Power storage system

Abstract

The first power storage device has a first switching section disposed between the wiring and the first power storage section, and switches an electrical connection relationship between the wiring and the first power storage section based on a voltage difference between the wiring and the first power storage section. The second power storage device has a second switching section disposed between the wiring and the second power storage section, and switches an electrical connection relationship between the wiring and the second power storage section based on a voltage difference between the wiring and the second power storage section. The first power storage section can include a first type of secondary battery. The second power storage section can include a second type of secondary battery. A charge termination voltage of the first power storage section is lower than a full charge voltage of the first power storage section, and is smaller than a charge termination voltage of the second power storage section.

Description

Technical Field

[0001] This invention relates to an energy storage system. Background Technology

[0002] In energy storage systems with multiple energy storage modules, these modules are sometimes connected in parallel (see, for example, Patent Document 1). Patent Documents 2-4 disclose an energy storage system with hot-swappable energy storage modules. [Background Technical Documents] [Patent Literature] [Patent Document 1] Japanese Patent Application Publication No. 11-98708 [Patent Document 2] International Publication No. 2017 / 086349 [Patent Document 3] International Publication No. 2017 / 086349 [Patent Document 4] Japanese Patent Application Publication No. 2019-092257 Summary of the Invention [The problem the invention aims to solve]

[0003] When multiple energy storage modules of different types are connected in parallel, depending on the combination of the types of energy storage modules, there may be a situation where at least one energy storage module cannot fully exert its performance. [Generally Public]

[0004] In this invention, an energy storage system is provided. The energy storage system includes, for example, a first energy storage device having a first energy storage section. The energy storage system also includes, for example, a second energy storage device having a second energy storage section. The energy storage system includes, for example, a wiring system for connecting the first energy storage device and the second energy storage device in parallel. In the energy storage system, the first energy storage device includes, for example, a first switching unit disposed between the wiring system and the first energy storage device, which switches the electrical connection between the wiring system and the first energy storage device based on the voltage difference between the wiring system and the first energy storage device. In the energy storage system, the second energy storage device includes, for example, a second switching unit disposed between the wiring system and the second energy storage device, which switches the electrical connection between the wiring system and the second energy storage device based on the voltage difference between the wiring system and the second energy storage device. In the energy storage system, the first energy storage section includes, for example, a first type of secondary battery. The second energy storage section includes, for example, a second type of secondary battery. The battery system of the first type of secondary battery is represented, for example, by a reaction formula in which the battery system, in principle, does not undergo irreversible changes even when an overcharged state persists. In the second type of secondary battery system, for example, when an overcharged state persists, the battery system will undergo an irreversible change in principle, as represented by the following reaction formula. In the energy storage system, the charging end voltage of the first energy storage unit is, for example, below the full charge voltage of the first energy storage unit and greater than the charging end voltage of the second energy storage unit.

[0005] In this invention, an energy storage system is provided. The energy storage system includes, for example, wiring for connecting a first energy storage device having a first energy storage section and a second energy storage device having a second energy storage section in parallel. In the energy storage system, the first energy storage device includes, for example, a first switching unit disposed between the wiring and the first energy storage device, which switches the electrical connection between the wiring and the first energy storage device based on the voltage difference between the wiring and the first energy storage device. In the energy storage system, the second energy storage device includes, for example, a second switching unit disposed between the wiring and the second energy storage device, which switches the electrical connection between the wiring and the second energy storage device based on the voltage difference between the wiring and the second energy storage device. In the energy storage system, the first energy storage device includes, for example, a first type of secondary battery. The second energy storage device includes, for example, a second type of secondary battery. The battery system of the first type of secondary battery is represented, for example, by a reaction formula in which, even when an overcharged state persists, the battery system in principle does not undergo irreversible changes. The battery system of the second type of secondary battery is represented, for example, by a reaction formula in which, when an overcharged state persists, the battery system in principle undergoes irreversible changes. In the energy storage system, the charging end voltage of the first energy storage unit is, for example, below the full charge voltage of the first energy storage unit and greater than the charging end voltage of the second energy storage unit.

