JP2017175785A - Power storage system, charge/discharge controller, control method therefor, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a power storage system for efficiently utilizing a surplus power of a photovoltaic power generation system, which can be set readily; a charge/discharge controller; a control method therefor; and a program.SOLUTION: A charge/discharge controller is connected to a power storage device in which an electric power generated by a DC power generator can be charged. The DC power generator is connected to a converter through a DC power line. The converter, to which the DC power line and an AC power line are connected, converts a DC power into an AC power. The AC power line is connected to a power system from the converter, and is connected to the DC power generator through the converter, to which a load can be connected. The power storage device is connected to the DC power line between the DC power generator and the converter. The charge/discharge controller comprises: an acquisition part for acquiring information concerning a direction of a current on the AC power line; and a control part which decides whether or not to charge the power storage device based on the direction of the current on the AC power line, and controls the charge and discharge of the power storage device.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a power storage system, a charge / discharge control device, a control method thereof, and a program.

  Patent Document 1 describes an example of a power storage device interconnected with a commercial power source. The power storage device of Patent Document 1 stores the power of the commercial power supply and discharges the stored power. At the time of discharge output of the power storage device, the voltage and current of the power storage device and the voltage / current of the AC output are measured, and the DC output of the power storage device is such that the ratio of the DC output power and the AC output effective power is substantially maximized from the measured values. The current is controlled.

  Patent Document 2 discloses a power supply system that performs so-called peak shift operation, in which an output of a solar power generation device is stored in a power storage device during a daytime period and is discharged at night to supply power to a load device. An example is described. In the system described in Patent Document 2, the charge / discharge amount of the power storage device is predicted from the demand prediction data of the load device and the power generation output prediction data predicted using the weather prediction data, and power generation is performed based on the predicted value. Stable power supply to the load device is realized by controlling the power generation amount of the device and suppressing the power consumption of the adjustment load device.

  Patent Document 3 describes an example of a power supply system interconnected with a power system. This system more effectively suppresses fluctuations in output power to the power system side by performing charge / discharge control of the power storage device.

  Patent Document 4 describes a power supply device that stably charges a secondary battery in a situation where the electric power generated from the solar battery fluctuates due to changes in sunlight intensity or ambient temperature.

Japanese Patent Laid-Open No. 2004-112954 JP 2013-176234 A International Publication No. 2011/122669 JP 2005-328862 A

The above-described patent document describes a system including a solar power generation system and a power storage device, or a power storage device that stores power from the system (Patent Document 1), but surplus power of an existing solar power generation system. In order to make effective use of the battery, a configuration for installing the power storage device later is not described.
When retrofitting a power storage device to an existing system, the installation cost is high, processing for coordinating with the operation of the photovoltaic power generation system is required, the processing and structure are complicated, and the charge / discharge efficiency of the storage battery is increased. There was a possibility of decline.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a power storage system, a charge / discharge control device, which can be easily installed and efficiently use surplus power of a solar power generation system, To provide a control method and a program.

  Each aspect of the present invention employs the following configurations in order to solve the above-described problems.

The first aspect relates to a power storage system.
The power storage system according to the first aspect is
Power storage means capable of charging electricity generated by the DC power generator;
Control means for controlling charging and discharging of the power storage means;
Have
The DC power generator is connected to the converter via a DC power line,
The conversion device connects the DC power line and the AC power line, and converts DC power into AC power,
The AC power line is connected to a power system, is connected to the DC power generator via the conversion device, and a load is connectable.
The power storage means is connected to the DC power line between the DC power generator and the converter,
The control means determines whether to charge the power storage means based on the direction of the current of the AC power line.

The second aspect relates to a charge / discharge control device.
The charge / discharge control device according to the second aspect is
A charge / discharge control device connected to a power storage device capable of charging electricity generated by a DC power generator,
The DC power generator is connected to the converter via a DC power line,
The conversion device connects the DC power line and the AC power line, and converts DC power into AC power,
The AC power line is connected to the power system from the conversion device, is connected to the DC power generation device via the conversion device, and a load is connectable.
The power storage device is connected to the DC power line between the DC power generator and the converter,
The charge / discharge control device comprises:
Obtaining means for obtaining information on the direction of the current of the AC power line;
Control means for determining whether to charge the power storage device based on the direction of the current of the AC power line, and for controlling charge / discharge of the power storage device;
Means.

A 3rd side is related with the control method of the charging / discharging control apparatus performed by at least 1 computer.
The control method of the charge / discharge control device according to the third aspect is as follows:
A control method for a charge / discharge control device connected to a power storage device capable of charging electricity generated by a DC power generator,
The DC power generator is connected to the converter via a DC power line,
The conversion device connects the DC power line and the AC power line, and converts DC power into AC power,
The AC power line is connected to the power system from the conversion device, is connected to the DC power generation device via the conversion device, and a load is connectable.
The power storage device is connected to the DC power line between the DC power generator and the converter,
The charge / discharge control device comprises:
Obtain information on the current direction of the AC power line,
Determining whether to charge the power storage device based on the direction of the current of the AC power line, and controlling charging / discharging of the power storage device.

As another aspect of the present invention, there may be a program for causing at least one computer to execute the method of the third aspect, or a computer-readable recording medium recording such a program. May be. This recording medium includes a non-transitory tangible medium.
This computer program includes computer program code that, when executed by a computer, causes the computer to perform its control method on the charge / discharge control device.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  The various components of the present invention do not necessarily have to be independent of each other. A plurality of components are formed as a single member, and a single component is formed of a plurality of members. It may be that a certain component is a part of another component, a part of a certain component overlaps with a part of another component, or the like.

  Moreover, although the several procedure is described in order in the method and computer program of this invention, the order of the description does not limit the order which performs a several procedure. For this reason, when the method and computer program of the present invention are implemented, the order of the plurality of procedures can be changed within a range that does not hinder the contents.

  Furthermore, the plurality of procedures of the method and the computer program of the present invention are not limited to being executed at different timings. For this reason, another procedure may occur during the execution of a certain procedure, or some or all of the execution timing of a certain procedure and the execution timing of another procedure may overlap.

  According to each said aspect, it can install simply and can provide the electrical storage system, charging / discharging control apparatus, its control method, and program which utilize the surplus electric power of a photovoltaic power generation system efficiently.

It is a schematic block diagram which shows the structural example of a solar energy power generation system. It is a schematic block diagram which shows the structural example of the electrical storage system which concerns on embodiment of this invention. It is a functional block diagram which shows logically the structure of the charging / discharging control apparatus which concerns on embodiment of this invention. It is a figure which shows an example of the time transition of the charging capacity by the charging / discharging control of the storage battery of the electrical storage system of this embodiment. It is a figure for demonstrating charging / discharging control of the storage battery of the electrical storage system of this embodiment. It is a figure which shows an example of a structure of the computer which implement | achieves the charging / discharging control apparatus of this embodiment. It is a flowchart which shows an example of operation | movement of the charging / discharging control apparatus of this embodiment. It is a flowchart which shows an example of operation | movement of the charging / discharging control apparatus of this embodiment. It is a flowchart which shows an example of the detailed procedure of the charge process of the charging / discharging control apparatus of this embodiment. It is a flowchart which shows an example of the detailed procedure of the discharge process of the charging / discharging control apparatus of this embodiment. It is a figure which shows an example of the time transition of the charging capacity by the charging / discharging control of the storage battery of the electrical storage system of this embodiment. It is a schematic block diagram which shows the structural example of the electrical storage system of this embodiment. It is a functional block diagram which shows logically the structure of the charging / discharging control apparatus of this embodiment. It is a flowchart which shows an example of operation | movement of the charging / discharging control apparatus of this embodiment. It is a schematic block diagram which shows the system configuration | structure of the electrical storage system of the Example of this invention. It is a functional block diagram which shows logically the structure of the charging / discharging control apparatus of a present Example. It is a figure which shows the electric power generation amount of PV panel of the electrical storage system of a present Example. It is a figure which shows an example of the data structure of the memory | storage device which memorize | stores the various setting values of the electrical storage system of a present Example. It is a flowchart which shows an example of the operation | movement at the time of charge of the charging / discharging control apparatus of a present Example. It is a flowchart which shows an example of the operation | movement at the time of discharge of the charging / discharging control apparatus of a present Example. It is a schematic block diagram which shows the structural example of the electrical storage system of the Example of this invention. It is a functional block diagram which shows the structure of the inverter of the electrical storage apparatus of a present Example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

(First embodiment)
A power storage system, a charge / discharge control device, a control method thereof, and a program according to a first embodiment of the present invention will be described below.
The charge / discharge control apparatus of this embodiment controls charge / discharge of a lithium ion secondary battery.

