Power storage system, power conditioner, and storage battery unit

Abstract

To reduce the possibility of damage and deterioration due to reverse connection.SOLUTION: A power storage system 10 has a storage battery unit 11 and a power conditioner 12. The storage battery unit 11 has a storage battery 15, a measuring unit 14, and a connection switch 13. The measuring unit 14 detects the voltage of the storage battery 15. The connection switch 13 is provided between the storage battery 15 and the measuring unit 14. The power conditioner 12 adjusts power. The power conditioner 12 applies first voltage to the storage battery unit 11 while the connection switch 13 is in an off state. When the storage battery unit 11 is determined to be reversely connected on the basis of comparison between the measured voltage and the first voltage, the off state of the connection switch 13 is maintained.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power storage system, a power conditioner, and a storage battery unit. [Background technology]

[0002] A storage battery unit including multiple secondary battery cells is connected to a power conditioner that performs orthogonal conversion and voltage adjustment between the storage battery unit and load equipment and other power sources. When an installer installs the storage battery unit and the power conditioner, the polarity may be mistaken and the battery may be connected in reverse. Reverse connection causes a large current to flow, which may result in damage to the power conditioner and deterioration of the storage battery unit. A power supply device has been proposed that protects the circuit even in the case of reverse connection (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-232995 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the power supply device described in Patent Document 1, a reverse voltage is applied to the power supply device when the device is reverse-connected. This may shorten the life of parts in the circuit. In addition, an additional circuit is required to protect against reverse connection.

[0005] In view of the above, an object of the present disclosure is to reduce the possibility of damage and deterioration due to reverse connection. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, a power storage system according to a first aspect of the present invention comprises: At least one storage battery unit including a storage battery, a measurement unit that detects a voltage of the storage battery, and a connection switch that is provided between the storage battery and the measurement unit; a power conditioner that adjusts the power input to the at least one storage battery unit and the power output from the at least one storage battery unit; When the connection switch is in the OFF state, a first voltage is applied from the power conditioner to the storage battery unit, and the OFF state of the connection switch is maintained when it is determined that the storage battery unit is reverse-connected based on a comparison between the measured voltage detected by the measurement unit and the first voltage.

[0007] The second aspect of the power conditioner is A power conditioner connected to at least one storage battery unit, The first control unit is configured to apply a first voltage to at least one of the storage battery units and determine whether the storage battery unit is reverse-connected based on a comparison between a measured voltage obtained from the storage battery unit and the first voltage, and if it is determined that the storage battery unit is not reverse-connected, transmit a first command to the storage battery unit to turn on a connection switch of the storage battery unit.

[0008] A storage battery unit according to a third aspect of the present invention comprises: A storage battery, A measurement unit that detects the voltage of the storage battery; A connection switch provided between the storage battery and the measurement unit; When the connection switch is in the OFF state and the measurement unit detects a voltage other than zero, a second control unit determines whether or not the connection is reversed based on a comparison between the measured voltage detected by the measurement unit and a first voltage indicated by voltage information obtained from a power conditioner connected to the storage battery via the connection switch, and maintains the connection switch in the OFF state if it is determined that the connection is reversed. Effect of the Invention

[0009] According to the present disclosure, the possibility of damage and deterioration due to reverse connection is reduced. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing a schematic configuration of a power storage system according to an embodiment of the present invention; [Diagram 2] 4 is a flowchart for explaining a reverse connection prevention process executed by a control unit of the power conditioner of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the following drawings, the same components are denoted by the same reference numerals.

[0012] As shown in FIG. 1, a power storage system 10 according to an embodiment of the present disclosure includes at least one storage battery unit 11 and a power conditioner 12. The at least one storage battery unit 11 may be a single storage battery unit 11 or may be multiple storage battery units 11. The power storage system 10 illustrated in FIG. 1 is described as including two storage battery units 11, a first storage battery unit 11a and a second storage battery unit 11b. In the following description, the storage battery unit 11 is used in the description common to the first storage battery unit 11a and the second storage battery unit 11b. The multiple storage battery units 11 may be connected in parallel.

[0013] As described below, when the connection switch 13 of the storage battery unit 11 is in the OFF state, a first voltage is applied from the power conditioner 12 to the storage battery unit 11. In response to the application of the first voltage, a measured voltage detected by a measurement unit 14 of the storage battery unit 11 is compared with the first voltage. If it is determined that the storage battery unit 11 is reverse-connected based on the comparison between the measured voltage and the first voltage, the OFF state of the connection switch 13 is maintained. The determination of whether or not the storage battery unit 11 is reverse-connected based on the comparison between the measured voltage and the first voltage may be performed by, for example, the power conditioner 12.