[0006] In the energy storage system of the first or second aspect, the full-charge voltage of the first energy storage unit may be less than the charging voltage of the charging device that charges the first and second energy storage devices connected in parallel. The energy storage system of the first or second aspect may include a charging voltage control unit that controls a set value of the charging voltage of the charging device. In the energy storage system, the charging device may charge the first and second energy storage devices by a constant current method for at least a portion of the charging period of the first and second energy storage devices. In the energy storage system, when the voltage of the first energy storage unit is below the charging end voltage, the charging device charges the first energy storage device by a constant current method. In the energy storage system, when the voltage of the first energy storage unit is above the charging end voltage, the charging device may charge the first energy storage device by a trickle charging method.

[0007] In the energy storage system of the first or second aspect, the first energy storage device may have a limiting part connected in parallel with a first switching part between the wiring and the first energy storage device, having a resistance larger than that of the first switching part, allowing current to flow from the wiring to the first energy storage device while suppressing current from flowing from the first energy storage device to the wiring. In the energy storage system, the limiting part may include a current limiting part that limits the amount of current flowing through the limiting part. In the energy storage system, the limiting part may include a current direction limiting part connected in series with the current quantity limiting part, allowing current to flow from the wiring to the first energy storage device while suppressing current from flowing from the first energy storage device to the wiring.

[0008] In the energy storage system of the first or second aspect, the first energy storage device may have a short-circuit section disposed between the wiring and the first energy storage unit, and connected in parallel with a first switching unit between the wiring and the first energy storage unit, for short-circuiting the first switching unit. In the energy storage system, the short-circuit section may include a short-circuit state switching unit that transitions the short-circuit section to a state that short-circuits the first switching unit. In the energy storage system, if it is detected that the output current of the energy storage system is greater than the charging current of the energy storage system, or if it is predicted that the output current of the energy storage system will be greater than the charging current of the energy storage system, the short-circuit state switching unit may short-circuit the first switching unit.

[0009] In the energy storage system, under at least one of the following conditions, the short-circuit state switching unit can switch the state of the short-circuit unit from a state where the short-circuit unit short-circuits the first switching unit to a state where the short-circuit unit does not short-circuit the first switching unit: (i) a predetermined time has elapsed after the short-circuit state switching unit short-circuits the first switching unit; and (ii) it is detected that the output current of the energy storage system is less than the charging current of the energy storage system, or it is predicted that the output current of the energy storage system will be less than the charging current of the energy storage system. In the energy storage system, when the energy storage system obtains information indicating that a load device using power supplied from the energy storage system has begun to use power, the short-circuit state switching unit can short-circuit the first switching unit. In the energy storage system, the short-circuit state switching unit can short-circuit the first switching unit before the energy storage system outputs current.

[0010] The energy storage system of the first or second aspect may include a fluctuation suppression unit for suppressing fluctuations in the output voltage of the energy storage system. In the energy storage system, a short-circuit switching unit may short-circuit the first switching unit after the energy storage system outputs current. In the energy storage system, the fluctuation suppression unit may be configured such that, when a load device using power supplied from the energy storage system is electrically connected to the energy storage system, the fluctuation suppression unit is connected in parallel with the load device.

[0011] The energy storage system of the first or second aspect may include a detection unit that detects the energy storage system supplying power to the load device. In the energy storage system, when the detection unit detects that the energy storage system has supplied power to the load device, a short-circuit switching unit may short-circuit a first switching unit. In the energy storage system, after the energy storage system supplies power to the load device, the current consumption of the load device may be increased continuously or in stages. The energy storage system may receive a request signal from the load device indicating the magnitude of the current to be supplied to the load device. The energy storage system may output a current of the magnitude indicated by the request signal. In the energy storage system, the load device may include a current consumption control unit that controls the amount of current consumed by the load device.

[0012] The energy storage system of the first or second aspect may have a plurality of first energy storage devices connected in parallel. In the energy storage system, at least two of the plurality of first energy storage devices may have a short-circuit section.

