Energy storage system

Abstract

To change operations at the timing intended by a user.SOLUTION: A server executes processing including: a step (S100) of determining whether or not there is a switching request of operation modes; a step (S102) of acquiring the current date and time when it is determined that there is the switching request of the operation modes (YES in S100); a step (S104) of setting the termination time of a first operation mode from the current date and time; a step (S106) of acquiring a second operation mode; a step (S108) of generating a switching instruction; and a step (S110) of transmitting the generated switching instruction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a power storage system. [Background technology]

[0002] 2. Description of the Related Art Conventionally, in addition to commercial power sources, stationary energy storage systems have been used as power sources for electrical equipment installed in buildings.

[0003] Regarding such stationary energy storage systems, for example, Japanese Patent Application Laid-Open No. 2017-085781 (Patent Document 1) discloses a technology that allows a user to manually set operations such as prioritizing charging of an energy storage device included in the energy storage system or prioritizing power supply to other energy storage devices such as electric vehicles. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-085781 Summary of the Invention [Problem to be solved by the invention]

[0005] A stationary energy storage system may be provided with an interface that accepts user instructions via a communication network in order to operate in accordance with the user's intentions as described above. However, if a communication failure in the communication network causes a delay in communication, the reception of the user's instructions may be delayed or the user's instructions may not be received during the communication failure. As a result, the operation of the energy storage system may not be changed at the timing intended by the user.

[0006] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a power storage system that allows the user to change the operation at the timing intended by the user. [Means for solving the problem]

[0007] According to an aspect of the present disclosure, there is provided a power storage system including: a power storage device installed in the building, capable of receiving and sending power to and from an electrical appliance installed in the building; a control device that performs one of a plurality of operations related to charging and discharging the power storage device; and a terminal that can communicate with the control device. When the terminal receives an operation to switch from a first operation to a second operation among the plurality of operations, the terminal generates a switching instruction using information indicating an end time of the first operation and information indicating that the second operation will be performed after the first operation, and transmits the generated switching instruction to the control device.

[0008] In this way, the terminal transmits to the control device a switching instruction including information indicating the end time of the first action and information indicating that the second action will be performed after the first action, so that the control device can switch from the first action to the second action in accordance with the received switching instruction even if a delay occurs in communication thereafter, thereby enabling the action to be switched at the timing intended by the user.

[0009] In one embodiment, when the control device receives a switching instruction from the terminal, the control device ends the first operation at the end time and performs the second operation.

[0010] In this way, by receiving a switching instruction from the terminal, the control device can switch from the first operation to the second operation in accordance with the received switching instruction even if a delay occurs in communication after that, so that the operation can be switched at the timing intended by the user.

[0011] In yet another embodiment, the information indicating the end time of the first action includes information about the time at which the switching instruction was generated and information about the period from the generation time until the first action is ended.

[0012] In this way, the end time can be obtained using the time when the switching instruction was generated and the period from the time when the first operation was generated to the time when the first operation was completed, so that the operation can be switched at the timing intended by the user even if there is a delay in communication. [Effects of the Invention]

[0013] According to the present disclosure, it is possible to provide a power storage system that allows the user to change the operation at the timing intended by the user. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a diagram illustrating an example of an overall configuration of a power storage system. [Figure 2] 10A and 10B are diagrams for explaining the occurrence of a delay in an instruction to switch an operation mode due to a communication failure. [Figure 3] 10 is a flowchart illustrating an example of a process executed in the server. [Figure 4] FIG. 10 is a diagram showing an example of information constituting a switching instruction in a table format. [Figure 5] 10 is a flowchart illustrating an example of processing executed in a PCS. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0016] 1 is a diagram schematically illustrating an example of the overall configuration of a power storage system 1. A part of the configuration of the power storage system 1, a distribution board 4, and an electric load 10 are provided in a building 3. The electric load 10 in the building 3 is connected to a power grid 2 connected to a commercial power source or the like, and a power conditioner system (hereinafter referred to as PCS) 30 (described later) of the power storage system 1 via the distribution board 4.