[0014] The storage battery unit 11 includes a storage battery 15, a measurement unit 14, a connection switch 13, and a control unit (second control unit) 16.

[0015] The storage battery 15 may include a single or multiple secondary battery cells. In a configuration having multiple secondary battery cells, the multiple secondary battery cells may be connected in series or parallel. The positive terminal of the storage battery 15 may be directly or indirectly connected to the positive terminal 17 of the storage battery unit 11. Specifically, the positive terminal of the storage battery 15 is connected to the positive terminal 17 of the storage battery unit 11 via the connection switch 13. The negative terminal of the storage battery 15 may be directly or indirectly connected to the negative terminal 18 of the storage battery unit 11. Specifically, the negative terminal of the storage battery 15 is connected to the negative terminal 18 of the storage battery unit 11.

[0016] The measurement unit 14 detects the voltage of the storage battery 15. To detect the voltage of the storage battery 15, the positive terminal of the measurement unit 14 may be connected to the first positive terminal 17. The first positive terminal 17 is the positive terminal of the storage battery unit 11. The negative terminal of the measurement unit 14 may be connected to the first negative terminal 18. The first negative terminal 18 is the negative terminal of the storage battery unit 11. As described later, a connection switch 13 is provided between the measurement unit 14 and the storage battery 15, so that when the connection switch 13 is in an OFF state, the measurement unit 14 can detect the voltages of the first positive terminal 17 and the first negative terminal 18. The measurement unit 14 is, for example, a voltmeter. The lower limit of the measurement range of the measurement unit 14 may be 0V or a negative value. The lower limit may be equal to or less than a voltage value obtained by inverting the polarity of the first voltage described later.

[0017] The connection switch 13 is provided between the storage battery 15 and the measurement unit 14. The connection switch 13 may be provided, for example, on the positive electrode side of the storage battery 15. The connection switch 13 may cut off current in the OFF state. The connection switch 13 may conduct current in the ON state. The connection switch 13 is, for example, an electromagnetic relay or a FET.

[0018] The control unit 16 includes at least one processor, at least one dedicated circuit, or a combination of these. The processor is a general-purpose processor such as a central processing unit (CPU) or a graphics processing unit (GPU), or a dedicated processor specialized for a specific process. The dedicated circuit may be, for example, a field-programmable gate array (FPGA), an application specific integrated circuit (ASIC), or the like. The control unit 16 controls the operation of the storage battery unit 11.

[0019] For example, control unit 16 may obtain a measured voltage of the voltage from measurement unit 14 as information. Control unit 16 may provide the measured voltage of the voltage as information to power conditioner 12. When control unit 16 obtains a first command, which will be described later, from power conditioner 12 in response to the application of the measured voltage, control unit 16 may switch connection switch 13 to the ON state. Note that control unit 16 may maintain connection switch 13 in the OFF state until it obtains the first command.

[0020] The power conditioner 12 adjusts the power input to the at least one storage battery unit 11 and the power output from the at least one storage battery unit 11. The power conditioner 12 may be provided, for example, between the storage battery unit 11 and other power sources and load devices. The other power sources may supply DC power, such as a solar power generation device or a fuel cell device, or may supply AC power, such as a grid or a generator. The power conditioner 12 may perform AC conversion as a power adjustment between the storage battery unit 11 and load devices that use AC power or other power sources that supply AC power. The power conditioner 12 may adjust the voltage as a power adjustment between the storage battery unit 11 and an AC conversion unit 22 described later.

[0021] The power conditioner 12 includes a voltage conversion unit 19 and a capacitor 20. The power conditioner 12 may further include a control unit (first control unit) 21, an AC-AC conversion unit 22, an interconnection relay 23, and a communication unit 24.

[0022] The voltage conversion unit 19 may adjust the voltage of the power supplied to the storage battery unit 11. Specifically, the voltage conversion unit 19 adjusts the voltages of the output terminals connected to the second positive terminal 25 and the second negative terminal 26, respectively, to a voltage set by the control unit 21. The second positive terminal 25 is a positive terminal connected to the storage battery unit 11 in the power conditioner 12. The second negative terminal 26 is a negative terminal connected to the storage battery unit 11 in the power conditioner 12. The voltage conversion unit 19 may also adjust the voltage of the power supplied to the orthogonal conversion unit 22. The voltage conversion unit 19 is, for example, a bidirectional DC / DC converter.