FIG. 1 is a schematic block diagram illustrating a configuration example of a photovoltaic power generation (PV: PhotoVoltaics) system 10.
FIG. 2 is a schematic block diagram showing a configuration example when the power storage system 1 according to the embodiment of the present invention is retrofitted to the DC power line 16 side of the existing PV system 10 of FIG.
In each drawing of the present specification, the configuration of parts not related to the essence of the present invention is omitted and is not shown.

  The AC power line 28 includes an AC power line 28 a between the PV-PCS 14 and the distribution board 24, and an AC power line 28 b between the distribution board 24 and the power system 22.

  The existing PV system 10 of FIG. 1 includes a PV panel 12, a PV-PCS (Power Conditioning System) 14, a distribution board 24, and a load 26. In the present embodiment, the PV panel 12 and the PV-PCS 14 are installed outdoors, and the distribution board 24 and the load 26 are installed indoors. The above is an example, and the PV-PCS 14 may be installed indoors, or the distribution board 24 and the load 26 may be installed outdoors.

The PV panel 12 and the PV-PCS 14 are connected by a DC power line 16 (shown by a broken line).
The PV-PCS 14, the distribution board 24, and the power system 22 are connected by an AC power line 28 (shown by a one-dot chain line (28 a, 28 b)). A load 26 is further connected to the AC power line 28 (28a, 28b) via a distribution board 24.

The PV panel 12 includes a plurality of solar cells that receive solar light energy and converts them into electricity, and is protected by tempered glass or acrylic resin. For example, the PV panel 12 is installed on a roof of a residence.
The DC current generated by the PV panel 12 is input to the PV-PCS 14 through the DC power line 16. The PV-PCS 14 has a function of converting a direct current generated by the PV panel 12 into an alternating current generally used in home appliances (load 26). In the present embodiment, the PV-PCS 14 also has a function of controlling the operation of the PV panel 12. For example, the PV-PCS 14 performs MPPT (Maximum Power Point Tracking) control of the PV panel 12 and receives an output suppression control signal (hereinafter also referred to as a PV output suppression signal) for the PV panel 12. The output of the PV panel 12 is suppressed according to the control signal. The PV output suppression signal includes, for example, an instruction to suppress the output at a predetermined ratio (%) of the rated output of the PV-PCS 14.

  The load 26 is at least one of various electric devices such as an air conditioner, a lighting device, a refrigerator, a television, a microwave oven, a dryer, a personal computer, a game machine, a telephone, a water heater, an electric vehicle, and a plug-in hybrid vehicle. There is no particular limitation.

Electricity is supplied from the electric power system 22 to the distribution board 24 of the customer's house via the power transmission network, and electricity is distributed to each load 26 via the distribution board 24.
The electricity generated by the PV panel 12 is input to the PV-PCS 14 via the DC power line 16, is converted into an AC current, and is output to the AC power line 28a. Then, it can be supplied to the load 26 through the distribution board 24 through the AC power line 28a.

  In addition to consuming the electric power generated by the PV panel 12 by the load 26 of the consumer, the surplus can be reversely flowed to the power system 22 via the distribution board 24. However, in the present embodiment, surplus power generated by the PV panel 12 is charged to the lithium ion secondary battery of the battery system 42 by the power storage device 40 without causing a reverse flow to the power system 22 as much as possible.

  As shown in FIG. 2, the power storage system 1 of the present embodiment includes a power storage device 40 and a clamp-type alternating current sensor 44.

The charge / discharge control apparatus 100 of this embodiment controls charge / discharge of the battery system 42 that is added later to the existing PV system 10. The power storage device 40 of this embodiment includes a battery system 42 and a charge / discharge control device 100. The power storage device 40 is electrically connected to the DC power line 16 between the PV panel 12 and the PV-PCS 14. Moreover, although the electrical storage apparatus 40 in this embodiment shall be installed outdoors, you may install indoors.
In the present embodiment, the PV system 10 is described as an example. However, the present invention is not limited to solar power generation, and can be similarly applied to a renewable energy power generation system that outputs other DC power.

  The battery system 42 includes at least one lithium-ion rechargeable battery (hereinafter also referred to as “storage battery”) and a battery management unit (Battery Management Unit) that manages the lithium ion secondary battery, not shown. BMU). The battery system 42 has an electric capacity indicated by a rated capacity (kWh) that can be charged by the system. In the battery system 42, charging / discharging of the storage battery is controlled by the charging / discharging control device 100.

  In the present embodiment, although detailed description is omitted, in the charge / discharge control of the storage battery, the charge / discharge control is performed within a predetermined range with respect to the rated capacity of the storage battery.

FIG. 3 is a functional block diagram logically showing the configuration of the charge / discharge control apparatus 100 according to the embodiment of the present invention. Hereinafter, the structure of the charge / discharge control apparatus 100 of this embodiment is demonstrated using FIG. 2 and FIG.
The charge / discharge control device 100 of this embodiment is connected to a power storage device (battery system 42) capable of charging electricity generated by a DC power generation device (PV panel 12).
The DC power generator (PV panel 12) is connected to the converter (PV-PCS 14) via the DC power line 16.
The converter (PV-PCS 14) connects the DC power line 16 and the AC power line 28a, and converts DC power into AC power.
The AC power line 28 (28a, 28b) is connected to the power system 22 from the converter, connected to the DC power generator (PV panel 12) via the converter (PV-PCS 14), and a general load. 26 can be connected.
The charge / discharge control device 100 determines whether or not to charge the power storage device (battery system 42) based on the acquisition unit 102 that acquires information on the direction of the current of the AC power line 28b and the direction of the current of the AC power line 28b. And a control unit 104 that controls charging and discharging of the power storage device (battery system 42).

  In this specification, “acquisition” means that the device itself obtains data or information stored in another device or storage medium (active acquisition), for example, requests or inquires of another device. Receiving data, accessing and reading out other devices and storage media, etc., and inputting data or information output from other devices into the device (passive acquisition), for example, distribution (or , Transmission, push notification, etc.) and / or receiving received data or information. It also includes selecting and acquiring from received data or information, or selecting and receiving distributed data or information.

  The charge / discharge control device 100 of the present embodiment may be further connected to a storage device 110 (not shown) so as to be accessible. The storage device 110 may be included in the charge / discharge control device 100 or may be a device external to the charge / discharge control device 100. In the present embodiment, the storage device 110 may be realized by a memory 84 or a storage 85 of the computer 80 shown in FIG.

Hereinafter, each component of the charge / discharge control apparatus 100 of FIG. 3 is demonstrated in detail.
The acquisition unit 102 acquires the value of current flowing through the AC power line 28b between the distribution board 24 and the power system 22 and the direction thereof. In the example of FIG. 2, for example, the acquisition unit 102 attaches the clamp-type AC current sensor (CT: Current Transformer) 44 of FIG. 2 to the AC power line 28 b between the distribution board 24 and the power system 22, and clamp-type AC current The sensor 44 measures the current value of the AC power line 28b. The acquisition unit 102 acquires a current value measured by the clamp-type alternating current sensor 44 and acquires information regarding the direction of the current.

  As described above, the control unit 104 determines whether or not to charge the power storage device (battery system 42) based on the direction of the current of the AC power line 28b, and controls charging / discharging of the power storage device (battery system 42). .

Specifically, the control unit 104 charges the power storage device (storage battery of the battery system 42) with the surplus (surplus power) that remains without being consumed by the load 26 among the power generated by the PV panel 12. Control.
As shown in FIG. 4, the difference (hatched portion) between the power generation amount of PV panel 12 per hour (shown by a solid line) and the power consumption of load 26 (shown by a broken line) is the surplus power of PV panel 12. Become.

The control unit 104 may also control discharge of the storage battery.
For example, instead of the power supplied from the power system 22 or the PV panel 12 to the load 26, the power charged in the storage battery can be discharged from the storage battery and supplied to the load 26.
Moreover, in this embodiment, the electric power discharged from a storage battery shall not be made to flow backward to the electric power grid | system 22, and shall be consumed with the load 26 of a consumer.

  In the present embodiment, the acquisition unit 102 acquires information related to the direction of the current flowing through the AC power line 28b, and based on the information, the control unit 104 controls charging / discharging of the storage battery, but is not limited thereto. . As shown below, a configuration for performing charge / discharge control of a storage battery under various information or conditions is not excluded. A plurality of the following may be combined within a consistent range.

In the present invention, whether or not charging is possible can be determined based on information indicating whether or not there is a surplus in the power generated by the PV panel 12.
The conditions for the control unit to determine whether charging is possible are exemplified below.
(A1) When the direction of the current of the AC power line 28b is from the distribution board 24 to the power system 22, that is, when a reverse power flow (sold power) to the power system 22 occurs.
(A2) When the power generation amount from the PV panel 12 is equal to or greater than the threshold, the surplus exceeding the threshold is charged.
(A3) The surplus power that is subjected to output suppression control by the PV output suppression signal is charged.

