is determined that the remaining battery charge is less than the upper limit, the process returns to step S44, whereas if it is determined that the remaining battery charge is equal to or greater than the upper limit, the process proceeds to step S46. Here, if it is determined in step S45 that the remaining battery charge is less than the upper limit, the process returns to step S44, but it may also return to step S41.

If it is determined in step S43 that the answer is No, i.e., P1≦P2, the storage battery unit 5 is discharged (step S47). The DC power discharged from the storage battery unit 5 is input from the input/output unit 43 and transformed by the transformer unit 42. The DC power output from the transformer unit 42 and the DC power input from the input unit 41 are converted to AC power by the converter unit 44 and supplied to the load 7 via the input/output unit 45.
Then, the control unit 46 determines whether the remaining battery charge of the storage battery unit 5 is equal to or lower than a predetermined lower limit value according to the rated capacity (step S48).
If it is determined in step S48 that the remaining battery charge is greater than the lower limit, the process returns to step S47, whereas if it is determined that the remaining battery charge is equal to or less than the lower limit, the process proceeds to step S46. Here, if it is determined in step S48 that the remaining battery charge is greater than the lower limit, the process returns to step S47, but it may also return to step S41.

In step S46, the control unit 46 determines whether or not to end the independent operation of the power storage system 1.
When the independent operation is to be terminated due to reasons such as the resumption of power supply from the power grid 6, the charge/discharge control of the storage battery unit 5 is terminated.
If the independent operation is to be continued, the process returns to step S41.

By controlling the charging and discharging of the storage battery unit 5 in this manner, the power generated by the power generation device 2 during independent operation is given priority for supply to the load 7 or specific load 71, and the storage battery unit 5 is charged when there is surplus power. Then, when the power generated by the power generation device 2 alone is insufficient to supply to the load 7 or specific load 71, the storage battery unit 5 is discharged to increase the power supplied to the load 7 or specific load 71. In this way, the load 7 or specific load 71 can be operated more stably even during independent operation.

When controlling the charging and discharging of the storage battery unit 5 described above, if the power generation device 2 is a PV unit, the control unit 34 of the transformer device 3 performs MPPT (Maximum Power Point Tracking) control and operates the PV unit to track the maximum power of the PV unit. When charging the storage battery unit 5, the charging power can be automatically set by a process described below. The charging power of the storage battery unit 5 may be set in advance according to the rated capacity, or may be set by the user via the operation unit 8. Also, the server 15 may set the charging power of the storage battery unit 5 via the network 14.

Example 3
Third Embodiment A power storage system 1 according to a third embodiment of the present invention will be described below in detail with reference to the drawings. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

<System Configuration>
Fig. 15 is a block diagram showing a schematic configuration of a power storage system 1 including a power storage power conditioner 4 according to an embodiment of the present invention. Fig. 16 is a diagram showing the overall configuration of a power storage system 1 according to an embodiment of the present invention.
The energy storage system 1 includes a power generation device 2 , a transformer device 3 , a storage power conditioner 4 , and a storage battery unit 5 .