[0013] Furthermore, the summary of the invention does not list all the essential features of the invention. Additionally, sub-combinations of these feature groups can also constitute an invention. Attached Figure Description

[0014] Figure 1 This is a simplified representation of the system configuration of the power supply system 10. Figure 2 This is a simplified representation of an example of the system configuration of the energy storage module 110. Figure 3 This is a simplified representation of an example of the system configuration of the energy storage module 130. Figure 4 This is a simplified representation of an example of the system configuration of the module control unit 240. Figure 5 Here is a simplified illustration of the circuit configuration of the energy storage module 110. Figure 6 This is a simplified representation of an example of the system configuration of the system control unit 140. Figure 7 This is a rough example illustrating the voltage and current variations of each energy storage module. Figure 8 This is a brief example of a variation in the charging voltage applied to the energy storage system 100. Figure 9 An example that roughly represents the output characteristics of the charging device 14. Figure 10 Here is a simplified example of the system configuration of the energy storage module 1010. Figure 11 Here is a simplified example of the system configuration of the module control unit 1040. Figure 12 Here is a simplified example of the circuit configuration of the module control unit 1040. Figure 13 This is a simplified example of the system configuration of the energy storage module 1330. Figure 14 This is a simplified example of the system configuration of the energy storage module 1430. Figure 15 This is a simplified representation of the system configuration of the power supply system 10. Figure 16 Here is a simplified example of the system configuration of the energy storage module 1630. Figure 17 This is a simplified representation of an example of the control of the module control unit 1640. Figure 18 This is a simplified representation of an example of current variation in the power supply system 10. Figure 19 This is a simplified representation of the system configuration of the power supply system in 1910. Figure 20 This is a simplified representation of an example of the control of the module control unit 1640. Figure 21 This is a simplified representation of an example of current variation in an electrical supply system in 1910. Figure 22 This is a simplified representation of the system configuration of the power supply system 2210. Figure 23 This is a simplified representation of an example of the control of the module control unit 1640. Figure 24 This is a simplified representation of an example of current variation in the power supply system 2210. Detailed Implementation

[0015] The present invention will now be described through embodiments thereof, but these embodiments do not limit the invention as defined in the claims. The combinations of features described in the embodiments are not necessarily all necessary for the solution of the invention. Furthermore, the embodiments will be described with reference to the accompanying drawings; however, in the drawings, the same or similar parts are sometimes given the same reference numerals and repeated descriptions are omitted.

[0016] Figure 1 This is a simplified example of the system configuration of the power supply system 10. In this embodiment, the power supply system 10 includes a charging device 14, a charging switching unit 16, and an energy storage system 100. The power supply system 10 may also include a load device 20 and a load switching unit 26. In this embodiment, the energy storage system 100 includes a connection terminal 102, a connection terminal 104, a wiring 106 electrically connecting the connection terminal 102 and the connection terminal 104, an energy storage module 110, an energy storage module 130, and a system control unit 140.

[0017] For the sake of simplicity, this embodiment uses the case where the energy storage system 100 has a single energy storage module 110 and a single energy storage module 130 as an example to describe the details of the power supply system 10 and the energy storage system 100. However, the power supply system 10 and the energy storage system 100 are not limited to this embodiment. In another embodiment, the energy storage system 100 may have multiple energy storage modules 110. In addition, the energy storage system 100 may have multiple energy storage modules 130.

[0018] In this embodiment, the power supply system 10 supplies power to the load device 20. In this embodiment, the power supply system 10 includes an energy storage device (e.g., an energy storage system 100) to supply the power stored in the energy storage device to the load device 20. However, the power supply system 10 is not limited to this embodiment. In another embodiment, the power supply system 10 may include a power generation device to supply the power generated by the power generation device to the load device 20. The power supply system 10 may also include both an energy storage device and a power generation device.

[0019] The power supply system 10 can be used, for example, in energy storage devices, electrical machinery, and transmission devices. Examples of transmission devices include electric vehicles, hybrid vehicles, electric two-wheelers, railway vehicles, aircraft, elevators, and cranes. The power supply system 10 can be a stationary energy storage device. The power supply system 10 can also be a stationary energy storage system manufactured or assembled by reusing used energy storage devices taken from transmission devices.

[0020] In this embodiment, the charging device 14 supplies power to the energy storage system 100. The charging device 14 receives power from the system power supply, for example, and supplies that power to the energy storage system 100. This charges the energy storage modules 110 and 130.

[0021] In one embodiment, during the period when the power supply system 10 supplies power to the load device 20, or at least a portion of said period, the power received by the charging device 14 from the system power source is less than the power output by the power supply system 10. For example, the rated power of the output device of the power supply system 10 is less than the rated power of the receiving device of the charging device 14.