  The configurations (a2) to (a3) will be described in other embodiments described later.

In (a1) above, whether or not charging is possible is determined based on the direction of the current of the AC power line 28b.
Specifically, the storage battery is charged when the direction of the current of the AC power line 28 b is from the distribution board 24 to the power system 22. If it is not the power system 22 from the distribution board 24, it is not charged.

  This configuration is the configuration of this embodiment. The acquisition unit 102 acquires information related to the current direction of the AC power line 28b (between the power system 22 and the distribution board 24). The direction of the current can be specified from the sign of the current value of the AC power line 28b. For example, if the current value when the current flows from the power system 22 in the direction of the distribution board 24 is a positive value, the current value when the current flows from the distribution board 24 in the direction of the power system 22 is a negative value. Become. Since the direction of current flow and the positive / negative of the current value are determined by the installation method of the clamp-type AC current sensor 44, the relationship between the current direction and the positive / negative of the current value is determined according to the installation condition of the clamp-type AC current sensor 44. Set in advance.

  Here, in the case of alternating current, since the direction of the current changes with time, when the alternating current is 0 ° ± 90 with respect to the phase of the alternating voltage, that is, alternating current power is output from the power system 22 to the distribution board 24. The current value is assumed to be positive. On the other hand, when the AC current is 0 ° ± 90 or more, that is, when AC power is output from the distribution board 24 in the direction of the power system 22, the current value is negative.

Furthermore, a control part may control charging / discharging of a storage battery using combining at least any one among several conditions illustrated below.
(B1) Charging / discharging is performed according to a predetermined first chargeable time zone and second dischargeable time zone of the storage battery.
In this configuration, information on the first time zone and the second time zone is stored in the storage device 110 in advance.
In the power storage device 40 of the present embodiment, it is assumed that a first time period in which the storage battery can be charged and a second time period in which the storage battery can be discharged are predetermined. The first time zone is from 6:00 to 18:00, and the second time zone is from 18:00 to 6:00 on the next day.

  The charge / discharge control apparatus 100 has a timepiece (not shown) and acquires time information from the timepiece. Further, the timepiece may not be included in the charge / discharge control device 100 and may be a device external to the charge / discharge control device 100.

  As shown in FIG. 5, even when the power generation amount of the PV panel 12 indicated by the solid line exceeds the power consumption amount of the load 26 indicated by the broken line, surplus power in the second time zone (in the figure, The battery is not charged).

(B2) When the storage battery is fully charged, it is not charged.
In this configuration, the acquisition unit 102 may acquire information indicating that the storage battery is fully charged from the BMU of the battery system 42.

(B3) When the storage battery is charged by a predetermined ratio (%) or more of the storage capacity, the charging is stopped.
In this configuration, a predetermined percentage (%) of the storage capacity of the storage battery is stored in advance in the storage device 110.

(B4) The charging / discharging of the storage battery is controlled according to the status of power purchase or power sale in the power system 22.
This configuration will be described in detail in an embodiment described later.

(B5) When the remaining storage capacity of the storage battery is less than the first threshold value or the free capacity is equal to or greater than the second threshold value, the discharge of the storage battery is stopped.
In this configuration, the acquisition unit 102 may acquire information related to the remaining storage capacity or free capacity of the storage battery from the BMU of the battery system 42. The threshold value is stored in advance in the storage device 110. Each threshold may have a configuration that can be updated from the outside.

FIG. 6 is a diagram illustrating an example of a configuration of a computer 80 that realizes the charge / discharge control apparatus 100 of the present embodiment.
The computer 80 of the present embodiment includes a CPU (Central Processing Unit) 82, a memory 84, a program 90 that implements the components of the charge / discharge control device 100 loaded in the memory 84, a storage 85 that stores the program 90, an I / O O (Input / Output) 86 and a network connection interface (communication I / F 87).

  The CPU 82, the memory 84, the storage 85, the I / O 86, and the communication I / F 87 are connected to each other via the bus 89, and the entire charge / discharge control device 100 is controlled by the CPU 82. However, the method of connecting the CPUs 82 and the like is not limited to bus connection.

  The memory 84 is a memory such as a RAM (Random Access Memory) or a ROM (Read Only Memory). The storage 85 is a storage device such as a hard disk, an SSD (Solid State Drive), or a memory card.

  The storage 85 may be a memory such as a RAM or a ROM. The storage 85 may be provided inside the computer 80 or may be provided outside the computer 80 and connected to the computer 80 by wire or wireless as long as the computer 80 is accessible. Alternatively, the computer 80 may be detachably provided.

  The CPU 82 reads out the program 90 stored in the storage 85 to the memory 84 and executes it, whereby each function of each unit of the charge / discharge control device 100 can be realized.

  The I / O 86 performs input / output control of data and control signals between the computer 80 and other input / output devices. The other input / output devices include, for example, an input device (not shown) such as a keyboard, a touch panel, a mouse, and a microphone connected to the computer 80, and an output device (not shown) such as a display, a printer, and a speaker, These input / output devices and the interface of the computer 80 are included. Further, the I / O 86 may perform data input / output control with a reading or writing device (not shown) of another recording medium.

  The communication I / F 87 is a network connection interface for performing communication between the computer 80 and an external device. The communication I / F 87 is not always necessary. The communication I / F 87 may be a network interface for connecting to a wired line or a network interface for connecting to a wireless line. For example, the computer 80 that implements the charge / discharge control device 100 may be connected to the HEMS via the network 3 by the communication I / F 87.

  Each component of the charge / discharge control apparatus 100 of this embodiment is implement | achieved by the arbitrary combinations of the hardware and software of the computer 80 of FIG. It will be understood by those skilled in the art that there are various modifications to the implementation method and apparatus. The functional block diagram showing the charge / discharge control device of each embodiment to be described below shows a block of logical functional units, not a configuration of hardware units.

  In addition, the charge / discharge control apparatus 100 does not exclude a configuration including a plurality of computers 80.

  The computer program 90 according to the present embodiment is a power storage device based on a procedure for acquiring information related to the current direction of the AC power line 28b in the computer 80 for realizing the charge / discharge control device 100, and the current direction of the AC power line 28b. It is described to determine whether or not (battery system 42) is charged and to execute a procedure for controlling charging / discharging of the power storage device (battery system 42).

  The computer program 90 of this embodiment may be recorded on a recording medium that can be read by the computer 80. The recording medium is not particularly limited, and various forms can be considered. The program 90 may be loaded from a recording medium into the memory 84 of the computer 80, or may be downloaded to the computer 80 through a network and loaded into the memory 84.

  The recording medium for recording the computer program 90 includes a medium that can be used by a non-transitory tangible computer 80, and a program code that can be read by the computer 80 is embedded in the medium. When the computer program 90 is executed on the computer 80, the computer 80 is caused to execute the following control method for realizing the charge / discharge control apparatus 100.

A control method of the charge / discharge control apparatus 100 of the present embodiment configured as described above will be described below.
FIG. 7 is a flowchart showing an example of the operation of the charge / discharge control apparatus 100 of the present embodiment.
The control method according to the embodiment of the present invention is a control method of the charge / discharge control device 100, and is a control method executed by the computer 80 that implements the charge / discharge control device 100.
In the control method of the present embodiment, the charge / discharge control device 100 acquires information related to the current direction of the AC power line 28b (step S101), and the power storage device (battery system 42) based on the current direction of the AC power line 28b. Or not (step S103), and charging / discharging of the power storage device (battery system 42) is controlled (step S105, step S107).

This will be described in more detail below.
First, the acquisition unit 102 acquires the value of the current flowing through the AC power line 28b between the distribution board 24 and the power system 22 and the direction of the current from the clamp-type AC current sensor 44 (step S101). Here, when a current flows from the power system 22 in the direction of the distribution board 24, the current value is a positive value, and when a current flows from the distribution board 24 in the direction of the power system 22, the current value is It shall be a negative value.

  And the control part 104 determines whether the direction of an electric current is toward the electric power grid | system 22 from the distribution board 24 (step S103). For example, the determination can be made based on whether or not the current value acquired by the acquisition unit 102 in step S101 is a negative value.

  When the direction of current is from distribution board 24 to power system 22 (YES in step S103), for example, when the current flowing through AC power line 28b is a negative value (less than 0), control unit 104 The storage battery is charged with surplus power derived from the PV panel 12 (step S105). Then, the process ends.

  At this time, surplus power generated by the PV panel 12 flows directly from the DC power line 16 to the power storage device 40 and is charged to the storage battery of the battery system 42.

