JPWO2019235220A1 - Power storage system for self-sustaining operation, power storage unit and control method - Google Patents

Abstract

Each power storage unit includes a plurality of power storage units and a control unit, and each power storage unit has a storage battery, an input terminal, an output terminal, and a switch for opening or short-circuiting the input terminal and the output terminal, and receives an instruction from the control unit. Therefore, the charging / discharging of the switch and the storage battery is controlled, and the plurality of power storage units are connected to the input terminal of each power storage unit and the output terminal of one of the plurality of power storage units, which is different from each power storage unit. The input terminal that is connected in series and is not connected to any output terminal is connected to the independent output terminal of the power generation device that operates independently in the event of a power failure and outputs the generated power, and is connected to any input terminal. The output terminals that are not connected are connected to a specific load to which power should be supplied in the event of a power failure, and the control unit generates an instruction to each power storage unit in the event of a power failure.

Description

The present disclosure relates to a power storage system for independent operation, a power storage unit, and a control method. This application claims priority based on Japanese Application No. 2018-108309 filed on June 6, 2018, and incorporates all the contents described in the Japanese application.

There is known a power storage system that is connected to a power system and can supply power once stored in a storage battery to a load via a power conversion device in the event of a power failure or the like. A power storage system that is also connected to a photovoltaic power generation system and stores generated power (surplus power) that exceeds the power supplied to the load is also known. In such a power storage system, it may be necessary to store a large amount of electric power for some reason after installing a power storage system having a predetermined capacity. Patent Document 1 described later discloses a technique for easily increasing the capacity of a backup power supply system after installation in an existing photovoltaic power generation system.

In order to increase the storage capacity of the existing power storage system, an expansion unit consisting only of storage batteries is added. With reference to FIG. 1, the power conditioner of the power storage unit 900 (hereinafter referred to as PCS (Power Conditioning System)) is connected to the specific outlet 906. When a power failure occurs in the power system, the PCS of the power storage unit 900 converts the power stored in the power storage unit 900 and the expansion unit 902 from direct current to alternating current according to the setting by the remote controller 904, and supplies the power to the specific outlet 906. .. As a result, power is supplied to the device connected to the specific outlet 906 even during a power failure. By connecting the storage battery of the expansion unit 902 in parallel to the storage battery of the power storage unit 900, the storage capacity is increased. Therefore, a request for a relatively small capacity can be met by the power storage unit 900 alone, and if the required capacity is larger, it can be met by adding an expansion unit 902.

Japanese Unexamined Patent Publication No. 2017-288884

The power storage system for self-sustaining operation according to a certain aspect of the present disclosure includes a plurality of power storage units and a control unit, and each power storage unit of the plurality of power storage units includes a storage battery, a power input terminal, and a power output terminal. It has a switch that opens or short-circuits the input terminal and the output terminal, controls the charge and discharge of the switch and the storage battery according to an instruction from the control unit, and the plurality of power storage units are each power storage unit of the plurality of power storage units. By connecting the input terminal of the above and the output terminal of one of the plurality of power storage units, which is a power storage unit separate from each power storage unit, the plurality of power storage units as a whole are connected in series. In a plurality of power storage units connected in series, the input terminal that is not connected to the output terminal of any of the power storage units is a power generation device that operates independently in the event of a power system power failure and outputs the generated power from the self-sustaining output terminal. In a plurality of power storage units connected in series to the self-sustaining output terminals of the above, the output terminals not connected to the input terminals of any of the power storage units are connected to a specific load to which power should be supplied in the event of a power failure and are controlled. The unit generates an instruction for each power storage unit of a plurality of power storage units in response to the power system being in a power failure state.

The power storage unit according to another aspect of the present disclosure is a power storage unit that includes a storage battery and controls charging / discharging of the storage battery according to an instruction from a control unit common to another power storage unit, and has a power input terminal and power. The power storage unit is connected in series with another power storage unit via at least one of the input terminal and the output terminal, and the switch controls the power storage unit. The unit opens or short-circuits the input terminal and the output terminal according to the instruction output in response to the power system being in a power failure state.

The control method according to still another aspect of the present disclosure includes a plurality of power storage units, and each power storage unit of the plurality of power storage units includes a storage battery, a power input terminal, a power output terminal, the input terminal, and the said power storage unit. It has a switch that opens or short-circuits the output terminal, and the plurality of power storage units are the input terminal of each power storage unit of the plurality of power storage units and a power storage unit separate from each power storage unit. By connecting to the output terminal of one of the power storage units, the plurality of power storage units as a whole are connected in series, and in the plurality of power storage units connected in series, they are connected to the output terminals of any of the power storage units. The input terminal that is not connected is connected to the self-sustaining output terminal of the power generation device that operates independently in the event of a power failure of the power system and outputs the generated power from the self-sustaining output terminal. The output terminal, which is not connected to the input terminal, is a control method for a system connected to a specific load to which power should be supplied in the event of a power failure, and is a determination step for determining whether or not the power system has been in a power failure state. In response to the determination that a power failure state has occurred by the determination step, a plurality of power storage units are supplied according to the amount of power supplied from the self-sustaining output terminal and the storage capacity of each storage battery of the plurality of storage units. Each switch of the power storage unit and a control step for controlling charging / discharging of the storage battery are included.

FIG. 1 is a block diagram showing a configuration of a conventional power storage system for independent operation. FIG. 2 is a block diagram showing a configuration of a power storage system for independent operation in which a plurality of power storage units of the same product are provided in parallel. FIG. 3 is a block diagram showing a configuration of a power storage system for independent operation according to the embodiment of the present disclosure. FIG. 4 is a flowchart showing the operation of the remote controller of FIG. FIG. 5 is a flowchart showing the operation of the power storage unit of FIG. FIG. 6 is a flowchart showing the operation of the expansion unit of FIG. FIG. 7 is a flowchart showing the operation of the power generation device of FIG. FIG. 8 is a block diagram showing a state of the power storage unit and the expansion unit of FIG. 3 at the time of a power failure. FIG. 9 is a block diagram showing a state different from that of FIG. 8 when the power storage unit and the expansion unit of FIG. 3 have a power failure. FIG. 10 is a block diagram showing a state different from that of FIGS. 8 and 9 when the power storage unit and the expansion unit of FIG. 3 have a power failure. FIG. 11 is a block diagram showing a state different from that of FIGS. 8 to 10 when the power storage unit and the expansion unit of FIG. 3 have a power failure. FIG. 12 is a block diagram showing a state different from that of FIGS. 8 to 11 when the power storage unit and the expansion unit of FIG. 3 have a power failure. FIG. 13 is a flowchart showing the operation of the remote controller in the second modification. FIG. 14 is a block diagram showing a configuration of a power storage system for independent operation according to a third modification.

[Issues to be solved by this disclosure]
In the configuration of FIG. 1, since the expansion unit 902 has a different configuration from the power storage unit 900, it is necessary to manage the power storage unit 900 and the expansion unit 902 with different product numbers. Further, it is also necessary to adjust the number of manufactured power storage units 900 and the number of manufactured expansion units 902, which is complicated.

Therefore, the present disclosure provides a power storage system for self-sustaining operation, a power storage unit, and a control method thereof, which are provided with a plurality of power storage units and can efficiently supply power to a specific load when a power failure occurs in the power system. The purpose is.

[Effect of the present disclosure]
According to the present disclosure, in a power storage system for self-sustaining operation including a plurality of power storage units, power can be efficiently supplied to a specific load when a power failure occurs in the power system.

[Explanation of Embodiments of the present disclosure]
First, the contents of the embodiments of the present disclosure will be listed and described. At least a part of the embodiments described below may be arbitrarily combined.

(1) The power storage system for self-sustaining operation according to a certain aspect of the present disclosure includes a plurality of power storage units and a control unit, and each power storage unit of the plurality of power storage units includes a storage battery, a power input terminal, and power. It has an output terminal and a switch that opens or short-circuits the input terminal and the output terminal, and controls the charge and discharge of the switch and the storage battery according to an instruction from the control unit. By connecting the input terminal of each power storage unit and the output terminal of one power storage unit among the plurality of power storage units, which is a power storage unit separate from each power storage unit, the plurality of power storage units as a whole are in series. In a plurality of power storage units that are connected and connected in series, the input terminal that is not connected to the output terminal of any of the power storage units operates independently in the event of a power system power failure and outputs the generated power from the self-sustaining output terminal. In a plurality of power storage units connected in series to the self-sustaining output terminal of the power generation device, the output terminal not connected to the input terminal of any of the power storage units is connected to a specific load to which power should be supplied in the event of a power failure. Then, the control unit generates an instruction for each power storage unit of the plurality of power storage units in response to the power system being in a power failure state.

