Energy storage systems, power conditioners, and battery units

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

[0003]

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

Background Art

[0002] A battery unit including a plurality of secondary battery cells is connected to a power conditioner that performs AC-DC conversion and voltage adjustment between the battery unit, load equipment, and other power sources. When installing the battery unit and the power conditioner, there is a possibility of incorrect polarity connection and reverse connection. When reverse-connected, a large current flows, which may cause damage to the power conditioner and deterioration of the battery unit. Even in the case of reverse connection, a power supply device for protecting the circuit has been proposed (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems 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 in the reverse-connected state. Therefore, there is a possibility that the component life is impaired in a part of the circuit. In addition, an additional circuit for protecting against reverse connection is required.

[0005] In view of such points, an object of the present disclosure is to reduce the possibility of damage and deterioration due to reverse connection.

Means for Solving the Problems

[0007] From a second perspective, the power conditioner is: A power conditioner connected to at least one battery unit, The system includes a first control unit that, when a first voltage is applied to at least one of the battery units, determines whether the battery unit is reverse-connected based on a comparison of the measured voltage obtained from the battery unit with the first voltage, and if it is determined that the battery unit is not reverse-connected, transmits a first command to the battery unit to turn on the connection switch of the battery unit.

[0008] From a third perspective, the battery storage unit is: Storage batteries and A measuring unit for detecting the voltage of the storage battery, A connection switch provided between the storage battery and the measuring unit, The system includes a second control unit that, when the connection switch is in the OFF state, detects a voltage other than zero, determines whether or not it is reverse-connected 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 battery via the connection switch, and maintains the OFF state of the connection switch if it is determined to be reverse-connected. [Effects of the Invention]

[0009] According to this disclosure, the possibility of damage and degradation due to reverse connection is reduced. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing the general configuration of the energy storage system according to this embodiment. [Figure 2] This is a flowchart illustrating the reverse connection prevention process performed by the control unit of the power conditioner shown in Figure 1. [Modes for carrying out the invention]

[0011] Embodiments of this disclosure will be described below with reference to the drawings. In the components shown in the following drawings, the same components are denoted by the same reference numerals.

[0012] As shown in Figure 1, an energy storage system 10 according to one embodiment of the present disclosure comprises at least one battery unit 11 and a power conditioner 12. The at least one battery unit 11 may be a single battery unit 11 or a plurality of battery units 11. The energy storage system 10 illustrated in Figure 1 is described as comprising two battery units 11, a first battery unit 11a and a second battery unit 11b. In the following description, the first battery unit 11a and the second battery unit 11b will be referred to as battery unit 11. The plurality of battery units 11 may be connected in parallel.

[0013] As described later, when the connection switch 13 of the battery unit 11 is in the OFF state, a first voltage is applied to the battery unit 11 from the power conditioner 12. The measured voltage detected by the measurement unit 14 of the battery unit 11 is compared with the first voltage in response to the application of the first voltage. If it is determined that the 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 battery unit 11 is reverse-connected based on the comparison between the measured voltage and the first voltage may be performed, for example, by the power conditioner 12.

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

[0015] The battery 15 may include one or more secondary battery cells. In a configuration with multiple secondary battery cells, the multiple secondary battery cells may be connected in series or in parallel. The positive electrode of the battery 15 may be directly or indirectly connected to the positive terminal 17 of the battery unit 11. Specifically, the positive electrode of the battery 15 is connected to the positive terminal 17 of the battery unit 11 via a connection switch 13. The negative electrode of the battery 15 may be directly or indirectly connected to the negative terminal 18 of the battery unit 11. Specifically, the negative electrode of the battery 15 is connected to the negative terminal 18 of the 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 will be described later, since the connection switch 13 is provided between the measurement unit 14 and the storage battery 15, in the OFF state of the connection switch 13, 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 value of the measurement range of the measurement unit 14 may be 0V or may be a negative value. The lower limit value may be below the 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 the current in the OFF state. The connection switch 13 may conduct the current in the ON state. The connection switch 13 is, for example, an electromagnetic relay or a FET.

[0018] The control unit 16 is configured to include at least one processor, at least one dedicated circuit, or a combination thereof. The processor is a general-purpose processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), or a dedicated processor specialized for specific processing. The dedicated circuit may be, for example, an FPGA (Field-Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), or the like. The control unit 16 controls the operation of the storage battery unit 11.

