Charging and discharging system, and method for controlling the charging and discharging system

Abstract

To provide a charge discharge system capable of realizing an efficient operation of power.SOLUTION: A charge discharge system 10 that is connected to a power system 20, performs charging and discharging to / from a power storage device 40, and supplies power to a power load 60, comprises: an acquisition part 410 that acquires a switching signal 441 indicating an instruction for switching a first operation mode that changes at least one of input power to the charge discharge system 10 containing discharge power to be discharged from the power storage device 40 and output power from the charge discharge system 10 containing charging power for charging the power storage device 40 in accordance with a predetermined condition and a second operation mode for maintaining the at least one power at a constant value; a switching part 420 that switches between the first operation mode and the second operation mode in accordance with the switching signal 441 acquired by the acquisition part 410; and a control part 430 that performs input and output of power to / from the charge discharge system 10 in accordance with the operation mode switched by the switching part 420.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a charge-discharge system that is connected to a power system, performs charge and discharge with a power storage device, and supplies power to a power load, and a control method for the charge-discharge system.

Background Art

[0002] Patent Document 1 discloses a power control system (charge-discharge system) that is connected to a power grid (power system), performs charge and discharge with a power storage device, and supplies power to a power load. In the power control system, a target charge amount of the power storage device is assumed, a predicted value is applied to the assumed target charge amount to update the target charge amount, and a charging operation or a discharging operation is executed based on the target charge amount, thereby performing peak cut or the like of the power received from the power grid.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional charge-discharge system as disclosed in Patent Document 1 above, the charge-discharge power of the power storage device is controlled, and by changing the charge-discharge power, power operation such as peak cut is performed. However, there is a desire to perform power operation such as peak cut more efficiently.

[0005] An object of the present invention is to provide a charge-discharge system capable of achieving efficient power operation and a control method for the charge-discharge system.

Means for Solving the Problems

[0006] A charge-discharge system according to one aspect of the present invention is a charge-discharge system connected to a power grid, which charges and discharges with an energy storage device and supplies power to a power load, comprising: an acquisition unit that acquires a switching signal indicating an instruction to switch between a first operating mode in which at least one of the input power to the charge-discharge system, which includes discharge power discharged from the energy storage device, and the output power from the charge-discharge system, which includes charging power for charging the energy storage device, is changed according to predetermined conditions, and a second operating mode in which the at least one of the powers is maintained at a constant value; a switching unit that switches between the first operating mode and the second operating mode according to the switching signal acquired by the acquisition unit; and a control unit that performs power input and output to the charge-discharge system according to the operating mode switched by the switching unit.

[0007] The present invention can be realized not only as such a charge / discharge system, but also as a control method for such a charge / discharge system. The present invention can also be realized as a program for causing a computer to execute the processing included in the control method for a charge / discharge system, and can also be realized as a recording medium such as a computer-readable CD-ROM on which the program is recorded. The program can be distributed via the recording medium and a transmission medium such as the Internet. The present invention can also be realized as an integrated circuit equipped with a processing unit included in the charge / discharge system. [Effects of the Invention]

[0008] The charging and discharging system and the like in the present invention enable efficient use of electricity. [Brief explanation of the drawing]

[0009] [Figure 1] This is a block diagram that functionally illustrates the configuration of the charge / discharge system and its surroundings according to an embodiment. [Figure 2] This is a block diagram that functionally illustrates the configuration of the control device included in the charge / discharge system according to the embodiment. [Figure 3] This flowchart shows the control method (processing performed by the control device) for a charge / discharge system according to an embodiment. [Figure 4] This flowchart shows the process by which the acquisition unit of the control device according to the embodiment acquires a switching signal. [Figure 5] This is a block diagram that functionally shows the configuration of the control device according to the modified example 1 of the embodiment. [Figure 6] This flowchart shows the process by which the acquisition unit of the control device according to the modified embodiment 1 acquires a switching signal. [Figure 7] This is a block diagram that functionally shows the configuration of the control device according to a modified example 2 of the embodiment. [Figure 8] This flowchart shows a control method (processing performed by the control device) for a charge / discharge system according to a modified example 2 of the embodiment. [Figure 9] This is a block diagram that functionally shows the configuration of the control device according to the third modified embodiment. [Figure 10] This flowchart shows a control method (processing performed by the control device) for a charge / discharge system according to a modified example 3 of the embodiment. [Modes for carrying out the invention]

[0010] A charge-discharge system according to one aspect of the present invention is a charge-discharge system connected to a power grid, which charges and discharges with an energy storage device and supplies power to a power load, comprising: an acquisition unit that acquires a switching signal indicating an instruction to switch between a first operating mode in which at least one of the input power to the charge-discharge system, which includes discharge power discharged from the energy storage device, and the output power from the charge-discharge system, which includes charging power for charging the energy storage device, is changed according to predetermined conditions, and a second operating mode in which the at least one of the powers is maintained at a constant value; a switching unit that switches between the first operating mode and the second operating mode according to the switching signal acquired by the acquisition unit; and a control unit that performs power input and output to the charge-discharge system according to the operating mode switched by the switching unit.

[0011] According to this, the charge / discharge system switches between operating modes according to a switching signal, which switches between a first operating mode that changes at least one of the input power and output power, and a second operating mode that maintains the power at a constant value, thereby performing power input and output. In this way, the charge / discharge system can perform power input and output in both the first operating mode, which changes the power, and the second operating mode, which maintains the power at a constant value. As a result, the charge / discharge system can operate in a way different from the first operating mode, by maintaining the power at a constant value in the second operating mode, thereby increasing the flexibility when performing power management such as peak shaving. Therefore, the charge / discharge system can achieve efficient power management.

[0012] The acquisition unit may acquire the switching signal from outside the charging / discharging system.

[0013] According to this, the charging and discharging system can receive a switching signal from an external source and switch operating modes according to that signal to perform power input and output. As a result, the charging and discharging system can adjust power input and output according to external conditions, thereby enabling efficient power utilization.

[0014] The charging and discharging system is connected to the power grid via a substation or power receiving equipment, and the acquisition unit may acquire the switching signal obtained according to the value of the power flowing from the power grid to the substation or power receiving equipment.

[0015] According to this, the charge / discharge system can obtain a switching signal according to the value of the power flowing from the power grid to the substation equipment or the power receiving equipment, and switch the operation mode according to the switching signal to perform power input / output. For example, when the charge / discharge system obtains a switching signal indicating that the value of the power flowing from the power grid to the substation equipment or the power receiving equipment is large, it can switch from the first operation mode to the second operation mode to perform power input / output so as to reduce the value of the power. Thus, the charge / discharge system can adjust the power input / output to the charge / discharge system according to the value of the power flowing from the power grid to the substation equipment or the power receiving equipment, so that efficient operation of the power can be achieved.

[0016] The charge / discharge system may further include a timer, and the acquisition unit may acquire the switching signal at the time set by the timer.