In order to solve the above-mentioned problems of the prior art, it is conceivable to add an expansion unit 912 of the same product as the power storage unit 910 as shown in FIG. The power storage unit 910 and the expansion unit 912 are connected in parallel to the self-sustaining output terminal of the power generation device 920. That is, the power storage unit 910 is connected to the first self-supporting output terminal 926 and is configured to be able to supply electric power to the first specific load 922 in the event of a power failure. The expansion unit 912 is connected to the second self-supporting output terminal 928 and is configured to be able to supply electric power to the second specific load 924 in the event of a power failure. Although the actual distribution line is a plurality of lines (2-phase or 3-phase), it is shown by one line in FIG.

When a power failure occurs, the remote controller 914 controls the PCS of the power storage unit 910 so that the generated power is supplied to the first specific load 922 if the power generation device 920 is generating power. When the power supplied from the first self-supporting output terminal 926 exceeds the power consumption of the first specific load 922 (when there is surplus power), the remote controller 914 charges the storage battery inside the power storage unit 910 with the surplus power. , Controls the PCS of the power storage unit 910. When the power supplied from the first self-sustaining output terminal 926 is smaller than the power consumption of the first specific load 922, the remote controller 914 of the power storage unit 910 supplies the insufficient power from the storage battery inside the power storage unit 910. Control PCS. If the power generation device 920 is not generating power, the remote controller 914 controls the PCS of the power storage unit 910 so as to supply power from the storage battery inside the power storage unit 910 to the first specific load 922.

The remote controller 916 operates in the same manner as the remote controller 914. That is, when a power failure occurs, the remote controller 916 controls the PCS of the expansion unit 912 so that the generated power is supplied to the second specific load 924 if the power generation device 920 is generating power. When the power supplied from the second self-supporting output terminal 928 exceeds the power consumption of the second specific load 924, the remote controller 916 sets the PCS of the expansion unit 912 so as to charge the storage battery inside the expansion unit 912 with the surplus power. Control. When the power supplied from the second self-supporting output terminal 928 is smaller than the power consumption of the second specific load 924, the remote controller 916 supplies the insufficient power from the storage battery inside the expansion unit 912, so that the expansion unit 912 supplies the insufficient power. Control PCS. If the power generation device 920 is not generating power, the remote controller 916 controls the PCS of the expansion unit 912 so as to supply electric power from the storage battery inside the expansion unit 912 to the second specific load 924.

However, in the configuration of FIG. 2, two independent outputs of the power generation device are required, and a total of two remote controllers are required to control each of the power storage unit 910 and the expansion unit 912, which is a redundant system. In addition, it is complicated because it is necessary to operate each of the two remote controllers when an abnormality occurs. On the other hand, in the power storage system for self-sustaining operation according to a certain aspect of the present disclosure described above, in addition to being able to solve the problems of the prior art, in the event of a power failure in the power system, a plurality of power storage units and power generation devices Power can be efficiently supplied to a specific load from either of them. Further, since a plurality of power storage units are connected in series, power can be supplied to a specific load for a longer time than when they are connected in parallel.

(2) Preferably, the control unit generates an instruction for each power storage unit of the plurality of power storage units according to the output power of the self-supporting output terminal. Thereby, the power source to be supplied to the specific load can be appropriately determined from the plurality of power storage units and the power generation device.

(3) More preferably, the sensor further includes a sensor that detects the current supplied to the specific load, and the control unit responds to the power consumption of the specific load obtained from the detected value of the sensor and the output power of the self-supporting output terminal. Generates an instruction for each power storage unit of a plurality of power storage units. Thereby, the power source to be supplied to the specific load can be more appropriately determined from the plurality of power storage units and the power generation device.

(4) More preferably, the control unit generates an instruction to the storage unit according to the amount of electricity stored in the storage battery of the power storage unit. As a result, the power source to be supplied to a specific load can be appropriately determined from a plurality of power storage units and power generation devices, and if the power storage amount becomes zero while power is being supplied from the storage battery of one power storage unit, Power can be supplied from the storage battery of another power storage unit.

(5) Preferably, the control unit is included in any one of the plurality of power storage units, and the control unit is wired or wirelessly connected to each of the plurality of power storage units excluding the power storage unit including the control unit. The control unit includes a communication unit that communicates with each other, and the control unit transmits an instruction to each of the plurality of power storage units excluding the power storage unit including the control unit via the communication unit.

(6) More preferably, the control unit charges and discharges the storage battery of the power storage unit connected to the specific load first among the plurality of power storage units connected in series. Generate instructions for.

(7) More preferably, the control unit charges and discharges the storage batteries of the power storage units connected at a position closer to the specific load in the plurality of power storage units connected in series. Generate instructions for each power storage unit.

(8) Preferably, the control unit turns off the switch of the power storage unit that supplies power to the specific load in response to the amount of power supplied from the self-supporting output terminal becoming less than a predetermined value. An instruction is generated for each power storage unit of a plurality of power storage units so as to stop the power supply from the self-sustaining output terminal to the storage battery and turn on the switch of the power storage unit located on the specific load side of the power storage unit.

(9) More preferably, the power storage unit transmits the amount of electricity stored in the storage battery of the power storage unit to the control unit in response to a request transmitted from the control unit in response to a power failure in the power system.

(10) More preferably, the power storage system for self-sustaining operation further includes a remote controller, and the control unit is included in the remote controller.

(11) Preferably, the power storage system for self-sustaining operation is a sensor that detects the power supplied from the power system, and a determination unit that determines whether or not the power system is in a power failure state according to the detection value of the sensor. And further include.

(12) More preferably, the control unit includes a receiving unit that receives a signal indicating that the power system has been in a power failure state from an external device.

(13) More preferably, the power storage system for self-sustaining operation further has a switching unit that disconnects a specific load from the power system and connects to a plurality of power storage units connected in series in response to a power failure in the power system. Including.

(14) The power storage unit according to another aspect of the present disclosure is a power storage unit that includes a storage battery and controls charging / discharging of the storage battery according to an instruction from a control unit common to another power storage unit, and is a power input terminal. And a switch that opens or short-circuits the input terminal and the output terminal, and the power storage unit is connected in series with another power storage unit via at least one of the input terminal and the output terminal, and is connected in series. In the connected power storage unit and another power storage unit, the input terminal that is not connected to the output terminal of any of the power storage units is a power generation device that operates independently in the event of a power system power failure and outputs the generated power from the self-sustaining output terminal. The switch is connected to the self-supporting output terminal of, and the switch opens or short-circuits the input terminal and the output terminal according to the instruction output by the control unit in response to the output power of the self-supporting output terminal of the power generation device being lost. To do.

(15) Preferably, the storage battery is connected to an electric circuit that short-circuits the input terminal and the output terminal when the switch is turned on, one end of the switch is connected to the storage battery, and the other end of the switch is connected to the input terminal. Has been done.

(16) The control method according to still another aspect of the present disclosure includes a plurality of power storage units, and each power storage unit of the plurality of power storage units includes a storage battery, a power input terminal, a power output terminal, and the input. It has a terminal and a switch that opens or short-circuits the output terminal, and the plurality of power storage units are an input terminal of each power storage unit of the plurality of power storage units and a plurality of power storage units separate from each power storage unit. By connecting to the output terminal of one of the power storage units, the plurality of power storage units as a whole are connected in series, and in the plurality of power storage units connected in series, to the output terminal of any power storage unit. The input terminal that is not connected is connected to the self-sustaining output terminal of the power generation device that operates independently in the event of a power failure of the power system and outputs the generated power from the self-sustaining output terminal. The output terminal, which is not connected to the input terminal of the power storage unit, is a control method for the system connected to a specific load to which power should be supplied in the event of a power failure, and determines whether or not the power system has been in a power failure state. In response to the determination step to be performed and the determination that a power failure state has occurred by the determination step, the amount of power supplied from the self-sustaining output terminal and the amount of electricity stored in each storage battery of the plurality of storage units are increased. , Each switch of the plurality of power storage units and a control step for controlling the charging / discharging of the storage battery.

(17) Preferably, the control step includes a step of first charging / discharging the storage battery of the power storage unit connected to the specific load among the plurality of power storage units.

(18) More preferably, the self-sustaining output determination step of determining whether or not the power is output from the self-sustaining output terminal is further included, and the control step is such that the power is output from the self-sustaining output terminal by the self-sustaining output determination step. In response to the determination, while controlling each switch of the plurality of power storage units so that the power output from the self-sustaining output terminal is supplied to the specific load, the surplus power of the power generation device is used to store the power. Including the step of charging each storage battery of the unit, the charging ratio of each storage battery of the plurality of power storage units is controlled so that the state of each storage battery of the plurality of power storage units becomes equal.

