JP2018038229A - Power storage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage system capable of effectively utilizing a power storage device and a power generator at the time of outage.SOLUTION: A power storage system comprises a power storage device and a controller. The power storage device stores power generated on the basis of natural energy by a power generator. The controller controls discharge and charge with respect to the power storage device and makes the power storage device perform self-sustained discharge at the time of outage. The controller comprises a detection unit and a control unit. The detection unit detects a power storage residual amount of the power storage device. The control unit, on the basis of an operation mode of the power generator, dynamically sets a threshold value with respect to the power storage residual amount of the power storage device; and stops the self-sustained discharge of the power storage device and to make it standby when the detected power storage residual amount is lower than the threshold value at the time of outage.SELECTED DRAWING: Figure 2

Description

  Embodiments described herein relate generally to a power storage system.

  In recent years, with the spread of solar power generation technology, power generation facilities such as solar panels and storage batteries are installed in a house to generate power and charge, and use electric power. For example, the DC power supply control device described in Patent Document 1 includes a solar power generation device and a storage battery. Then, the DC power supply control device performs control so that the power stored in the storage battery is supplied to the load at the time of a power failure when the power supply from the commercial power supply is stopped.

  Moreover, the power storage system described in Patent Document 2 stores the power generated by the power generation device in a storage battery. In addition, the power storage system supplies, to a load, power output by a power generation device including a solar panel or the like by a self-sustaining operation function at the time of a power failure.

JP 2013-42627 A JP2015-12730A

  However, in the conventional power storage system, if all the power stored in the storage battery is consumed, there is a problem that the operation of the storage battery cannot be resumed during a power failure without power supply from a commercial power source. For this reason, once the remaining amount of electricity stored in the storage battery becomes equal to or less than a predetermined value, the generated power could not be stored even if power generation by a solar panel or the like was possible thereafter.

  The problem to be solved by the present invention is to provide a power storage system capable of effectively utilizing a power storage device and a power generation device during a power failure.

  The power storage system according to the embodiment includes a power storage device and a control device. The power storage device stores the power generated by the power generation device based on natural energy. The control device controls the discharging and charging of the power storage device and causes the power storage device to self-discharge during a power failure. The control device includes a detection unit and a control unit. The detection unit detects the remaining amount of power stored in the power storage device. The control unit dynamically sets a threshold value related to the remaining amount of electricity stored in the power storage device based on the operation mode of the power generation device, and stops self-sustained discharge of the power storage device when the detected remaining power storage amount is less than the threshold during a power failure To enter standby mode.

FIG. 1 is a diagram illustrating an example of a configuration of a power storage system according to the embodiment. FIG. 2 is a diagram illustrating an example of a configuration of a power conditioner included in the power storage system according to the embodiment. FIG. 3 is a diagram illustrating an example of a configuration of information stored in a storage unit included in the power storage system according to the embodiment. FIG. 4 is a diagram for explaining power control by the power storage system according to the embodiment. FIG. 5 is a flowchart illustrating an example of a flow of power control by the power storage system according to the embodiment. FIG. 6 is a diagram conceptually showing the relationship between the flow of power control shown in FIG. 5 and the remaining amount of electricity stored in the storage battery. FIG. 7 is a flowchart illustrating an example of a flow of capacity control processing of the power storage system according to the embodiment.

  The power storage system 1 according to the embodiment described below includes a power storage device (storage battery 50) and a control device (power conditioner 100). The power storage device stores the power generated by the power generation device (solar panel PN) based on natural energy. The control device controls the discharging and charging of the power storage device and causes the power storage device to self-discharge during a power failure. The control device includes a detection unit (remaining power storage amount detection unit 133) and a control unit (capacity control unit 135). The detection unit detects the remaining amount of power stored in the power storage device. The control unit dynamically sets a threshold value related to the remaining amount of electricity stored in the power storage device based on the operation mode of the power generation device, and stops self-sustained discharge of the power storage device when the detected remaining power storage amount is less than the threshold during a power failure To enter standby mode.

  In addition, the control unit (capacity control unit 135) included in the power storage system 1 according to the embodiment described below corresponds to the threshold according to the time when the control unit stops self-sustained discharge of the power storage device and the power generation start time by the power generation device. Set dynamically.

  In addition, the control unit (capacity control unit 135) included in the power storage system 1 according to the embodiment described below includes the power generation start time by the power generation device, at least the date and time when the self-sustained discharge is stopped, and the past power generation history by the power generation device. The threshold value is dynamically set by determining it according to any one of weather information and weather information.

  In addition, the control unit (capacity control unit 135) included in the power storage system 1 according to the embodiment described below executes charging of the power storage device when the power generation amount of the power generation device is equal to or greater than a predetermined threshold, While the self-sustaining discharge of the power storage device in the middle is stopped, charging from the power generation device to the power storage device is executed based on a threshold value lower than the threshold value when no power failure occurs.

  In addition, the control unit (capacity control unit 135) included in the power storage system 1 according to the embodiment described below sets a predetermined threshold according to the power generation capacity of the power generation device, and the threshold value set by the power generation amount of the power generation device When it is above, the power storage device is charged.

  Hereinafter, an embodiment of a power storage system according to the present invention will be described in detail with reference to the drawings. In the embodiment, configurations having the same functions are denoted by the same reference numerals, and redundant description is omitted.