[0017] According to this, the charge / discharge system can obtain a switching signal at the time set by the timer, and at that time, switch the operation mode to perform power input / output. For example, the charge / discharge system obtains a switching signal for switching from the first operation mode to the second operation mode during a time period when it is more efficient to perform power input / output in the second operation mode. Thus, the charge / discharge system can switch the operation mode and adjust the power input / output at the time set by the timer, so that efficient operation of the power can be achieved.

[0018] When the switching unit switches to the second operation mode, the control unit may perform power input / output to the charge / discharge system so as to maintain the at least one power at the rated power of the charge / discharge system.

[0019] In some cases, during peak hours such as daytime when power consumption is high, it may be more efficient to maintain the rated power of a charge / discharge system rather than fluctuating the power output. Therefore, in the second operating mode, the charge / discharge system controls power input and output to maintain at least one of the input and output power at the rated power. This allows for efficient power utilization by the charge / discharge system.

[0020] The acquisition unit may acquire the switching signal including power value information indicating a constant value in the second operating mode, and the control unit may, when the switching unit switches to the second operating mode, perform power input and output to the charge / discharge system so as to maintain at least one of the powers at the value indicated by the power value information.

[0021] According to this, the charge / discharge system, in the second operating mode, performs power input and output in such a way that it maintains at least one of the input power and output power at a value indicated by the power value information included in the switching signal. In other words, the charge / discharge system performs input and output at a constant power level in the second operating mode when it is more efficient to maintain a constant power level than to vary the power level. This allows the charge / discharge system to operate power efficiently.

[0022] The charging and discharging system is connected to a power generation facility, and the input power includes the discharge power and the power generated by the power generation facility. The control unit may control the input power by controlling the discharge power.

[0023] According to this, a charge / discharge system controls the input power by controlling the discharge power when the input power includes both the discharge power of the energy storage device and the power generated by the power generation equipment. In other words, the charge / discharge system prioritizes accepting the power generated by the power generation equipment and adjusts the input power with the discharge power of the energy storage device. This prevents wasting the power generated by the power generation equipment and reduces the power generation efficiency by reducing the power generated by the power generation equipment. Therefore, the charge / discharge system enables the efficient use of electricity.

[0024] The charging and discharging system may be connected to the power generation equipment that generates electricity using renewable energy.

[0025] According to this, the charging and discharging system is connected to a power generation facility that uses renewable energy, and therefore prioritizes receiving electricity generated from renewable energy sources. This helps to prevent the waste of electricity generated from renewable energy sources and to prevent a decrease in power generation efficiency caused by reducing the power output of renewable energy power generation facilities. If the renewable energy source is solar power, surplus electricity can also be supplied to the power grid (reverse power flow, selling electricity). Therefore, the charging and discharging system can enable the efficient use of electricity.

[0026] A control method for a charge-discharge system according to one aspect of the present invention is a control method for a charge-discharge system connected to a power grid, which performs charging and discharging with an energy storage device and supplies power to a power load, and the method acquires a switching signal indicating an instruction to switch between a first operating mode in which at least one of the input power to the charge-discharge system, which includes discharge power discharged from the energy storage device, and the output power from the charge-discharge system, which includes charging power for charging the energy storage device, changes according to predetermined conditions, and a second operating mode in which at least one of the powers is maintained at a constant value, and switches between the first operating mode and the second operating mode according to the acquired switching signal, and performs power input and output to the charge-discharge system according to the switched operating mode.

[0027] According to this, the control method for the charge / discharge system switches between two operating modes according to a switching signal, which switches between a first operating mode that changes at least one of the input power and output power, and a second operating mode that maintains the power at a constant value, thereby performing power input and output. As described above, this control method for the charge / discharge system enables efficient use of power.

[0028] The following description will explain, with reference to the drawings, a charge / discharge system according to an embodiment of the present invention (including its modifications), and a control method for the charge / discharge system. The embodiments described below are all comprehensive or specific examples. The numerical values, components, arrangement and connection configurations of components, control processes, and the order of control processes shown in the following embodiments are examples and are not intended to limit the present invention. The figures are schematic and not necessarily strictly illustrative. In each figure, the same or similar components are denoted by the same reference numerals.

[0029] (Embodiment) [1. Description of the charging / discharging system 10] First, a general explanation of the charge / discharge system 10 will be given. Figure 1 is a block diagram that functionally shows the configuration of the charge / discharge system 10 and its surroundings according to this embodiment.

[0030] As shown in Figure 1, the charge / discharge system 10 is connected to the power grid 20 and performs charging and discharging with the energy storage device 40 to supply power to the power load 60. In this embodiment, the charge / discharge system 10 is connected to the power grid 20 via the substation 30. Specifically, the charge / discharge system 10 is a power conditioner (PCS) connected to the power grid 20 (substation 30), the energy storage device 40, the power generation equipment 50, and the power load 60, and exchanges power with them. The charge / discharge system 10 receives power from the power grid 20 (substation 30), the energy storage device 40, and the power generation equipment 50, and supplies power to the power grid 20 (substation 30), the energy storage device 40, and the power load 60.

[0031] The power grid 20 is, for example, a commercial power grid owned by a power company, and AC power generated by grid power sources 21 such as a thermal power plant flows through it. The power grid 20 supplies this AC power to the charging and discharging system 10 via the substation equipment 30.

[0032] Substation 30 is owned by a power company, a company other than a power company, or a consumer such as a general household, and is supplied with electricity from the power grid 20. Substation 30 steps down or rectifies the electricity supplied from the power grid 20 and supplies it to the charging and discharging system 10. Substation 30 also supplies electricity to the power load 60 (general load 61 described later).

[0033] A measuring instrument 71, which is a sensor for measuring the value of power (AC power) flowing from the power system 20 to the substation 30, is located in the path through which power flows from the power system 20 to the substation 30 (the power inlet to the substation 30). A measuring instrument 72, which is a sensor for measuring the value of power (AC power) flowing from the substation 30 to the charge / discharge system 10, is located in the path through which power flows after the substation 30 has supplied power to the general load 61, and measures the value of power after the substation 30 has supplied power to the general load 61 (power flowing from the substation 30 to the charge / discharge system 10).

[0034] The energy storage device 40 is a power supply device that can charge electricity from an external source and discharge electricity to the outside. The energy storage device 40 charges and discharges power via the charge / discharge system 10. Specifically, the energy storage device 40 has a plurality of energy storage elements connected in series and / or parallel. The energy storage elements are secondary batteries (single cells) that can charge and discharge electricity, such as non-aqueous electrolyte secondary batteries like lithium-ion secondary batteries. The energy storage elements are not limited to non-aqueous electrolyte secondary batteries, and may be secondary batteries other than non-aqueous electrolyte secondary batteries, capacitors, or batteries using solid electrolytes, etc.

[0035] The power generation equipment 50 is power generation equipment connected to the charge / discharge system 10, and in this embodiment, it is power generation equipment that generates electricity using renewable energy. In other words, the charge / discharge system 10 is connected to the power generation equipment 50 that generates electricity using renewable energy. Renewable energy includes solar, wind, hydro, wave, biomass, or geothermal energy. In this embodiment, the power generation equipment 50 is power generation equipment that generates electricity using natural energy such as solar power generation equipment. The power generation equipment 50 supplies the generated electricity to the charge / discharge system 10.