[0023] The capacitor 20 is connected in parallel to the voltage conversion unit 19. More specifically, the capacitor 20 is connected to an output terminal that is connected to the second positive terminal 25 and the second negative terminal 26 of the voltage conversion unit 19. The capacitor 20 may be built into the voltage conversion unit 19. The capacitor 20 is, for example, a smoothing capacitor.

[0024] The orthogonal conversion unit 22 may convert AC power into DC power and convert DC power into AC power. The orthogonal conversion unit 22 may be connected to the voltage conversion unit 19 on the DC side. The orthogonal conversion unit 22 may be connected to an AC terminal 27 on the AC side. The orthogonal conversion unit 22 is, for example, a bidirectional DC / AC converter.

[0025] The grid-connection relay 23 may be provided between the DC-AC converter 22 and the AC terminal 27. The grid-connection relay 23 may cut off current in an OFF state. The connection switch 13 may conduct current in an ON state.

[0026] The communication unit 24 may communicate with the storage battery unit 11 via a wired or wireless manner. The communication unit 24 may provide information and commands to the storage battery unit 11 under the control of the control unit 21. The communication unit 24 may provide information acquired from the storage battery unit 11 to the control unit 21. The acquired information may be a voltage value measured by the measurement unit 14, or a voltage value recorded in the second control unit 16 may be read out.

[0027] The control unit 21 includes at least one processor, at least one dedicated circuit, or a combination of these. The processor is a general-purpose processor such as a CPU or a GPU, or a dedicated processor specialized for a specific process. The dedicated circuit may be, for example, an FPGA or an ASIC. The control unit 21 controls the operation of the power conditioner 12.

[0028] When charging the storage battery unit 11, the control unit 21 may switch the grid-connection relay 23 to the ON state. Furthermore, the control unit 21 may control the DC-AC conversion unit 22 to convert AC power supplied from a system connected to the AC terminal 27 into DC power. Furthermore, the control unit 21 may control the voltage conversion unit 19 to adjust the voltage of the DC power output from the DC-AC conversion unit 22 to a voltage value for charging the storage battery unit 11. Note that in a configuration in which another power source connected to the power conditioner 12 supplies DC power, the voltage conversion unit 19 may be operated without operating the DC-AC conversion unit 22.

[0029] When discharging from the storage battery unit 11, the control unit 21 may switch the grid-connection relay 23 to the ON state. Furthermore, the control unit 21 may control the voltage conversion unit 19 to adjust the voltage of the DC power output from the storage battery unit 11 to a controllable voltage value of the DC conversion unit 22. Furthermore, the control unit 21 may control the DC conversion unit 22 to convert the DC power output from the voltage conversion unit 19 into AC power.

[0030] The control unit 21 may perform reverse connection prevention processing when the storage battery unit 11 is electrically connected to the power conditioner 12. The control unit 21 may start reverse connection prevention processing when directly or indirectly recognizing the connection of the storage battery unit 11. The usage method of the power conditioner 12 may be defined as switching the power supply to ON while the power conditioner 12 is electrically connected to the storage battery unit 11 and other power sources. The control unit 21 may recognize the connection to the storage battery unit 11 when the power supply of the power conditioner 12 is switched ON. Alternatively, the control unit 21 may recognize the connection to the storage battery unit 11 by an operation input by an installer to an input device of the power conditioner 12.

[0031] In the reverse connection prevention process, when the connection switch 13 is in the OFF state, the control unit 21 may control the voltage conversion unit 19 so that the voltage of the power supplied to the storage battery unit 11 becomes the first voltage by using the power supplied to the voltage conversion unit 19 from another power source via the DC-AC conversion unit 22. The control unit 21 applies the first voltage to the storage battery unit 11 connected to the power conditioner 12 by adjusting it to the first voltage. The first voltage may be less than a lower limit value of the usage voltage determined for the storage battery unit 11 that is expected to be connected. The lower limit value of the usage voltage is a voltage value at which the control unit 16 determines the end of discharge to protect the storage battery from over-discharge. For example, if the nominal voltage of the storage battery 15 is 200V, the lower limit value of the usage voltage is approximately 162V. The first voltage may be set to a low voltage such as 10V so that an inrush current is unlikely to flow to the storage battery unit 11 side. Furthermore, the control unit 21 may confirm that the connection switch 13 of the storage battery unit 11 is not in the ON state as a condition for starting the adjustment to the first voltage. Furthermore, the control unit 21 may confirm that there is no voltage between the second positive terminal 25 and the second negative terminal 26 as a condition for starting the adjustment to the first voltage.