[0022] When the power supply system 10 has multiple output devices, the rated power of a single output device may be less than the rated power of the receiving device of the charging device 14. When the power supply system 10 can simultaneously supply power to multiple load devices 20, the rated power that can be supplied to a single load device 20 may also be less than the rated power of the receiving device of the charging device 14. Furthermore, when the power supply system 10 has multiple receiving devices, the combined rated power of one or more output devices configured in the power supply system 10 may be less than the rated power of a single receiving device, and the rated power of a single output device configured in the power supply system 10 may also be less than the rated power of a single receiving device.

[0023] According to the described embodiment, most of the power consumed by the load device 20 can be supplied by the power stored in the energy storage system 100. Therefore, even if the power received by the charging device 14 from the system power source is less than the power output by the power supply system 10, the power supply system 10 can continue to supply power to the load device 20. This allows for miniaturization or simplification of the receiving device of the charging device 14. Furthermore, the unit price of the power received from the system power source may be reduced.

[0024] In another embodiment, the power received by the charging device 14 from the system power source is greater than the power output by the power supply system 10. Therefore, even when the remaining energy in the energy storage system 100 is low, the power supply system 10 can continue to supply power to the load device 20.

[0025] In this embodiment, the charging switching unit 16 switches the electrical connection between the charging device 14 and the energy storage system 100. For example, the charging switching unit 16 switches between a state where the charging device 14 is electrically connected to the energy storage system 100 and a state where the charging device 14 is electrically disconnected from the energy storage system 100. In one embodiment, the charging switching unit 16 switches the electrical connection between the charging device 14 and the energy storage system 100 based on a control signal from the charging device 14. In another embodiment, the charging switching unit 16 switches the electrical connection between the charging device 14 and the energy storage system 100 based on a control signal from the system control unit 140.

[0026] The charging switching unit 16 can be implemented in hardware, software, or a combination of both. The charging switching unit 16 can also be implemented using analog circuits, digital circuits, or a combination of analog and digital circuits.

[0027] The charging switching unit 16 may have one or more components. The charging switching unit 16 may have one or more switching components. One or more switching components may be respectively disposed between the connection terminal 102 and the charging device 14, or between the connection terminal 104 and the charging device 14. Examples of switching components include relays, thyristors, and transistors. The thyristor may also be a bidirectional thyristor (sometimes called a bidirectional silicon controlled rectifier (TRIAC)). The transistor may also be a semiconductor transistor. The semiconductor transistor may be a bipolar transistor or a field-effect transistor. The field-effect transistor may also be a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor).

[0028] The charging switching unit 16 may replace the switching assembly and have one or more DC-DC converters, or it may have a switching assembly and one or more DC-DC converters. The DC-DC converters may be isolated DC-DC converters. The DC-DC converters may be unidirectional or bidirectional DC-DC converters. The charging switching unit 16 may also replace the switching assembly and have a transformer, or it may have both a switching assembly and a transformer.

[0029] In this embodiment, the charging switching unit 16 is part of the charging device 14. However, the charging switching unit 16 is not limited to this embodiment. In another embodiment, the charging switching unit 16 may be part of the energy storage system 100.

[0030] In this embodiment, the load device 20 is electrically connected to the connection terminal 102 and the connection terminal 104, and receives power supplied by the power supply system 10. The load device 20 can be an electrical machine that consumes electricity or an energy storage machine that stores electricity. When the load device 20 is an energy storage machine, the power supply system 10 functions as a charging machine that charges the load device 20.

[0031] In this embodiment, the load switching unit 26 switches the electrical connection between the load device 20 and the energy storage system 100. For example, the load switching unit 26 switches between a state where the load device 20 is electrically connected to the energy storage system 100 and a state where the load device 20 is electrically disconnected from the energy storage system 100. In one embodiment, the load switching unit 26 switches the electrical connection between the load device 20 and the energy storage system 100 based on a control signal from the load device 20. In another embodiment, the load switching unit 26 switches the electrical connection between the load device 20 and the energy storage system 100 based on a control signal from the system control unit 140.

[0032] The load switching unit 26 can be implemented in hardware, software, or a combination of both. The load switching unit 26 can also be implemented using analog circuits, digital circuits, or a combination of analog and digital circuits.