[0036] The power load 60 is the power load consumed by power-consuming equipment inside a building (such as an office) or power-consuming equipment installed outdoors. The power load 60 consists of a general load 61 used under normal circumstances and a specific load 62 used even in emergencies such as power outages. The specific load 62 includes power loads used in elevators or commercial air conditioning in offices and other facilities, and lighting loads used for lighting or outlets in offices and other facilities. The general load 61 is the power load other than the specific load 62, and includes household appliances or loads used to operate machinery in factories.

[0037] Power is supplied to the power load 60 (general load 61 and specific load 62) from the power system 20 (substation equipment 30) or from the energy storage device 40 and power generation equipment 50 via the charge / discharge system 10. Under normal circumstances, power is supplied to the power load 60 (general load 61 and specific load 62) from at least one of the power system 20, the energy storage device 40, and the power generation equipment 50. In the event of an emergency, such as a power outage in the power system 20, power is supplied to the specific load 62 from at least one of the energy storage device 40 and the power generation equipment 50. In such an emergency, power may also be supplied to the general load 61 from at least one of the energy storage device 40 and the power generation equipment 50.

[0038] The charging and discharging system 10 includes a first converter circuit 100, a second converter circuit 200, a bidirectional inverter circuit 300, and a control device 400.

[0039] The first converter circuit 100 is a bidirectional power converter (bidirectional DC / DC converter) that performs conversion between DC powers. The first converter circuit 100 is connected to the energy storage device 40 and the bidirectional inverter circuit 300, and charges and discharges the energy storage device 40 by boosting or lowering the voltage of the DC power between the energy storage device 40 and the bidirectional inverter circuit 300. The first converter circuit 100 may also be a bidirectional chopper. The energy storage device 40 can store surplus power from the power generation equipment 50 and power from the power grid 20 via the first converter circuit 100. If the amount of power generated by the power generation equipment 50 is insufficient, the energy storage device 40 can discharge and compensate for the shortage of power generation via the first converter circuit 100.

[0040] The second converter circuit 200 is a power converter (DC / DC converter) that performs the conversion between DC powers. The second converter circuit 200 is connected to the power generation equipment 50 and the bidirectional inverter circuit 300, and boosts the voltage of the DC power generated by the power generation equipment 50 and outputs it to the bidirectional inverter circuit 300. The second converter circuit 200 may also be a boost chopper.

[0041] The bidirectional inverter circuit 300 is a bidirectional conversion circuit that performs inverse conversion (converting) of DC power to AC power and forward conversion (converting) of AC power to DC power. The bidirectional inverter circuit 300 is connected to the first converter circuit 100, the second converter circuit 200, the power system 20 (substation equipment 30), and the power loads 60 (general loads 61 and specific loads 62). The bidirectional inverter circuit 300 converts DC power from the first converter circuit 100 and the second converter circuit 200 to AC power and outputs it, and converts AC power from the power system 20 (substation equipment 30) to DC power and outputs it.

[0042] A measuring instrument 73, which is a sensor for measuring the value of AC power, is placed in the path through which AC power is output from or input to the bidirectional inverter circuit 300. The measuring instrument 73 measures the value of AC power converted from DC power from the first converter circuit 100 and the second converter circuit 200, or the value of AC power after power has been supplied from the power system 20 (substation equipment 30) to the power load 60 (general load 61 and specific load 62). In other words, the measuring instrument 73 measures the power value after the discharge power discharged by the energy storage device 40 and the generated power generated by the power generation equipment 50 have been converted into AC power, or the power value of AC power before the power used to charge the energy storage device 40 has been converted into DC power. In the normal operation described above, the measuring instrument 73 measures the value of AC power input to and output from the bidirectional inverter circuit 300.

[0043] The control device 400 is a control device that controls various devices within the charge / discharge system 10. The control device 400 is configured to acquire information from measuring instruments 71-73 via wired or wireless connection. In this embodiment, the control device 400 is a circuit board or the like built into the charge / discharge system 10, but it may also be a desktop or laptop personal computer, or a so-called smartphone or tablet type communication terminal. The control device 400 may be implemented by a general-purpose computer system executing a program, or it may be implemented by a dedicated computer system. The control device 400 may have a display panel (display unit) such as a liquid crystal display, and input devices (operation unit) such as a keyboard and mouse or touch panel. The specific configuration of the control device 400 will be described in detail below.

[0044] The control device 400 further includes a current detection unit and a voltage detection unit (not shown). The current detection unit is, for example, a through-type Hall sensor that detects the current flowing through the power lines in the charge / discharge system 10. The voltage detection unit detects the voltage of the power lines in the charge / discharge system 10. The control device 400 has the function of calculating and acquiring the power (active power) entering and leaving the power lines based on the detected current and voltage. The control device 400 also has the function of calculating the received power from the received current and system voltage detected by the measuring instruments 71-73, or acquiring the received power calculated by the measuring instruments 71-73. In this way, the control device 400 is configured to acquire the power flowing between the charge / discharge system 10, the power system 20 (substation equipment 30), the energy storage device 40, the power generation equipment 50, and the power load 60. The control device 400 may also be configured to acquire information other than the above, such as the SOC (State of Charge) of the energy storage device 40.

[0045] [2. Description of the control device 400] Figure 2 is a block diagram that functionally shows the configuration of the control device 400 included in the charge / discharge system 10 according to this embodiment.

[0046] As shown in Figure 2, the control device 400 includes an acquisition unit 410, a switching unit 420, a control unit 430, and a storage unit 440.

[0047] The acquisition unit 410 acquires a switching signal 441 indicating an instruction to switch between the first operating mode and the second operating mode. The first operating mode is an operating mode in which at least one of the input power to the charge / discharge system 10 and the output power from the charge / discharge system 10 is changed according to predetermined conditions. The first operating mode may be an operating mode in which only one of the input power and the output power is changed according to predetermined conditions, but in this embodiment, it is an operating mode in which both the input power and the output power are changed according to predetermined conditions. The second operating mode is an operating mode in which at least one of the input power to the charge / discharge system 10 and the output power from the charge / discharge system 10 is maintained at a constant value. The second operating mode may be an operating mode in which only one of the input power and the output power is maintained at a constant value, but in this embodiment, it is an operating mode in which both the input power and the output power are maintained at a constant value.

[0048] The input power to the charge / discharge system 10 is the power input to the charge / discharge system 10 from external devices (excluding the power grid 20) connected to the charge / discharge system 10. Since the charge / discharge system 10 is connected to the energy storage device 40 and receives discharge power discharged from the energy storage device 40 as input, the input power to the charge / discharge system 10 includes the discharge power discharged from the energy storage device 40. Furthermore, since the charge / discharge system 10 is connected to the power generation equipment 50 and receives power generated by the power generation equipment 50 as input, the input power to the charge / discharge system 10 includes the discharge power of the energy storage device 40 and the power generated by the power generation equipment 50. Thus, the input power to the charge / discharge system 10 is the power input to the charge / discharge system 10 other than the power input to the charge / discharge system 10 from the power grid 20 (substation equipment 30). In this embodiment, the input power to the charge / discharge system 10 is the AC power output from the bidirectional inverter circuit 300 (power flowing to the right through the measuring instrument 73 in Figure 1), and is measured by the measuring instrument 73.