[0032] The control unit 21 acquires the measured voltage as information from the storage battery unit 11 in a state where the first voltage is applied. As described above, the measured voltage is the voltage between the first positive electrode terminal 17 and the first negative electrode terminal 18 detected by the measurement unit 14. The control unit 21 determines whether or not the storage battery unit 11 is reverse-connected to the power conditioner 12 based on a comparison between the measured voltage and the first voltage. Reverse connection means that the polarity of the terminals of the storage battery unit 11 is reversed and the storage battery unit 11 is connected to the power conditioner 12.

[0033] Specifically, the control unit 21 may determine that the reverse connection is present when the difference between the measured voltage and the first voltage is not equal to or less than the discrimination threshold, in other words, when the difference exceeds the discrimination threshold. The discrimination threshold is a value determined to determine a range in which the measured voltage and the first voltage can be regarded as being the same. The control unit 21 may determine that the reverse connection is not present when the difference between the measured voltage and the first voltage is equal to or less than the discrimination threshold. The discrimination threshold is a value determined by adding the measurement error of the measurement unit 14 and the like to the first voltage set below the lower limit of the above-mentioned operating voltage. For example, in a configuration in which the first voltage is set to 10V, the discrimination threshold is 12V on the premise that the measurement errors of the measurement unit 14 and the control unit 21 are each 10%.

[0034] When it is determined that the reverse connection is not present, the control unit 21 may control the communication unit 24 to transmit a first command to the storage battery unit 11. The first command is a command to switch the connection switch 13 of the storage battery unit 11 to the ON state.

[0035] When the control unit 21 determines that the reverse connection is not present, the control unit 21 may apply to the capacitor 20 a second voltage that is closer to the operating voltage of the storage battery unit 11 than the first voltage, and then switch the connection switch 13 of the storage battery unit 11 to the ON state. Specifically, when the control unit 21 determines that the reverse connection is not present, the control unit 21 controls the voltage conversion unit 19 so that the voltage of the power supplied to the storage battery unit 11 becomes the second voltage, using power supplied from another power source to the voltage conversion unit 19 via the orthogonal conversion unit 22. The second voltage is between the first voltage and the operating voltage of the storage battery unit 11 and is closer to the first voltage. Furthermore, the control unit 21 transmits the first command to the storage battery unit 11 after adjusting to the second voltage.

[0036] When the control unit 21 determines that the reverse connection is not established, the control unit 21 controls the communication unit 24 to transmit a first command to the storage battery unit 11. When the control unit 21 determines that the reverse connection is established, the control unit 21 may control the communication unit 24 to transmit a second command to the storage battery unit 11. The second command is a command to maintain the connection switch 13 of the storage battery unit 11 in the OFF state. There is a risk that the control unit 16 switches the connection switch 13 to the ON state due to another condition determination or a manual operation by the user. On the other hand, by receiving the second command, it is possible to prevent the connection switch 13 from being switched to the ON state due to another command. Note that in a configuration designed from the viewpoint of safety so that the connection switch 13 is maintained in the OFF state until the storage unit 11 receives the first command from the control unit 21, the transmission of the second command may be omitted.

[0037] When determining that the power conditioner 12 is reversely connected, the control unit 21 may notify the user of an abnormal state. The control unit 21 may transmit a command to notify the user of the abnormal state to electronic devices including output devices such as a display and a speaker connected by wire or wirelessly to the power conditioner 12. The electronic devices are, for example, the power conditioner 12, a remote control for the power conditioner 12, a Home Energy Management System (HEMS), an external server, and the like.

[0038] The control unit 21 may compare a measured voltage newly acquired from the storage battery unit 11 with the first voltage after a predetermined waiting time has elapsed since it was determined that the storage battery unit 11 is reverse-connected. The control unit 21 may again determine whether or not the storage battery unit 11 is reverse-connected based on the comparison between the measured voltage and the first voltage.