The input/output unit 45 outputs AC power to the power system 6 or the load 7. In addition, AC power output from the power system 6 is input to the input/output unit 45. Single-phase three-wire AC power is input from the power system 6 via the grid-connection input/output terminals 452a, 452b, and 452c. Here, the grid-connection input/output terminals 452a, 452b, and 452c are connected to the U-phase, O-phase, and W-phase power lines of the power system 6, respectively. An electric circuit 4501 connecting the grid-connection input/output terminals 452a, 452b, and 452c to the conversion unit 44 is provided with an electric circuit 4501 that opens and closes the electric circuit 4501 in order to connect or disconnect the storage power conditioner 4 to the power system 6. In addition, the input/output unit 45 is provided with an electric circuit 4502 that is connected at one end to the electric circuit 4501 between the conversion unit 44 and the grid-connection relay 453 and is connected at the other end to the independent output terminals 454a and 454b. The electric circuit 4502 connects the conversion unit 44 and the independent output terminals 454a and 454b via the electric circuit 4501. An independent relay 455 for opening and closing the electric circuit 4502 is provided on the conversion unit 44 side of the electric circuit 4502. A switching relay 456 is provided on the independent output terminals 454a and 454b side of the electric circuit 4502. The switching relay 456 is connected to an electric circuit 4501u connected to the U phase of the power system 6 and an electric circuit 4501o connected to the O phase via an electric circuit 4503. One end of the switching relay 456 is connected to the electric circuit 4502 on the independent output terminals 454a and 454b side, and the other end is switched between terminals a and a connected to the electric circuit 4502 on the independent relay 455 side and terminals b and b connected to the electric circuit 4503. In addition, an electric circuit 4504 is provided, one end of which is connected to the electric circuit 4502 between the independent relay 455 and the switching relay 456, and the other end of which is connected to the independent input terminals 457a and 457b. The electric circuit 4504 is provided with an independent input relay 458 that opens and closes the electric circuit 4504. The other end of the independent input relay 458 is connected to the independent input terminals 457a and 457b. Here, the independent input terminals 457a and 457b are connected to the independent input PV power conditioner 16 and the PV 17. The interconnection relay 453, the independent relay 455, the switching relay 456, and the independent input relay 458 provided in the input/output unit 45 are controlled by the control unit 46. The interconnection input/output terminals 452a, 452b, and 452c, and the independent output terminals 454a and 454b are examples of the first output unit of the present invention. The grid-connection relay 453, the independent relay 455, the switching relay 456, and the independent input relay 458 are examples of an output selection unit of the present invention, and the switching or opening/closing of these is also the selection of an output unit by the output selection unit of the present invention. The independent input PV power conditioner 16 is an example of a connection candidate device of the present invention.

In the energy storage system 1 shown in FIG. 15, the specific load distribution board 11 is connected to the independent output terminals 454a, 454b, but as shown in FIG. 18, a transformer unit 12 can be connected to the independent output terminals 454a, 454b. At this time, a load 7 is connected to the transformer unit 12 via a full load switching distribution board 13. An independent input PV power conditioner 16 and an independent input PV 17 can be connected to the independent input terminals 457a, 457b.

In Example 3, the storage power conditioner 4 acquires, among the system configuration information, whether the transformer unit 12 is connected to the storage power conditioner 4 and whether the PV power conditioner 16 for independent input is connected, without relying on settings via the operation unit 8. That is, in Example 3, the setting acquisition unit 4611 acquires, as the detected system configuration information, whether the transformer unit 12 is connected and whether the PV power conditioner 16 for independent input is connected.

There is no particular limitation on the method of detecting whether the transformer unit 12 is connected to the independent output terminals 454a, 454b. For example, the control unit 46 can detect whether the transformer unit 12 is connected by acquiring a signal from a sensor 121 such as a CT built into the transformer unit 12, detecting a change in the potential of a specific part of the storage power conditioner 4 due to the transformer unit 12 being connected to the independent output terminals 454a, 454b, etc.

There is no particular limitation on the method of detecting whether the independent input terminals 457a, 457b are connected to the independent input PV power conditioner 16. For example, the control unit 46 can transmit a predetermined command to the independent input PV power conditioner 16 via the communication unit 47, and detection can be made based on the response of the independent input PV power conditioner 16 to the command.