[0033] The load switching unit 26 may have more than one component. The load switching unit 26 may also have more than one switching assembly. The more than one switching assembly may be respectively disposed between the connection terminal 102 and the load device 20, or between the connection terminal 104 and the load device 20. Examples of switching assemblies include relays, thyristors, and transistors. The thyristor may also be a bidirectional thyristor (sometimes called a bidirectional silicon controlled rectifier). The transistor may also be a semiconductor transistor. The semiconductor transistor may be a bipolar transistor or a field-effect transistor. The field-effect transistor may also be a MOSFET.

[0034] The load switching unit 26 may replace the switching assembly and have one or more DC-DC converters, or have a switching assembly and one or more DC-DC converters. The DC-DC converters may be isolated DC-DC converters. The DC-DC converters may be unidirectional or bidirectional DC-DC converters. The load switching unit 26 may also replace the switching assembly and have a transformer, or have both a switching assembly and a transformer.

[0035] In this embodiment, the load switching unit 26 is part of the load device 20. However, the load switching unit 26 is not limited to this embodiment. In another embodiment, the load switching unit 26 may be part of the power supply system 10.

[0036] In this embodiment, the energy storage system 100 stores electrical energy. Additionally, the energy storage system 100 supplies power to an external machine upon request. More specifically, the energy storage system 100 is electrically connected to the charging device 14 to store electrical energy (sometimes referred to as charging the energy storage system). Furthermore, the energy storage system 100 is electrically connected to the load device 20 to supply power to the load device 20 (sometimes referred to as discharging the energy storage system 100).

[0037] In this embodiment, the energy storage system 100 is electrically connected to the charging device 14 via connection terminals 102 and 104. Additionally, the energy storage system 100 is electrically connected to the load device 20 via connection terminals 102 and 104. Connection terminals 102 and 104 can also function as interfaces between the power supply system 10 and external machines connected to the power supply system 10.

[0038] In this embodiment, both the energy storage module 110 and the energy storage module 130 have an energy storage section (not shown) for storing electricity. Furthermore, in this embodiment, the energy storage module 110 and the energy storage module 130 are connected in parallel using a wiring 106. That is, a portion of the wiring 106 is used to electrically connect the positive terminal of the energy storage module 110 to the positive terminal of the energy storage module 130, and another portion of the wiring 106 is used to electrically connect the negative terminal of the energy storage module 110 to the negative terminal of the energy storage module 130.

[0039] Energy storage module 110 and energy storage module 130 are each detachably mounted and detachably held in the frame (not shown) of energy storage system 100. Thus, energy storage module 110 and energy storage module 130 can be replaced individually.

[0040] In this embodiment, each of the energy storage modules 110 and 130 can switch the connection between the energy storage section of each energy storage module and the wiring 106 based on control signals from the system control unit 140 or user operations. For example, each of the energy storage modules 110 and 130 can electrically connect the energy storage section of each energy storage module to the wiring 106 or electrically disconnect the energy storage section of each energy storage module from the wiring 106 based on control signals from the system control unit 140 or user operations.

[0041] Therefore, even if the voltage of a newly installed energy storage module in the energy storage system 100 differs from the voltage of an existing energy storage module in the energy storage system 100, there is no need to worry about damage or deterioration of the energy storage module; each of the multiple energy storage modules included in the energy storage system 100 can be replaced individually. The reasons are as follows.

[0042] In recent years, with the improvement of lithium-ion battery performance, the impedance of lithium-ion batteries has decreased to around 10mΩ. Therefore, for example, even when the voltage difference between two battery modules is only 0.4V, when these two modules are connected in parallel, a large current of 40A will flow from the module with the higher voltage to the module with the lower voltage. As a result, the battery modules will deteriorate or break down. Furthermore, the voltage of a battery module can also be the voltage between the positive and negative terminals (sometimes called the inter-terminal voltage of the battery module).

[0043] To prevent degradation or damage to the battery modules during replacement, when replacing one of multiple parallel-connected battery modules individually, it's advisable to allow time to adjust the voltage between the newly installed and existing modules until the voltage difference is minimal. Minimizing this voltage difference prevents large currents from flowing into each module during replacement, thus suppressing degradation or damage. However, as the impedance of lithium-ion batteries decreases, the permissible voltage difference between the newly installed and existing modules may also decrease, and the adjustment time may become very long.