(19) More preferably, the control step is connected to the self-supporting output terminal among the plurality of power storage units in response to the determination that the power is not output from the self-supporting output terminal by the self-supporting output determination step. The first switch, which is a switch of the power storage unit, is opened, and power is supplied to a specific load from the storage battery of the power storage unit connected in series at a position closer to the power generation device among the plurality of power storage units. It includes a first step of controlling each switch of a plurality of power storage units other than the first switch.

(20) More preferably, the control step further includes, after the first step, a storage amount determination step of determining whether or not the storage amount of the storage battery of the storage unit that has output power to a specific load has become zero. In the control step, the second switch, which is a switch of the power storage unit, receives the determination that the power storage amount of the storage battery of the power storage unit that has output power to a specific load has become zero by the power storage amount determination step. A plurality of switches other than the first switch and the second switch so that power is supplied to the specific load from the storage battery of the power storage unit connected in series at a position closer to the specific load than the power storage unit. A second step of controlling each switch of the power storage unit is further included.

[Details of Embodiments of the present disclosure]
In the following embodiments, the same parts are given the same reference number. Their names and functions are also the same. Therefore, detailed explanations about them will not be repeated.

(Embodiment)
[overall structure]
With reference to FIG. 3, the self-sustaining operation power storage system 100 according to the embodiment of the present disclosure includes a power storage unit 102, an expansion unit 104, a remote controller 106, a switching unit 108, a first sensor 110, and a second sensor. Includes 132 and. The power storage unit 102 is connected to the self-sustaining output terminal 122 of the power generation device 120. The expansion unit 104 is connected in series with the power storage unit 102. The remote controller 106 includes a communication unit 107. The remote controller 106 communicates with the power storage unit 102 and the extension unit 104 via the communication unit 107 by wire or wirelessly. The switching unit 108 is connected to the expansion unit 104. The first sensor 110 measures the power supplied to the specific load 124. The second sensor 132 detects the power supply from the power system 130. The specific load 124 is supplied with power not only when a power failure has not occurred in the power system 130 (hereinafter, also referred to as a normal time) but also when a power failure has occurred (hereinafter, also referred to as a power failure). Power load. The general load 134 is a load to which electric power is normally supplied but not supplied during a power failure. Although the actual distribution line is a plurality of lines (2-phase or 3-phase), it is shown by one line in FIG.

The power generation device 120 is connected to a distribution line for supplying electric power from the electric power system 130 to the general load 134, and can normally supply the generated electric power to the general load 134. In the event of a power failure in the power system 130, the power generation device 120 opens the connection to the distribution line for supplying power to the second sensor 132, starts self-sustaining operation, and supplies power from the self-sustaining output terminal 122. The second sensor 132 is, for example, a voltage sensor that detects the voltage supplied from the power system 130, and the power generation device 120 can determine the presence or absence of a power failure based on the detection value of the second sensor 132. When the self-sustaining operation is started, the power generation device 120 transmits information representing the amount of electric power supplied from the self-sustaining output terminal 122 (hereinafter, also referred to as self-sustaining output information) to the remote controller 106. Here, the power generation device 120 is a photovoltaic power generation system including a solar panel and a PCS. The PCS of the power generation device 120 includes a control unit (CPU, microcomputer, etc.), a storage unit (for example, a rewritable non-volatile memory), and a communication unit, and communicates with the communication unit of the remote controller 106.

The power storage unit 102 and the expansion unit 104 each include a PCS and a storage battery (lithium ion secondary battery or the like). Each of the power storage unit 102 and the expansion unit 104 converts the electric power (alternating current) supplied from the outside from alternating current to direct current via the PCS and stores it in the internal storage battery. Each PCS of the power storage unit 102 and the expansion unit 104 includes a control unit (CPU, microcomputer, etc.), a storage unit (for example, a rewritable non-volatile memory), and a communication unit. Each PCS communicates with the communication unit 107 of the remote controller 106 via the communication unit of its own unit, and receives instructions such as start / stop. Each PCS executes a charge / discharge operation in response to an instruction from the remote controller 106. Here, it is assumed that the power storage unit 102 and the expansion unit 104 have the same configuration and the capacity of the storage battery is also the same. That is, the power storage unit 102 and the expansion unit 104 are provided on the market as the same product.

Further, the power storage unit 102 and the expansion unit 104 are provided with a first bypass switch 112 and a second bypass switch 114, respectively. One end (input end of the power storage unit 102) of the first bypass switch 112 of the power storage unit 102 is connected to the self-supporting output terminal 122, and the other end (output end of the power storage unit 102) is connected to the PCS. That is, the first bypass switch 112 is arranged closer to the input terminal side of the power storage unit 102 than the PCS and the storage battery. One end (the input end of the expansion unit 104) of the second bypass switch 114 of the expansion unit 104 is connected to the output end of the power storage unit 102, and the other end (the output end of the expansion unit 104) is connected to the PCS. That is, the second bypass switch 114 is arranged closer to the input terminal side of the expansion unit 104 than the PCS and the storage battery.

In the switching unit 108, one input end 140 is connected to the output end of the expansion unit 104, the other input end 142 is connected to a distribution line for supplying power from the power system 130, and the output end 144 is specified. It is connected to load 124. The switching unit 108 is controlled by the remote controller 106, and normally connects the other input terminal 142 and the output terminal 144, and connects one input terminal 140 and the output terminal 144 during a power failure of the power system 130. As a result, the power supply source to be supplied to the specific load 124 is changed between the normal time and the power failure of the power system 130.

The remote controller 106 includes a control unit (CPU, microcomputer, etc.), a storage unit (for example, a rewritable non-volatile memory), and a communication unit. The remote controller 106 communicates with the power storage unit 102 and the expansion unit 104, and appropriately stores the received information in the storage unit. The remote controller 106 can obtain the amount of electric power supplied to the specific load 124 by receiving the detected value of the first sensor 110. The first sensor 110 is, for example, a current sensor, which detects a current (alternating current) flowing through a distribution line at an installed position and outputs corresponding information (current value, etc.). Further, the remote controller 106 can determine whether or not a power failure has occurred in the power system 130 by receiving the detected value of the second sensor 132. When the remote controller 106 detects that a power failure has occurred, it controls the switching unit 108 to switch the connection as described above, and according to the self-sustaining output information acquired from the power generation device 120, the power storage unit 102 and the expansion unit 104. Control each PCS.

[Control operation]
Hereinafter, the operations performed by the remote controller 106, the power storage unit 102, the expansion unit 104, and the power generation device 120 during a power failure of the power system 130 will be specifically described with reference to FIGS. 4 to 7. Here, it is assumed that in the power storage unit 102 and the expansion unit 104, the first bypass switch 112 and the second bypass switch 114 are opened (off), respectively, and the respective PCSs are stopped in the normal state (initial state). .. In the state where the PCS is stopped, the PCS has stopped the charge / discharge control operation, but is in a state where it can communicate with the remote controller 106.

The flowchart of FIG. 4 is executed by the remote controller 106. Specifically, the control unit of the remote controller 106 reads a predetermined program from the storage unit inside the remote controller 106 and executes it.

In step 200, the remote controller 106 measures the power consumption of the specific load 124. Specifically, the remote controller 106 obtains the electric power supplied to the specific load 124 from the information (current value) input from the first sensor 110 and stores it in the internal storage unit. As will be described later, step 200 is repeated, so that the latest power value may be stored. The control then shifts to step 202.

In step 202, the remote controller 106 determines whether or not a power failure has occurred in the power system 130. Specifically, the remote controller 106 determines whether or not there is a power failure based on the information (voltage value) from the second sensor 132. For example, if the voltage is equal to or less than a predetermined value (a value close to zero), it can be determined that a power failure has occurred. If it is determined that a power failure has occurred, control shifts to step 204. Otherwise, control returns to step 200.

In step 204, the remote controller 106 sets the switching unit 108 to the setting at the time of power failure (the input end 140 and the output end 144 are connected) as described above, and the amount of electricity stored in the storage battery inside the expansion unit 104 (hereinafter, SOC (System Of Charge)). )) Is transmitted to the expansion unit 104 with a request code (hereinafter, also referred to as an SOC request code). As will be described later, since step 204 is repeated, if the switching unit 108 is already set at the time of power failure, that state is maintained. After that, control shifts to step 206.

In step 206, the remote controller 106 determines whether or not the SOC requested to the expansion unit 104 in step 204 and the information on the self-sustaining output power of the power generation device 120 have been acquired. As described above, the information on the self-sustaining output power is the self-sustaining output information (the amount of power supplied from the self-sustaining output terminal 122) transmitted from the power generation device 120 to the remote controller 106 when a power failure occurs. When it is determined that both have been acquired, the remote controller 106 stores the acquired SOC and the self-sustaining output information in the storage unit, and the control shifts to step 208. Otherwise, step 206 is repeated. As will be described later, since step 206 is repeated, it is sufficient that the latest values of the SOC and the self-sustaining output information are stored.