  In addition, when the direction of the current is not from the distribution board 24 to the power system 22 (NO in step S103), for example, processing when the current flowing through the AC power line 28b is a positive value (0 or more) will be described later. It will be described in the embodiment, and the description is omitted here. Moreover, since the charging process stop condition will be described in an embodiment described later, the description thereof is omitted here.

  The process of the flowchart in FIG. 7 may be repeatedly executed at a predetermined period during a first time period in which the storage battery can be charged, for example. Moreover, the process of each step may be performed asynchronously.

As described above, in the charge / discharge control device 100 of the present embodiment, the acquisition unit 102 acquires the current direction of the AC power line 28b, and the control unit 104 determines the storage battery of the battery system 42 based on the current direction. Whether or not to charge the battery is determined, and charge / discharge control of the storage battery of the battery system 42 is performed.
Thus, according to the charge / discharge control apparatus 100 of this embodiment, the storage battery of the battery system 42 can be efficiently charged with the surplus power of the PV panel 12 with a simple configuration.

  In the case of the configuration of the present embodiment, the charge / discharge efficiency of the storage battery is such that only the charge / discharge control device 100 is interposed between the battery system 42 and the PV panel 12 because the power storage device 40 is connected to the DC power line 16. To do. In this case, the charge / discharge efficiency is determined by combining the efficiency (95%) between the PV panel 12 and the charge / discharge control device 100 and the efficiency (95%) between the charge / discharge control device 100 and the battery system 42. 90% is obtained as the overall charge / discharge efficiency.

As the number of devices between the battery system 42 and the PV panel 12 increases, the charge / discharge efficiency decreases and the efficiency deteriorates. For example, the charge / discharge efficiency of the configuration in which the power storage device 40 is connected to the AC power line 28 (28a, 28b) includes the efficiency (95%) between the PV panel 12 and the PV-PCS 14, the PV-PCS 14 and the charge / discharge control device. The efficiency (95%) between 100 and the efficiency (95%) between the charge / discharge control device 100 and the battery system 42 are combined to obtain 85% as the charge / discharge efficiency of the entire power storage system 1.
In this way, the configuration in which the power storage device 40 of the present embodiment is connected to the DC power line 16 is connected to the AC power line 28 (28a, 28b) from the viewpoint of charge / discharge efficiency (90%). It can be seen that the charge / discharge efficiency (85%) is better.

  Furthermore, since the power storage system 1 of the present embodiment is retrofitted to the DC power line 16 side of the PV system 10, it is not necessary to perform grid connection, that is, the AC power line 28 connected to the power system 22 is retrofitted. Thus, the grid connection protection function and complicated application procedures necessary for grid connection are also eliminated.

(Second Embodiment)
Hereinafter, the power storage system according to the second embodiment of the present invention will be described.
The power storage system of the present embodiment is assumed to have the same configuration as that of the power storage system 1 of the above-described embodiment of FIG. 2, and will be described below with reference to FIGS.
In the present embodiment, an example of a storage battery charge / discharge control method in the control unit 104 of the above embodiment will be described in detail.

  In the control part 104 of the charging / discharging control apparatus 100 of this embodiment, according to the direction of the electric current which flows between the distribution board 24 and the electric power grid | system 22, charging / discharging to a storage battery is controlled.

(C1) When the direction of current is distribution board 24 → power system 22 When the current flows from the distribution board 24 to the power system 22 in the direction of the power system 22 (at the time of power sale, there is surplus power), The charge amount to the power storage device (storage battery of the battery system 42) is increased until the current becomes zero.

(C2) When the direction of current is from the power system 22 to the distribution board 24 When the current flows from the power system 22 to the distribution board 24 (at the time of power purchase, there is no surplus power), The amount of discharge from the power storage device (the storage battery of the battery system 42) is increased until the current becomes zero.

A specific example will be described below.
Here, when the current flowing through the AC power line 28 b acquired by the acquisition unit 102 flows from the distribution board 24 in the direction of the power system 22, the current takes a negative value, and the direction from the power system 22 to the distribution board 24. If the current is flowing in, the positive value shall be taken.

  The control unit 104 determines whether the current flowing through the AC power line 28b acquired by the acquisition unit 102 is positive or negative. When the current value is negative (less than 0), control unit 104 increases the charging current value by a predetermined value (for example, 1 A) and charges the storage battery. Thereafter, the current value flowing through the AC power line 28b is acquired by the acquisition unit 102, and the determination process is repeated until the current value becomes zero.

  When the current value is positive (current value> 0), control unit 104 increases the discharge current value by a predetermined value (for example, 1 A) and discharges the storage battery. Thereafter, the current value flowing through the AC power line 28b is acquired by the acquisition unit 102, and the determination process is repeated until the current value becomes zero.

  And if an electric current becomes 0, the control part 104 will continue charging / discharging of a storage battery with the electric current value at that time. Then, the current direction between the distribution board 24 and the power system 22 is monitored again.

  Also in this embodiment, the CPU 82 of the computer 80 in FIG. 6 reads out the program 90 stored in the storage 85 to the memory 84 and executes it, thereby realizing each function of each unit in FIG. 3 of the charge / discharge control device 100. can do.

The computer program 90 according to the present embodiment is a power storage device based on a procedure for acquiring information related to the current direction of the AC power line 28b in the computer 80 for realizing the charge / discharge control device 100, and the current direction of the AC power line 28b. (Battery system 42) is determined to charge or not, a procedure for controlling charging / discharging of the power storage device (battery system 42) is executed, and further, current flows from the distribution board 24 in the direction of the power system 22. (When surplus power is present, there is surplus power), a procedure for increasing the amount of charge to the power storage device (storage battery of the battery system 42) until the current becomes zero is described.
Furthermore, the computer program 90 according to the present embodiment is used when a current flows from the power system 22 to the distribution board 24 in the computer 80 for realizing the charge / discharge control device 100 (when purchasing power, there is no surplus power). ), And a procedure for increasing the amount of discharge from the power storage device (storage battery of the battery system 42) until the current becomes zero is described.

Hereinafter, the control method of the charge / discharge control apparatus 100 of this embodiment is demonstrated.
FIG. 8 is a flowchart showing an example of the operation of the charge / discharge control apparatus 100 of the present embodiment.
The control method according to the embodiment of the present invention is a control method of the charge / discharge control device 100, and is a control method executed by the computer 80 that implements the charge / discharge control device 100.

  In the control method of the present embodiment, the charge / discharge control device 100 acquires the current value and direction of the current flowing through the AC power line 28b between the distribution board 24 and the power system 22 (step S301), and the AC power line 28b. Determining whether to charge the power storage device (battery system 42) based on the current direction (step S303) (step S305 to step S307), and controlling charging / discharging of the power storage device (battery system 42). including.

This will be described in more detail below.
First, the acquisition unit 102 of the charge / discharge control device 100 acquires the value of the current flowing through the AC power line 28b between the distribution board 24 and the power system 22 and the direction of the current from the clamped AC current sensor 44 (step S301).

  And the control part 104 determines the direction of the electric current which flows through the alternating current power line 28b between the distribution board 24 and the electric power grid | system 22 (step S303). In this embodiment, it is determined whether the current value is less than 0 (negative value), 0, or greater than 0 (positive value).

When the direction of current is from the distribution board 24 to the power system 22 (current value <0 in step S303), the power generation amount of the PV panel 12 exceeds the consumption amount of the load 26, and surplus power of the PV panel 12 is generated. Means that.
For example, the amount of power in the hatched portion where the power generation amount of the PV panel 12 indicated by the solid line in FIG. 4 exceeds the consumption amount of the load 26 indicated by the broken line is surplus power. This surplus power is sold.

  In the present embodiment, when the direction of current is from the distribution board 24 to the power system 22 (current value <0 in step S303), that is, when power sale occurs, the surplus power is not sold to the storage battery. Operates to charge. Here, the charging process routine of FIG. 9 is executed.

  When the direction of current is from the power system 22 to the distribution board 24 (current value> 0 in step S303), the power generation amount of the PV panel 12 is less than the consumption amount of the load 26, power shortage occurs, and the power system This means that power purchase from 22 has occurred.

  For example, the power generation amount of the PV panel 12 indicated by the solid line in FIG. 11 is insufficient for the hatched portion where the power consumption of the load 26 indicated by the broken line is lower. This shortage is purchased from the power system 22. Or if it is a discharge possible time slot | zone, it may discharge from the storage battery of the battery system 42, and may compensate for a shortage.

  In the present embodiment, when the current direction is from the power system 22 to the distribution board 24 (current value> 0 in step S303), that is, when power purchase occurs, the power shortage is not purchased from the storage battery. Operates to discharge. Here, the discharge processing routine of FIG. 10 is executed.

If the current value = 0 in step S303, that is, if neither power purchase nor power sale has occurred, the charging process in step S305 and the discharge process in step S307 are bypassed and the process returns to step S301.
After step S305 and step S307, the process returns to step S301. The process of the flowchart in FIG. 8 is repeatedly executed at a predetermined cycle.