[0017] The distribution board 4 is configured to be able to select a power transmission path between the PCS 30 of the power storage system 1, the power grid 2, and the electric load 10.

[0018] The distribution board 4 can, for example, select a power transmission path for supplying power supplied from the power grid 2 to the electric load 10 via the distribution board 4. Furthermore, the distribution board 4 can select a power transmission path for supplying power supplied from the PCS 30 of the power storage system 1 to the electric load 10 via the distribution board 4. Furthermore, the distribution board 4 can select a power transmission path for supplying power supplied from the power grid 2 to the PCS 30 of the power storage system 1 via the distribution board 4. Furthermore, the distribution board 4 can select a power transmission path for supplying power supplied from the PCS 30 of the power storage system 1 to the power grid 2 via the distribution board 4.

[0019] The electric load 10 includes an electric device installed inside or outside the building 3. The electric load 10 includes, for example, a lighting device and various home appliances.

[0020] The power storage system 1 includes a solar power generation device 20, a PCS 30, a router 40, a battery unit 70, a server 100, and a mobile terminal 150. The battery unit 70 is installed outside (outdoors) of a building 3. The battery unit 70 may also be installed inside (indoors) of the building 3.

[0021] The solar power generation device 20 is configured, for example, by a solar panel or the like installed outdoors, such as on the roof of the building 3. The solar power generation device 20 is connected to the PCS 30. The solar power generation device 20 receives sunlight to generate DC power and supplies the generated DC power to the PCS 30.

[0022] The PCS 30 includes various power conversion devices (not shown), a control device 32, and a communication device 34. The PCS 30 converts DC power supplied from at least one of the battery unit 70 and the solar power generation device 20 into AC power and supplies the AC power to the distribution board 4. Alternatively, the PCS 30 supplies DC power supplied from the solar power generation device 20 to the battery unit 70. Alternatively, the PCS 32 converts AC power supplied from the power grid 2 into DC power and supplies the DC power to the battery unit 70.

[0023] The control device 32 is configured to include a CPU (Central Processing Unit), memory (such as ROM (Read Only Memory) and RAM (Random Access Memory)), and input / output ports for inputting and outputting various signals. The various controls performed by the control device 32 are software processes, that is, programs stored in memory are read out by the CPU. The various controls by the control device 32 can also be realized by a general-purpose computer (not shown) executing programs stored in a storage medium. The various controls by the control device 32 are not limited to software processes and may be processed by dedicated hardware (electronic circuits).

[0024] The communication device 34 is configured to be able to communicate with, for example, the router 40 and the ECU (Electronic Control Unit) 80 of the battery unit 70 via wired or wireless communication. The communication device 34, for example, exchanges predetermined information with the ECU 80. Furthermore, the communication device 34 is configured to be able to communicate with the server 100 via the router 40 and a communication network 6 such as the Internet. The communication network 6 is connected to, for example, a wireless base station 8, which is communicatively connected to the mobile terminal 150. Therefore, the communication device 34 is configured to be able to communicate with the mobile terminal 150 via the router 40 and the communication network 6.

[0025] The router 40 is installed in the building 3. In addition to the communication device 34, the router 40 is connected to communication terminals such as personal computers and smartphones in the building 3 so as to be able to communicate with them via wired or wireless communication.

[0026] The battery unit 70 includes an ECU 80 and a battery pack (not shown). The battery pack is configured, for example, using a plurality of cells. The cells are configured, for example, by nickel-metal hydride batteries or lithium-ion batteries having a liquid or solid electrolyte. The battery pack is configured by connecting a plurality of cells in series. Note that the battery pack may also be configured, for example, by connecting a plurality of battery groups in series, each of which is configured by connecting a predetermined number of cells in parallel.

[0027] The battery unit 70 further includes, for example, a system main relay (hereinafter referred to as SMR) (not shown) that connects the battery pack and the PCS 30. The ECU 80 controls the operation of the SMR to switch between a conductive state in which the battery pack and the PCS 30 are electrically connected and a cut-off state in which the battery pack and the PCS 30 are electrically cut off. The ECU 80 operates the SMR in response to a control signal received from the control device 32, for example.