(Embodiment)
The power storage system according to the embodiment is supplied with a predetermined power system, for example, a commercial power supply (CP), and supplies power to a load (LD) such as a home appliance. The power storage system supplies power generated by a power generation device using natural energy such as a solar panel to a load such as a home appliance. In addition, the power storage system stores power supplied from a commercial power source and power generated by the power generation device in a power storage device such as a storage battery. When the power supply by the power system (commercial power supply) is stopped due to a power failure or the like, the power storage system performs a self-sustained operation by discharging the power stored in the power storage device and supplying it to the load. In addition, when the power generation device can generate power during a power failure, the power storage system detects a self-sustained output generated from the self-sustained operation terminal of the power generation device. The power storage system supplies the power generated by the power generation device to the load and stores the surplus in the power storage device.

  The power storage system according to the present embodiment prevents a situation in which the power stored in the power storage device is depleted during a power failure and the power storage device cannot be operated. The power storage system prevents a situation where power cannot be stored because the power storage device cannot operate when power generation by the power generation device is possible even during a power failure, for example. For this reason, the power storage system controls the remaining amount of power stored in the power storage device. In particular, the power storage system according to the present embodiment stores power so that the power storage device and the power generation device can be operated continuously and power usage can be continued without losing the function of the power storage device when a power failure continues for a long period of time. Controls the remaining charge of the device.

[Example of Configuration of Power Storage System 1 According to Embodiment]
FIG. 1 is a diagram illustrating an example of a configuration of a power storage system 1 according to the embodiment. In the example of FIG. 1, the power storage system 1 is provided in a home HM of a user (customer), and for example, power generated by a solar panel PN (power generation device) installed on a roof is consumed in the home HM. Or can be stored in a storage battery (power storage device) 50.

  As shown in FIG. 1, the power storage system 1 includes a solar panel PN, a connection box BX, a power conditioner 100, a controller 200 having an output unit 210 and an input unit 220, a storage battery 50, and a distribution board DP. And a power meter MT. Further, in the power storage system 1 shown in FIG. 1, the controller 200 (or the power conditioner 100) can be connected to the Internet and can send and receive information to and from various information processing apparatuses outside the power storage system 1. May be.

  The solar panel PN is an example of a power generator that can generate electric power based on natural energy. The solar panel PN is a solar cell module in which, for example, a required number of solar cell elements (cells) are arranged and packaged with resin, tempered glass, or the like, and is also called a solar panel. In addition, what kind of cell may be sufficient as the cell used for solar panel PN. For example, as the cell used in the solar panel PN, various cells such as a silicon cell, a compound cell, and an organic cell may be appropriately selected depending on the purpose. Moreover, although this embodiment demonstrates using the solar panel PN as an example of an electric power generating apparatus, if the electric power can be produced | generated using natural energy, the electric power generating apparatus of this embodiment will be sunlight. It is not limited to panels. The power generation device may be a device that generates electric power using gas, wind power, hydraulic power, or the like, for example. In addition, when a device that generates power using gas, wind power, hydraulic power, or the like is used as a power generation device, power control is performed based on the timing of starting power generation using gas, wind power, hydraulic power, or the like. In the following description, a photovoltaic power generation device is also called a PV (Photovoltaic) device, and a power generation state using solar power generation is also called a PV state.

  The connection box BX is a device that collects power generated by the solar panel PN, for example. For example, the connection box BX aggregates a plurality of wires from the solar panel PN into one and transmits it to the power conditioner 100. The connection box BX may be integrated with the power conditioner 100.

  The power conditioner 100 is also called a power conditioner or a PCS (Power Conditioning System). The power conditioner 100 is a device that makes it possible to use the power transmitted from the solar panel PN via the connection box BX in the electrical device LD in the house HM. For example, the power conditioner 100 converts DC power transmitted from the solar panel PN via the connection box BX into AC power. In addition, for example, after converting into AC power, the power conditioner 100 adjusts the power to an output corresponding to use in the house HM, charging the storage battery 50, selling power to the commercial power supply CP, and the like. The power conditioner 100 of the present embodiment is a control device that controls discharging and charging of the storage battery 50 and causes the power storage device to self-discharge during a power failure.

  The controller 200 notifies the user of various types of information in the power storage system 1 and receives user operations on the power storage system 1. The controller 200 is a device capable of transmitting / receiving information to / from the power conditioner 100. The controller 200 has an output unit 210 that can output various types of information. The controller 200 also includes an input unit 220 that receives an instruction input from the user.

  The output unit 210 of the controller 200 may have a configuration and a function for displaying information by sound or image. For example, the output unit 210 may be a monitor that displays information or a speaker that outputs information as sound. The output unit 210 outputs various information received from the power conditioner 100, for example. For example, the output unit 210 displays information related to the remaining amount of the storage battery 50. Further, for example, the output unit 210 outputs an alert (described later) for notifying the user that the discharge from the storage battery 50 is stopped by voice or an image.

  The input unit 220 of the controller 200 receives an input corresponding to an alert or message output from the output unit 210. For example, the user can input an instruction for an alert or a message from the input unit 220. The input unit 220 is a device that can accept external input such as a keyboard, a touch panel, and a microphone. Note that the controller 200 may be integrated with the power conditioner 100.