Next, the charging process in step S305 of FIG. 8 will be described in detail below.
FIG. 9 is a flowchart illustrating an example of a detailed procedure of the charging process of the charge / discharge control device 100 of the present embodiment. In this process, the surplus power generated by the PV panel 12 is charged to the storage battery so that the power sale becomes zero.

  First, the acquisition unit 102 acquires a current value and a current direction flowing through the AC power line 28b between the distribution board 24 and the power system 22 (step S311). Then, the control unit 104 determines whether the current value is greater than 0 (positive value), 0, or less than 0 (negative value) (step S313).

  In step S313, when the current value is <0, the control unit 104 increases the amount of charge when the surplus power derived from the PV panel 12 is charged to the storage battery of the battery system 42 by a predetermined value (step S315). Then, the storage battery is charged with the set charge amount (step S317). Then, it returns to step S311 and repeats a process.

Therefore, in step S313, while the current value <0, the charge amount is increased by a predetermined value, and the storage battery is charged.
The process is repeated until the current value becomes 0. When the current value becomes 0 in step S313, the charge amount is set as it is (step S319), and the storage battery is charged with the set charge amount (step S317). . Then, it returns to step S311 and repeats a process.

  When the current value becomes> 0 due to the current value of the AC power line 28b acquired in step S311, the control unit 104 decreases the charge amount when charging the storage battery of the battery system 42 by a predetermined value ( Step S323). Then, the storage battery is charged with the set charge amount (step S317). Then, it returns to step S311 and repeats a process.

The process is repeated until the current value becomes 0. When the current value becomes 0 in step S313, the charge amount is set as it is (step S319), and the storage battery is charged with the set charge amount (step S317). . Then, it returns to step S311 and repeats a process.
As described above, in the present embodiment, the charging process of FIG. 9 is repeatedly performed so that the power sale becomes 0 while the power sale occurs.

  In this way, during the charging process, the storage battery is charged with the amount of charge out of the amount of power generated by the PV panel 12 so that there is no power sale to the power system 22. Thereby, the surplus power in the hatched portion in FIG. 4 is charged in the storage battery.

  In the power storage system 1 of FIG. 2, surplus power generated by the PV panel 12 flows directly from the DC power line 16 to the power storage device 40 and is charged to the storage battery of the battery system 42.

Next, the discharge process in step S307 of FIG. 8 will be described in detail below.
FIG. 10 is a flowchart illustrating an example of a detailed procedure of the discharge process of the charge / discharge control device 100 of the present embodiment. In this process, electric power is supplied from the storage battery to the load 26 so that power purchase is zero.
First, the acquisition part 102 acquires the electric current value and direction of an electric current which flow through the alternating current power line 28b between the power distribution boards 24 from the distribution board 24 (step S331). Then, the control unit 104 determines whether the current value is greater than 0 (positive value), 0, or less than 0 (negative value) (step S333).

  In step S333, when the current value is> 0, the control unit 104 increases the discharge amount when discharging the insufficient power from the storage battery of the battery system 42 by a predetermined value (step S335). Then, the storage battery is discharged with the set discharge amount (step S337). Then, it returns to step S331 and repeats a process.

Therefore, when the current value> 0 in step S333, the discharge amount is increased by a predetermined value and discharged from the storage battery.
The process is repeated until the current value becomes 0. When the current value becomes 0 in step S333, the discharge amount is set as it is (step S339), and the storage battery is discharged with the set discharge amount (step S337). . Thereafter, the process returns to step S331.

  Then, when the current value <0 due to the current value of the AC power line 28b acquired in step S331, the control unit 104 decreases the discharge amount discharged from the storage battery of the battery system 42 by a predetermined value (step S343). . And it discharges with the discharge amount set from the storage battery (step S337). Then, it returns to step S331 and repeats a process.

The process is repeated until the current value becomes 0. When the current value becomes 0 in step S333, the discharge amount is set as it is (step S339), and the storage battery is discharged with the set discharge amount (step S337). . Thereafter, the process returns to step S331.
Thus, in the present embodiment, the electric discharge process of FIG. 10 is repeatedly performed so that the electric power purchase becomes 0 while the electric power purchase occurs.

  In this way, during the discharging process, the shortage of the power consumed by the load 26 is discharged from the storage battery so that there is no power purchase to the power system 22. Thereby, the insufficient power in the hatched portion of FIG. 11 is discharged from the storage battery and supplied to the load 26.

  In the power storage system 1 of FIG. 2, the power stored in the storage battery as a surplus of the PV panel 12 is supplied from the power storage device 40 to the DC power line 16, and the PV-PCS 14, the AC power line 28 a, and the distribution board 24 are connected. To the load 26.

  Moreover, the process of each step of the flowchart of FIG. 8 may be performed asynchronously. For example, the process of step S305 when power sale is detected in step S303 may be executed only during a first time period in which the storage battery can be charged. On the other hand, the process of step S307 when power purchase is detected in step S303 may be executed only during the second time period in which the storage battery can be discharged.

  Alternatively, the charging process of FIG. 9 may be performed only during the first time period, and the discharging process of FIG. 10 may be performed only during the second time period. Further, the charging process and the discharging process may be executed asynchronously in separate routines.

  As described above, in the power storage system 1 of the present embodiment, when a current flows from the distribution board 24 toward the power system 22, the control unit 104 charges the storage battery until the current becomes zero. Is increased. Further, when a current flows from the electric power system 22 in the direction of the distribution board 24, the amount of discharge from the storage battery is increased by the control unit 104 until the current becomes zero.

According to this configuration, the same effect as in the above embodiment is obtained, and when the power generation amount from the PV panel 12 exceeds the consumption amount of the load 26, the surplus power is charged to the storage battery so that no power sale occurs. And when the electric power generation amount from the PV panel 12 is less than the consumption amount of the load 26, a shortage can be discharged from a storage battery so that electric power purchase may not arise.
Thus, according to this embodiment, electric power can be efficiently charged and discharged by the power storage system 1. Furthermore, since the power storage system 1 of this embodiment is retrofitted to the DC power line 16 side of the PV system 10, it is not necessary to perform grid interconnection, and the grid interconnection protection function and complicated application necessary for grid interconnection are not required. There is also an effect that the procedure becomes unnecessary.

(Third embodiment)
Hereinafter, a power storage system according to the third embodiment of the present invention will be described.
FIG. 12 is a schematic block diagram illustrating a configuration example of the power storage system 401 of the present embodiment.
The power storage system 401 of this embodiment in FIG. 12 is different from the power storage system 1 of the above-described embodiment in FIG. 2 in that the wiring of the power storage device 440 is only outdoors.

  The power storage system 401 of the present embodiment includes a power storage device 440 and a clamp type DC current sensor 46. Power storage device 440 is electrically connected to DC power line 16 between PV panel 12 and PV-PCS 14.

FIG. 13 is a functional block diagram logically showing the configuration of the charge / discharge control apparatus 400 of the present embodiment.
The charge / discharge control apparatus 400 according to the present embodiment includes a power generation amount acquisition unit 402 and a control unit 404.
The power generation amount acquisition unit 402 acquires the power generation amount from the PV panel 12 of the DC power line 16 that is measured by the clamp type DC current sensor 46. Precisely, the current value from the PV panel 12 of the DC power line 16 measured by the clamp type DC current sensor 46 and the voltage of the DC power line 16 measured by a voltage sensor (not shown) included in the charge / discharge control device 400 are measured. Based on the voltage value, the power generation amount (electric power) from the PV panel 12 is calculated.
When the power generation amount of the PV panel 12 acquired by the power generation amount acquisition unit 402 exceeds a preset threshold value, the control unit 404 performs control for charging the power storage device 440 with surplus power exceeding the threshold value.

In the present embodiment, as a configuration for detecting the presence / absence of surplus power in the PV panel 12, the current direction between the power system 22 and the distribution board 24 is not measured unlike the above-described embodiment. This is because in the present embodiment, only the outdoor wiring is used.
Instead, in this embodiment, using the threshold value, if the power generation amount of the PV panel 12 exceeds the threshold value, it is determined that there is surplus power.

  The threshold can be set, for example, based on the actual value of the total power consumption by the load 26 of the customer's house. Moreover, it can set based on the performance value etc. of the time transition of the power consumption by the load 26 collected with HEMS etc. which were installed in the consumer's house.

  Alternatively, as another configuration, the charge / discharge control device 400 (or the power storage system 401) of the present embodiment stores historical information on the power consumption of the customer's house and stores various information such as an average value on the website dedicated to the customer. The information acquisition unit (not shown) that acquires the average value of the power consumption of the customer's house and the average value of the power consumption acquired by the information acquisition unit by linking with the information providing service presented to the consumer You may further provide the threshold value setting part (not shown) which sets a threshold value originally.