[0039] The control unit 21 may determine whether each storage battery unit 11 is reverse-connected in a state in which the multiple storage battery units 11 are connected in parallel to the power conditioner 12. Specifically, the control unit 21 may determine whether each of the multiple storage battery units 11 is reverse-connected based on a comparison between a measured voltage measured by the measurement unit 14 and a first voltage. The control unit 21 may transmit a first command to a storage battery unit 11 that is determined not to be reverse-connected among the multiple storage battery units 11, to switch the connection switch 13 to the ON state.

[0040] Next, the reverse connection prevention process executed by the control unit 21 in this embodiment will be described with reference to the flowchart in Fig. 2. The reverse connection prevention process starts, for example, when it is recognized that the storage battery unit 11 is connected to the power conditioner 12.

[0041] In step S100, control unit 21 controls voltage conversion unit 19 to adjust the voltage of the power supplied to storage battery unit 11 to a first voltage. After adjusting the voltage, the process proceeds to step S101.

[0042] In step S101, the control unit 21 determines whether or not the measured voltage has been acquired as information from the storage battery unit 11. If the measured voltage has not been acquired, the process returns to step S101. If the measured voltage has been acquired, the process proceeds to step S102.

[0043] In step S102, the control unit 21 determines whether the difference between the measured voltage confirmed to have been acquired in step S101 and the first voltage is equal to or less than the discrimination threshold. If the difference is equal to or less than the discrimination threshold, the process proceeds to step S103. If the difference is not equal to or less than the discrimination threshold, the process proceeds to step S105.

[0044] In step S103, control unit 21 controls voltage conversion unit 19 to adjust the voltage of the power supplied to storage battery unit 11 to the second voltage. After adjusting the voltage, the process proceeds to step S104.

[0045] In step S104, the control unit 21 controls the communication unit 24 to transmit a first command to the storage battery unit 11. After the command is transmitted, the reverse connection prevention process ends.

[0046] In step S105, the control unit 21 controls the communication unit 24 to transmit a second command to the storage battery unit 11. After transmission, the process proceeds to step S106.

[0047] In step S106, the control unit 21 controls the communication unit 24 to transmit a command to notify the electronic devices including the output device of the abnormal state. After the command is transmitted, the reverse connection prevention process ends.

[0048] The energy storage system 10 of the present embodiment configured as described above includes at least one storage battery unit 11 having a storage battery 15, a measuring unit 14 for detecting the voltage of the storage battery 15, and a connection switch 13 provided between the storage battery 15 and the measuring unit 14, and a power conditioner 12 for adjusting the power input to the at least one storage battery unit 11 and the power output from the at least one storage battery unit 11. When the connection switch 13 is in an OFF state, a first voltage is applied from the power conditioner 12 to the storage battery unit 11, and when it is determined that the storage battery unit 11 is reverse-connected based on a comparison between the measured voltage detected by the measuring unit 14 and the first voltage, the OFF state of the connection switch 13 is maintained. With this configuration, the energy storage system 10 can determine reverse connection before applying the voltage from the storage battery 15 of the storage battery unit 11 to the power conditioner 12. Therefore, the energy storage system 10 can reduce the possibility of damage to the power conditioner 12 due to reverse connection.

[0049] In the energy storage system 10, the power conditioner 12 has a control unit 21 that issues a first command to the storage battery unit 11 to switch the connection switch 13 to an ON state when the difference between the measured voltage and the first voltage is equal to or less than the discrimination threshold. With this configuration, the energy storage system 10 can make the storage battery unit 11 available via the power conditioner 12 when the storage battery unit 11 is normally connected.

[0050] In addition, in the energy storage system 10, after it is determined that the storage battery unit 11 is reversely connected, a determination as to whether or not the storage battery unit 11 is reversely connected is performed again based on a comparison between the measured voltage after a predetermined waiting time has elapsed and the first voltage. With this configuration, the energy storage system 10 can automatically connect the storage battery 15 and the power conditioner 12 when an operator who has been notified of the abnormal state correctly reconnects the storage battery unit 11. In particular, automatic connection is effective in a configuration in which a plurality of storage battery units 11 are connected to the energy storage system 10. For example, the energy storage system 10 may switch the connection switch 13 to the OFF state when the first storage battery unit 11a stops charging or discharging, and perform a determination as to whether or not the second storage battery unit 11b is reversely connected, without forcibly interrupting charging or discharging in the first storage battery unit 11a. Furthermore, the power storage system 10 may issue a first command to all the storage battery units 11 to switch the connection switch 13 to the ON state when the second storage battery unit 11b is not in reverse connection.