[0028] Furthermore, the ECU 80 manages the state of the battery pack. For example, the ECU 80 estimates the SOC of the battery pack using the temperature, current, and voltage within the battery pack. The SOC indicates the ratio of the remaining amount of power to the fully charged capacity. Note that various known methods can be used to calculate the SOC, such as a method based on current integration (coulomb counting) or a method based on open circuit voltage (OCV) estimation.

[0029] The server 100 is a terminal including a control device 102, a storage device 104, a communication device 106, and a user interface (hereinafter referred to as UI) 108. The control device 102, the storage device 104, the communication device 106, and the UI 108 are communicatively connected to one another by a communication bus 110.

[0030] Like control device 32, control device 102 includes a CPU, memory (ROM, RAM, etc.), input / output ports for inputting and outputting various signals, etc. Therefore, detailed description thereof will not be repeated.

[0031] The storage device 104 stores information relating to the operation of various electrical devices such as the PCS 30, the solar power generation device 20, or the battery unit 70, as well as information relating to operation instructions and control instructions received from the user.

[0032] The communication device 106 is configured to be capable of two-way communication with the communication device 34 via the communication network 6. Note that the communication target of the communication device 106 is not limited to the communication device 34, but may be a PCS communication device connected to a battery unit in a building other than the building 3.

[0033] The UI 108 includes various input devices such as a keyboard, a mouse, a touch panel, etc. The UI 108 outputs an operation signal generated by receiving an operation from a user to the control device 102. The control device 102 acquires an operation instruction from the user using the operation signal input from the UI 108.

[0034] When the operation instruction acquired using the operation signal from the UI 108 is an operation instruction for switching the operation mode of the battery unit 70, the control device 102 transmits an instruction for switching the operation mode to the PCS 30. The operation modes of the battery unit 70 include, for example, a charge mode, a discharge mode, and a standby mode. The charge mode is an operation mode in which charging power is supplied from the PCS 30 to the battery pack of the battery unit 70 to charge the battery pack. The discharge mode is an operation mode in which power from the battery pack of the battery unit 70 is supplied to the PSC 30 to discharge the battery pack. The standby mode is an operation mode in which the battery pack is in a standby state without charging or discharging.

[0035] Mobile terminal 150 includes a control device, a storage device, a communication device, and a UI (none of which are shown). The functions of the control device, storage device, communication device, and UI of mobile terminal 150 are similar to the functions of control device 102, storage device 104, communication device 106, and UI 108 of server 100. Therefore, detailed description thereof will not be repeated.

[0036] In the energy storage system 1 having the above-described configuration, if a communication failure occurs between the communication device 34 and the communication device 106, even if the communication device 106 transmits a switching instruction to switch the operating mode of the battery unit 70, there may be a delay in receiving the switching instruction at the communication device 34.

[0037] In this embodiment, communication failures include not only those caused by increased traffic or equipment failures in the communication network 6, but also those caused by equipment failures on the communication path within the building 3, such as malfunction of the router 40.

[0038] Hereinafter, a delay in issuing an instruction to switch the operation mode due to a communication failure will be described with reference to Fig. 2. Fig. 2 is a diagram for explaining the occurrence of a delay in issuing an instruction to switch the operation mode due to a communication failure. Fig. 2 shows various control instructions and various information exchanged between the server 100, the PCS 30, and the battery unit 70.

[0039] As shown in Fig. 2(A), for example, it is assumed that a communication failure occurs in the communication network 6. At this time, as shown in Fig. 2(B), when the server 100 receives an operation instruction from the user to switch the operation mode of the battery unit 70, the server 100 transmits a switching instruction to the PCS 30 to switch the operation mode of the battery unit 70.

[0040] However, if a communication failure occurs and the PCS 30 is delayed in receiving the instruction to switch the operation mode from the server 100, as shown in Fig. 2(C), the operation mode of the battery unit 70 cannot be switched until the instruction to switch is received. As a result, as shown in Fig. 2(D), there are cases where the operation mode of the battery unit 70 cannot be switched at the timing intended by the user.