  The storage battery 50 is a secondary battery (battery) used in the house HM. For example, the storage battery 50 is charged with electric power supplied from the power conditioner 100. For example, the storage battery 50 supplies the stored electric power to the electric device LD in the house HM via the power conditioner 100 and the distribution board DP. The storage battery 50 may be any battery as long as it can store electricity by charging and can be repeatedly charged and discharged. For example, as the storage battery 50, various storage batteries, such as a lithium ion battery, a lead battery, and a nickel metal hydride battery, may be appropriately selected. The storage battery 50 may have any configuration as long as it has a function of storing electric power, and may be, for example, an electric vehicle, a plug-in hybrid vehicle, or the like.

  The distribution board DP is a device that divides electricity into the wiring of the house HM. For example, the distribution board DP includes various devices such as an earth leakage breaker and a wiring breaker. For example, the distribution board DP supplies the electric power converted into alternating current by the power conditioner 100 to the electric device LD of the house HM, or supplies the surplus power generated in the solar panel PN to the commercial power supply CP of the electric power company. Or supply to. For example, the distribution board DP supplies the electric power supplied from the commercial power supply CP to the electrical equipment LD of the house HM when purchasing power, that is, when receiving power from the commercial power supply CP.

  The power meter MT is a meter that measures the power supplied to the commercial power supply CP side, that is, the power sold, or the power supplied from the commercial power supply CP, that is, the power purchased from the commercial power supply CP. For example, the power meter MT may include a meter that measures the sold power and a meter that measures the purchased power. For example, the power meter MT is provided between the distribution board DP and the commercial power supply CP, and measures the sold power or the purchased power.

[Example of configuration of power conditioner 100]
FIG. 2 is a diagram illustrating an example of a configuration of the power conditioner 100 included in the power storage system 1 according to the embodiment. FIG. 2 illustrates only the configuration related to the control of the remaining amount of power stored in the storage battery 50 among the configurations of the power conditioner 100 according to the embodiment, and the illustration of the configurations of the other power conditioners 100 is omitted. As shown in FIG. 2, the power conditioner 100 includes a communication unit 110, a storage unit 120, and a control unit 130.

  The communication unit 110 is realized by a predetermined communication circuit, for example. For example, the communication unit 110 can communicate with the controller 200.

  The storage unit 120 is realized by, for example, a semiconductor memory element such as a RAM (Random Access Memory) or a flash memory, or a storage device such as a hard disk or an optical disk. As illustrated in FIG. 2, the storage unit 120 according to the embodiment includes a power supply information storage unit 121, a power generation time storage unit 122, and a set capacity storage unit 123.

[Example of information stored in storage unit 120]
The power information storage unit 121 stores power information. The power supply information is information related to various power supply states. FIG. 3 is a diagram illustrating an example of a configuration of information stored in the storage unit 120 included in the power storage system 1 according to the embodiment. 3A shows an example of the configuration of power information stored in the power information storage unit 121. FIG. As shown in FIG. 3A, the power supply information includes “time stamp”, “CP state”, “PV state”, and “remaining power storage”. The “time stamp” indicates the time when each piece of information is detected. The “CP state” indicates a state of power supply from the commercial power source CP. The “CP state” indicates, for example, whether power is supplied from the commercial power source CP. That is, “CP state” indicates whether or not a power failure is occurring. The “PV state” indicates a power generation state of the solar panel PN. That is, the “PV state” indicates whether or not the solar panel PN is generating power. The “remaining power storage amount” indicates the remaining amount of electric power stored in the storage battery 50.

  In the example of FIG. 3A, the power source information storage unit 121 associates with “time stamp, 0:00:00”, for example, “CP state, OK”, “PV state, no power generation”, “power storage”. “Remaining amount, 7,000 Wh” is stored. This indicates that power is supplied from the commercial power supply CP to the house HM at the time indicated by the time stamp “0:00:00”. In addition, at the time indicated by the time stamp “0:00: 00”, it indicates that the power generation by the solar panel PN was not performed. Further, at the time indicated by the time stamp “0:00:00”, it indicates that the remaining amount of electricity stored in the storage battery 50 was 7000 watt hours. The power information storage unit 121 receives and stores information about various power sources at predetermined intervals.

  The power generation time storage unit 122 stores power generation time information that is time information related to power generation by the solar panel PN. (B), (C), and (D) of FIG. 3 show an example of the configuration of the power generation time information. As shown in FIG. 3B, the power generation time information includes information regarding the time when the solar panel PN actually generates power. In other words, the power generation time information includes the date when the solar panel PN generates power and the time zone during which power was generated. In the example of FIG. 3B, the power generation time storage unit 122 stores “date” and “power generation time” in association with each other. “Date” is the date when the solar panel PN generates power. “Power generation time” indicates from what time to what time on the corresponding date the solar panel PN generates power. For example, in the example of FIG. 3B, “power generation time 09: 14-15: 45” is stored in association with “date, 2016/8/1”. This indicates that on August 1, 2016, power generation by the solar panel PN was performed from 9:14 to 15:45.

  The power generation time information includes information related to past weather. For example, the power generation time information includes sunshine hours observed in the past, information on sunrise / sunset times, and information on past weather. Such information is acquired by the controller 200 (or the power conditioner 100) from an external communication network such as the Internet.