[0019] The control unit 16 may, for example, acquire the measured voltage of the voltage from the measurement unit 14 as information. The control unit 16 may provide the measured voltage of the voltage as information to the power conditioner 12. When the control unit 16 acquires a first command, which will be described later, from the power conditioner 12 with respect to the provision of the measured voltage, the connection switch 13 may be switched to the ON state. Note that the control unit 16 may maintain the connection switch 13 in the OFF state until the first command is acquired.

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

[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 orthogonal conversion unit 22, a link relay 23, and a communication unit 24.

[0022] The voltage conversion unit 19 may adjust the voltage of the power supplied to the 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 to voltages set by the control unit 21. The second positive terminal 25 is the positive terminal in the power conditioner 12 that is connected to the battery unit 11. The second negative terminal 26 is the negative terminal in the power conditioner 12 that is connected to the battery unit 11. 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] Capacitor 20 is connected in parallel to the voltage conversion unit 19. More specifically, capacitor 20 is connected to the output terminals connected to the second positive terminal 25 and the second negative terminal 26 of the voltage conversion unit 19. Capacitor 20 may be built into the voltage conversion unit 19. Capacitor 20 is, for example, a smoothing capacitor.

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

[0025] The interconnection relay 23 may be provided between the orthogonal conversion unit 22 and the AC terminal 27. The interconnection relay 23 may interrupt the current when it is in the OFF state. The connection switch 13 may conduct current when it is in the ON state.

[0026] The communication unit 24 may communicate with the battery unit 11 by wire or wireless connection. The communication unit 24 may provide information and commands to the battery unit 11 based on the control of the control unit 21. The communication unit 24 may provide the control unit 21 with information obtained from the battery unit 11. The information obtained may be a voltage value measured by the measurement unit 14, or it may be a voltage value read from the second control unit 16.

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

[0028] The control unit 21 may switch the grid connection relay 23 to the ON state when charging the battery unit 11. Furthermore, the control unit 21 may control the orthogonal conversion unit 22 to convert the AC power supplied from the grid 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 orthogonal conversion unit 22 to a voltage value for charging the battery unit 11. In a configuration where another power source connected to the power conditioner 12 supplies DC power, the voltage conversion unit 19 may be operated without operating the orthogonal conversion unit 22.

[0029] The control unit 21 may switch the grid-connection relay 23 to the ON state when discharging from the battery unit 11. Furthermore, the control unit 21 may control the voltage conversion unit 19 to adjust the voltage of the DC power output from the battery unit 11 to a controllable voltage value of the orthogonal conversion unit 22. Furthermore, the control unit 21 may control the orthogonal 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 battery unit 11 is electrically connected to the power conditioner 12. The control unit 21 may start reverse connection prevention processing when it directly or indirectly recognizes the connection of the battery unit 11. The operation method may be defined as switching the power ON of the power conditioner 12 while it is electrically connected to the battery unit 11 and other power sources. The control unit 21 may recognize the connection with the battery unit 11 when the power of the power conditioner 12 is switched ON. Alternatively, the control unit 21 may recognize the connection with the battery unit 11 through operation input by the installer to the 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 using power supplied to the voltage conversion unit 19 from another power source via the orthogonal conversion unit 22 so that the voltage of the power supplied to the battery unit 11 becomes the first voltage. By adjusting to the first voltage, the control unit 21 applies the first voltage to the battery unit 11 connected to the power conditioner 12. The first voltage may be less than the lower limit of the operating voltage set for the battery unit 11 that is expected to be connected. The lower limit of the operating voltage is the voltage value at which the control unit 16 determines the termination of discharge in order to protect the battery from over-discharge. For example, if the nominal voltage of the battery 15 is 200V, the lower limit of the operating voltage is approximately 162V. The first voltage may be set to a low voltage such as 10V so that inrush current is less likely to flow to the battery unit 11. Furthermore, the control unit 21 may confirm that the connection switch 13 of the 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 battery unit 11 while the first voltage is applied. The measured voltage is, as described above, the voltage between the first positive terminal 17 and the first negative terminal 18 detected by the measurement unit 14. Based on a comparison of the measured voltage and the first voltage, the control unit 21 determines whether or not the battery unit 11 is reverse-connected to the power conditioner 12. Reverse connection means reversing the polarity of the terminals of the battery unit 11 and connecting it to the power conditioner 12.

[0033] Specifically, the control unit 21 may determine that the voltages are reversed if the difference between the measured voltage and the first voltage is not below a discrimination threshold, or in other words, if it exceeds the discrimination threshold. The discrimination threshold is a value determined to define the range in which the measured voltage and the first voltage can be considered the same. The control unit 21 may determine that the voltages are not reversed if the difference between the measured voltage and the first voltage is below the discrimination threshold. The discrimination threshold is a value determined by taking into account the measurement error of the measurement unit 14, etc., on the first voltage, which is set below the lower limit of the operating voltage mentioned above. For example, in a configuration where the first voltage is set to 10V, the discrimination threshold is 12V, assuming that the measurement error of the measurement unit 14 and the control unit 21 are each 10%.