[0041] Therefore, in this embodiment, when server 100 receives an operation to switch the operation mode of battery unit 70, server 100 generates a switching instruction using information indicating the end time of the first operation mode before the change and information indicating that the operation mode can be switched to the second operation mode after the first operation mode, and transmits the generated switching instruction to control device 32 of PCS 30. When control device 32 receives the switching instruction from server 100, it ends operation in the first operation mode at the end time and operates in the second operation mode.

[0042] In this way, even if a delay occurs in communication with the server 100 after receiving the switching instruction, the control device 32 can switch the operation mode of the battery unit 70 from the first operation mode to the second operation mode in accordance with the received switching instruction. Therefore, the operation can be switched at the timing intended by the user.

[0043] An example of processing executed in the server 100 (specifically, the control device 102 of the server 100) will be described below with reference to Fig. 3. Fig. 3 is a flowchart showing an example of processing executed in the server 100. A series of processing shown in this flowchart is repeatedly executed by the server 100 at predetermined intervals.

[0044] In step (hereinafter, step will be abbreviated as S) 100, server 100 determines whether or not there is a request to switch the operation mode. Server 100 determines that there is a request to switch the operation mode when, for example, the user's operation instruction is an operation instruction to switch the operation mode of battery unit 70. If it is determined that there is a request to switch the operation mode (YES in S100), the process proceeds to S102.

[0045] In S102, server 100 acquires the current date and time (hereinafter referred to as the current date and time). Server 100 may acquire the current date and time using, for example, a built-in clock device, or may acquire the current date and time by communicating with an external server (for example, an NTP (Network Time Protocol) server) via communication network 6. Server 100 stores the acquired current date and time in storage device 104. Thereafter, the process proceeds to S104.

[0046] In S104, the server 100 sets the end time of the first operation mode from the current time. For example, the server 100 sets the end time of the first operation mode to the period from the current time until the operation of the first operation mode is ended. For example, the server 100 may set the end time of the first operation mode to a predetermined time, or may set the end time of the first operation mode to the time required to switch the operation mode from the first operation mode to the second operation mode, or may set the end time of the first operation mode based on a delay time caused by a communication failure. The predetermined time may be, for example, on the order of several minutes or on the order of several hours. The server 100 stores the set end time of the first operation mode in the storage device 104. Thereafter, the process proceeds to S106.

[0047] In S106, server 100 acquires a second operation mode. Server 100 acquires the changed operation mode specified by the user's operation instruction as the second operation mode. Server 100 stores the acquired second operation mode in storage device 104. Thereafter, the process proceeds to S108.

[0048] At S108, server 100 generates a switching instruction. Server 100 generates, as the switching instruction, information that associates the acquired current date and time, the set end time of the first operation mode, and the acquired second operation mode. Figure 4 is a diagram showing, in table form, an example of information that constitutes the switching instruction.

[0049] 4, the server 100 generates a switching instruction by associating the information about the current date and time acquired in S102, the information about the end time of the first operation mode set in S104, and the acquired information about the second operation mode. Then, the process proceeds to S110.

[0050] In S110, server 100 transmits a switching instruction to communication device 34 of PCS 30. If it is determined that there is no request to switch the operation mode (NO in S100), this process ends.

[0051] Next, an example of processing executed in the PCS 30 (specifically, the control device 32 of the PCS 30) will be described with reference to Fig. 5. Fig. 5 is a flowchart showing an example of processing executed in the PCS 30. A series of processing shown in this flowchart is repeatedly executed by the PCS 30 at predetermined intervals.

[0052] In S200, PCS 30 determines whether or not to receive a switching instruction. If it is determined that a switching instruction is received from server 100 (YES in S200), the process proceeds to S202.

[0053] In S202, the PCS 30 acquires the current date and time of the destination using the received switching instruction. The PCS 30 stores the acquired current date and time in the memory of the control device 32. Thereafter, the process proceeds to S204.