In step 208, the remote controller 106 determines whether or not the SOC (the amount of electricity stored in the storage battery of the expansion unit 104) acquired in step 206 is zero. If it is determined that SOC = 0, control shifts to step 210. Otherwise, control proceeds to step 218.

In step 210, the remote controller 106 transmits an instruction to the expansion unit 104 to bypass output the input power and stop the PCS. The instruction may include, for example, a set of bypass parameters (bypass switch ON / OFF) and charge / discharge parameters. Regarding the bypass parameters, for example, "1" indicates a bypass output instruction, that is, an instruction to turn on (short-circuit) the bypass switch inside the unit, and "0" indicates an instruction not to bypass output, that is, the bypass switch inside the unit. Indicates an instruction to turn off. Regarding the charge / discharge parameters, for example, "-1" indicates a charge instruction, "1" indicates a discharge instruction, and "0" indicates a stop (no charge / discharge) instruction. If such a rule is set in advance, the remote controller 106 sets the data of (1,0) (bypass parameter is “1” (bypass output) and charge / discharge parameter is “0” (PCS) to the expansion unit 104. All you have to do is send an instruction that includes (stop)). The control then shifts to step 212.

In step 212, the remote controller 106 determines whether or not the self-sustaining output power acquired in step 206 is equal to or greater than the power of the specific load 124 measured in step 200. If it is determined that the self-sustaining output power is equal to or greater than the specified load power, the control shifts to step 214. Otherwise, control proceeds to step 216.

In step 214, the remote controller 106 transmits an instruction to the power storage unit 102 so as to bypass output the power input to the power storage unit 102 and charge the power storage unit 102. Specifically, if the bypass parameter and the charge / discharge parameter are set as described above, the remote controller 106 may transmit an instruction including the data of (1, -1) to the power storage unit 102. The control then shifts to step 226. The data of (1, -1) represents a bypass parameter of "1" (bypass output) and a charge / discharge parameter of "-1" (charging).

In step 216, the remote controller 106 transmits an instruction to the power storage unit 102 so that the power input to the power storage unit 102 is not bypass-output and is discharged. Specifically, if the bypass parameter and the charge / discharge parameter are set as described above, the remote controller 106 may transmit an instruction including the data of (0,1) to the power storage unit 102. The data of (0,1) represents a bypass parameter of "0" (no bypass output) and a charge / discharge parameter of "1" (discharge). The control then shifts to step 226.

On the other hand, when SOC = 0 (see step 208), in step 218, the remote controller 106 transmits an instruction to the power storage unit 102 so as to bypass output the power input to the power storage unit 102 and stop the PCS. To do. Specifically, if the bypass parameter and the charge / discharge parameter are set as described above, the remote controller 106 may transmit an instruction including the data of (1,0) to the power storage unit 102. The data of (1,0) represents a bypass parameter of "1" (bypass output) and a charge / discharge parameter of "0" (PCS stopped). The control then shifts to step 220.

In step 220, the remote controller 106 determines whether or not the self-sustaining output power acquired in step 206 is equal to or greater than the power of the specific load 124 measured in step 200. If it is determined that the self-sustaining output power is equal to or greater than the specified load power, the control shifts to step 222. Otherwise, control proceeds to step 224.

In step 222, the remote controller 106 transmits an instruction to the expansion unit 104 to bypass output the power input to the expansion unit 104 and charge the expansion unit 104. Specifically, if the bypass parameter and the charge / discharge parameter are set as described above, the remote controller 106 may transmit an instruction including the data of (1, -1) to the expansion unit 104. The data of (1, -1) represents a bypass parameter of "1" (bypass output) and a charge / discharge parameter of "-1" (charging). The control then shifts to step 226.

In step 224, the remote controller 106 transmits an instruction to the expansion unit 104 so that the power input to the expansion unit 104 is not bypass-output and is discharged. Specifically, if the bypass parameter and the charge / discharge parameter are set as described above, the remote controller 106 may transmit an instruction including the data of (0,1) to the expansion unit 104. The data of (0,1) represents a bypass parameter of "0" (no bypass output) and a charge / discharge parameter of "1" (discharge). The control then shifts to step 226.

In step 226, the remote controller 106 determines whether or not to terminate. For example, when the power failure of the power system 130 is resolved and the power supply from the power system 130 is started, the remote controller 106 is determined to be terminated. When it is determined that the operation is completed, the remote controller 106 changes the switching unit 108 to the normal state, and transmits a stop instruction to the power storage unit 102 and the expansion unit 104. After that, this program ends. Otherwise, control returns to step 200 and the process of step 200 through step 226 is repeated until it is determined to end. Even if this program ends once, it is preferable that this program is started again if the power system 130 recovers from the power failure.

The flowchart of FIG. 5 is executed by the power storage unit 102. Specifically, the control unit of the power storage unit 102 reads a predetermined program from the storage unit inside the power storage unit 102 and executes it.

In step 300, the power storage unit 102 determines whether or not data has been received. If it is determined that the signal has been received, the control proceeds to step 302. Otherwise, step 300 is repeated.

In step 302, the power storage unit 102 determines whether or not the data received in step 300 includes a bypass output instruction. If it is determined that it is included, control proceeds to step 304. Otherwise, control shifts to step 306. If the bypass parameter is "1", it is determined that the bypass output is instructed, and if the bypass parameter is "0", it is determined that the bypass output is not instructed.

In step 304, the power storage unit 102 turns on the first bypass switch 112. Control then shifts to step 308.

In step 306, the power storage unit 102 turns off the first bypass switch 112. Control then shifts to step 308.

In step 308, the power storage unit 102 determines whether the charge, discharge, or stop instruction has been received. If the charge / discharge parameter is "-1", it is determined to be a charge instruction, if it is "1", it is determined to be a discharge instruction, and if it is "0", it is determined to be a stop instruction. If it is determined that it is a charge instruction, the control shifts to step 310, if it is determined that it is a discharge instruction, the control shifts to step 312, and if it is determined that it is a stop instruction, the control is stepped. Move to 314.

In step 310, the power storage unit 102 starts charging the storage battery by the PCS. The control then shifts to step 316.

In step 312, the power storage unit 102 starts discharging the storage battery by the PCS. The control then shifts to step 316.

In step 314, the power storage unit 102 stops the PCS. The control then shifts to step 316.

In step 316, the power storage unit 102 determines whether or not the termination instruction has been received. If it is determined that the end instruction has been received, this program will end. Otherwise, control returns to step 300 and the process from step 300 to step 316 is repeated. The end instruction is given, for example, by transmitting a stop instruction from the remote controller 106 to the power storage unit 102. Even if this program ends once, it is preferable that this program is started again if the power system 130 recovers from the power failure.

The flowchart of FIG. 6 is executed by the expansion unit 104. Specifically, the control unit of the expansion unit 104 reads a predetermined program from the storage unit inside the expansion unit 104 and executes it.

The flowchart of FIG. 6 is an addition of steps 400 and 402 to the flowchart of FIG. FIG. 6 is different from FIG. 5 in that the main body of operation is changed from the power storage unit 102 to the expansion unit 104, and the processing target is the second bypass switch 114 and the PCS inside the expansion unit 104. Since the processing of the steps with the same numbers as in FIG. 5 is the same as the processing in FIG. 5, the duplicate explanation will not be repeated, and the differences will be mainly described.

Similar to the power storage unit 102, the expansion unit 104 determines whether or not data has been received (step 300), and if it is determined that the data has been received, the expansion unit 104 receives the SOC transmission request in step 400. Determine if it has been done. Specifically, the expansion unit 104 determines whether or not the data received in step 300 is the SOC request code transmitted from the expansion unit 104 in step 204 (see FIG. 4). If it is determined that the SOC request code has been received, control proceeds to step 402. Otherwise, control proceeds to step 302.

In step 402, the expansion unit 104 detects the current storage amount (SOC) of the storage battery inside the expansion unit 104, and transmits the value to the remote controller 106. After that, control shifts to step 302.

Like the power storage unit 102, the expansion unit 104 repeats the processes of step 300 to step 316, step 400, and step 402 until the end instruction is received. The expansion unit 104 turns on the second bypass switch 114 in step 304 and turns off the second bypass switch 114 in step 306. In step 310, the expansion unit 104 starts charging by the PCS inside the expansion unit 104, in step 312, discharge starts by the PCS inside the expansion unit 104, and in step 314, the PCS inside the expansion unit 104 is stopped. .. In step 316, when the expansion unit 104 receives the stop instruction transmitted from the remote controller 106 to the expansion unit 104, the program ends. Even if this program ends once, it is preferable that this program is started again if the power system 130 recovers from the power failure.