[0051] Moreover, in the power storage system 10, the first voltage is less than the lower limit of the operating voltage determined for the storage battery unit 11. With this configuration, the power storage system 10 improves the accuracy of determining whether or not the reverse connection is present, since the first voltage for determining whether or not the reverse connection is present is different from the voltage that may be detected for the storage battery 15. Moreover, since the power storage system 10 uses a voltage lower than the voltage of the storage battery unit 11, the risk of electric shock can be further reduced.

[0052] Furthermore, when the difference between the measured voltage and the first voltage exceeds the determination threshold, the power storage system 10 notifies an abnormal state. With this configuration, the power storage system 10 can make the worker who installs the power storage system 10 recognize the reverse connection and urge him / her to make a normal connection again.

[0053] Furthermore, in the energy storage system 10, the connection switch 13 of the storage battery unit 11 that is determined not to be reverse-connected based on a comparison between the measured voltage detected by the measuring unit 14 and the first voltage among the multiple storage battery units 11 is switched to the ON state. With this configuration, the energy storage system 10 can operate only with the normal storage battery units 11 that are not reverse-connected, and the energy storage system 10 can be used using the other normally connected storage battery units 11 even during the period until the reverse connection state of the reverse-connected storage battery unit 11 is repaired.

[0054] In the energy storage system 10, the power conditioner 12 has a voltage conversion unit 19 that adjusts the voltage of the power supplied to the storage battery unit 11 and a capacitor 20 connected in parallel to the voltage conversion unit 19. When the difference between the measured voltage and the first voltage is equal to or less than the discrimination threshold, the second voltage, which is closer to the voltage used by the storage battery unit 11 than the first voltage, is applied to the capacitor 20, and then the connection switch 13 is switched to the ON state. With this configuration, the energy storage system 10 can reduce the voltage difference between the storage battery unit 11 and the power conditioner 12 before switching the connection switch 13 to the ON state. Therefore, the energy storage system 10 reduces the voltage difference between the storage battery unit 11 and the power conditioner 12 before conducting the power storage system 10, and therefore the current value of the inrush current between the storage battery unit 11 and the power conditioner 12 can be reduced. Therefore, the energy storage system 10 does not require a circuit for preventing inrush current in the power conditioner 12, and therefore the configuration of the power conditioner 12 can be simplified and the number of parts can be reduced.

[0055] In one embodiment, (1) the power storage system includes: At least one storage battery unit including a storage battery, a measurement unit that detects a voltage of the storage battery, and a connection switch that is provided between the storage battery and the measurement unit; a power conditioner that adjusts the power input to the at least one storage battery unit and the power output from the at least one storage battery unit; When the connection switch is in the OFF state, a first voltage is applied from the power conditioner to the storage battery unit, and the OFF state of the connection switch is maintained when it is determined that the storage battery unit is reverse-connected based on a comparison between the measured voltage detected by the measurement unit and the first voltage.

[0056] (2) In the energy storage system described above in (1), The power conditioner has a first control unit that issues a first command to the storage battery unit to switch the connection switch to an ON state when a difference between the measured voltage and the first voltage is equal to or less than a discrimination threshold.

[0057] (3) In the energy storage system described above in (1), The storage battery unit further includes a second control unit that switches the connection switch to an ON state when a difference between the measured voltage and the first voltage is equal to or smaller than a discrimination threshold value.

[0058] (4) In any one of the storage systems (1) to (3) above, After it is determined that the storage battery unit is reverse-connected, a determination is again made as to whether the storage battery unit is reverse-connected based on a comparison between the measured voltage and the first voltage after a predetermined waiting time has elapsed.

[0059] (5) In any one of the storage systems (1) to (4) above, The first voltage is less than a lower limit of a working voltage determined for the storage battery unit.

[0060] (6) In any one of the storage systems (1) to (5) above, When the difference between the measured voltage and the first voltage exceeds a discrimination threshold, an abnormal state is reported.

[0061] (7) In any one of the storage systems (1) to (6) above, the at least one storage battery unit includes a plurality of storage battery units; Among the plurality of storage battery units, the connection switch of a storage battery unit that is determined to not be reverse-connected based on a comparison between the measured voltage detected by the measuring unit and the first voltage is switched to an ON state.