[0054] In S204, the PCS 30 acquires the second operation mode using the received switching instruction, and stores the acquired second operation mode in the memory of the control device 32. Thereafter, the process proceeds to S206.

[0055] In S206, the PCS 30 sets the time (hereinafter referred to as the end time) at which the first operation mode is ended and the second operation mode is switched to. For example, the PCS 30 sets the end time to the time obtained by adding the end time to the current date and time. Thereafter, the process proceeds to S208.

[0056] In S208, PCS 30 acquires the current time. The method for acquiring the current time is the same as the method for acquiring the current time by server 100. Therefore, detailed description thereof will not be repeated. Thereafter, the process proceeds to S210.

[0057] In S210, the PCS 30 determines whether the current time has reached the end time. For example, the PCS 30 determines that the current time has reached the end time if the current time is a time after the end time. If it is determined that the current time has reached the end time (YES in S210), the process proceeds to S212.

[0058] In S212, the PCS 30 changes the operation mode of the battery unit 70 to the acquired second operation mode. If it is determined that a switching instruction has not been received (NO in S200), this process ends. If it is determined that the current time has not yet reached the end time (NO in S210), the process returns to S210.

[0059] An example of the operation of the electricity storage system 1 based on the above-described structure and flowchart will be described.

[0060] For example, assume that the battery unit 70 is operating in standby mode. In this case, the battery unit 70 maintains a state in which it is neither charging nor discharging. When a user's operation instruction is received via the UI 108 of the server 100 and the received operation instruction corresponds to an instruction to change the operation mode to the charging mode, the server 100 determines that there is a request to switch the operation mode (YES in S100). Therefore, the current date and time are acquired (S102), and an end time of the first operation mode is set (S104). Based on the received operation instruction, the charging mode is acquired as the second operation mode (S106). A switching instruction is generated using the current date and time, the end time of the first operation mode, and the second operation mode (S108), and the generated switching instruction is transmitted to the PCS 30 (S110).

[0061] When the PCS 30 receives a switching instruction (YES in S200), the current date and time of the destination is acquired (S202), the second operation mode is acquired using the switching instruction (S204), and the end time of the first operation mode is set (S206).The current time is then acquired (S208), and it is determined whether the current time has reached the end time (S210).

[0062] If it is determined that the current time has reached the end time (YES in S210), the operation mode is changed to the second operation mode, that is, the charging mode (S212).

[0063] As a result, even if a communication failure occurs in the communication network 6 or the router 40 and reception of the switching instruction is delayed, if the delayed time is within the end time, the operation mode will be changed when the current time reaches the end time. This makes it possible to change the operation mode in accordance with the user's intention.

[0064] As described above, in the power storage system 1 according to the present embodiment, the server 100 transmits to the PCS 30 a switching instruction including information indicating the end time of the first operation mode and information indicating that the second operation mode will be performed after the first operation mode. Therefore, even if a delay occurs in communication thereafter, the PCS 30 can switch from the first operation mode to the second operation mode in accordance with the received switching instruction. Therefore, the operation can be switched at a timing intended by the user. Therefore, it is possible to provide a power storage system that allows the operation to be changed at a timing intended by the user.

[0065] Furthermore, the power storage system 1 in this embodiment can fulfill two roles: one role of providing value (hereinafter referred to as individual value) such as energy saving (hereinafter referred to as energy saving) and disaster prevention to an individual who owns the power storage system, and the other role of providing value (hereinafter referred to as societal value) such as the ability to adjust power in a power grid to a society (region such as a city, town, or village) that owns multiple power storage systems. When prioritizing one of the roles, the power storage system 1 can flexibly switch fail-safe operations according to the role that takes priority.

[0066] For example, when prioritizing the role of providing personal value, the first operation can be switched to charging mode upon receiving weather information such as a weather warning at the location where the storage system is installed, and then the second mode, in which PCS30 operates alone as a fail-safe, can be realized by using the above-mentioned switching instruction, for example, to return to energy-saving automatic control mode.