[0049] The output power from the charge / discharge system 10 is the power output from the charge / discharge system 10 to external devices connected to the charge / discharge system 10 (excluding the power grid 20 and the power load 60). Since the charge / discharge system 10 is connected to the energy storage device 40 and outputs charging power to charge the energy storage device 40, the output power from the charge / discharge system 10 includes the charging power to charge the energy storage device 40. Thus, the output power from the charge / discharge system 10 is the power output from the charge / discharge system 10 other than the power output from the charge / discharge system 10 to the power grid 20 and the power load 60. In this embodiment, the output power from the charge / discharge system 10 is the AC power input to the bidirectional inverter circuit 300 (the power flowing to the left through the measuring instrument 73 in Figure 1), and is measured by the measuring instrument 73.

[0050] The predetermined conditions in the first operating mode are the operating conditions for performing an automatic control operating mode that automatically controls the input power and output power of the charge / discharge system 10. These predetermined conditions may be set in advance, manually set by the customer who has installed the charge / discharge system 10, or automatically set according to the customer's power usage status. These predetermined conditions may be pre-written and stored in the memory unit 440, written and stored in the memory unit 440 by an input operation by the customer, or automatically written and stored in the memory unit 440 according to the customer's power usage status. The predetermined conditions stored in the memory unit 440 may be updated as appropriate by an input operation by the customer or automatically.

[0051] In this embodiment, the predetermined condition is an operating condition that keeps the power measured by the measuring instrument 72 (power flowing from the substation 30 to the charge / discharge system 10) at a constant value. In other words, in the first operating mode, the input power and output power of the charge / discharge system 10 are automatically controlled under the condition that the power measured by the measuring instrument 72 is at a constant value. The predetermined condition may also be an operating condition that keeps the power measured by the measuring instrument 71 (power flowing from the power system 20 to the substation 30) at a constant value. This prevents the value of power flowing from the power system 20 to the substation 30 from becoming too large.

[0052] The switching signal 441 includes one of two signals: a first switching signal indicating an instruction to switch from the first operating mode to the second operating mode, and a second switching signal indicating an instruction to switch from the second operating mode to the first operating mode. The signals included in the switching signal 441 may be a single signal indicating an instruction to switch between the first and second operating modes, rather than the two signals of the first and second switching signals, but it is preferable to include the two signals so that it is clear which operating mode to switch to.

[0053] In this embodiment, the acquisition unit 410 acquires a switching signal 441 from outside the charge / discharge system 10. Specifically, the acquisition unit 410 acquires a switching signal 441 obtained according to the value of the power flowing from the power system 20 to the substation 30. The acquisition unit 410 acquires a switching signal 441 from a measuring instrument 71 for measuring the value of the power flowing from the power system 20 to the substation 30. The acquisition unit 410 acquires a switching signal 441 including a first switching signal when the value of the power exceeds a predetermined threshold, or acquires a switching signal 441 including a second switching signal when the value of the power falls below a predetermined threshold. The acquisition unit 410 may acquire a switching signal 441 that is automatically generated by the measuring instrument 71 based on the value of the power, or the acquisition unit 410 may automatically acquire a switching signal 441 based on the value of the power measured (or calculated) by the measuring instrument 71. The acquisition unit 410 may also acquire a switching signal 441 when a consumer or the like performs an input operation based on the value of the power.

[0054] The acquisition unit 410 writes the acquired switching signal 441 to the storage unit 440 for storage. In other words, if the acquisition unit 410 acquires a switching signal 441 that includes a first switching signal indicating an instruction to switch from the first operating mode to the second operating mode, it writes the switching signal 441 that includes the first switching signal to the storage unit 440 for storage. If the acquisition unit 410 acquires a switching signal 441 that includes a second switching signal indicating an instruction to switch from the second operating mode to the first operating mode, it writes the switching signal 441 that includes the second switching signal to the storage unit 440 for storage.

[0055] The switching unit 420 switches between the first operating mode and the second operating mode according to the switching signal 441 acquired by the acquisition unit 410. If the switching signal 441 acquired by the acquisition unit 410 includes a first switching signal indicating an instruction to switch from the first operating mode to the second operating mode, the switching unit 420 switches the operating mode from the first operating mode to the second operating mode. If the switching signal 441 acquired by the acquisition unit 410 includes a second switching signal indicating an instruction to switch from the second operating mode to the first operating mode, the switching unit 420 switches the operating mode from the second operating mode to the first operating mode.

[0056] Specifically, the switching unit 420 reads a switching signal 441 from the storage unit 440 and switches the operating mode according to the read switching signal 441. The switching unit 420 stores the switched operating mode in the operating mode 442 of the storage unit 440. In other words, if the switching signal 441 includes a first switching signal and the operating mode is switched from the first operating mode to the second operating mode, the switching unit 420 writes "second operating mode" to the operating mode 442 of the storage unit 440 and stores it. If the switching signal 441 includes a second switching signal and the operating mode is switched from the second operating mode to the first operating mode, the switching unit 420 writes "first operating mode" to the operating mode 442 of the storage unit 440 and stores it.

[0057] The control unit 430 performs power input and output to the charge / discharge system 10 according to the operating mode switched by the switching unit 420. If the operating mode switched by the switching unit 420 is the second operating mode, the control unit 430 performs power input and output to the charge / discharge system 10 according to the second operating mode. If the operating mode switched by the switching unit 420 is the first operating mode, the control unit 430 performs power input and output to the charge / discharge system 10 according to the first operating mode. Specifically, the control unit 430 reads the operating mode 442 from the storage unit 440, and if the operating mode written in the operating mode 442 is the second operating mode, it performs power input and output to the charge / discharge system 10 according to the second operating mode. If the operating mode written in the operating mode 442 is the first operating mode, the control unit 430 performs power input and output to the charge / discharge system 10 according to the first operating mode.

[0058] When the switching unit 420 switches to the first operating mode, the control unit 430 changes at least one of the input power to the charge / discharge system 10 and the output power from the charge / discharge system 10 according to predetermined conditions. In this embodiment, the control unit 430 changes the input power to the charge / discharge system 10 and the output power from the charge / discharge system 10 according to predetermined conditions to perform power input and output to the charge / discharge system 10. In other words, in the first operating mode, the control unit 430 performs an automatic control operation mode in which it automatically controls the input power and output power of the charge / discharge system 10 under the condition that the power measured by the measuring instrument 72 (power flowing from the substation equipment 30 to the charge / discharge system 10) is a constant value. In the first operating mode, the control unit 430 may also perform an automatic control operation mode in which it automatically controls the input power and output power of the charge / discharge system 10 under the condition that the power measured by the measuring instrument 71 (power flowing from the power system 20 to the substation equipment 30) is a constant value, or under other conditions.