  As shown in FIG. 3C, the power generation time storage unit 122 stores “position information”, “average sunshine time”, “time”, and “sunrise / sunset” as power generation time information. “Position information” is information indicating the position of the place where the solar panel PN is installed. For example, the latitude and longitude of the corresponding position are stored. The location information may be stored when the power storage system is installed, or may be configured to be acquired by the power storage system 1 using a function such as GPS. “Average sunshine time” indicates the average sunshine time at the position. “Time” indicates which time of the year the corresponding “average sunshine duration” is the average sunshine duration of the year. “Sunrise / sunset” is an average of the sunrise time and sunset time of the corresponding “time”. In the example of FIG. 3C, “E139 ° 45′N35 ° 41 ′” is stored as “position information”. This indicates that the installation position of the solar panel PN is 139 degrees 45 minutes east longitude and 35 degrees 41 minutes north latitude. In addition, “average sunshine hours, 7h”, “time, January”, “sunrise / sunset, 07: 00-16: 50” are stored. This indicates that the average daylight time in January is 7 hours, and the sunrise time and sunset time in January are 7 o'clock and 16:50 respectively. In the example of FIG. 3C, the average sunshine hours and the sunrise / sunset times for each month are stored, but the sunshine hours of the day and the sunrise / sunset times may be stored. It is good also as what memorize | stores the average sunshine time and sunrise / sunset time for every season.

  The power generation time information includes prediction information. Prediction information is information about future weather predicted based on past observation information and past weather information. For example, as shown in FIG. 3D, the power generation time storage unit 122 stores “position information”, “expected sunshine time”, “date”, “expected time (sunrise / sunset)”, and “expected weather”. To do. The “position information” is the same as that shown in (C). The “expected sunshine time” is the expected sunshine time of the relevant day. “Date” is the date of the prediction target. “Expected time (sunrise / sunset)” is the expected sunrise and sunset times for the day. The “forecast weather” is the weather expected for the corresponding day. The prediction information shown in (D) of FIG. 3 is acquired by the controller 200 (or the power conditioner 100) from an external communication network such as the Internet.

  The set capacity storage unit 123 stores set capacity information used by the power conditioner 100 to control the remaining amount of power stored in the storage battery 50. FIG. 3E shows an example of the configuration of the set capacity information. As shown in (E) of FIG. 3, the set capacity storage unit 123 can maintain the standby state depending on the remaining amount of storage necessary for maintaining the storage battery 50 in the standby state in the event of a power failure, and the remaining amount of storage. Is stored. In the example of FIG. 3E, the set capacity storage unit 123 stores “time” and “required remaining amount” in association with each other. “Time” indicates the length of time that the storage battery 50 can be maintained in a standby state. “Necessary remaining amount” indicates the remaining amount of electricity necessary for maintaining the storage battery 50 in the standby state for the corresponding “time”. For example, in the example of FIG. 3E, “required remaining amount, 350 Wh” is stored in association with “time 10”. This indicates that a minimum remaining power of 350 Wh is necessary to maintain the storage battery 50 in the standby state for 10 hours.

  Here, the standby state will be described. FIG. 4 is a diagram for describing power control by the power storage system 1 according to the embodiment. The rectangle shown in the example of FIG. 4 indicates the storage capacity when the storage battery 50 is fully charged. As shown in FIG. 4, the operation of the storage battery 50 changes according to the remaining amount of electricity stored. The power storage system 1 of the present embodiment controls the remaining power storage so that the storage battery 50 is operated as long as possible in cooperation with the solar panel PN. For this reason, the mode of power supply from the storage battery 50 is switched in accordance with the remaining amount of stored electricity. The power storage system 1 of the embodiment switches the control of the storage battery 50 in the following modes (1) to (4).

(1) First, when there is a sufficient remaining amount of electricity, the electricity storage system 1 performs self-sustained discharge from the storage battery 50 and supplies power to the electrical equipment LD or the like.

(2) After that, when the remaining amount of power storage decreases, the power storage system 1 stops the self-sustaining discharge of the storage battery 50 and continues to detect whether or not the solar panel PN generates power and whether or not the commercial power supply CP is restored. That is, the power storage system 1 supplies power for maintaining the basic control function and the function for detecting whether or not the solar panel PN generates power and whether or not the commercial power supply CP is restored from the storage battery 50. The above “standby state” means this state.

(3) After that, when the remaining amount of power storage further decreases, it becomes difficult to operate the storage battery 50 with the power generated by the solar panel PN. At this time, the power storage system 1 stops the power supply from the storage battery 50 for detecting whether or not the solar panel PN generates power. And the electrical storage system 1 supplies only the electric power for maintaining the detection function of the return | restoration presence or absence of commercial power supply CP, and a basic control function from the storage battery 50. FIG. Even in this state, if the commercial power supply CP is restored, the storage battery 50 can automatically perform normal operation. Hereinafter, this state is also referred to as a power saving mode.

(4) When the remaining amount of power storage further decreases, the storage battery 50 is in a state where it cannot automatically return to normal operation even when it receives power supply from the commercial power source CP. If it will be in this state, the electrical storage system 1 will complete | finish control of the storage battery 50. FIG.