[0067] Furthermore, for example, when prioritizing the role of providing social value, when the server 100 is coordinating the multiple power storage systems 1 to operate each power storage system 1 in a predetermined operation mode (charge mode or discharge mode) as a first mode for the purpose of improving energy efficiency throughout the entire area in which the multiple power storage systems 1 are installed, even if a communication failure occurs, the operation of returning to the standby mode as a second operation mode, for example, can be realized using the above-mentioned switching instruction. By returning to the standby mode, it is possible to prevent charging and discharging from being performed in a power storage system that does not receive the control instruction from the server 100.

[0068] Modifications will be described below. In the above embodiment, a configuration in which the battery unit 70 is connected to the PCS 30 has been described as an example, but a bidirectional DC / DC converter may be provided between the PCS 30 and the battery unit 70 to convert (boost or step down) the DC power supplied from the PCS 30 into power capable of charging the assembled battery 90 of the battery unit 70, or to convert (boost or step down) the DC power supplied from the battery unit 70 into power of an appropriate voltage as input power to the PCS 30. The bidirectional DC / DC converter may operate in response to a control signal from the ECU 80, for example, or may operate in response to a control signal from a control device (not shown) of the PCS 30.

[0069] Furthermore, in the above-described embodiment, a configuration in which the solar power generation device 20 and the battery unit 70 are connected to the PCS 30 has been described as an example, but for example, a vehicle equipped with a power storage device may also be connected to the PCS 30 so that DC power is supplied from the vehicle's power storage device, or the DC power of the vehicle's power storage device may be converted into AC power and supplied.

[0070] Furthermore, in the above embodiment, the case where the processing shown in the flowchart of FIG. 5 is executed by the control device 32 of the PCS 30 has been described as an example, but it may also be executed by the ECU 80 of the battery unit 70.

[0071] Furthermore, in the above-described embodiment, the end time is set in the switching instruction regardless of whether a communication failure occurs between the control device of the PCS 30 and the server 100. However, the server 100 may set the end time of the pre-change operation mode in the switching instruction, for example, when a communication failure occurs between the control device 32 of the PCS 30 and the server 100. For example, when the response time indicated by a ping value or the like to the control device 32 of the PCS 30 is equal to or greater than a predetermined value, the server 100 may determine that a delay due to a communication failure has occurred between the control device 32 of the PCS 30 and the server 100 and set the end time. In this case, the end time may be set according to the response time. For example, the end time may be set to be longer as the response time becomes longer.

[0072] Furthermore, in the above embodiment, the UI 108 of the server 100 is described as accepting an operation instruction, but when an operation instruction is accepted, the user may be notified of the end time of the current operation mode of the battery unit 70.

[0073] Furthermore, in the above-described embodiment, the processing shown in the flowchart of FIG. 3 is described as being executed by the control device 102 of the server 100 as an example, but it may also be executed by the control device of the mobile terminal 150 instead of the control device 102 of the server 100.

[0074] The above-described modifications may be implemented in whole or in part in appropriate combination. The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0075] 1 Energy storage system, 2 Power grid, 3 Building, 4 Distribution board, 6 Communication network, 8 Wireless base station, 10 Electrical load, 20 Photovoltaic power generation equipment, 30 PCS, 32, 102 Control equipment, 34, 106 Communication equipment, 40 Router, 70 Battery unit, 80 ECU, 90 Battery pack, 100 Server, 104 Storage device, 108 UI, 110 Communication bus, 150 Mobile terminal.

Claims

1. a power storage device installed in the building, capable of sending and receiving electric power to and from electrical equipment installed in the building; a control device that performs any one of a plurality of operations related to charging and discharging the power storage device; a terminal capable of communicating with the control device, When the terminal receives an operation to switch from a first operation to a second operation among the plurality of operations, the terminal generates a switching instruction using information indicating an end time of the first operation and information indicating that the second operation will be performed after the first operation, and transmits the generated switching instruction to the control device; The information indicating the end time of the first operation includes information about the time at which the switching instruction was generated and information about the period from the time of generation until the first operation is terminated.

2. The power storage system according to claim 1 , wherein the control device, when receiving the switching instruction from the terminal, ends the first operation at the end time and performs the second operation.

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