[0059] When the switching unit 420 switches to the second operating mode, the control unit 430 performs power input and output to the charge / discharge system 10 so as to maintain at least one of the input power to the charge / discharge system 10 and the output power from the charge / discharge system 10 at the rated power of the charge / discharge system 10. In this embodiment, the control unit 430 performs power input and output to the charge / discharge system 10 so as to maintain the input power to the charge / discharge system 10 and the output power from the charge / discharge system 10 at the rated power of the charge / discharge system 10.

[0060] Specifically, in the second operating mode, the control unit 430 controls the input and output of power to the charge / discharge system 10 so as to maintain the power measured by the measuring instrument 73 at the rated power of the charge / discharge system 10. In other words, the control unit 430 controls the discharge power of the energy storage device 40 and the generated power of the power generation equipment 50 to input power to the charge / discharge system 10 so as to maintain the AC power output from the bidirectional inverter circuit 300 (the power flowing to the right through the measuring instrument 73 in Figure 1) at the rated power of the charge / discharge system 10. The control unit 430 controls the charging power of the energy storage device 40 to output power to the charge / discharge system 10 so as to maintain the AC power input to the bidirectional inverter circuit 300 (the power flowing to the left through the measuring instrument 73 in Figure 1) at the rated power of the charge / discharge system 10.

[0061] If the input power to the charge / discharge system 10, or the maximum output power from the charge / discharge system 10, is less than the rated power, the control unit 430 performs power input / output at the maximum value of the input power or the output power. When performing power input / output to the charge / discharge system 10, the control unit 430 prioritizes power generation by the power generation equipment 50, such as a solar power generation system, and controls the energy storage device 40 without suppressing power generation by the power generation equipment 50. In other words, the control unit 430 controls the input power to the charge / discharge system 10 by controlling the discharge power discharged from the energy storage device 40.

[0062] The memory unit 440 is a memory that stores data for the control unit 430 to input and output power to the charge / discharge system 10. The memory unit 440 stores the switching signal 441 acquired by the acquisition unit 410, and the operating mode 442 switched by the switching unit 420, etc. The memory unit 440 may also store other data necessary when the control unit 430 inputs and outputs power to the charge / discharge system 10. If there is a change in this data in the memory unit 440, this data is updated each time, but this data may also be accumulated.

[0063] [3. Explanation of the control method for the charge / discharge system 10] Next, the control method for the charge / discharge system 10 (processing performed by the control device 400 of the charge / discharge system 10) will be explained. Figure 3 is a flowchart showing the control method for the charge / discharge system 10 according to this embodiment (processing performed by the control device 400).

[0064] As shown in Figure 3, the acquisition unit 410 acquires a switching signal 441 indicating an instruction to switch between the first operating mode and the second operating mode (S102). The acquisition unit 410 acquires a switching signal 441 indicating an instruction to switch between a first operating mode, which changes at least one of the input power to the charge / discharge system 10, including the discharge power discharged from the energy storage device 40, and the output power from the charge / discharge system 10, including the charging power used to charge the energy storage device 40, according to predetermined conditions, and a second operating mode, which maintains at least one of these powers at a constant value. Specifically, the acquisition unit 410 acquires a switching signal 441 obtained according to the value of the power flowing from the power grid 20 to the substation equipment 30. A detailed explanation of the process by which the acquisition unit 410 acquires the switching signal 441 will be given later.

[0065] The switching unit 420 switches between the first operating mode and the second operating mode according to the switching signal 441 acquired by the acquisition unit 410 (S104).

[0066] The control unit 430 performs power input and output to the charge / discharge system 10 according to the operating mode switched by the switching unit 420 (S106). When the switching unit 420 switches to the second operating mode, the control unit 430 performs power input and output to the charge / discharge system 10 in such a way that at least one of the input power to the charge / discharge system 10 and the output power from the charge / discharge system 10 is maintained at the rated power of the charge / discharge system 10. The control unit 430 controls the input power to the charge / discharge system 10 by prioritizing power generation by the power generation equipment 50 and controlling the discharge power discharged from the energy storage device 40.

[0067] As described above, the processing performed by the charge / discharge system 10 (control device 400) (control method for the charge / discharge system) is completed.

[0068] Next, the process by which the acquisition unit 410 acquires the switching signal 441 (S102 in Figure 3) will be described in detail. Figure 4 is a flowchart showing the process by which the acquisition unit 410 of the control device 400 according to this embodiment acquires the switching signal 441.

[0069] As shown in Figure 4, the acquisition unit 410 determines whether the value of the power flowing from the power system 20 to the substation equipment 30 exceeds a predetermined threshold (S202). Specifically, the acquisition unit 410 acquires the value of the power measured (or calculated) by the measuring instrument 71 and determines whether the value of the power exceeds a predetermined threshold.

[0070] If the acquisition unit 410 determines that the power value exceeds a predetermined threshold (YES in S202), it acquires a switching signal 441 (S204). In other words, if the power value flowing from the power system 20 to the substation 30 is large, it is preferable to increase the input power to the charge / discharge system 10 by discharging more power from the energy storage device 40 or generating more power from the power generation equipment 50 in order to reduce the power value. For this reason, the acquisition unit 410 acquires a switching signal 441, including the first switching signal, in order to switch to a second operating mode that maintains the input power to the charge / discharge system 10 at the rated power of the charge / discharge system 10.

[0071] Subsequently, the acquisition unit 410 determines whether the value of the power flowing from the power system 20 to the substation equipment 30 has fallen below a predetermined threshold (S206). Specifically, the acquisition unit 410 acquires the value of the power measured (or calculated) by the measuring instrument 71 and determines whether the value of the power has fallen below a predetermined threshold.

[0072] If the acquisition unit 410 determines that the power value has fallen below a predetermined threshold (YES in S206), it acquires a switching signal 441 (S208). In other words, when the power value flowing from the power system 20 to the substation 30 decreases, there is no need to lower the power value, and therefore there is no need to increase the input power to the charge / discharge system 10. For this reason, the acquisition unit 410 acquires a switching signal 441, which includes a second switching signal, in order to return from the second operating mode to the first operating mode.

[0073] As described above, the process by which the acquisition unit 410 acquires the switching signal 441 (S102 in Figure 3) is completed. The above-mentioned decision processing performed by the acquisition unit 410 (S202 and S206 in Figure 4) may also be performed by the measuring instrument 71, or by input operations from the customer, etc.

[0074] In the process in which the acquisition unit 410 acquires the switching signal 441 described above, if the value of the power flowing from the power system 20 to the substation equipment 30 becomes even smaller, the value of said power may be increased. Therefore, in order to increase the power used to charge the energy storage device 40, the output power from the charge / discharge system 10 may be increased (it may be set to the rated power). In such a case, the acquisition unit 410 may acquire the switching signal 441 again, similar to the process described above.

[0075] [4. Explanation of Effects] As described above, the charge / discharge system 10 according to this embodiment switches between operating modes according to a switching signal 441 that switches between a first operating mode that changes at least one of the input power and output power and a second operating mode that maintains the power at a constant value, thereby performing power input and output. In this way, the charge / discharge system 10 can perform power input and output in a second operating mode that maintains the power at a constant value, in addition to the first operating mode that changes the power. As a result, the charge / discharge system 10 can operate in a way that is different from the first operating mode, by maintaining the power at a constant value in the second operating mode, thereby improving the degree of flexibility when operating power such as peak cutting. Therefore, the charge / discharge system 10 can achieve efficient power operation.