The system configuration table T is set based on the information on the connection or non-connection of the transformer unit 12 and the connection or non-connection of the independent input PV power conditioner 16 acquired in this manner. FIG. 17(A) and FIG. 17(B) show examples of the system configuration table T set based on the detected system configuration information. FIG. 17(A) is an example of a case where the connection or non-connection of the transformer unit 12 is detected as "not connected" and the connection or non-connection of the independent input PV power conditioner 16 is detected as "connected", and FIG. 17(B) is an example of a case where the connection or non-connection of the transformer unit 12 is detected as "connected" and the connection or non-connection of the independent input PV power conditioner 16 is detected as "connected". Here, the connection or non-connection of the transformer unit 12 and the connection or non-connection of the independent input PV power conditioner 16 are not limited to being acquired by the setting acquisition unit 4611 as detected configuration information and set in the system configuration table T, but may be set via the operation unit 8 as set information and set in the system configuration table T.

The control table Tc converted from the system configuration table T, which includes whether or not the transformer unit 12 is connected and whether or not the independent input PV power conditioner 16 is connected, is referenced by the second control unit 462 of the storage power conditioner 4 and the control unit 34 of the transformer device 3 to determine the control content.

The control unit 46 controls the interconnection relay 453, the independent relay 455, the switching relay 456, and the independent input relay 458 provided in the input/output unit 45. When the storage system 1 including the storage power conditioner 4 is operated in interconnection with the power grid 6, the interconnection relay 453 is closed, and the conversion unit 44 and the power grid 6 are connected by the electric circuit 4501. Although omitted in FIG. 15, in detail, the power grid 6 branches off from the electric circuit connected to the interconnection input/output terminals 452a, 452b, and 452c, and is connected to the main distribution board via the full load switching distribution board 13 described later. A load 7 is connected to the main distribution board, and when the storage system 1 including the storage power conditioner 4 is operated in interconnection with the power grid 6, the AC power supplied from the power grid 6 is supplied to the load 7 via the main distribution board. When the energy storage system 1 including the energy storage power conditioner 4 is operated in connection with the power grid 6, the independent relay 455 and the independent input relay 458 are opened, and the switching relay 456 is connected to contact b.

When the storage system 1 including the storage power conditioner 4 is operated in a state where it is disconnected from the power grid 6, the interconnection relay 453 is opened and the electric circuit 4501 connecting the conversion unit 44 to the power grid 6 is interrupted. Then, the independent relay 455 is closed and the switching relay 456 is switched to the contact a side, connecting the conversion unit 44 to the independent output terminals 454a and 454b. Here, the specific load distribution board 11 is connected to the independent output terminals 454a and 454b. A specific load that is specified in advance to be operated during independent operation is connected to the specific load distribution board 11. At this time, single-phase two-wire 100V AC power is output from the conversion unit 44 through the electric circuit 4502 and the independent output terminals 454a and 454b.

The independent input terminals 457a and 457b of the input/output unit 45 can be connected to the independent input PV power conditioner 16 to which the independent input PV is connected. When the storage system 1 including the storage power conditioner 4 to which the independent input PV power conditioner 16 to which the independent input PV is connected is operated in parallel with the power grid 6, the independent input relay 458 is closed. As a result, the independent input PV power conditioner 16 is connected to the conversion unit 44 and the specific load distribution board 11, so that the AC power output from the independent input PV power conditioner 16 is supplied to the specific load 71 via the specific load distribution board 11, or is converted to DC power by the conversion unit 44, transformed by the transformer unit 42, and output from the input/output unit 43 to charge the storage battery unit 5.

<Other system configurations>
An example of a different system configuration in the power storage system 1 including the power storage power conditioner 4 according to the present embodiment 3 will be described with reference to Fig. 18. Fig. 19 shows the overall configuration of the power storage system 1 having a different configuration.