The flowchart of FIG. 7 is executed by the power generation device 120. Specifically, the control unit inside the power generation device 120 reads a predetermined program from the storage unit inside the power generation device 120 and executes it.

In step 500, the power generation device 120 determines whether or not a power failure has occurred in the power system 130. Specifically, the power generation device 120 determines whether or not a power failure has occurred in the power system 130 based on the information (voltage value) from the second sensor 132. For example, if the voltage is equal to or less than a predetermined value (a value close to zero), it can be determined that a power failure has occurred. If it is determined that a power failure has occurred, control shifts to step 502. Otherwise, step 500 is repeated.

In step 502, the power generation device 120 starts the self-sustaining operation. Specifically, as described above, the power generation device 120 opens the connection to the distribution line for supplying power to the second sensor 132, and starts outputting power from the self-supporting output terminal 122. After that, control shifts to step 504.

In step 504, as described above, the power generation device 120 transmits the self-sustaining output information representing the amount of power supplied from the self-supporting output terminal 122 to the remote controller 106. After that, control shifts to step 506.

In step 506, the power generation device 120 determines whether or not to terminate. For example, it is determined that the power generation device 120 is terminated when the power failure of the power system 130 is resolved and the power supply from the power system 130 is started. When it is determined to end, the power generation device 120 connects to a distribution line for supplying electric power to the general load 134, starts supplying electric power, and stops supplying electric power from the self-supporting output terminal 122. After that, this program ends. Otherwise, control returns to step 504 and the process of step 504 is repeated until it is determined to end. Even if this program ends once, it is preferable that this program is started again if the power system 130 recovers from the power failure.

As described above, when a power failure occurs in the power system 130, the remote controller 106 sets the switching unit 108 to the state at the time of the power failure, disconnects the specific load 124 from the power system 130, and transmits SOC (storage amount) to the expansion unit 104. Request (step 204 in FIG. 4). As a result, the specific load 124 is in a connected state in which electric power can be supplied from the self-sustaining output terminal 122 of the power generation device 120, the power storage unit 102, and the expansion unit 104. When a power failure occurs in the power system 130, the power generation device 120 starts the self-sustaining operation and transmits the self-sustaining output information (the amount of output power from the self-sustaining output terminal 122) to the remote controller 106 (steps 502 and 504 in FIG. 7). Upon receiving the SOC request code, the expansion unit 104 transmits the SOC to the remote controller 106 (step 402 in FIG. 6). Whether the remote controller 106 supplies power to the specific load 124 from the power generation device 120, the power storage unit 102, or the expansion unit 104 according to the self-sustaining output power supplied by the self-sustaining operation of the power generation device 120 and the SOC of the expansion unit 104. To determine. Subsequently, the remote controller 106 transmits an instruction according to the determination to the power storage unit 102 and the expansion unit 104 (see steps 208 to 224 in FIG. 4). The power storage unit 102 sets the first bypass switch 112 in response to the instruction received from the remote controller 106, and starts charging / discharging by the PCS or stops the PCS (steps 302 to 314 in FIG. 5). Similarly, the expansion unit 104 sets the second bypass switch 114 in response to the instruction received from the remote controller 106, starts charging / discharging by the PCS, or stops the PCS (steps 302 to 314 in FIG. 6). .. As a result, in the event of a power failure, power can be supplied to the specific load 124 from any of the power generation device 120, the power storage unit 102, and the expansion unit 104.

With reference to FIGS. 8 to 11, how the power is supplied to the specific load 124 according to the self-sustaining output power and the storage amount (SOC) of the expansion unit 104 will be specifically described. Note that FIGS. 8 to 11 show only the elements related to the change in the electric power supplied to the specific load 124 at the time of a power failure among the configurations shown in FIG. The dashed arrow represents the current. Here, it is assumed that the storage batteries of the power storage unit 102 and the expansion unit 104 are normally charged (not limited to full charge).

In FIG. 8, the power generation device 120 is generating power at the time of a power failure, the power output from the self-sustaining output terminal 122 (self-sustaining output power) is larger than the power consumption of the specific load 124, and SOC = 0 (SOC = 0). The case (stored in the storage battery) is shown. In this case, the determination result of step 208 in FIG. 4 is NO, and step 218 is executed. Further, the determination result of step 220 is YES, and step 222 is executed. Therefore, an instruction including the data of (1,0) (bypass parameter is "1" (bypass output) and charge / discharge parameter is "0" (PCS is stopped)) is transmitted to the power storage unit 102. Further, an instruction including the data (1, -1) (bypass parameter is "1" (bypass output) and charge / discharge parameter is "-1" (charging)) is transmitted to the expansion unit 104. As a result, as shown in FIG. 8, the PCS of the power storage unit 102 is stopped, the first bypass switch 112 is turned on, the input power is bypassed, and the power is output to the expansion unit 104. The expansion unit 104 bypasses the input power and outputs it to the specific load 124, and charges the internal storage battery with the surplus power.

FIG. 9 shows a case where the power generation amount of the power generation device 120 decreases from the state of FIG. 8 and the power output from the self-supporting output terminal 122 (self-supporting output power) becomes smaller than the power consumption of the specific load 124 (SOC =). (Not 0) is shown. In this case, the determination result of step 208 in FIG. 4 is NO, and step 218 is executed. Further, the determination result in step 220 is NO, and step 224 is executed. Therefore, as in the case of FIG. 8, an instruction including the data of (1,0) is transmitted to the power storage unit 102. Further, unlike the case of FIG. 8, the expansion unit 104 is instructed to include the data (0,1) (bypass parameter is “0” (no bypass output), charge / discharge parameter is “1” (discharge)). Will be sent. As a result, as shown in FIG. 9, the PCS of the power storage unit 102 is stopped, and the state in which the first bypass switch 112 is turned on (bypass output) is maintained. The expansion unit 104 turns off the second bypass switch 114 (does not bypass output), discharges the internal storage battery, and supplies electric power to the specific load 124.

In FIG. 10, from the state of FIG. 9, the remaining charge of the expansion unit 104 becomes zero (SOC = 0), the generated power of the power generation device 120 increases, and the power output from the self-supporting output terminal 122 (self-supporting output power). ) Is larger than the power consumption of the specific load 124. In this case, the determination result of step 208 in FIG. 4 is YES, and step 210 is executed. Further, the determination result of step 212 is YES, and step 214 is executed. Therefore, an instruction including the data (1,0) (bypass parameter is “1” (bypass output) and charge / discharge parameter is “0” (PCS is stopped)) is transmitted to the expansion unit 104. An instruction including the data of (1, -1) (bypass parameter is "1" (bypass output) and charge / discharge parameter is "-1" (charge)) is transmitted to the power storage unit 102. As a result, as shown in FIG. 10, the power storage unit 102 turns on (bypass output) the first bypass switch 112, bypasses the power consumed by the specific load 124 among the input power, and the expansion unit 104. The surplus power is charged to the internal storage battery. The expansion unit 104 stops the PCS, turns on the second bypass switch 114 (bypass output), bypasses the input power, and outputs the power to the specific load 124.

FIG. 11 shows a case where the amount of power generated by the power generation device 120 decreases from the state of FIG. 10 and the power output from the self-supporting output terminal 122 (self-supporting output power) becomes smaller than the power consumption of the specific load 124 (SOC =). 0) is shown. In this case, the determination result of step 208 in FIG. 4 is YES, and step 210 is executed. Further, the determination result of step 212 is NO, and step 216 is executed. Therefore, as in the case of FIG. 10, an instruction including the data of (1,0) is transmitted to the expansion unit 104. Unlike the case of FIG. 10, an instruction including the data (0,1) (bypass parameter is “0” (no bypass output) and charge / discharge parameter is “1” (discharge)) is transmitted to the power storage unit 102. To. As a result, as shown in FIG. 11, the power storage unit 102 turns off the first bypass switch 112 (does not perform bypass output), discharges the internal storage battery, and outputs power to the expansion unit 104. The expansion unit 104 stops the PCS, maintains the state in which the second bypass switch 114 is on (bypass output), bypasses the input power, and outputs the power to the specific load 124.

In this way, of the two power storage units connected in series, the unit (expansion unit 104) connected at a position closer to the specific load 124 is charged and discharged. When the amount of electricity stored in the unit (expansion unit 104) is exhausted and discharge cannot be performed, the remaining unit (storage unit 102) is charged and discharged. As a result, when a power failure occurs, electric power can be efficiently supplied to the specific load 124 from any of the power generation device 120, the power storage unit 102, and the expansion unit 104.