[0076] The charge / discharge system 10 can receive a switching signal 441 from an external source and switch operating modes according to the external switching signal 441 to perform power input and output. As a result, the charge / discharge system 10 can adjust power input and output according to external conditions, thereby enabling efficient power utilization.

[0077] The charging and discharging system 10 can switch operating modes according to a switching signal 441 that corresponds to the value of power flowing from the power grid 20 to the substation 30, and perform power input and output accordingly. For example, if the charging and discharging system 10 receives a switching signal 441 indicating that the value of power flowing from the power grid 20 to the substation 30 is large, it can switch from the first operating mode to the second operating mode to reduce the value of that power and perform power input and output accordingly. In this way, the charging and discharging system 10 can adjust the power input and output to itself according to the value of power flowing from the power grid 20 to the substation 30, thereby enabling efficient use of power.

[0078] During peak hours such as daytime when power consumption is high, the charging and discharging system 10 may operate more efficiently by maintaining the power at its rated level rather than varying it. Therefore, in the second operating mode, the charging and discharging system 10 controls power input and output to maintain at least one of the input power and output power at the rated level. This allows the charging and discharging system 10 to operate power efficiently.

[0079] The charge / discharge system 10 controls the input power by controlling the discharge power when the input power includes the discharge power of the energy storage device 40 and the power generated by the power generation equipment 50. In other words, the charge / discharge system 10 preferentially accepts the power generated by the power generation equipment 50 and adjusts the input power with the discharge power of the energy storage device 40. This prevents wasting the power generated by the power generation equipment 50 and reduces the power generation efficiency by reducing the power generated by the power generation equipment 50. Therefore, the charge / discharge system 10 enables efficient use of electricity.

[0080] Since the charging and discharging system 10 is connected to the power generation equipment 50 that generates electricity from renewable energy, it preferentially accepts the electricity generated from renewable energy. This prevents the waste of electricity generated from renewable energy and reduces the power generation efficiency of the power generation equipment 50, which generates electricity from renewable energy. If the renewable energy generation is solar power, surplus electricity can also be supplied to the power grid 20 (reverse power flow, electricity sales). Therefore, the charging and discharging system 10 enables the efficient use of electricity.

[0081] [5 Explanation of variations] Although the charge / discharge system 10 according to this embodiment has been described above, the present invention is not limited to the above embodiment. The embodiments disclosed herein are illustrative and not restrictive in all respects, and the scope of the present invention includes all modifications in the sense and scope equivalent to the claims.

[0082] (Variation 1) In the above embodiment, the acquisition unit 410 of the control device 400 provided in the charge / discharge system 10 acquires the switching signal 441 from outside the charge / discharge system 10, but the switching signal 441 may also be acquired from inside the charge / discharge system 10. Figure 5 is a block diagram functionally showing the configuration of the control device 401 according to Modification 1 of this embodiment. Figure 5 corresponds to Figure 2. Figure 6 is a flowchart showing the process by which the acquisition unit 410 of the control device 401 according to Modification 1 of this embodiment acquires the switching signal 441. Figure 6 corresponds to Figure 4.

[0083] As shown in Figure 5, the control device 401 in this modified example further includes a timer 450 in addition to the configuration of the control device 400 in the above embodiment. The other configurations of this modified example are the same as in the above embodiment, so a detailed explanation is omitted.

[0084] The acquisition unit 410 acquires the switching signal 441 at the time set by the timer 450. Specifically, as shown in Figure 6, the acquisition unit 410 determines whether or not the time set by the timer 450 has arrived (S302). If the acquisition unit 410 determines that the time set by the timer 450 has arrived (YES in S302), it acquires the switching signal 441 (S304).

[0085] During the daytime hours when power consumption is at its peak, it is preferable to increase the input power to the charge / discharge system 10 by discharging a large amount of power from the energy storage device 40 or generating a large amount of power from the power generation equipment 50. In this case, the timer 450 is set for the daytime hours. As a result, the acquisition unit 410 can acquire a switching signal 441, including the first switching signal, in order to switch to a second operating mode that maintains the input power to the charge / discharge system 10 at the rated power of the charge / discharge system 10 during the daytime hours.

[0086] Furthermore, after daytime hours, there is no need to increase the input power to the charge / discharge system 10. For this reason, the timer 450 is set even after daytime hours. This allows the acquisition unit 410 to acquire a switching signal 441, including the second switching signal, in order to switch back from the second operating mode to the first operating mode after daytime hours. During nighttime hours (midnight) when power consumption is low, the output power from the charge / discharge system 10 may be increased (or set to rated power) in order to increase the power used to charge the energy storage device 40. For this reason, by setting the timer 450 at nighttime hours (midnight), the acquisition unit 410 can acquire a switching signal 441, including the first switching signal, in order to switch to the second operating mode, which maintains the output power to the charge / discharge system 10 at rated power, at nighttime hours (midnight). The same applies to subsequent operations.

[0087] As described above, the charge / discharge system 10 according to this modified example can achieve the same effects as the embodiment described above. In particular, the charge / discharge system 10 can switch the operating mode and input / output power at the time set by the timer 450 by acquiring a switching signal 441 at that time. For example, the charge / discharge system 10 acquires a switching signal 441 to switch from the first operating mode to the second operating mode during a time when power can be used more efficiently by inputting / outputting power in the second operating mode (such as during the daytime when power consumption is at its peak). In this way, the charge / discharge system 10 can adjust the input / output of power by switching the operating mode at the time set by the timer 450, thereby enabling efficient power use.

[0088] (Modification 2) In the above embodiment, the charge / discharge system 10 performed power input and output to maintain the input power and output power of the charge / discharge system 10 at the rated power in the second operating mode, but is not limited to this. Figure 7 is a block diagram functionally showing the configuration of the control device 402 according to Modification 2 of this embodiment. Figure 7 corresponds to Figure 2. Figure 8 is a flowchart showing the control method (processing performed by the control device 402) of the charge / discharge system 10 according to Modification 2 of this embodiment. Figure 8 corresponds to Figure 3.

[0089] As shown in Figure 7, in this modified example, the control device 402 acquires a switching signal 441a instead of the switching signal 441 in the above embodiment. Specifically, in the second operating mode, the acquisition unit 410 acquires a switching signal 441a that includes power value information 443 indicating a constant value. The acquisition unit 410 writes the acquired switching signal 441a, including the power value information 443, to the storage unit 440 for storage. When the switching unit 420 switches to the second operating mode, the control unit 430 performs power input and output to the charge / discharge system 10 so as to maintain at least one of the input power and output power of the charge / discharge system 10 at the value indicated by the power value information 443. The other configurations of this modified example are the same as in the above embodiment, so a detailed explanation is omitted.