[0034] If the control unit 21 determines that the connections are not reversed, it may control the communication unit 24 to send a first command to the battery unit 11. The first command is a command to switch the connection switch 13 of the battery unit 11 to the ON state.

[0035] If the control unit 21 determines that there is no reverse connection, it may apply a second voltage to the capacitor 20 that is closer to the operating voltage of the battery unit 11 than the first voltage, and then switch the connection switch 13 of the battery unit 11 to the ON state. Specifically, if the control unit 21 determines that there is no reverse connection, it uses the power supplied to the voltage conversion unit 19 from another power source via the orthogonal conversion unit 22 to control the voltage conversion unit 19 so that the voltage of the power supplied to the battery unit 11 becomes the second voltage. The second voltage is between the first voltage and the operating voltage of the battery unit 11, and is a value closer to the first voltage. Furthermore, after adjusting to the second voltage, the control unit 21 transmits the first command to the battery unit 11.

[0036] If the control unit 21 determines that the connection is not reversed, it controls the communication unit 24 to send a first command to the battery unit 11. If the control unit 21 determines that the connection is reversed, it may control the communication unit 24 to send a second command to the battery unit 11. The second command is a command to keep the connection switch 13 of the battery unit 11 in the OFF state. There is a risk that the control unit 16 may switch the connection switch 13 to the ON state due to other condition checks or 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 by other commands. Note that in a configuration designed from a safety standpoint so that the battery unit 11 keeps the connection switch 13 in the OFF state until it receives the first command from the control unit 21, the transmission of the second command may be omitted.

[0037] If the control unit 21 determines that the connections are reversed, it may notify that an abnormal condition exists. The control unit 21 may, for example, transmit a command to electronic equipment, including output devices such as displays and speakers, which are connected to the power conditioner 12 by wire or wireless connection, to notify that an abnormal condition exists. Examples of electronic equipment include the power conditioner 12, the remote control for the power conditioner 12, a HEMS (Home Energy Management System), and an external server.

[0038] The control unit 21 may compare the first voltage with a newly obtained measured voltage from the battery unit 11 after a predetermined waiting period has elapsed since it was determined that the battery unit 11 is reverse-connected. The control unit 21 may then perform the determination again whether or not the 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 battery unit 11 is connected in reverse when multiple battery units 11 are connected in parallel to the power conditioner 12. Specifically, the control unit 21 may determine whether each of the multiple battery units 11 is connected in reverse based on a comparison between the measured voltage measured by the measurement unit 14 and the first voltage. The control unit 21 may transmit a first command to the battery unit 11 to switch the connection switch 13 of the battery unit 11 that it has determined is not connected in reverse to the ON state.

[0040] Next, the reverse connection prevention process performed by the control unit 21 in this embodiment will be explained using the flowchart in Figure 2. The reverse connection prevention process is started, for example, when it is recognized that the battery unit 11 has been connected to the power conditioner 12.

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

[0042] In step S101, the control unit 21 determines whether or not it has acquired the measured voltage as information from the battery unit 11. If it has not been acquired, the process returns to step S101. If it 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 in step S101 and the first voltage is less than or equal to a discrimination threshold. If the difference is less than or equal to the discrimination threshold, the process proceeds to step S103. If the difference is not less than or equal to the discrimination threshold, the process proceeds to step S105.

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

[0045] In step S104, the control unit 21 controls the communication unit 24 to transmit the first command to the battery unit 11. After transmission, 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 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 send a command to the electronic equipment, including the output device, to notify it of the abnormal condition. After transmission, the reverse connection prevention process ends.

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

[0049] Furthermore, in the energy storage system 10, the power conditioner 12 has a control unit 21 that issues a first command to the battery unit 11 to switch the connection switch 13 to the ON state when the difference between the measured voltage and the first voltage is below a discrimination threshold. With this configuration, the energy storage system 10 can make the battery unit 11 available for use via the power conditioner 12 when it is properly connected.

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

[0051] Furthermore, in the energy storage system 10, the first voltage is below the lower limit of the operating voltage set for the battery unit 11. With this configuration, the energy storage system 10 improves the accuracy of detecting reverse connection because the first voltage used to determine whether a reverse connection is present is different from the voltage that may be detected for the battery 15. In addition, since the energy storage system 10 uses a voltage lower than the voltage of the battery unit 11, the risk of electric shock can be further reduced.