In the above, among the power storage unit 102 and the expansion unit 104 connected in series, the expansion unit 104 connected at a position closer to the specific load 124 (that is, a position farther from the power generation device 120) is first charged and discharged. The case has been described, but the case is not limited to this. For example, when a power failure occurs and the self-sustaining output power of the power generation device 120 is larger than the power consumption of the specific load 124, the power storage unit 102 and the expansion unit are supplied by the surplus power of the power generation device 120 while supplying power to the specific load 124. 104 may be charged. At this time, the ratio of the electric power for charging the power storage unit 102 and the expansion unit 104 becomes equal in consideration of each state of the power storage unit 102 and the expansion unit 104, that is, at least one of the SOC and the degree of deterioration. It may be controlled as follows. The degree of deterioration is an index indicating the deterioration state of the battery, for example, SOH (State Of Health). SOH is expressed as a ratio (%) of the storage capacity (Ah) at a certain point in time (at the time of deterioration) to the initial full charge capacity (Ah).

On the other hand, when the self-sustaining output power of the power generation device 120 disappears (when it becomes zero), the first bypass switch 112 of the power storage unit 102 is turned off. Then, power is supplied to the specific load 124 from either the power storage unit 102 or the expansion unit 104 connected in series. For example, as in FIG. 11, the second bypass switch 114 of the expansion unit 104 is turned on, and the specific load 124 is connected from the storage battery of the power storage unit 102 connected at a position farther from the specific load 124 (that is, a position closer to the power generation device 120). Power to. Here, it is assumed that the storage battery of the expansion unit 104 is stored (SOC = 0 is not). After that, when the remaining charge of the storage battery of the power storage unit 102 disappears (when it becomes zero), as shown in FIG. 12, the second bypass switch 114 of the expansion unit 104 is turned off, and a specific load is applied from the storage battery of the expansion unit 104. Power the 124.

[effect]
In the self-sustaining operation power storage system 100 in which two power storage units 102 and expansion units 104, which are the same products, are connected in series, when a power failure occurs, either the power generation device 120, the power storage unit 102, or the expansion unit 104 Power can be supplied to the specific load 124. Further, when the amount of power generated by the power generation device 120 changes, the charge / discharge state of the power storage unit 102 and the expansion unit 104 can be appropriately controlled to maintain the power supply to the specific load 124.

When the amount of power generated by the power generation device 120 decreases, the power storage unit 102 or the expansion unit 104 controls to supply power to the specific load 124. At that time, since the power storage unit 102 and the expansion unit 104 are connected in series, power can be supplied to the specific load 124 for a longer time than when they are connected in parallel.

Further, if it becomes necessary to increase the amount of power supplied to the specific load 124 in the event of a power failure after one power storage unit 102 is installed, it is easy to add the same product (expansion unit 104) as the power storage unit 102. Can correspond to.

(First modification)
In the above, the case where two power storage units are connected in series between the self-sustaining output terminal 122 of the power generation device 120 and the specific load 124 has been described, but the present invention is not limited to this. Three or more power storage units may be connected in series between the self-sustaining output terminal 122 of the power generation device 120 and the specific load 124. Even in that case, of the plurality of power storage units connected in series, the power storage unit connected at the position closest to the specific load 124 is charged and discharged. When the amount of electricity stored in the electricity storage unit becomes zero and discharge cannot be performed, the electricity storage unit connected to the specific load 124 at the second closest position is charged and discharged. Similarly, when the amount of electricity stored in the power storage unit connected to the specific load 124 at the position closest to the second becomes zero, the power storage unit connected to the specific load 124 at the position closest to the third is charged and discharged. In this way, by preferentially charging and discharging the power storage unit closest to the specific load 124, power is efficiently supplied to the specific load 124 from either the power generation device or the plurality of power storage units in the event of a power failure. it can. Further, since a plurality of power storage units are connected in series, power can be supplied to the specific load 124 for a longer time than when they are connected in parallel. The power storage unit far from the specific load 124, that is, the power storage unit close to the power generation device 120 may be charged and discharged preferentially.

When three or more power storage units are connected in series between the self-sustaining output terminal 122 of the power generation device 120 and the specific load 124, the remote controller 106 may operate in the same manner as when two power storage units are connected in series. .. That is, the remote controller 106 may generate an instruction regarding the setting of the internal bypass switch and the operation of the PCS for each power storage unit according to the output power of the self-supporting output terminal 122. Thereby, the power source to be supplied to the specific load 124 can be appropriately determined from the plurality of power storage units and the power generation device 120.

Further, the remote controller 106 sets an internal bypass switch for each power storage unit according to the power consumption of the specific load 124 and the output power of the independent output terminal 122 obtained from the detection value of the first sensor 110. And may generate instructions regarding the operation of the PCS. Thereby, the power source to be supplied to the specific load 124 can be more appropriately determined from the plurality of power storage units and the power generation device.

Further, the remote controller 106 generates an instruction regarding the setting of the internal bypass switch and the operation of the PCS to the storage unit according to at least one of the storage amount and the deterioration degree (SOH) of the storage battery of each power storage unit. May be good. As a result, the power source to be supplied to the specific load 124 can be appropriately determined from the plurality of power storage units and the power generation device, and if the power storage amount becomes zero when the power is supplied from the storage battery of one power storage unit. , Power can be supplied from the storage battery of another power storage unit.

In the above, the case where the instruction including the bypass parameter and the charge / discharge parameter is transmitted has been described, but the present invention is not limited to this. For each unit (storage unit 102 and expansion unit 104), the setting of each bypass switch and the operation of the PCS may be specified. For example, the remote controller and each unit store the possible combinations of bypass switch settings and PCS operation in a table format, and the remote controller transmits information (for example, a number) for identifying one combination to each unit. You may. Each unit can search the table by number to identify bypass switch settings and PCS behavior.

In the above, the case where the remote controller 106 determines the presence or absence of a power failure from the detected value of the second sensor 132 has been described, but the present invention is not limited to this. The remote controller 106 may receive information indicating the occurrence of a power failure from an external device (for example, the power generation device 120).

(Second modification)
In the above, the case where the current supplied to the specific load 124 is detected by the first sensor 110 has been described, but the present invention is not limited to this. The power storage unit 102 and the expansion unit 104 are provided with a current sensor inside, and the output power of each unit can be measured. Therefore, in FIG. 3, the configuration may not include the first sensor 110. In that case, the remote controller 106 does not need to execute the process of step 200 in the flowchart of FIG. The remote controller 106 measures the output current of each unit with an internal current sensor for each of the power storage unit 102 and the expansion unit 104, and compares the output power calculated from the measured value with the maximum output power of each unit. Depending on the comparison result, the remote controller 106 can determine whether or not to supply electric power from each of the power storage unit 102 and the expansion unit 104.

For example, the remote controller 106 may execute the flowchart of FIG. In the flowchart of FIG. 13, step 200 is deleted, steps 212, 216, 220 and 224 are replaced with steps 242, 244, 248 and 250, respectively, and steps 240 and 246 are added. is there. For each step in FIG. 13, the processing of the steps numbered the same as in FIG. 4 is the same as in FIG. Therefore, the duplicate explanation will not be repeated, and the differences will be mainly described.

When a power failure occurs, the remote controller 106 acquires SOC and self-sustaining output power. After that, when the determination result in step 208 is YES (SOC = 0), the remote controller 106 instructs the expansion unit 104 to bypass output the input power and stop the PCS in step 210. To send. After that, in step 240, the remote controller 106 transmits an instruction to the power storage unit 102 to bypass output the input power.

Subsequently, in step 242, the remote controller 106 requests the power storage unit 102 to transmit the output power of the power storage unit 102 (a value calculated from the output current value measured by the internal current sensor). The remote controller 106 determines whether or not the acquired value (output power of the power storage unit 102) is less than the maximum self-sustaining output value. If the output power of the power storage unit 102 is less than the maximum self-sustaining output value, the control shifts to step 214, and if not, the control shifts to step 244. This self-sustaining output maximum value is the maximum value of the power that can be output by the power generation device 120 at present, that is, the self-sustaining output power acquired in step 206 (the amount of power supplied from the self-sustaining output terminal 122 transmitted from the power generation device 120). Independent output information that represents). Both the power storage unit 102 and the extension unit 104 are instructed to bypass (steps 210 and 240), the bypass switch is turned on, and the extension unit 104 has SOC = 0. Therefore, the output power of the power storage unit 102 calculated from the measured value of the current sensor inside the power storage unit 102 represents the power consumption of the specific load 124. Further, the output power of the power storage unit 102 may include the output power from the power generation device 120 in addition to the output power of the power storage unit 102 itself.