  In FIGS. 4A and 4B, a rectangle displayed as “(1) self-sustained discharge” corresponds to the remaining amount of power stored in (1) for continuing the self-sustained discharge from the storage battery 50. That is, an amount that is equal to or less than the first remaining threshold TH1 when the storage battery 50 is fully charged corresponds to the remaining remaining power. Further, the rectangle displayed as “(2) PV standby” indicates that the self-sustained discharge of the storage battery 50 in the above (2) is stopped, but the storage battery 50 for the detection function of whether or not the solar panel PN generates power and whether or not the commercial power supply CP returns. This corresponds to the remaining amount of electricity that continues to be supplied from the power source. That is, it is a remaining power amount that is less than the first threshold TH1 and greater than or equal to the second threshold TH2. In addition, the rectangle displayed as “(3) CP standby” indicates that power supply from the storage battery 50 to the function of detecting whether or not the commercial power supply CP is restored is executed while the self-sustaining discharge of the storage battery 50 is stopped in (3) above. This corresponds to the remaining amount of electricity to be stored. In other words, it is the remaining amount of electricity stored below the second threshold TH2 and above the third threshold TH3. Further, the rectangle displaying “(4) Stop” corresponds to the remaining amount of power stored in (4) above, which cannot be automatically restored to the normal operation when the remaining amount of power stored in the storage battery 50 is depleted. That is, the remaining amount of electricity stored is less than the third threshold TH3.

  In the example of FIG. 4A, the remaining amount of electricity for executing “(1) self-sustained discharge” is set to an amount that can supply power to the electric device LD in the house HM for about 12 hours. And the electrical storage remaining amount which performs "(2) PV standby" is set to the quantity which can maintain a standby state over about 1 hour. Furthermore, the remaining amount of electricity for executing “(3) CP standby” is set to an amount that can continue the power supply from the storage battery 50 for about one week. The remaining amount of power storage reaching the “(4) stop” state is determined by the performance of the storage battery 50 and the like.

  By the way, in the example of FIG. 4A, the “PV standby” state has only about 1 hour. Then, if a power failure occurs at night and power generation by the solar panel PN is not possible, if the remaining amount of storage is low, before the battery 50 can be charged by receiving power generation by the solar panel PN, ”And“ PV standby ”may consume power. Then, when power generation by the solar panel PN becomes possible in the morning, the remaining amount of power stored in the storage battery 50 may have already reached an amount corresponding to “CP standby” or “stop”. This makes it difficult to effectively use the storage battery 50 and the solar panel PN to realize power supply when a power outage is prolonged.

  Therefore, as shown in FIG. 4B, the power storage system 1 according to the embodiment lengthens the period in which the “PV standby” state is set. As shown in FIG. 4B, the power storage system 1 sets the remaining power storage amount corresponding to “PV standby” to an amount that can maintain the standby state for about 24 hours. By setting in this way, if the power generation start by the solar panel PN is within at least 24 hours from the start of the standby state, the power storage system 1 maintains the function of the storage battery 50 while maintaining the function of the solar panel PN. Can use the generated power.

  However, it is difficult to uniformly determine when the solar panel PN starts power generation depending on the situation. For example, the power generation start timing differs between winter and summer. Moreover, there is a difference in the daylight hours depending on the position where the solar panel PN is installed.

  Thus, in the present embodiment, the storage unit 120 stores in advance how much remaining power is necessary to maintain the standby state of the “battery standby” of the storage battery 50 for a desired time. This is the set capacity information shown in FIG. That is, the “time” and “required remaining amount” in FIG. 3E indicate how much remaining power is necessary to keep the storage battery 50 in the “PV standby” state for “time”. Indicates. The “required remaining amount” stored as the set capacity information corresponds to the first threshold TH1 shown in FIG. In the present embodiment, the set capacity information is calculated in advance based on the performance of the storage battery 50 and stored in the power conditioner 100.

[Configuration Example of Control Unit 130 of Power Conditioner 100]
Returning to FIG. 2, the control unit 130 of the power conditioner 100 will be described. The control unit 130 controls the operation and function of each unit of the power conditioner 100. The control unit 130 has an internal memory that stores a program that defines various processing procedures and the like, and controls various processes. For example, the control unit 130 may be an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a central processing unit (CPU), or a micro processing unit (MPU). In the example of FIG. 2, the control unit 130 includes a commercial power supply detection unit 131, a power generation detection unit 132, a remaining power storage detection unit 133, an information acquisition unit 134, a capacity control unit 135, a warning unit 136, and a clock unit 137.

  The commercial power source detection unit 131 detects the presence or absence of power supply from the commercial power source CP at predetermined time intervals. The commercial power supply detection unit 131 transmits the detection result to the power supply information storage unit 121 for storage.

  The power generation detection unit 132 detects the presence or absence of power generation by the solar panel PN at predetermined time intervals. The power generation detection unit 132 transmits the detection result to the power information storage unit 121 and stores it. The power generation detection unit 132 also stores the result of power generation in the power generation time storage unit 122 (see FIG. 3B).

  The remaining power storage detection unit 133 detects the remaining power storage of the storage battery 50 at predetermined time intervals. The remaining power storage detection unit 133 transmits the detection result to the power supply information storage unit 121 for storage.