In the storage power conditioner 4, as shown in FIG. 18, instead of the specific load distribution board 11, the transformer unit 12 can be connected to the independent output terminals 454a and 454b. As an example, the rated voltage of the transformer unit 12 is single-phase two-wire 200V. The transformer unit 12 is connected to the load 7 via the full-load switching distribution board 13. At this time, the conversion unit 44 outputs single-phase two-wire 200V AC power via the independent output terminals 454a and 454b. Then, the transformer unit 12 transforms this single-phase two-wire 200V AC power to single-phase three-wire 200V and outputs it to the full-load switching distribution board. Although omitted in FIG. 18, as shown in FIG. 19, a main distribution board 18 is connected between the full-load switching distribution board 13 and the load 7. The power system 6 and the full-load switching distribution board 13 are connected by a power line 62 branched from a power line 61 connecting the power system 6 and the grid-connected input terminals 452a, 452b, 452c of the storage power conditioner 4. Single-phase three-wire 200V AC power is input from the power system 6 through the power line 62 to the full-load switching distribution board 13. The full-load switching distribution board 13 switches the electric path so as to supply the AC power input from the power system 6 to the load 7 during grid-connected operation, and to supply the AC power input from the transformer unit 12 to the load 7 during independent operation.

As described above, the specific load distribution board 11 (see Figures 15 and 16) and the transformer unit 12 (see Figures 18 and 19) can be selectively connected to the independent output terminals 454a, 454b of the storage power conditioner 4, and the voltage of the AC power output from the conversion unit 44 via the independent output terminals 454a, 454b during independent operation can be switched between when the specific load distribution board 11 is connected and when the transformer unit 12 is connected.

<Output voltage change process>
The process of changing the voltage of the AC power output from the converter 44 via the independent output terminals 454a, 454b during independent operation will be described below with reference to Fig. 20. The process of changing the output voltage described here is an example of control content that is determined with reference to the control table Tc including the connection or non-connection of the transformer unit 12 and the connection or non-connection of the independent input PV power conditioner 16 acquired as described above.
The process shown in Fig. 19 is performed when the independent operation is started. When the supply of AC power from the power grid 6 is stopped due to a power outage or an abnormality in the equipment, the operation mode may be switched so that the grid-connected operation is automatically stopped and the independent operation is started. When the user recognizes that the supply of AC power from the power grid 6 has stopped through the display unit 9 described later, the operation unit 8 may instruct the grid-connected operation to be stopped and the independent operation to be started. In addition, the server 15 may transmit a command to the communication unit 10 via the network 14 to stop the grid-connected operation and start the independent operation, and the operation unit 8 may instruct the storage power conditioner 4 to stop the grid-connected operation and start the independent operation.

First, the control unit 46 opens the interconnection relay 453 (step S61).
Next, the control unit 46 closes the self-supporting relay 455 (step S62).
Next, the control unit 46 switches the switching relay 456 from the b-contact side to the a-contact side (step S63).

Next, the control unit 46 refers to the control table Tc to determine whether the transformer unit 12 is connected to the independent output terminals 454a, 454b (step S64).
If it is determined in step S64 that the transformer unit 12 is not connected to the independent output terminals 454a, 454b, the control unit 46 sets the output of the conversion unit 44 to single-phase two-wire 100V (step S65) and terminates the processing.
If it is determined in step S64 that the transformer unit 12 is connected to the independent output terminals 454a, 454b, the control unit 46 refers to the control table Tc to determine whether or not an independent input PV power conditioner 16 is connected to the independent input terminals 457a, 457b (step S66).

If it is determined in step S66 that the independent input PV power conditioner 16 is connected to the independent input terminals 457a, 457b, the control unit 46 opens the independent input relay 458 (step S67), interrupts the electrical circuit 4503 connecting the electrical circuit 4502 to the independent input terminals 457a, 457b, and proceeds to step S8.
If it is determined in step S66 that the independent input PV power conditioner 16 is not connected to the independent input terminals 457a, 457b, the process proceeds to step S68.

In step S68, the control unit 46 switches the output of the conversion unit 44 to single-phase two-wire 200V and ends the process.