[0052] Furthermore, the energy storage system 10 notifies of an abnormal condition if the difference between the measured voltage and the first voltage exceeds a discrimination threshold. With this configuration, the energy storage system 10 can make the worker installing the energy storage system 10 aware of the reverse connection and prompt them to reconnect it correctly.

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

[0054] Furthermore, 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 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 below a discrimination threshold, a second voltage, which is closer to the operating voltage of the 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 battery unit 11 and the power conditioner 12 before switching the connection switch 13 to the ON state. Therefore, since the energy storage system 10 reduces the voltage difference between the two before conducting, the inrush current value between the battery unit 11 and the power conditioner 12 can be reduced. Consequently, the energy storage system 10 eliminates the need for a circuit to prevent inrush current in the power conditioner 12, thus simplifying the configuration of the power conditioner 12 and reducing the number of parts.

[0055] In one embodiment, (1) the energy storage system is A battery unit comprising a battery, a measuring unit for detecting the voltage of the battery, and a connecting switch provided between the battery and the measuring unit, The system includes a power conditioner that adjusts the power input to the at least one battery unit and the power output from the at least one battery unit, When the connection switch is in the OFF state, a first voltage is applied from the power conditioner to the battery unit, and the OFF state of the connection switch is maintained if it is determined that the 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 in (1) above, The power conditioner has a first control unit that issues a first command to the battery unit to switch the connection switch to the ON state when the difference between the measured voltage and the first voltage is less than or equal to a discrimination threshold.

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

[0058] (4) In any of the energy storage systems described in (1) to (3) above, After it is determined that the battery unit is connected in reverse, the determination of whether the battery unit is connected in reverse is performed again based on a comparison of the measured voltage and the first voltage after a predetermined waiting period has elapsed.

[0059] (5) In any of the energy storage systems described in (1) through (4) above, The first voltage is less than the lower limit of the operating voltage set for the battery unit.

[0060] (6) In any of the energy storage systems described in (1) through (5) above, If the difference between the measured voltage and the first voltage exceeds a discrimination threshold, an abnormal condition is reported.

[0061] (7) In any of the energy storage systems described in (1) through (6) above, The aforementioned at least one battery unit includes a plurality of battery units, Among the plurality of battery units, the connection switch of the battery unit that is determined not to be reverse-connected based on a comparison of the measured voltage detected by the measurement unit with the first voltage is switched to the ON state.

[0062] (8) In either of the energy storage systems described in (2) or (3) above, The power conditioner includes a voltage conversion unit that adjusts the voltage of the power supplied to the battery unit, and a capacitor connected in parallel to the voltage conversion unit. If the difference between the measured voltage and the first voltage is less than or equal to the discrimination threshold, a voltage closer to the operating voltage of the 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, (9) the power conditioner is A power conditioner connected to at least one battery unit, The system includes a first control unit that, when a first voltage is applied to at least one of the battery units, determines whether the battery unit is reverse-connected based on a comparison of the measured voltage obtained from the battery unit with the first voltage, and if it is determined that the battery unit is not reverse-connected, transmits a first command to the battery unit to turn on the connection switch of the battery unit.

[0064] In one embodiment, (10) the battery unit is Storage batteries and A measuring unit for detecting the voltage of the storage battery, A connection switch provided between the storage battery and the measuring unit, The system includes a second control unit that, when the connection switch is in the OFF state, detects a voltage other than zero, determines whether or not it is reverse-connected 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 battery via the connection switch, and maintains the OFF state of the connection switch if it is determined to be reverse-connected.

[0065] While embodiments of the energy storage system 10 have been described above, embodiments of the present disclosure may also include not only methods or programs for implementing the device, but also a storage medium on which the program is recorded (for example, an optical disc, magneto-optical disc, CD-ROM, CD-R, CD-RW, magnetic tape, hard disk, or memory card).

[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 also be in the form of a program module embedded in an operating system. Moreover, the program may or may not be configured so that all processing is performed only on the CPU on the control board. The program may also be configured so that some or all of its processing is performed by another processing unit implemented on an expansion board or expansion unit attached to the board, as needed.

[0067] The diagrams illustrating the embodiments described herein are schematic. Dimensions and proportions shown in the drawings do not necessarily correspond to actual dimensions.

[0068] While embodiments relating to this 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 this disclosure. Therefore, it should be noted that these modifications or alterations are within the scope of this disclosure. For example, the functions and other elements included in each component can be rearranged in a logically consistent manner, and multiple components can be combined into one or separated.