[0090] Specifically, as shown in Figure 8, the acquisition unit 410 acquires a switching signal 441a that includes power value information 443 (S402). In other words, the switching signal 441a is a signal that indicates an instruction to switch between the first operating mode and the second operating mode, the second operating mode being an operating mode in which at least one of the input power to the charge / discharge system 10 and the output power from the charge / discharge system 10 is maintained at a constant value. The switching signal 441a includes power value information 443 that indicates this constant value in the second operating mode.

[0091] The switching unit 420 switches between the first operating mode and the second operating mode according to the switching signal 441a acquired by the acquisition unit 410 (S404).

[0092] The control unit 430 performs power input and output to the charge / discharge system 10 according to the operating mode switched by the switching unit 420 (S406). Specifically, the switching signal 441a includes power value information 443 that indicates a certain value in the second operating mode. Therefore, when the switching unit 420 switches to the second operating mode, the control unit 430 performs control using the certain value indicated by the power value information 443. In other words, the control unit 430 performs power input and output to the charge / discharge system 10 in such a way that at least one of the input power to the charge / discharge system 10 and the output power from the charge / discharge system 10 is maintained at the value indicated by the power value information 443. In this embodiment, the control unit 430 performs power input and output to the charge / discharge system 10 in such a way that the input power to the charge / discharge system 10 and the output power from the charge / discharge system 10 are maintained at the value indicated by the power value information 443.

[0093] As described above, the charge / discharge system 10 according to this modified example can achieve the same effects as the embodiment described above. In particular, in the second operating mode, the charge / discharge system 10 performs power input and output in such a way that it maintains at least one of the input power and output power at a value indicated by the power value information 443 included in the switching signal 441a. In other words, the charge / discharge system 10 performs input and output at a constant power in the second operating mode when it is more efficient to maintain a constant power rather than changing the power. This enables the charge / discharge system 10 to operate power efficiently.

[0094] In this modified example, the power value information 443 may be information that shows different values ​​for the input power to the charge / discharge system 10 and the output power from the charge / discharge system 10. The power value information 443 may also be information that shows the rated power of the charge / discharge system 10, as in the above embodiment. The acquisition unit 410 may acquire the switching signal 441a from inside the charge / discharge system 10, as in the above modified example 1.

[0095] (Variation 3) In the above embodiment, the charge / discharge system 10 controls the input power and output power (AC power measured by the measuring instrument 73), but it may also control the charge / discharge power (DC power) of the energy storage device 40. Figure 9 is a block diagram functionally showing the configuration of the control device 403 according to Modification 3 of this embodiment. Figure 9 corresponds to Figure 2. Figure 10 is a flowchart showing the control method (processing performed by the control device 403) of the charge / discharge system 10 according to Modification 3 of this embodiment. Figure 10 corresponds to Figure 3.

[0096] As shown in Figure 9, in the control device 403 of this modified example, the acquisition unit 410 acquires a switching signal 441b instead of the switching signal 441 in the above embodiment, and writes the acquired switching signal 441b to the storage unit 440 for storage. The switching unit 420 switches between the first operating mode and the second operating mode according to the switching signal 441b acquired by the acquisition unit 410, and the control unit 430 performs power input and output to the charge / discharge system 10 according to the operating mode switched by the switching unit 420. The other configurations of this modified example are the same as in the above embodiment, so a detailed explanation is omitted.

[0097] Specifically, as shown in Figure 10, the acquisition unit 410 acquires a switching signal 441b indicating an instruction to switch between the first operating mode and the second operating mode (S502). The first operating mode is an operating mode in which at least one of the power, which is the charging power used to charge the energy storage device 40 and the discharge power discharged from the energy storage device 40, is changed according to predetermined conditions. The second operating mode is an operating mode in which at least one of the power, which is the charging power used to charge the energy storage device 40 and the discharge power discharged from the energy storage device 40, is maintained at a constant value. In other words, the acquisition unit 410 acquires a switching signal 441b indicating an instruction to switch between the first operating mode, in which at least one of the power (DC power) of the charging power used to charge the energy storage device 40 and the discharge power discharged from the energy storage device 40 is changed according to predetermined conditions, and the second operating mode, in which at least one of the power (DC power) is maintained at a constant value.

[0098] The switching unit 420 switches between the first operating mode and the second operating mode according to the switching signal 441b acquired by the acquisition unit 410 (S504).

[0099] The control unit 430 charges and discharges the energy storage device 40 according to the operating mode switched by the switching unit 420 (S506). When the switching unit 420 switches to the first operating mode, the control unit 430 changes at least one of the power (DC power) of the charging power used to charge the energy storage device 40 and the discharge power discharged from the energy storage device 40 according to predetermined conditions. When the switching unit 420 switches to the second operating mode, the control unit 430 charges and discharges the energy storage device 40 in such a way that at least one of the power (DC power) of the charging power used to charge the energy storage device 40 and the discharge power discharged from the energy storage device 40 is maintained at the rated power of the energy storage device 40. The control unit 430 may, in the second operating mode, charge and discharge the energy storage device 40 in such a way that at least one of the power (DC power) of the charging power of the energy storage device 40 and the discharge power discharged from the energy storage device 40 is maintained at a constant value, similar to the modified example 2 described above.

[0100] Thus, in this modified example, the "input power to the charge / discharge system 10" in the above embodiment is replaced with the input power from the energy storage device 40 to the charge / discharge system 10, that is, the "discharge power discharged from the energy storage device 40". Similarly, in this modified example, the "output power from the charge / discharge system 10" in the above embodiment is replaced with the output power from the charge / discharge system 10 to the energy storage device 40, that is, the "charging power used to charge the energy storage device 40".

[0101] As described above, the charge / discharge system 10 according to this modified example can achieve the same effects as the embodiment described above. In particular, the charge / discharge system 10 can perform charging and discharging of the energy storage device 40 in a second operating mode that maintains the charge / discharge power of the energy storage device 40 at a constant value, in addition to a first operating mode that changes the charge / discharge power of the energy storage device 40. As a result, the charge / discharge system 10 can be operated differently from the first operating mode by using the second operating mode, thereby improving the degree of freedom when operating power such as peak cutting. Therefore, the charge / discharge system 10 can achieve efficient power operation. In this modified example, the acquisition unit 410 may acquire the switching signal 441b from inside the charge / discharge system 10, similar to the modification 1 described above.

[0102] (Other variations) The following describes other modifications of the above embodiment, but modifications 1 to 3 can also be similarly modified.

[0103] In the above embodiment, the acquisition unit 410 of the control device 400 of the charge / discharge system 10 acquires the switching signal 441, which is obtained according to the value of the power flowing from the power system 20 to the substation 30, from outside the charge / discharge system 10, but it is not limited to this. The acquisition unit 410 may acquire the switching signal 441, which is obtained according to the value of the power flowing from the power system 20 to the substation 30, from inside the charge / discharge system 10. The acquisition unit 410 may acquire the switching signal 441, which is obtained regardless of the value of the power flowing from the power system 20 to the substation 30, from outside or inside the charge / discharge system 10. In this case, the substation 30 does not need to be provided between the charge / discharge system 10 and the power system 20.