Since the total power consumption of the consumer varies depending on the season, it is preferable that the threshold can be updated in accordance with the fluctuation of the total power consumption.
The information providing service may provide information to the customer's HEMS or the like. In the configuration, the threshold value may be set using an operation unit (not shown) of the HEMS.

  The threshold setting unit may automatically set the average value itself of the power consumption acquired by the acquisition unit, or a value obtained by multiplying or adding or subtracting a predetermined coefficient to the average value as a threshold. .

  Alternatively, a consumer may set a threshold value on the website based on the average value of power consumption of the consumer presented on the website, and a reception unit (not shown) that receives the set value may be further provided. . The information acquisition unit may acquire the received setting value, and the threshold setting unit may set the setting value acquired by the information acquisition unit as a threshold. As described above, the threshold value may be set based on the average value of the total power consumption by the load 26 of the consumer.

  The threshold value set in this way is stored in the storage device 110 and can be read out by the control unit 404 and used at the time of determination. In addition, a predetermined threshold value may be stored in the storage device 110 in advance, and a configuration in which a change in threshold value by a consumer is received and updated may be provided.

The power generation amount acquisition unit 402 acquires a current value measured using the clamped DC current sensor 46 that is electrically connected to the DC power line 16 between the PV panel 12 and the PV-PCS 14.
Moreover, in the structure of other embodiment, you may combine the structure which detects the presence or absence of surplus electric power based on a threshold value, and the electric power generation amount acquisition part is the alternating current between PV-PCS14 and the distribution board 24 in that case. You may acquire the electric current value measured using the clamp type alternating current sensor 44 electrically connected to the power line 28a.

  Also in this embodiment, the CPU 82 of the computer 80 in FIG. 6 reads out the program 90 stored in the storage 85 to the memory 84 and executes it, thereby realizing each function of each unit in FIG. 13 of the charge / discharge control device 400. can do.

  The computer program 90 of the present embodiment is a procedure for acquiring the power generation amount from the PV panel 12 of the DC power line 16 in the computer 80 for realizing the charge / discharge control device 400, and the PV panel 12 acquired by the power generation amount acquisition unit 402. The procedure for charging the power storage device 440 when the power generation amount exceeds the threshold is described.

Hereinafter, the control method of the charge / discharge control apparatus 400 of this embodiment is demonstrated.
FIG. 14 is a flowchart showing an example of the operation of the charge / discharge control apparatus 400 of the present embodiment.
First, the power generation amount acquisition unit 402 acquires the power generation amount of the PV panel 12 (step S401).
When the power generation amount of the PV panel 12 exceeds the threshold value (YES in step S403), the control unit 404 causes the power storage device 440 to charge the surplus power amount obtained by subtracting the threshold value from the power generation amount (step S405). On the other hand, when the power generation amount of the PV panel 12 does not exceed the threshold value (NO in step S403) and the storage battery of the battery system 42 is charged, the control unit 404 charges the power storage device 440. Stop (step S407).

  In step S405, the value obtained by subtracting the threshold value from the power generation amount may be used as the surplus power amount, or a value corrected by multiplying the obtained value by a predetermined coefficient, subtracting, or adding is used. Also good.

  The process of the flowchart of FIG. 14 may be repeatedly executed at a predetermined cycle. Moreover, the process of each step may be performed asynchronously. Further, this process may be executed only in the first time zone. Further, when the storage battery capacity is fully charged, the present process may not be performed. When the stored capacity of the storage battery is equal to or greater than a predetermined ratio of the storage capacity of the storage battery, the storage battery is charged or discharged by combining other conditions such as charging the storage battery or stopping charging, such as a configuration in which the storage battery is not charged. You may control.

As described above, in the charge / discharge control apparatus 400 of the present embodiment, when the power generation amount from the PV panel 12 is acquired by the power generation amount acquisition unit 402 and the power generation amount is equal to or greater than the threshold value, the surplus amount is obtained. Is charged into the storage battery.
According to this structure, there exists an effect similar to the said embodiment.

As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.
For example, in the above-described embodiment, an example in which the DC power generation device is a solar power generation facility and the conversion device is a PV-PCS (PhotoVoltaics Power Conditioning System: solar power generation power conditioner) has been described.

  The DC power generation device may include at least one of a photovoltaic power generation facility, a fuel cell, and a private power generation facility that uses fossil energy.

(Charging surplus power for PV output suppression)
Furthermore, in other embodiments, surplus power that is subjected to output suppression control by a PV output suppression signal may be charged.
When the PV-PCS 14 receives an output suppression control signal for the PV panel 12, the PV-PCS 14 may be controlled to be lower than the actual power generation amount of the PV panel 12.
Here, the PV output suppression signal includes, for example, an instruction to suppress the output to a predetermined ratio (%) of the rated output of the PV-PCS 14.
In the present invention, the amount of power that is suppressed is charged to the storage battery as surplus power.

  The control unit tries to charge the storage battery with a predetermined amount of the output from the PV panel 12. At this time, a clamp type DC current sensor (not shown) is electrically connected to the DC power line 16 between the connection position of the power storage device 40 and the PV-PCS 14 or between the PV-PCS 14 and the distribution board 24. A clamp type AC current sensor (not shown) is electrically connected to the AC power line 28. And an acquisition part acquires the electric current value measured with the sensor. The control unit monitors increase / decrease of the current value. When the current value decreases, it is determined that there is no surplus power. If the current value does not decrease, it is determined that there is surplus power.

  According to this configuration, surplus power whose PV output is suppressed can be charged, so that the power generated by the PV panel 12 can be efficiently charged without waste.

(Charging for electricity sales)
Furthermore, in another embodiment, when a reverse power flow (power sale) to the power system 22 occurs, the storage battery is charged.
In this configuration, even if the acquisition unit acquires the value of meter reading data (power consumption, reverse power flow value) or the like from a smart meter (not shown) or a HEMS (Home Energy Management System) (not shown), etc. Good. In this embodiment, the acquisition unit may have a configuration that wirelessly communicates with a smart meter or a HEMS using the communication I / F 87 of FIG.
According to this structure, the electric power sold by simple structure can be charged to a storage battery efficiently.

Example 1
Example 1 of the power storage system of the present invention will be described below.
In the power storage system of the present embodiment, an example of charge / discharge control of the storage battery will be described in detail.

FIG. 15 is a schematic block diagram illustrating a system configuration of the power storage system 501 of the present embodiment.
The power storage system 501 includes a power storage device 540, a clamp type AC current sensor 44, and a clamp type DC current sensor 46.
The power storage system 501 acquires currents of both the DC power line 16 and the AC power line 28 and controls charging / discharging of the storage battery.

  Regarding the discharge control, the clamp type AC current sensor 44 is also provided in the second time zone during which discharge is possible, as in the other embodiments, so that the control unit 404 controls the discharge amount so that no reverse power flow to the power system 22 occurs. You may control.

FIG. 16 is a functional block diagram logically showing the configuration of the charge / discharge control apparatus 500 of this embodiment.
The charge / discharge control device 500 includes an acquisition unit 102, a power generation amount acquisition unit 402, and a control unit 504.
The acquisition unit 102 has a function similar to that of the acquisition unit 102 of the charge / discharge control device 100 of the above embodiment of FIG. The power generation amount acquisition unit 402 has the same function as the power generation amount acquisition unit 402 of the charge / discharge control device 400 of FIG.

The control unit 504 has the same function as the control unit 404 of the charge / discharge control device 400 of FIG. 13 and further has the following functions.
The control unit 504 controls the discharge of the storage battery according to the direction of the current between the distribution board 24 and the power system 22 acquired by the acquisition unit 102.

FIG. 17 is a diagram illustrating the power generation amount of the PV panel 12 of the power storage system 501 of the present embodiment.
FIG. 18 is a diagram illustrating an example of a data structure of the storage device 210 that stores various setting values of the power storage system 501 of the present embodiment.
In the present embodiment, the rated output of the PV-PCS 14 is 5 kW, and the rating of the charge / discharge control device 400 of the power storage device 440 is 1 kW. Further, assuming that the load of the load 26 is 3 kW, the charging start threshold value for the power storage device 440 is 3 kW. In this example, the threshold value is a fixed value, but in another example, a different value may be taken depending on the time zone, season, and the like.

In addition, the first time period in which the power storage device 540 of this embodiment can be charged is from 6:00 to 18:00, and the second time period in which it can be discharged is from 18:00 to 6:00 on the next day.
Such setting information is stored in the storage device 210 shown in FIG.