In this way, during independent operation, the storage power conditioner 4 not only supplies power to the specific load 71 connected to the specific load distribution board 11, but also, upon detecting the connection of a transformer unit 12 that requires input of AC power different from the independent output to the specific load distribution board 11, switches the output from the independent output terminals 454a, 454b to AC power suitable for the transformer unit 12, thereby enabling operation of the storage system 1 including the transformer unit 12. In other words, according to the present invention, the freedom of configuration of the storage system 1 including the storage power conditioner 4 is improved. In addition, since the specific load distribution board 11 and the transformer unit 12 are connected to the common independent output terminals 454a, 454b, the installation space can be reduced, and costs can also be reduced.

In the above embodiment, the control unit 46 determines whether the transformer unit 12 is connected to the independent output terminals 454a and 454b at the start of independent operation, but the control unit 46 may determine whether the transformer unit 12 is connected during grid-connected operation. When the transformer unit 12 is connected to the independent output terminals 454a and 454b, the switching relay 456 is connected to the contact b during grid-connected operation, so that the AC power supplied from the power system 6 is not connected to the transformer unit 12. At this time, the output AC power is supplied to the load 7 through the power line 62 to the full-load switching distribution board 13 without passing through the transformer unit 12. The AC power input from the power system 6 to the grid-connected input/output terminals 452a, 452b, and 452c is output to the transformer unit 12 through the electric circuit 4501, the electric circuit 4504, the switching relay 456, the electric circuit 4502, and the independent output terminals 454a and 454b. In addition, the output power from the conversion unit 44 is supplied to the load 7 via the electric circuit 4501, the power line 61, and the power line 62 to the full load switching distribution board 13.

In the above-mentioned storage system 1, the power generation device 2 and the transformer device 3, the independent input PV 17 and the independent input PV power conditioner 16 are connected to the storage power conditioner 4, and either the specific load distribution board 11 or the transformer unit 12 is connected to the independent output terminals 454a and 454b. The configuration of the storage system 1 is not limited to this. The power generation device 2 and the transformer device 3, the independent input PV 17 and the independent input PV power conditioner 16 may be selectively connected to the storage power conditioner 4. That is, when the power generation device 2 and the transformer device 3 are connected to the storage power conditioner 4, the independent input PV 17 and the independent input PV power conditioner 16 are not connected, and when the independent input PV 17 and the independent input PV power conditioner 16 are connected to the storage power conditioner 4, the power generation device 2 and the transformer device 3 may not be connected.

In the following, the components of the present invention will be described with reference to the reference numerals in the drawings in order to make it possible to compare the components of the present invention with the configurations of the embodiments.
<Invention 1>
An input unit (41) to which DC power is input;
A first transformer unit (42) that transforms the voltage of the DC power;
a first input/output unit (43) that outputs the DC power transformed by the first transformer unit (42) to the storage battery unit (5) and receives DC power from the storage battery unit (5);
A conversion unit (44) for converting DC power into AC power;
a second input/output unit (45) that outputs the AC power converted by the conversion unit (44) to a power system (6) or a load (7) and receives AC power from the power system (6);
a first control unit (46) that controls the first transformer unit (42) and the converter unit (44);
A first communication unit (47) for communicating with the storage battery unit (5);
Equipped with
The first transformer unit (42) receives the DC power input to the input unit (41) and the DC power input to the second input/output unit (45) and converted by the conversion unit (44),
A power control device (4) in which the DC power output from the first transformer unit (42) and the DC power input to the input unit (41) are input to the conversion unit (44),
The first control unit (46) is
a connection candidate device information acquisition unit (4611) that is connected to the power control device (4) and is capable of inputting and outputting at least one of power between the power control device (4) and the power control device (4), and that acquires connection candidate device information that is information about a connection candidate device including the storage battery unit (5);
A control content determination unit (4622) that determines control content based on the connection candidate device information;
A power control device (4).