  The information acquisition unit 134 acquires power generation time information from an external communication network via the controller 200 or the like. For example, the information acquisition unit 134 acquires information shown in (C) and (D) of FIG. The information acquisition unit 134 stores the acquired information in the power generation time storage unit 122.

  The capacity control unit 135 controls the remaining amount and operation of the storage battery 50 based on information stored in the storage unit 120. That is, the capacity control unit 135 is detected by the commercial power source detection unit 131, the power generation detection unit 132, and the remaining power storage detection unit 133, and is acquired by the information acquisition unit 134 and stored in the storage unit 120, and the set capacity. The storage battery 50 is controlled based on the set capacity information stored in the storage unit 123.

  The warning unit 136 issues a warning to the user under the control of the capacity control unit 135. The warning may be, for example, an audio output from the output unit 210, a screen display, or the like. For example, the warning unit 136 transmits a warning when the autonomous operation of the storage battery 50 is stopped. The output unit 210 executes output according to the received warning. Further, when a power failure is detected or the commercial power supply CP is restored, the warning unit 136 can output a warning by transmitting an instruction to the output unit 210.

  The timer 137 acquires the current time.

[Example of power control flow of power storage system 1]
FIG. 5 is a flowchart illustrating an example of a flow of power control by the power storage system 1 according to the embodiment. As shown in FIG. 5, in the power storage system 1, the capacity control unit 135 first refers to the power supply information storage unit 121 and determines whether or not the power supply from the commercial power supply CP is stopped (step S501). And when it determines with the electric power supply not having stopped (step S501, No), the capacity | capacitance control part 135 performs a normal driving | operation (step S508). In other words, the capacity control unit 135 supplies the electric device LD if the power is generated by the solar panel PN while using the commercial power source CP. Moreover, the capacity | capacitance control part 135 will be stored in the storage battery 50, if there is a surplus in the electric power generation amount by the solar panel PN.

  On the other hand, when it is determined that the power supply from the commercial power supply CP is stopped (Yes in step S501), the capacity control unit 135 has a remaining power storage amount less than the first threshold value TH1 (see FIG. 4B). Whether or not (step S502). If the capacity control unit 135 determines that the remaining power amount is not less than the first threshold TH1 (No in step S502), the capacity control unit 135 continues the self-sustained discharge from the storage battery 50 (step S504). Then, the capacity control unit 135 returns to step S502. On the other hand, when it determines with the electrical storage residual amount being less than 1st threshold value TH1 (step S502, Yes), the capacity | capacitance control part 135 stops the self-sustained discharge from the storage battery 50 (step S503). Thereafter, the capacity control unit 135 determines whether or not power generation from the solar panel PN is detected (step S505). If it is determined that power generation has not been detected (No at Step S505), the capacity control unit 135 repeats Step S503. On the other hand, when it determines with having detected electric power generation (step S505, Yes), the capacity | capacitance control part 135 charges the storage battery 50 with the surplus of the electric power generation by solar panel PN (step S506). Then, the capacity control unit 135 determines whether or not the commercial power supply CP has been restored (step S507). When it is determined that the commercial power supply CP has not been restored (No at Step S507), the capacity control unit 135 returns to Step S502 and repeats the process. On the other hand, if it is determined that the commercial power supply CP has been restored (step S507, Yes), the capacity control unit 135 proceeds to normal operation (step S508). This is an example of the flow of power control in the power storage system 1 according to the embodiment.

  FIG. 6 is a diagram conceptually showing the relationship between the flow of power control shown in FIG. 5 and the remaining amount of power stored in the storage battery 50. With reference to FIG. 6, the electrical storage residual amount of the storage battery 50 of embodiment and its control are further demonstrated.

  The power storage system 1 executes the power supply control process of the embodiment when the power supply from the commercial power supply CP is stopped (Yes in step S501 in FIG. 5). At the time of the power failure, if the storage battery 50 has a remaining amount of storage equal to or greater than the first threshold value TH1 (No in step S502 in FIG. 5), the capacity control unit 135 continues to discharge from the storage battery 50 to the electrical device LD. (Step (1) in FIG. 6, step S504 in FIG. 5). When the use of the storage battery 50 is continued, the remaining amount of storage gradually decreases and reaches the level of the first threshold value TH1 (Yes in step S502 in FIG. 5). At this time, the capacity control unit 135 stops power supply to the electric device LD using the storage battery 50 ((2) in FIG. 6). When the remaining amount of electricity stored in the storage battery 50 satisfies the relationship of the second threshold TH2 ≦ the remaining amount of storage <the first threshold TH1, the power supply from the storage battery 50 to the power conditioner 100, etc. The start of power generation can be detected, and the storage battery 50 can be charged from the solar panel PN. Therefore, while the state of the second threshold TH2 ≦ the remaining amount of power storage <the first threshold TH1 continues, the capacity control unit 135 monitors the presence / absence of power generation by the solar panel PN (step S505 in FIG. 5). When power generation is detected (step S505 in FIG. 5, Yes, (3) in FIG. 6), the power generated by the solar panel PN is supplied to the electric device LD, and the storage battery 50 is charged by the surplus ( Step S506 in FIG. 5, (4) in FIG. 6). As a result, when the remaining amount of electricity stored in the storage battery 50 is equal to or greater than the first threshold TH1 ((5) in FIG. 6), the capacity control unit 135 starts discharging from the storage battery 50 again ((7) in FIG. 6). . On the other hand, if the remaining amount of power storage is less than the first threshold value TH1 ((6) in FIG. 6), the capacity control unit 134 keeps discharging from the storage battery 50 stopped.