[0104] Furthermore, instead of the substation 30, a power receiving facility that does not have a substation function (does not perform voltage boosting, voltage reduction, or rectification, etc.) may be installed. In this case as well, it can be implemented with the same configuration as the substation 30 and can achieve the same effects as the substation 30. In other words, the charging / discharging system 10 is connected to the power grid 20 via the substation 30 or the power receiving facility, and the acquisition unit 410 is configured to acquire a switching signal 441 obtained according to the value of the power flowing from the power grid 20 to the substation 30 or the power receiving facility.

[0105] In the above embodiment, the switching signal 441 acquired by the acquisition unit 410 of the control device 400 may include a signal indicating an instruction to switch between inputting power to the charge / discharge system 10 or outputting power from the charge / discharge system 10.

[0106] In the above embodiment, the control unit 430 of the control device 400 prioritizes power generation by the power generation equipment 50 and controls the discharge power of the energy storage device 40 to control the input power to the charge / discharge system 10, but it is not limited to this. The control unit 430 may prioritize charging and discharging of the energy storage device 40 and control the power generated by the power generation equipment 50. The control unit 430 may also perform control according to the operating mode switched by the switching unit 420, such as increasing the power generated by the power generation equipment 50 when it is desired to increase the charging power of the energy storage device 40, and decreasing the power generated by the power generation equipment 50 when it is desired to increase the discharge power of the energy storage device 40.

[0107] In the above embodiment, the control device 400 is provided with a storage unit 440, but it may also be provided without a storage unit 440, by storing information on an external recording medium and retrieving information from the recording medium.

[0108] In the above embodiment, the energy storage device 40 is located outside the charge / discharge system 10. However, the charge / discharge system 10 may also be a so-called battery-equipped power conditioner, which has the energy storage device 40 built inside. This would allow for space savings and other improvements.

[0109] In the above embodiment, the power generation equipment 50 is assumed to be a power generation equipment that generates electricity using renewable energy, but it is not limited to this. The power generation equipment 50 may be a diesel power generation equipment, a small gas turbine power generation equipment, a fuel cell, a micro hydroelectric generator, a distributed power generation equipment such as binary power generation, or other medium-sized or large-sized power generation equipment. The charge / discharge system 10 may not be connected to any power generation equipment and may not be supplied with power generated by any power generation equipment.

[0110] The present invention can be realized not only as a charge / discharge system 10 and a control method for the charge / discharge system 10, but also as a control device 400 and a control method for the control device 400. The present invention can also be realized as a program for causing a computer to execute the processing included in the control method of the charge / discharge system 10 (control device 400). In other words, each component of the charge / discharge system 10 (control device 400) may be realized by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory. The present invention can also be realized as a computer-readable non-temporary recording medium on which the program is recorded, such as a flexible disk, hard disk, CD-ROM, MO, DVD, DVD-ROM, DVD-RAM, BD (Blu-ray® Disc), or semiconductor memory. The program can be distributed via the recording medium and a transmission medium such as the Internet. The present invention can also be realized as an integrated circuit that includes a processing unit included in the charge / discharge system 10 (control device 400). In other words, each functional block of the charge / discharge system 10 (control device 400) may be realized as an integrated circuit, which is an LSI (Large Scale Integration). These may be individually integrated into a single chip, or some or all of them may be integrated into a single chip. Thus, the charge / discharge system 10 (control device 400) may be implemented by each component being composed of dedicated hardware, or by executing a software program suitable for each component.

[0111] Forms constructed by combining any of the components in the above embodiments and their variations are also included within the scope of the present invention. [Industrial applicability]

[0112] This invention can be applied to a charge / discharge system that is connected to a power grid, performs charging and discharging with an energy storage device, and supplies power to a power load. [Explanation of Symbols]

[0113] 10. Charging and discharging systems 20 Power system 21 Grid power supply 30 Substations 40 Energy storage devices 50 Power generation facilities 60 power load 61 General load 62 Specific load 71, 72, 73 Measuring Instruments 100 First converter circuit 200 Second converter circuit 300 Bidirectional Inverter Circuit 400, 401, 402, 403 Control Units 410 Acquisition Department 420 Switching section 430 Control Unit 440 Storage section 441, 441a, 441b switching signal 442 Operating Modes 443 Power Value Information 450 Timer

Claims

1. A charge / discharge system connected to a power grid, which performs charging and discharging with a power storage device and supplies power to a power load, An acquisition unit acquires a switching signal indicating an instruction to switch between a first operating mode, which changes at least one of the input power to the charge / discharge system, including the discharge power discharged from the energy storage device, and the output power from the charge / discharge system, including the charging power used to charge the energy storage device, according to predetermined conditions, and a second operating mode, which maintains the input power to the charge / discharge system at the rated power of the charge / discharge system. A switching unit that switches between the first operating mode and the second operating mode according to the switching signal acquired by the acquisition unit, The system comprises a control unit that performs power input and output to the charge / discharge system according to the operating mode switched by the switching unit, The charging and discharging system is connected to the power grid via a substation or power receiving equipment. The acquisition unit acquires a switching signal indicating an instruction to switch to the second operating mode when the value of the power flowing from the power system to the substation or the power receiving equipment exceeds a predetermined threshold, and acquires a switching signal indicating an instruction to switch to the first operating mode when the value of the power falls below the predetermined threshold. Charging and discharging system.

2. The acquisition unit acquires the switching signal from outside the charge / discharge system. The charge / discharge system according to claim 1.

3. The aforementioned charging and discharging system further includes a timer, The acquisition unit acquires the switching signal at the time set by the timer. The charge / discharge system according to claim 1 or 2.

4. The aforementioned charging and discharging system is connected to the power generation equipment. The input power includes the discharge power and the power generated by the power generation equipment. The control unit controls the input power by controlling the discharge power. A charge / discharge system according to any one of claims 1 to 3.

5. The charging and discharging system is connected to the power generation facility that generates electricity using renewable energy. The charge / discharge system according to claim 4.

6. A control method for a charge / discharge system that is connected to a power grid via a substation or power receiving equipment, performs charging and discharging with a power storage device, and supplies power to a power load, A switching signal is acquired that indicates an instruction to switch between a first operating mode in which at least one of the input power to the charge / discharge system, including the discharge power discharged from the energy storage device, and the output power from the charge / discharge system, including the charging power used to charge the energy storage device, is changed according to predetermined conditions, and a second operating mode in which the input power to the charge / discharge system is maintained at the rated power of the charge / discharge system. In accordance with the acquired switching signal, the first operating mode and the second operating mode are switched. In accordance with the switched operating mode, power is input and output to the charging and discharging system. When acquiring the switching signal, if the value of the power flowing from the power system to the substation or the power receiving equipment exceeds a predetermined threshold, the switching signal indicating an instruction to switch to the second operating mode is acquired, and if the value of the power falls below the predetermined threshold, the switching signal indicating an instruction to switch to the first operating mode is acquired. A method for controlling a charging and discharging system.

7. A program for causing a computer to execute the processing included in the control method for a charge / discharge system described in claim 6.

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