[0069] For example, in the embodiment disclosed above, the control unit 21 of the power conditioner 12 performs reverse connection prevention processing. However, the control unit 16 of the battery unit 11 may perform reverse connection prevention processing. Specifically, when the connection switch 13 is in the OFF state, the control unit 16 may compare the measured voltage with the first voltage when the measurement unit 14 detects a measured voltage other than zero. 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 electrical equipment such as the power conditioner 12. Therefore, based on the detection of a voltage other than zero, the reverse connection prevention processing may be started in the battery unit 11. The control unit 16 may acquire the first voltage as voltage information from the power conditioner 12 connected to the 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 memory. Voltage information may be acquired at the time of factory shipment, or by input operations to the input device of the power conditioner 12 or by communication from an external device. The control unit 16 may determine whether or not the connections are reversed based on a comparison of the measured voltage and the first voltage. If the control unit 16 determines that the connections are reversed, it may maintain the OFF state of the connection switch 13. If the control unit 16 determines that the connections are not reversed, it may control the connection switch 13 to switch to the ON state.

[0070] All of the constituent elements described in this disclosure, and / or all of the disclosed methods or steps of processing, can be combined in any combination except for any combination in which these features are mutually exclusive. Furthermore, each of the features described in this disclosure can be replaced by an alternative feature that works for the same, equivalent, or similar purpose, unless expressly disregarded. Thus, unless expressly disregarded, each of the disclosed features is merely an example of a comprehensive set of identical or equivalent features.

[0071] Furthermore, the embodiments relating to this disclosure are not limited to any specific configuration of the embodiments described above. The embodiments relating to this disclosure can be extended to all novel features or combinations thereof described herein, or all novel methods or processing steps or combinations thereof described herein.

[0072] In this disclosure, the designations "First," "Second," etc., are identifiers used to distinguish the configurations. Configurations distinguished by the designations "First," "Second," etc., in this disclosure may have their numbers swapped. For example, the first voltage and the second voltage may have their identifiers "First" and "Second" swapped. The swapping of identifiers occurs simultaneously. The configurations remain distinguishable even after the swapping of identifiers. Identifiers may be deleted. Configurations from which identifiers have been deleted are distinguished by their codes. The designations "First," "Second," etc., in this disclosure should not be used alone to interpret the order of the configurations or to justify the existence of smaller numbered identifiers. [Explanation of Symbols]

[0073] 10 Energy storage systems 11 Battery Unit 11a First battery unit 11b First battery unit 12 Power Conditioner 13. Connection switch 14 Measurement Unit 15 Storage batteries 16 Control Unit (Second Control Unit) 17. First positive terminal 18 First negative terminal 19 Voltage conversion section 20 Capacitors 21 Control Unit (First Control Unit) 22 Orthogonal Transformation Unit 23-connection relay 24 Communications Department 25 Second positive terminal 26 Second negative terminal 27 AC terminal

Claims

1. A battery unit comprising a battery, a measuring unit for detecting the voltage of the battery, and a connecting switch provided between the battery and the measuring unit, The system includes a power conditioner that adjusts the power input to the at least one battery unit and the power output from the at least one battery unit, When the connection switch is in the OFF state, a first voltage is applied from the power conditioner to the battery unit, and the OFF state of the connection switch is maintained if it is determined that the battery unit is reverse-connected based on a comparison between the measured voltage detected by the measurement unit and the first voltage. Energy storage system.

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

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

4. In the energy storage system according to any one of claims 1 to 3, After it is determined that the battery unit is connected in reverse, the determination of whether the battery unit is connected in reverse is performed again based on a comparison of the measured voltage and the first voltage after a predetermined waiting period has elapsed. Energy storage system.

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

6. In the energy storage system according to any one of claims 1 to 3, If the difference between the measured voltage and the first voltage exceeds a discrimination threshold, an abnormal condition is reported. Energy storage system.

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

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

9. A power conditioner connected to at least one battery unit, The system includes a first control unit which, when a first voltage is applied to at least one of the battery units, determines whether the battery unit is reverse-connected based on a comparison of the measured voltage obtained from the battery unit with the first voltage, and if it is determined that the battery unit is not reverse-connected, transmits a first command to the battery unit to turn on the connection switch of the battery unit. Power conditioner.

10. Storage batteries and A measuring unit for detecting the voltage of the storage battery, A connection switch provided between the storage battery and the measuring unit, The system includes a second control unit that, when the connection switch is in the OFF state, detects a voltage other than zero, and determines whether or not it 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 the power conditioner connected to the battery via the connection switch, and maintains the OFF state of the connection switch if it is determined to be reversed. Battery storage unit.

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