  The capacity control unit 135 switches to the power saving mode when the remaining amount of power stored in the storage battery 50 decreases and is less than the second threshold value TH2 ((8) in FIG. 6) without detecting the power generation by the solar panel PN. Transition. During the power saving mode, that is, while the remaining amount of electricity is greater than or equal to the third threshold TH3 and less than the second threshold TH2, the storage battery 50 returns to normal operation when the power supply from the commercial power source CP is resumed. However, when the remaining amount of power storage is less than the third threshold TH3, the storage battery 50 cannot automatically return to normal operation even when it receives power from the commercial power source CP. Therefore, when the remaining amount of electricity stored is less than the third threshold value TH3 ((9) in FIG. 6), the capacity control unit 135 stops the operation of the storage battery 50.

[Variable threshold setting]
FIG. 7 is a flowchart illustrating an example of the flow of the capacity control process of the power storage system 1 according to the embodiment. The capacity control process in FIG. 7 corresponds to the processes in steps S502, S503, and S504 in FIG. The capacity control process is a process for determining a first threshold value used when determining whether or not to continue the self-sustained discharge of the storage battery 50. The power storage system 1 of the present embodiment variably sets the first threshold value TH1 based on a plurality of factors.

  First, the capacity control unit 135 acquires the current time from the time measuring unit 137 (step S701). Next, the capacity control unit 135 refers to the power generation time storage unit 122 to acquire the power generation start scheduled time (step S702). Processing for acquiring the scheduled power generation start time will be described later. The capacity control unit 135 calculates the difference between the acquired scheduled power generation start time and the current time (step S703). Then, the capacity control unit 135 refers to the set capacity storage unit 123 and acquires the capacity stored in association with the calculated difference (step S704). The acquired capacity corresponds to the first threshold value TH1. Then, the capacity control unit 135 compares the current remaining power amount with the acquired capacity (first threshold value TH1) (step S705). As a result, when it is determined that the current remaining power storage is greater than or equal to the first threshold value TH1 (No at Step S705), the capacity control unit 135 continues the self-sustaining discharge of the storage battery 50 (Step S707). On the other hand, when it determines with the present electrical storage residual amount being less than 1st threshold value TH1 (step S705, Yes), the capacity | capacitance control part 135 stops the independent discharge of the storage battery 50 (step S706). This ends the capacity control process.

[Example of obtaining the scheduled power generation start time]
Next, a method for acquiring the scheduled power generation start time in step S702 of FIG. 7 will be described. There are several possible variations in the method for obtaining the scheduled power generation start time. First, when the power storage system 1 is installed, a scheduled power generation start time may be set and stored in the storage unit 120. Further, every time the capacity control process is performed, the scheduled power generation start time may be calculated.

The capacity control unit 135 calculates the scheduled power generation start time by the following method.
(1) The expected power generation time is calculated based on the actual power generation time of the solar panel PN over the most recent predetermined period (see FIG. 3B).
(2) An expected power generation time is calculated based on the same sunrise time observed in the past. You may average the sunrise time over the past predetermined period (refer (C) of FIG. 3).
(3) Based on the weather information acquired from the external network, an expected power generation time is calculated (see (D) in FIG. 3).

  By the way, the solar panel PN does not generate power immediately after the sun begins to shine, but it is considered that it takes some time until the power generation actually starts after the sun starts to shine. Therefore, the capacity control unit 135 calculates the “power generation scheduled start time” in step S702 by adding, for example, one hour to the time calculated based on the information stored in the storage unit 120.

[Effect of the embodiment]
As described above, the power storage system of the embodiment includes the power storage device (storage battery 50) and the control device (power conditioner 100). The power storage device stores the power generated by the power generation device (solar panel PN) based on natural energy. The control device controls the discharging and charging of the power storage device and causes the power storage device to self-discharge during a power failure. The control device includes a detection unit (remaining power storage amount detection unit 133) and a control unit (capacity control unit 135). The detection unit detects the remaining amount of power stored in the power storage device. The control unit dynamically sets a threshold value related to the remaining amount of electricity stored in the power storage device based on the operation mode of the power generation device, and stops self-sustained discharge of the power storage device when the detected remaining power storage amount is less than the threshold during a power failure To enter standby mode. For this reason, the power storage system can dynamically set the remaining amount of power stored in the power storage device according to the operation mode of the power generation device, and can control the self-sustained discharge of the power storage device. For this reason, the power storage system according to the embodiment can effectively utilize the power storage device and the power generation device during a power failure.

  In addition, the control unit included in the power storage system of the embodiment dynamically sets the threshold according to the time when the control unit stops self-sustained discharge of the power storage device and the power generation start time by the power generation device. For this reason, for example, if a power failure occurs at night, the power storage system can store the remaining power remaining in the power storage device so that the power storage device can operate normally until the time when power generation by the power generation device is expected to start the next day. Can be determined.