[0062] (8) In the storage system of either (2) or (3) above, The power conditioner includes a voltage conversion unit that adjusts a voltage of power supplied to the storage battery unit, and a capacitor that is connected in parallel to the voltage conversion unit, When the difference between the measured voltage and the first voltage is equal to or less than the discrimination threshold, a voltage that is closer to the operating voltage of the storage battery unit than the first voltage is applied to the capacitor, and then the connection switch is switched to the ON state.

[0063] In one embodiment, the power conditioner (9) comprises: A power conditioner connected to at least one storage battery unit, The first control unit is configured to apply a first voltage to at least one of the storage battery units and determine whether the storage battery unit is reverse-connected based on a comparison between a measured voltage obtained from the storage battery unit and the first voltage, and if it is determined that the storage battery unit is not reverse-connected, transmit a first command to the storage battery unit to turn on a connection switch of the storage battery unit.

[0064] In one embodiment, the storage battery unit (10) comprises: A storage battery, A measurement unit that detects the voltage of the storage battery; A connection switch provided between the storage battery and the measurement unit; When the connection switch is in the OFF state and the measurement unit detects a voltage other than zero, a second control unit determines whether or not the connection is reversed based on a comparison between the measured voltage detected by the measurement unit and a first voltage indicated by voltage information obtained from a power conditioner connected to the storage battery via the connection switch, and maintains the connection switch in the OFF state if it is determined that the connection is reversed.

[0065] The above describes an embodiment of the energy storage system 10. However, the embodiment of the present disclosure can also be implemented as a method or program for implementing the device, or as a storage medium on which a program is recorded (for example, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a CD-RW, a magnetic tape, a hard disk, or a memory card, etc.).

[0066] Furthermore, the implementation form of the program is not limited to application programs such as object code compiled by a compiler or program code executed by an interpreter, but may be in the form of a program module incorporated into an operating system, etc. Furthermore, the program may or may not be configured so that all processing is performed only by the CPU on the control board. The program may be configured so that a part or all of it is executed by another processing unit mounted on an expansion board or expansion unit added to the board as necessary.

[0067] The drawings for explaining the embodiments according to the present disclosure are schematic, and the dimensional ratios and the like in the drawings do not necessarily correspond to the actual ones.

[0068] Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art can make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications or alterations are included in the scope of the present disclosure. For example, the functions, etc. included in each component, etc. can be rearranged so as not to cause logical inconsistencies, and multiple components, etc. can be combined into one or divided.

[0069] For example, in the embodiment disclosed above, the control unit 21 of the power conditioner 12 performs the reverse connection prevention process. However, the control unit 16 of the storage battery unit 11 may perform the reverse connection prevention process. Specifically, when the measurement unit 14 detects a measurement voltage other than zero when the connection switch 13 is in an OFF state, the control unit 16 may compare the measurement voltage with the first voltage. The measurement unit 14 detects a voltage other than zero when the first positive terminal 17 and the first negative terminal 18 are connected to an electrical device such as the power conditioner 12. Therefore, based on the detection of a voltage other than zero, the reverse connection prevention process may be started in the storage battery unit 11. The control unit 16 may acquire the first voltage as voltage information from the power conditioner 12 connected to the storage battery 15 via the connection switch 13. Alternatively, the control unit 16 may acquire the first voltage as voltage information in advance and store it in a memory. The voltage information may be acquired at the time of shipment from the factory, or may be acquired by an input operation to an input device of the power conditioner 12 or by communication from an external device. The control unit 16 may determine whether or not the reverse connection is present based on a comparison between the measured voltage and the first voltage. When the control unit 16 determines that the reverse connection is present, the control unit 16 may maintain the OFF state of the connection switch 13. When the control unit 16 determines that the reverse connection is not present, the control unit 16 may control the connection switch 13 to switch to the ON state.

[0070] All of the features described in this disclosure and / or all steps of any method or process disclosed herein may be combined in any combination except those combinations in which the features are mutually exclusive. Also, each feature described in this disclosure may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly denied. Thus, unless expressly denied, each disclosed feature is only one example of a generic series of the same or equivalent features.

[0071] Furthermore, the embodiments of the present disclosure are not limited to any of the specific configurations of the embodiments described above, but rather extend to any novel feature or combination of features described herein, or any novel method or process step or combination of features described herein.