In step 214, as described above, the same process as in FIG. 4 is executed. On the other hand, in step 244, the remote controller 106 transmits an instruction to the power storage unit 102 to bypass and discharge.

As a result, when the output power of the power storage unit 102 (power consumption at the specific load 124) exceeds the maximum power of the power generation device 120, the shortage can be supplied by discharging the power storage unit 102 (step 244).

When the determination result in step 208 is NO (SOC> 0), in step 218, the remote controller 106 sends an instruction to the power storage unit 102 to bypass output the input power and stop the PCS. To do. Then, in step 246, the remote controller 106 transmits an instruction to the expansion unit 104 to bypass output the input power.

Subsequently, in step 248, the remote controller 106 requests the expansion unit 104 to transmit the output power of the expansion unit 104 (a value calculated from the output current value measured by the internal current sensor). The remote controller 106 determines whether or not the acquired value (output power of the expansion unit 104) is less than the maximum self-sustaining output value. If the output power of the expansion unit 104 is less than the maximum self-sustaining output value, the control shifts to step 222, and if not, the control shifts to step 250. This self-sustaining output maximum value means the maximum value of the power that can be output by the expansion unit 104 itself. Both the power storage unit 102 and the extension unit 104 are instructed to bypass (steps 218 and 246), and the bypass switch is turned on. Therefore, the output power of the expansion unit 104 calculated from the measured value of the current sensor inside the expansion unit 104 includes the output power from the power generation device 120 and the power storage unit 102 in addition to the output power of the expansion unit 104 itself. It can be. However, here, the output power from the power storage unit 102 is set to 0 by step 218.

In step 222, as described above, the same process as in FIG. 4 is executed. On the other hand, in step 250, the remote controller 106 transmits an instruction to discharge to the expansion unit 104 and the power storage unit 102.

As a result, when the output power of the expansion unit 104 (power consumption at the specific load 124) exceeds the maximum self-sustaining output value of the expansion unit 104 itself, the shortage can be supplied by discharging the power storage unit 102 (step 250). For example, when the maximum output power (maximum self-sustaining output value) of the expansion unit 104 is 1500 W, and the output power (measured value) of the expansion unit 104 exceeds 1600 W, the shortage (100 W) can be supplied from the power storage unit 102. ..

The maximum power that can be output by the expansion unit 104 itself may be stored in advance in the storage unit inside the remote controller 106.

Further, with respect to the process of step 242 in FIG. 13, the maximum value of the electric power that can be output by the power storage unit 102 itself may be used as the maximum value of the self-sustaining output. In that case, in the process following step 242, when the output power of the power storage unit 102 (power consumption at the specific load 124) exceeds the maximum self-sustaining output of the power storage unit 102 itself, the shortfall is generated from the power generation device 120. You just have to supply it. Further, in that case, in step 206, the remote controller 106 does not have to acquire the self-sustaining output power (self-sustaining output information transmitted from the power generation device 120).

(Third modification example)
In the above, the case where the remote controller 106 plays a central role in controlling the power storage unit 102 and the expansion unit 104 has been described, but the present invention is not limited to this. At least one of the power storage unit 102 and the expansion unit 104 may play a central role in performing the same control. In the third modification, the power storage unit 102 is the main body, and the same control as that of the remote controller 106 is performed. The self-sustaining operation power storage system 150 according to the third modification can be configured as shown in FIG. The self-sustaining operation power storage system 150 is obtained by deleting the remote controller 106 from the self-sustaining operation power storage system 100 of FIG. The power storage system 150 for self-sustaining operation further includes a communication path 160 for connecting the PCS 152 of the power storage unit 102 and the PCS 154 of the expansion unit 104 so as to be able to communicate with each other, and the PCS 152 of the power storage unit 102 for acquiring information and controlling each device. Includes lines 162-168. The communication path 160 may be by wired communication or wireless communication.

The PCS 152 of the power storage unit 102 executes the same processing as the flowchart shown in FIG. 4 in addition to the processing of the flowchart shown in FIG. The PCS 154 of the expansion unit 104 executes the same process as the flowchart shown in FIG. The power generation device 120 executes the same process as the flowchart shown in FIG. Therefore, each step of FIGS. 4 to 7 is referred to as appropriate.

The PCS 152 obtains the power supplied to the specific load 124 from the information (current value) input from the first sensor 110 via the specific load power detection line 162 (see step 200 in FIG. 4). Subsequently, the PCS 152 determines whether or not a power failure has occurred in the power system 130 based on the information (voltage value) input from the second sensor 132 via the power failure detection line 164 (see step 202 in FIG. 4). ).

The PCS 152 outputs an instruction to the switching unit 108 via the switching unit control line 166, and sets the switching unit 108 at the time of a power failure (the input end 140 and the output end 144 are connected). Further, the PCS 152 transmits an SOC request code for requesting the transmission of the SOC of the storage battery inside the expansion unit 104 to the expansion unit 104 via the communication path 160 (see step 204 in FIG. 4). In response to this, the PCS154 of the expansion unit 104 detects the current SOC of the storage battery inside the expansion unit 104 and transmits the value to the PCS152 via the communication path 160 (see step 402 in FIG. 6).

The PCS 152 acquires self-sustaining output information (the amount of power supplied by the power generation device 120) from the power generation device 120 via the self-sustaining output information acquisition line 168, and acquires SOC from the expansion unit 104 via the communication path 160 (FIG. 4). See step 206). Subsequently, the PCS 152 determines whether or not the SOC is zero (see step 208 in FIG. 4). When SOC = 0, the PCS 152 sends an instruction to the expansion unit 104 via the communication path 160 so as to bypass output the input power and stop the PCS (see step 210 in FIG. 4). .. In response to this, the PCS 154 of the expansion unit 104 executes the process according to the instruction (see steps 302 to 314 of FIG. 6).

The PCS 152 determines whether or not the self-sustaining output power is equal to or greater than the power of the specific load 124 (see step 212). If the self-sustaining output power is equal to or higher than the specific load power, the PCS 152 controls the power storage unit 102 so as to bypass output the power input to the power storage unit 102 and charge the power storage unit 102 (see step 214 in FIG. 4). That is, the PCS 152 turns on the first bypass switch 112 (see step 304 in FIG. 5) and starts charging the storage battery (see step 310 in FIG. 5).

If the self-sustaining output power is less than the specific load power, the PCS 152 controls the power storage unit 102 so that the power input to the power storage unit 102 is not bypass-output and is discharged (see step 216 in FIG. 4). .. That is, the PCS 152 turns off the first bypass switch 112 (see step 306 in FIG. 5) and starts discharging the storage battery (see step 312 in FIG. 5).

When SOC = 0, the PCS 152 controls the power storage unit 102 so as to bypass output the power input to the power storage unit 102 and stop the charge / discharge control function (see step 218 in FIG. 4). That is, the PCS 152 turns on the first bypass switch 112 (see step 304 in FIG. 5) and stops the function of controlling the charge / discharge of the storage battery of the power storage unit 102 (see step 314 in FIG. 5). Subsequently, the PCS 152 determines whether or not the self-sustaining output power is equal to or greater than the power of the specific load 124 (see step 220 in FIG. 4).

If the self-sustaining output power is equal to or higher than the specific load power, the PCS152 bypasses the power input to the expansion unit 104 and transmits an instruction to the expansion unit 104 via the communication path 160 so as to charge the power (bypass output). See step 222 in FIG. 4). If the self-sustaining output power is less than the specific load power, the PCS 152 transmits an instruction to the expansion unit 104 via the communication path 160 so that the power input to the expansion unit 104 is not bypass-output and is discharged. (See step 224 of FIG. 4). In response to this, the PCS 154 of the expansion unit 104 executes the process according to the instruction (see steps 302 to 314 of FIG. 6).