4: Storage power conditioner 5: Storage battery unit 6: Power system 7: Load 41: Input unit 42: Transformation unit 43: Input/output unit 44: Conversion unit 45: Input/output unit 46: Control unit 47: Communication unit 4611: Setting acquisition unit 4622: Control content determination unit

Claims (10)

an input unit to which DC power is input;
a first transformer unit that transforms a voltage of the DC power;
a first input/output unit that outputs the DC power transformed by the first transformer unit to a storage battery unit and receives the DC power from the storage battery unit;
A converter for converting DC power into AC power;
a second input/output unit that outputs the AC power converted by the conversion unit to a power system or a load and receives AC power from the power system;
A first control unit that controls the first transformer unit and the converter unit;
A first communication unit that communicates with the storage battery unit ;
Equipped with
The first transformer receives the DC power input to the input unit and the DC power input to the second input/output unit and converted by the conversion unit,
A power control device in which the conversion unit receives the DC power output from the first transformer unit and the DC power input to the input unit,
The first control unit is
a connection candidate device information acquisition unit that is connected to the power control device and is capable of inputting and outputting power between the power control device and the connection candidate device information acquisition unit, the connection candidate device information being information related to a connection candidate device including the storage battery unit;
a system configuration basic information generation unit that generates system configuration basic information regarding a configuration of a system including the power control device and the connection candidate device connected to the power control device based on the connection candidate device information acquired by the connection candidate device information acquisition unit;
a control information derivation unit that derives control system configuration information based on the system configuration basic information;
a control content determination unit that determines control content based on the control system configuration information, the control content including a control mode for at least one of the power control device and the connection candidate device that can be connected to the input unit, the control mode being derived based on the system configuration basic information related to the storage battery unit and the connection candidate device that can be connected to the input unit or the second input/output unit;
A power control device comprising: 2. The power control device according to claim 1 , wherein the control system configuration information is not changed while the power control device is running. The connection candidate device includes a transformer device having a second transformer unit that transforms DC power generated by a power generation device, a second output unit that outputs the DC power output from the second transformer unit to the input unit, a second control unit that controls the second transformer unit, and a second communication unit that communicates with the power control device,
The first control unit has a control information output unit that outputs the control system configuration information,
the first communication unit communicates with the connection candidate device including the storage battery unit;
The power control device described in claim 1 or 2, characterized in that the second control unit receives the control system configuration information transmitted from the first control unit via the first communication unit via the second communication unit, and controls the second transformer unit based on the control system configuration information. the connection candidate device information acquisition unit transmits a command in which a response corresponding to a characteristic of the storage battery unit is defined to the storage battery unit via the first communication unit, and acquires the characteristic as the connection candidate device information based on the response of the storage battery unit to the command;
The power control device according to any one of claims 1 to 3 , characterized in that the control content determination unit controls the output of the first transformer unit or the conversion unit based on the control system configuration information including the characteristics of the storage battery unit. The power control device according to claim 4 , wherein the characteristic is a rated capacity of the storage battery unit. the second input/output unit has a plurality of first output units for outputting AC power input to the second input/output unit to an outside of the power control device, and an output selection unit for selecting the first output unit to which the AC power input to the second input/output unit should be output,
the connection candidate device information acquisition unit detects the connection candidate device connected to the first output unit, and acquires the connection candidate device information regarding the connection candidate device;
The power control device according to claim 1 , wherein the first control unit controls the output selection unit based on the control system configuration information derived from the connection candidate device information. The power control device according to claim 6 , wherein the first control unit changes a voltage of the AC power output from the conversion unit to the connection candidate device based on the connection candidate device information. 8. The power control device according to claim 6 , wherein the connection candidate device is a transformer unit that changes a voltage of an output of AC power and supplies the power to the load. The power control device according to claim 8, characterized in that the first output section to which the transformer unit is connected is connected to either the transformer unit or a specific load distribution board which is a connection candidate device for supplying AC power to a specific load specified in advance . A power control device according to any one of claims 1 to 9 ,
the connection candidate device connected to the power control device;
A power control system comprising:

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