[0072] In this disclosure, descriptions such as "first" and "second" are identifiers for distinguishing the configuration. In the configurations distinguished by descriptions such as "first" and "second" in this disclosure, the numbers in the configurations can be exchanged. For example, a first voltage can be exchanged with a second voltage, and the identifiers "first" and "second" can be exchanged. The exchange of identifiers is performed simultaneously. The configurations remain distinguished even after the exchange of identifiers. The identifiers may be deleted. A configuration from which an identifier has been deleted is distinguished by a symbol. The descriptions of identifiers such as "first" and "second" in this disclosure should not be used solely to interpret the order of the configurations or to justify the existence of an identifier with a smaller number. [Explanation of symbols]

[0073] 10 Energy Storage System 11 Battery unit 11a First storage battery unit 11b First storage battery unit 12 Power conditioner 13 Connection switch 14 Measurement section 15. Storage battery 16 Control section (second control section) 17 First positive terminal 18 First negative terminal 19 Voltage conversion section 20 Capacitor 21 Control unit (first control unit) 22 Orthogonal transformation section 23 Grid-connected relay 24 Communications Department 25 Second positive terminal 26 Second negative terminal 27 AC terminal

Claims

1. At least one storage battery unit including a storage battery, a measurement unit that detects a voltage of the storage battery, and a connection switch that is provided between the storage battery and the measurement unit; a power conditioner that adjusts power input to the at least one storage battery unit and power output from the at least one storage battery unit; When the connection switch is in an OFF state, a first voltage is applied from the power conditioner to the storage battery unit, and when it is determined that the storage battery unit is reverse-connected based on a comparison between a measured voltage detected by the measurement unit and the first voltage, the OFF state of the connection switch is maintained. Energy storage system.

2. The power storage system according to claim 1 , The power conditioner has a first control unit that issues a first command to the storage battery unit to switch the connection switch to an ON state when a difference between the measured voltage and the first voltage is equal to or smaller than a discrimination threshold. Energy storage system.

3. The power storage system according to claim 1 , The storage battery unit further includes a second control unit that switches the connection switch to an ON state when a difference between the measured voltage and the first voltage is equal to or less than a discrimination threshold. Energy storage system.

4. In the power storage system according to any one of claims 1 to 3, After it is determined that the storage battery unit is reversely connected, a determination as to whether or not the storage battery unit is reversely connected is performed again based on a comparison between the measured voltage and the first voltage after a predetermined waiting time has elapsed. Energy storage system.

5. In the power storage system according to any one of claims 1 to 3, The first voltage is less than a lower limit of a voltage used for the storage battery unit. Energy storage system.

6. In the power storage system according to any one of claims 1 to 3, When the difference between the measured voltage and the first voltage exceeds a discrimination threshold, an abnormal state is notified. Energy storage system.

7. In the power storage system according to any one of claims 1 to 3, the at least one storage battery unit includes a plurality of storage battery units; The connection switch of a storage battery unit that is determined not to be reverse-connected based on a comparison between a measured voltage detected by the measurement unit and the first voltage among the plurality of storage battery units is switched to an ON state. Energy storage system.

8. The power storage system according to claim 2 or 3, The power conditioner includes a voltage conversion unit that adjusts a voltage of power supplied to the storage battery unit, and a capacitor that is connected in parallel to the voltage conversion unit, When the difference between the measured voltage and the first voltage is equal to or less than the discrimination threshold, a voltage closer to a voltage used by the storage battery unit than the first voltage is applied to the capacitor, and then the connection switch is switched to an ON state. Energy storage system.

9. A power conditioner connected to at least one storage battery unit, a first control unit that determines whether or not the storage battery unit is reverse-connected based on a comparison between a measured voltage obtained from the storage battery unit and the first voltage while a first voltage is applied to the at least one storage battery unit, and transmits a first command to the storage battery unit to turn on a connection switch of the storage battery unit when it is determined that the storage battery unit is not reverse-connected. Power conditioner.

10. A storage battery, A measurement unit that detects the voltage of the storage battery; A connection switch provided between the storage battery and the measurement unit; and a second control unit that, when the connection switch is in an OFF state and the measurement unit detects a voltage other than zero, determines whether or not the connection is reversed based on a comparison between a measured voltage detected by the measurement unit and a first voltage indicated by voltage information acquired from a power conditioner connected to the storage battery via the connection switch, and maintains the OFF state of the connection switch when it is determined that the connection is reversed. Battery storage unit.

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