The control unit 504 acquires time information of a clock (not shown) included in the charge / discharge control device 500, and permits charging of the storage battery in the first time zone in which the power storage device 540 can be charged.
In addition, the control unit 504 determines whether or not the PV panel 12 power generation amount acquired by the power generation amount acquisition unit 402 exceeds a charging start threshold (3 kW). The surplus power (over 3 kW and the portion shown by hatching in FIG. 17 of 4 kW or more) is charged to the storage battery.

  Furthermore, control unit 504 further has a function of detecting full charge of power storage device 540, and stops charging when power storage device 540 is fully charged. The charging is also stopped when the first time period ends.

19 and 20 are flowcharts showing an example of the operation of the charge / discharge control apparatus 500 of the present embodiment. First, the operation during charging will be described with reference to FIG.
First, the power generation amount acquisition unit 402 acquires the power generation amount of the PV panel 12 (step S521).

  Then, the control unit 504 determines whether or not the current time is the first time zone (step S523). In the first time zone (YES in step S523), it is determined whether power storage device 540 is fully charged (step S525). If it is not fully charged (NO in step S525), it is determined whether or not the PV panel 12 power generation amount acquired by the power generation amount acquiring unit 402 exceeds 3 kW (step S527).

  For example, since the condition is satisfied when the power generation amount of the PV panel 12 at 12:00 is 5 kW (YES in Step S527), the control unit 504 charges the storage battery with 1 kW of surplus power of the PV panel 12 (Step S529). .

  Further, when the power generation amount of the PV panel 12 at 15:00 is less than 3 kW, the condition is not satisfied (NO in step S527), so the control unit 504 stops charging the storage battery (step S531).

  Also, in step S523, when the current time is not the first time zone (NO in step S523), charging of the storage battery is stopped (step S531).

  The process of the flowchart of FIG. 19 may be repeatedly executed at a predetermined cycle. Moreover, the process of each step may be performed asynchronously.

Next, the operation | movement at the time of discharge of the charging / discharging control apparatus 500 of a present Example is demonstrated.
FIG. 20 is a flowchart illustrating an example of the operation of the charge / discharge control apparatus 500 of the present embodiment.
The flowchart in FIG. 20 includes step S101 similar to the flowchart in FIG. 7, and further includes steps S501 to S507.

  First, the acquisition unit 102 inputs the current value of the AC power line 28b between the power system 22 and the distribution board 24 measured by the clamp-type AC current sensor 44, and acquires the current direction (step S101).

  Then, the control unit 504 determines whether or not the current time is in the second time zone (step S501). When it is the second time zone (YES in step S501), the control unit 504 purchases power from the direction of the current acquired by the acquisition unit 102 in step S101 (current flows from the power system 22 to the distribution board 24). Is detected (step S503). When power purchase is detected (YES in step S503), the control unit 504 instructs the battery system 42 to discharge from the storage battery (step S505).

  The discharge process in step S505 can be, for example, the discharge process described with reference to FIG.

  If it is determined in step S501 that the current time is not in the second time zone (NO in step S501), the process proceeds to step S507, and the battery system 42 is instructed to stop discharging from the storage battery. If no power purchase is detected in step S503 (NO in step S503), the process returns to step S101.

  After step S505 or step S507, the process returns to step S101 to repeat this process.

  The process of the flowchart of FIG. 20 may be repeatedly executed at a predetermined cycle. Moreover, the process of each step may be performed asynchronously.

  Thus, according to the present embodiment, surplus power derived from the PV panel 12 can be efficiently charged with a simple configuration, and in the time zone where discharge is possible, the power of the storage battery is discharged until the amount of power purchased becomes zero. can do.

(Example 2)
A second embodiment of the power storage system of the present invention will be described below.
In the power storage system of the present embodiment, a configuration capable of supplying power by switching the power system 22 and the storage battery to a specific load that can supply power from the storage battery will be described.

FIG. 21 is a schematic block diagram illustrating a configuration example of the power storage system 601 according to the embodiment of the present invention.
The power storage system 601 has a configuration in which a power storage device 640 is added to the DC power line 16 side.
The power storage system 601 includes a power storage device 640, a clamp-type AC current sensor 44, and a clamp-type DC current sensor 46.
Power storage device 640 includes a battery system 42, a control unit 600, a charge / discharge circuit 602, and an inverter 610.
Further, the charge / discharge circuit 602 of the power storage device 640 is electrically connected to the DC power line 16 between the PV panel 12 and the PV-PCS 14.

  The controller 600, the charge / discharge circuit 602, and the inverter 610 correspond to at least one of the charge / discharge control devices of the above embodiment. The control unit 600 acquires information related to the current from the clamp-type AC current sensor 44 or the clamp-type DC current sensor 46. To be exact, in addition to the current from the clamp type DC current sensor 46, information on the voltage from a voltage sensor (not shown) provided in the charge / discharge circuit 602 is also acquired. On the other hand, the power system 22 side can be controlled only by the current from the clamp-type AC current sensor 44. The charge / discharge circuit 602 controls charging / discharging of the storage battery of the battery system 42 according to the control of the control unit 600.

FIG. 22 is a functional block diagram showing the configuration of the inverter 610 of the power storage device 640 according to the embodiment of the present invention.
The inverter 610 includes a DC / AC converter (abbreviated as “DC / AC” in the drawing) 612 and a switching circuit 614.

The inverter 610 of the power storage system 601 of this embodiment includes a switch (switching circuit 614) and a DC / AC converter 612.
The inverter 610 is connected between the specific load 27 and the battery system 42 (or the PV panel 12 via the charge / discharge circuit 602).
The switch (switching circuit 614 in FIG. 22) is connected to the AC power line 28b between the power system 22 and the converter (PV-PCS 14) via the distribution board 24, and further to the battery system 42 in the DC / AC converter 612. And is further connected to a specific load 27.
The switch (switching circuit 614) connects the specific load 27 to the battery system 42 (or the PV panel 12 via the charge / discharge circuit 602) via the DC / AC converter 612 and the AC power line 28 b via the distribution board 24. Connect to one.
When supplying power from the power system 22 to the specific load 27, the control unit 600 supplies a control signal for connecting the specific load 27 to the distribution board 24 side by the switch (switching circuit 614).
Further, when power is supplied to the specific load 27 from the PV system 12 via the battery system 42 or the charge / discharge circuit 602, the control unit 600 converts the specific load 27 into a DC / AC converter using a switch (switching circuit 614). A control signal to be connected to the battery system 42 or the charge / discharge circuit 602 is supplied to the switching circuit 614 via 612.

  In this configuration, control unit 600 controls inverter 610 in consideration of the chargeable time zone or the dischargeable time zone, the direction of current between power system 22 and distribution board 24, and the value of the remaining battery level. Control the discharge from the storage battery. A specific load 27 is electrically connected to the inverter 610, and electric power corresponding to the load amount of the specific load 27 is discharged from the storage battery and supplied to the specific load 27.

While the present invention has been described with reference to the embodiments and examples, the present invention is not limited to the above embodiments and examples. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.
In addition, when acquiring and using the information regarding a user in this invention, this shall be done legally.

Hereinafter, examples of the reference form will be added.
1. A control method for a charge / discharge control device connected to a power storage device capable of charging electricity generated by a DC power generator,
The DC power generator is connected to the converter via a DC power line,
The conversion device connects the DC power line and the AC power line, and converts DC power into AC power,
The AC power line is connected to the power system from the conversion device, is connected to the DC power generation device via the conversion device, and a load is connectable.
The power storage device is connected to the DC power line between the DC power generator and the converter,
The charge / discharge control device comprises:
Obtain information on the current direction of the AC power line,
A control method for a charge / discharge control device, which determines whether or not to charge the power storage device based on a direction of the current of the AC power line and controls charge / discharge of the power storage device.
2. The charge / discharge control device comprises:
1. When the current is flowing from the distribution board in the direction of the power system, the amount of charge to the power storage device is increased until the current becomes zero. The control method of the charging / discharging control apparatus as described in 2.
3. The charge / discharge control device comprises:
1. When the current flows from the power system in the direction of the distribution board, increase the amount of discharge from the power storage device until the current becomes zero. Or 2. The control method of the charging / discharging control apparatus as described in 2.
4). The charge / discharge control device has a switch and a DC / AC converter,
The power storage device can supply power to a specific load without going through the AC power line,
The DC / AC converter is connected between the specific load and the power storage device,
The switch is connected to the AC power line between the power system and the converter, the power storage device, and the specific load.
The switch connects the specific load to either the power storage device or the AC power line via the DC / AC converter,
The charge / discharge control device comprises:
When supplying the power from the power system to the specific load, the specific load is connected to the DC power line by the switch,
When the power is supplied from the power storage device to the specific load, the specific load is connected to the power storage device by the switch. To 3. The control method of the charging / discharging control apparatus as described in any one.
5. The DC power generation device includes at least one of a solar power generation facility, a fuel cell, and a private power generation facility that uses fossil energy. To 4. The control method of the charging / discharging control apparatus as described in any one.
6). The DC power generator is a photovoltaic power generation facility,
The converter is a PV-PCS (PhotoVoltaics Power Conditioning System). To 5. The control method of the charging / discharging control apparatus as described in any one.