As described above, the self-sustaining operation power storage system 150 operates in the same manner as the self-sustaining operation power storage system 100 (FIG. 3). That is, when a power failure occurs in the power system 130, the PCS 152 sets the switching unit 108 to the state at the time of the power failure, disconnects the specific load 124 from the power system 130, and requests the expansion unit 104 to transmit SOC (storage amount). (See step 204 in FIG. 4). As a result, the specific load 124 is in a connected state in which electric power can be supplied from the self-sustaining output terminal 122 of the power generation device 120, the power storage unit 102, and the expansion unit 104. When a power failure occurs in the power system 130, the power generation device 120 starts the self-sustaining operation and transmits the self-sustaining output information to the PCS 152 (see step 502 and step 504 in FIG. 7). Upon receiving the SOC request code, the expansion unit 104 transmits the SOC to the PCS 152 (see step 402 in FIG. 6). The PCS 152 determines whether the power generation device 120, the power storage unit 102, or the expansion unit 104 supplies power to the specific load 124 according to the self-sustaining output power supplied by the self-sustaining operation of the power generation device 120 and the SOC of the expansion unit 104. decide. Subsequently, the PCS 152 sets the power storage unit 102 according to the determination, and transmits an instruction to the expansion unit 104 (see steps 208 to 224 in FIG. 4). That is, the PCS 152 sets the first bypass switch 112 and starts charging / discharging or stops the charging / discharging control function according to the determination (see steps 302 to 314 in FIG. 5). Similarly, the expansion unit 104 sets the second bypass switch 114 in response to the instruction received from the PCS 152, starts charging / discharging by the PCS 154, or stops the charging / discharging control function of the PCS 154 (FIG. 6). See steps 302 to 314). As a result, in the event of a power failure, power can be supplied to the specific load 124 from any of the power generation device 120, the power storage unit 102, and the expansion unit 104.

As described above, the PCS 152 of the power storage unit 102 can take on the function of the remote controller 106. The expansion unit 104 may be the main body instead of the power storage unit 102 to perform the same control as described above. That is, it is conceivable that the power storage unit 102 includes a remote controller, or the expansion unit 104 includes a remote controller.

In the above, when the bypass switch (112, 114) is arranged only between the input terminal and the PCS in each power storage unit (102, 104), and the PCS and the output terminal are directly connected without the switch. However, it is not limited to this. A switch may be provided between the PCS and the output terminal. Further, in each power storage unit, switches may be provided before and after the PCS to control a total of two switches.

Although the present invention has been described above by explaining the embodiments, the above-described embodiments are examples, and the present invention is not limited to the above-described embodiments. The scope of the present invention is indicated by each claim of the scope of claims, taking into consideration the description of the detailed description of the invention, and includes all modifications within the meaning and scope equivalent to the wording described therein. ..

100, 150 Power storage system for independent operation 102, 900, 910 Power storage unit 104, 902, 912 Expansion unit 106, 904, 914, 916 Remote control 108 Switching unit 110 First sensor 112 First bypass switch 114 Second bypass switch 120, 920 Power generation device 122 Independent output terminal 124 Specific load 130 Power system 132 Second sensor 134 General load 140, 142 Input end 144 Output end 152, 154 PCS
160 Communication path 162 Specific load power detection line 164 Power failure detection line 166 Switching unit control line 168 Independent output information acquisition line 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 300, 302, 304, 306, 308, 310, 312, 314, 316, 400, 402, 500, 502, 504, 506 Step 906 Specific outlet 922 1st specific load 924 2nd specific load 926 1st independent output Terminal 928 2nd self-supporting output terminal

Claims (12)

With multiple power storage units
Including the control unit
Each power storage unit of the plurality of power storage units has a storage battery, a power input terminal, a power output terminal, and a switch for opening or short-circuiting the input terminal and the output terminal, and is instructed by the control unit. The charge / discharge of the switch and the storage battery is controlled according to the above.
The plurality of power storage units are an input terminal of each power storage unit of the plurality of power storage units and a power storage unit different from each power storage unit, and are output terminals of one of the plurality of power storage units. By connecting with, the plurality of power storage units as a whole are connected in series.
In the plurality of power storage units connected in series, the input terminal that is not connected to the output terminal of any of the power storage units is a power generation device that performs self-sustaining operation in the event of a power failure of the power system and outputs the generated power from the self-sustaining output terminal. Connected to the self-supporting output terminal
In the plurality of power storage units connected in series, the output terminals that are not connected to the input terminals of any of the power storage units are connected to a specific load to which power should be supplied in the event of a power failure.
The control unit is a power storage system for self-sustaining operation that generates the instruction to each power storage unit of the plurality of power storage units in response to a power failure of the power system. The power storage system for self-sustaining operation according to claim 1, wherein the control unit generates the instruction to each power storage unit of the plurality of power storage units according to the output power of the self-sustaining output terminal. It further includes a sensor that detects the current supplied to the specific load.
The control unit generates the instruction for each power storage unit of the plurality of power storage units according to the power consumption of the specific load obtained from the detection value of the sensor and the output power of the self-sustaining output terminal. 1 or the power storage system for self-sustaining operation according to claim 2. The self-sustaining operation power storage system according to any one of claims 1 to 3, wherein the control unit generates the instruction to the power storage unit according to the power storage amount of the storage battery of the power storage unit. The control unit is included in any of the plurality of power storage units.
The control unit includes a communication unit that communicates with each of the plurality of power storage units excluding the power storage unit including the control unit by wire or wirelessly.
The control unit transmits the instruction to each of the plurality of power storage units excluding the power storage unit including the control unit via the communication unit, according to any one of claims 1 to 4. The described power storage system for self-sustaining operation. A power storage unit that includes a storage battery and controls charging / discharging of the storage battery according to instructions from a control unit common to another power storage unit.
Power input terminal and
Power output terminal and
Further including a switch for opening or short-circuiting the input terminal and the output terminal.
The power storage unit is connected in series with the other power storage unit via at least one of the input terminal and the output terminal.
In the power storage unit and the other power storage units connected in series, the input terminals that are not connected to the output terminals of any of the power storage units perform self-sustaining operation in the event of a power failure of the power system and output the generated power from the self-sustaining output terminals. Connected to the self-supporting output terminal of the power generation device
The switch opens or short-circuits the input terminal and the output terminal in response to an instruction output by the control unit in response to the output power of the self-sustaining output terminal of the power generation device being lost. Power storage unit. The storage battery is connected to an electric circuit that short-circuits the input terminal and the output terminal when the switch is turned on.
One end of the switch is connected to the storage battery and
The power storage unit according to claim 6, wherein the other end of the switch is connected to the input terminal. Including multiple power storage units
Each power storage unit of the plurality of power storage units has a storage battery, a power input terminal, a power output terminal, and a switch for opening or short-circuiting the input terminal and the output terminal.
The plurality of power storage units are an input terminal of each power storage unit of the plurality of power storage units and a power storage unit different from each power storage unit, and are output terminals of one of the plurality of power storage units. By connecting with, the plurality of power storage units as a whole are connected in series.
In the plurality of power storage units connected in series, the input terminal that is not connected to the output terminal of any of the power storage units is a power generation device that performs self-sustaining operation in the event of a power failure of the power system and outputs the generated power from the self-sustaining output terminal. Connected to the self-supporting output terminal
In the plurality of power storage units connected in series, the output terminal not connected to the input terminal of any of the power storage units is a control method for a system connected to a specific load to which power should be supplied in the event of a power failure. ,
A determination step for determining whether or not the power system is in a power failure state, and
In response to the determination that the power failure state has occurred by the determination step, the amount of power supplied from the independent output terminal and the amount of electricity stored in the storage battery of each of the plurality of storage units are increased. A control method including a switch for each of the plurality of power storage units and a control step for controlling charging / discharging of the storage battery. The control method according to claim 8, wherein the control step includes a step of first charging / discharging the storage battery of the power storage unit connected to the specific load among the plurality of power storage units. Further including an independent output determination step for determining whether or not power is being output from the independent output terminal.
In the control step, the power output from the self-supporting output terminal is supplied to the specific load in response to the determination that the power is being output from the self-supporting output terminal by the self-supporting output determination step. Including the step of charging the storage battery of each of the plurality of power storage units with the surplus power of the power generation device while controlling the switch of each of the plurality of power storage units.
The control method according to claim 8 or 9, wherein the charging ratio of the storage battery of each of the plurality of power storage units is controlled so that the state of the storage battery of each of the plurality of power storage units is equalized. In the control step, in response to the determination by the self-sustaining output determination step that power is not output from the self-sustaining output terminal, the power storage connected to the self-supporting output terminal among the plurality of power storage units The first switch, which is a switch of the unit, is opened, and power is supplied to the specific load from the storage battery of the power storage unit connected in series at a position closer to the power generation device among the plurality of power storage units. The control method according to any one of claims 8 to 10, further comprising a first step of controlling the switch of each of the plurality of power storage units other than the first switch. The control step further includes, after the first step, a storage amount determination step of determining whether or not the storage amount of the storage battery of the storage unit that has output power to the specific load has become zero.
The control step is a switch of the storage unit in response to the determination by the storage amount determination step that the storage amount of the storage battery of the storage unit that has output power to the specific load has become zero. The first switch and the said first switch so that the two switches are opened and power is supplied to the specified load from the storage battery of the power storage unit connected in series at a position closer to the specific load than the power storage unit. The control method according to claim 11, further comprising a second step of controlling the switch of each of the plurality of power storage units other than the second switch.

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