  In addition, the control unit included in the power storage system of the embodiment determines the power generation start time by the power generation device according to at least one of the date and time when the self-sustained discharge is stopped, the past power generation history by the power generation device, and weather information. By doing so, the threshold value is dynamically set. For this reason, the power storage system can determine the remaining amount of power remaining in the power storage device depending on the case, for example, when stopping self-sustained discharge at night or when stopping self-sustained discharge during the day. In addition, the power storage system can determine the remaining amount of power stored in the power storage device according to the past power generation history, and therefore can determine the remaining power storage according to the actual performance of the power generation device. In addition, since the power storage system can determine the remaining amount of power stored in the power storage device according to weather information, the normal operation of the power storage device can be maintained with a high degree of certainty.

[Modification 1—Adjustment of Charging to Storage Battery 50]
The power storage system 1 may be set with a time zone (cooperation time zone) in which the storage battery 50 is charged with power generated by the solar panel PN in advance during normal operation. In this case, the power storage system 1 is set so that the storage battery 50 can be charged even in a time zone other than the cooperation time zone during a power failure. Moreover, the electrical storage system 1 may request | require that the electric power generation amount by the solar panel PN exceeds a predetermined value as conditions in the case of performing charge to the storage battery 50 at the time of normal operation. In this case, at the time of a power failure, the power storage system 1 is set so that charging from the solar panel PN to the storage battery 50 can be performed even if the power generation amount is equal to or less than a predetermined value set as a condition during normal operation. Moreover, the power generation capacity of the solar panel PN is set in the power storage system 1 in advance, and based on the power generation capacity, a predetermined value as a charging condition during normal operation and a predetermined value as a charging condition during a power failure are set. It may be set. In this case, the predetermined value as the charging condition during a power failure is set lower than the predetermined value as the charging condition during normal operation.

  The control unit (capacity control unit 135) included in the power storage system of the embodiment charges the power storage device (storage battery 50) when the power generation amount of the power generation device (solar panel PN) is equal to or greater than a predetermined threshold. Run. Then, the control unit (capacity control unit 135) performs charging from the power generation device to the power storage device based on a threshold value lower than the threshold value when the power failure does not occur while the self-sustaining discharge of the power storage device during a power failure is stopped. . For this reason, even when the amount of power generated by the power generation device is not large, the power storage device can be charged. For this reason, the power storage system can use power by effectively linking the power generation device and the power storage device during a power failure.

  In addition, the control unit included in the power storage system of the embodiment sets a predetermined threshold according to the power generation capacity of the power generation device, and performs charging of the power storage device when the power generation amount of the power generation device is equal to or greater than the set threshold value. May be. For this reason, the power storage system can perform charging during normal times and power outages, taking into account the power generation capacity of the power generation device. Can be prevented.

[Modification 2-Application other than solar power generation]
In the said embodiment, the case where the electric power generating apparatus which produces electric power using sunlight was demonstrated. Not limited to this, for example, even in the case of a power storage system that generates power using other natural energy such as gas, wind power, and hydropower, the timing of future power generation is based on the past power generation status as in the above embodiment. Power supply control can be executed.

  As described above, according to the embodiment, the power storage device and the power generation device can be effectively used during a power failure.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Power storage system 50 Storage battery 100 Power conditioner 110 Communication part 120 Storage part 121 Power supply information storage part 122 Power generation time storage part 123 Set capacity storage part 130 Control part 131 Commercial power supply detection part 132 Power generation detection part 133 Power storage residual quantity detection part 134 Information Acquisition unit 135 Capacity control unit 136 Warning unit 137 Timekeeping unit 200 Controller 210 Output unit 220 Input unit BX Junction box CP Commercial power supply DP Distribution board HM Housing LD Electrical equipment (load)
MT Power meter PN Solar panel

Claims (5)

A power storage device for storing electric power generated by the power generation device based on natural energy;
A control device for controlling the discharging and charging of the power storage device, and for self-discharging the power storage device in the event of a power failure;
A power storage system comprising:
The controller is
A detection unit for detecting a remaining amount of electricity stored in the electricity storage device;
Based on the operation mode of the power generation device, a threshold related to the remaining amount of power stored in the power storage device is dynamically set, and when the detected remaining power storage is less than the threshold during a power failure, the self-sustained discharge of the power storage device is stopped And a control unit to enter a standby state;
A power storage system comprising:   The power storage system according to claim 1, wherein the control unit dynamically sets the threshold according to a time when the control unit stops self-sustained discharge of the power storage device and a power generation start time by the power generation device.   The control unit determines the power generation start time by the power generation device according to at least one of the date and time when the self-sustained discharge is stopped, the past power generation history by the power generation device, and weather information. The power storage system according to claim 2, which is set dynamically.   The control unit executes the charging of the power storage device when the power generation amount of the power generation device is equal to or greater than a predetermined threshold, and when the self-sustaining discharge of the power storage device during a power outage is stopped, the power outage is not The power storage system according to any one of claims 1 to 3, wherein charging from the power generation device to the power storage device is performed based on a threshold value lower than the threshold value.   The control unit sets the predetermined threshold according to the power generation capacity of the power generation device, and executes charging of the power storage device when the power generation amount of the power generation device is equal to or greater than the set threshold. The electricity storage system described.

Images