7). A computer program for realizing a charge / discharge control device connected to a power storage device capable of charging power generated by a DC power generator,
The DC power generator is connected to the converter via a DC power line,
The conversion device connects the DC power line and the AC power line, and converts DC power into AC power,
The AC power line is connected to the power system from the conversion device, is connected to the DC power generation device via the conversion device, and a load is connectable.
The power storage device is connected to the DC power line between the DC power generator and the converter,
On the computer,
A procedure for obtaining information on the direction of the current of the AC power line;
A program for determining whether or not to charge the power storage device based on a direction of the current of the AC power line, and executing a procedure for controlling charge / discharge of the power storage device.
8). 6. When the current flows from the distribution board in the direction of the power system, the amount of charge to the power storage device is increased until the current becomes zero. The program described in.
9. 6. causing the computer to execute a procedure for increasing the amount of discharge from the power storage device until the current becomes zero when the current flows from the power system in the direction of the distribution board; Or 8. The program described in.
10. The charge / discharge control device has a switch and a DC / AC converter,
The power storage device can supply power to a specific load without going through the AC power line,
The DC / AC converter is connected between the specific load and the power storage device,
The switch is connected to the AC power line between the power system and the converter, the power storage device, and the specific load.
The switch connects the specific load to either the power storage device or the AC power line via the DC / AC converter,
On the computer,
When supplying the power from the power system to the specific load, the procedure of connecting the specific load to the DC power line by the switch,
6. When supplying the electric power from the power storage device to the specific load, causing the computer to execute a procedure of connecting the specific load to the power storage device by the switch; To 9. The program according to any one of the above.
11. 6. The DC power generation device includes at least one of a photovoltaic power generation facility, a fuel cell, and a private power generation facility that uses fossil energy. To 10. The program according to any one of the above.
12 The DC power generator is a photovoltaic power generation facility,
6. The converter is a PV-PCS (PhotoVoltaics Power Conditioning System). To 11. The program according to any one of the above.

1 Power Storage System 3 Network 10 PV System 12 PV Panel 14 PV-PCS
16 DC power line 22 Power system 24 Distribution board 26 General load 27 Specific load 28, 28a, 28b AC power line 40 Power storage device 42 Battery system 44 Clamp type AC current sensor 46 Clamp type DC current sensor 80 Computer 82 CPU
84 Memory 85 Storage 86 I / O
87 Communication I / F
89 Bus 90 Computer program 100 Charge / discharge control device 102 Acquisition unit 104 Control unit 110 Storage device 210 Storage device 400 Charge / discharge control device 401 Power storage system 402 Power generation amount acquisition unit 404 Control unit 440 Power storage device 500 Charge / discharge control device 501 Power storage system 504 Control unit 540 Power storage device 600 Control unit 601 Power storage system 602 Charge / discharge circuit 610 Inverter 612 DC / AC converter 614 Switching circuit 640 Power storage device

Claims (14)

Power storage means capable of charging electricity generated by the DC power generator;
Control means for controlling charging and discharging of the power storage means;
With
The DC power generator is connected to the converter via a DC power line,
The conversion device connects the DC power line and the AC power line, and converts DC power into AC power,
The AC power line is connected to a power system, is connected to the DC power generator via the conversion device, and a load is connectable.
The power storage means is connected to the DC power line between the DC power generator and the converter,
The said control means is an electrical storage system which determines whether the said electrical storage means is charged based on the direction of the electric current of the said alternating current power line. A distribution board is interposed between the converter and the power system,
The load is electrically connected to the AC power line through the distribution board, and power is supplied from the AC power line,
2. The power storage system according to claim 1, wherein when the current flows from the distribution board in the direction of the power system, the control unit increases a charge amount of the power storage unit until the current becomes zero. . A distribution board is interposed between the converter and the power system,
The load is electrically connected to the AC power line through the distribution board, and power is supplied from the AC power line,
The said control means increases the amount of discharge from the said electrical storage means until the said electric current becomes 0, when the said electric current is flowing from the said electric power grid to the direction of the said distribution board. Power storage system. The control means has a switch and a DC / AC converter,
The power storage means can supply power to a specific load without going through the AC power line,
The DC / AC converter is connected between the specific load and the power storage means,
The switch is connected to the AC power line between the power system and the conversion device, the power storage means, and the specific load.
The switch connects the specific load to any of the power storage means and the AC power line via the DC / AC converter,
The control means includes
When supplying the power from the power system to the specific load, the specific load is connected to the DC power line by the switch,
4. The power storage system according to claim 1, wherein, when the electric power is supplied from the power storage unit to the specific load, the specific load is connected to the power storage unit by the switch. 5.   5. The power storage system according to claim 1, wherein the DC power generation device includes at least one of a photovoltaic power generation facility, a fuel cell, and a private power generation facility that uses fossil energy. The DC power generator is a photovoltaic power generation facility,
The power storage system according to any one of claims 1 to 5, wherein the conversion device is a PV-PCS (PhotoVoltaics Power Conditioning System). A charge / discharge control device connected to a power storage device capable of charging electricity generated by a DC power generator,
The DC power generator is connected to the converter via a DC power line,
The conversion device connects the DC power line and the AC power line, and converts DC power into AC power,
The AC power line is connected to the power system from the conversion device, is connected to the DC power generation device via the conversion device, and a load is connectable.
The power storage device is connected to the DC power line between the DC power generator and the converter,
The charge / discharge control device comprises:
Obtaining means for obtaining information on the direction of the current of the AC power line;
A charge / discharge control device comprising: control means for determining whether to charge the power storage device based on a direction of the current of the AC power line, and controlling charge / discharge of the power storage device. A distribution board is interposed between the converter and the power system,
The load is electrically connected to the AC power line through the distribution board, and power is supplied from the AC power line,
The charge / discharge according to claim 7, wherein when the current is flowing from the distribution board in the direction of the power system, the control unit increases a charge amount of the power storage device until the current becomes zero. Control device. A distribution board is interposed between the converter and the power system,
The load is electrically connected to the AC power line through the distribution board, and power is supplied from the AC power line,
9. The control unit according to claim 7, wherein, when the current flows from the power system in the direction of the distribution board, the amount of discharge from the power storage device is increased until the current becomes zero. Charge / discharge control device. The control means has a switch and a DC / AC converter,
The power storage device can supply power to a specific load without going through the AC power line,
The DC / AC converter is connected between the specific load and the power storage device,
The switch is connected to the AC power line between the power system and the converter, the power storage device, and the specific load.
The switch connects the specific load to either the power storage device or the AC power line via the DC / AC converter,
The control means includes
When supplying the power from the power system to the specific load, the specific load is connected to the DC power line by the switch,
10. The charge / discharge control device according to claim 7, wherein when the electric power is supplied from the power storage device to the specific load, the specific load is connected to the power storage device by the switch.   11. The charge / discharge control device according to claim 7, wherein the DC power generation device includes at least one of a solar power generation facility, a fuel cell, and a private power generation facility that uses fossil energy. The DC power generator is a photovoltaic power generation facility,
The charge / discharge control device according to any one of claims 7 to 11, wherein the conversion device is a PV-PCS (PhotoVoltaics Power Conditioning System). A control method for a charge / discharge control device connected to a power storage device capable of charging electricity generated by a DC power generator,
The DC power generator is connected to the converter via a DC power line,
The conversion device connects the DC power line and the AC power line, and converts DC power into AC power,
The AC power line is connected to the power system from the conversion device, is connected to the DC power generation device via the conversion device, and a load is connectable.
The power storage device is connected to the DC power line between the DC power generator and the converter,
The charge / discharge control device comprises:
Obtain information on the current direction of the AC power line,
A control method for a charge / discharge control device, which determines whether or not to charge the power storage device based on a direction of the current of the AC power line and controls charge / discharge of the power storage device. A computer program for realizing a charge / discharge control device connected to a power storage device capable of charging power generated by a DC power generator,
The DC power generator is connected to the converter via a DC power line,
The conversion device connects the DC power line and the AC power line, and converts DC power into AC power,
The AC power line is connected to the power system from the conversion device, is connected to the DC power generation device via the conversion device, and a load is connectable.
The power storage device is connected to the DC power line between the DC power generator and the converter,
On the computer,
A procedure for obtaining information on the direction of the current of the AC power line;
A program for determining whether or not to charge the power storage device based on a direction of the current of the AC power line, and executing a procedure for controlling charge / discharge of the power storage device.

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