[0044] In response to this, according to the energy storage system 100 of this embodiment, energy storage modules 110 and 130 can switch the connection relationship between the energy storage section of each energy storage module and the wiring 106 based on control signals from the system control unit 140 and user operations. Furthermore, energy storage module 110 can be replaced, for example, through the following steps.

[0045] First, the user removes the old energy storage module 110 from the energy storage system 100. Next, before installing the new energy storage module 110 into the energy storage system 100, the user performs an operation to disconnect the energy storage section of the new energy storage module 110 from the wiring 106. For example, the user manually operates the switch assembly configured between the positive terminal and the energy storage section of the energy storage module 110 to disconnect the positive terminal from the energy storage section.

[0046] Next, the user installs the energy storage module 110, with the positive terminal and energy storage unit electrically disconnected, into the energy storage system 100. At this time, because the positive terminal and energy storage unit are electrically disconnected, no current flows between energy storage modules 110 and 130, even if the voltage difference between them is relatively large. Then, when the voltage difference between energy storage modules 110 and 130 reaches an appropriate value, the system control unit 140 performs an operation to electrically connect energy storage module 110 to wiring 106. Details of the system control unit 140 will be described below.

[0047] As described above, according to the energy storage system 100 of this embodiment, when replacing or installing energy storage modules, it is not necessary to strictly adjust the voltage of the newly installed energy storage module and the voltage of the existing energy storage module in the energy storage system 100. Therefore, energy storage modules can be easily and quickly replaced or installed.

[0048] [Differences between energy storage module 110 and energy storage module 130] In this embodiment, the specifications of the energy storage unit of energy storage module 110 are different from those of the energy storage unit of energy storage module 130. In one embodiment, the type of secondary battery constituting the energy storage unit of energy storage module 110 is different from that constituting the energy storage unit of energy storage module 130. In another embodiment, the battery system of energy storage module 110 is different from that of energy storage module 130. Furthermore, in another embodiment, the inter-terminal voltage of energy storage module 110 is different from that of energy storage module 130. Details of energy storage modules 110 and 130 will be described below.

[0049] [Overview of System Control Unit 140] In this embodiment, the system control unit 140 controls each part of the energy storage system 100. For example, the system control unit 140 (i) determines the state of each part of the energy storage system 100; (ii) monitors the state of each part of the energy storage system 100; or (iii) controls the operation of each part of the energy storage system 100.

[0050] [Determining the state of the system] In one embodiment, the system control unit 140 determines the state of the energy storage system 100. Examples of the state of the energy storage system 100 include charging state, discharging state, standby state, or stopped state. For example, the system control unit 140 receives information about charging and discharging events. Based on this information about charging and discharging events, the system control unit 140 determines the state of the energy storage system 100.

[0051] Information regarding charging and discharging events may indicate that the energy storage system 100 has been discharged or charged, or it may indicate that the energy storage system 100 will be discharged or charged thereafter. Examples of information regarding charging and discharging events include (i) charging or discharging requests from external devices such as charging device 14 and load device 20; (ii) information indicating that an external device is connected to the energy storage system 100; (iii) information indicating the type of the external device; (iv) information indicating the operation of the external device; (v) information indicating the status of the external device; (vi) information indicating instructions or operations by the user to the external device; (vii) information indicating instructions or operations by the user to the power supply system 10 or the energy storage system 100; and (viii) combinations of the above information.

[0052] For example, the system control unit 140 determines that the energy storage system 100 is in a charging state when it has detected that the charging device 14 is connected, or when it has received a signal indicating the type of the charging device 14. The system control unit 140 may also determine that the energy storage system 100 is in a charging state when it has received a signal indicating that charging has started from the charging device 14. The system control unit 140 may also determine that the energy storage system 100 is in a charging state when it has received a signal from the load device 20 indicating that a recharge current has been generated or that a recharge current may be generated.

[0053] For example, the system control unit 140 determines that the energy storage system 100 is in a discharging state when it detects that the load device 20 is connected, or when it receives a signal indicating the type of the load device 20. The system control unit 140 may also determine that the energy storage system 100 is in a discharging state when it receives a signal indicating power consumption from the load device 20. Examples of signals indicating power consumption include: a signal indicating that the power supply to the load device 20 is turned on; a signal indicating that the power supply to the load device 20 is already turned on; a signal indicating that the load device 20 has switched to an operating mode; and a signal indicating that the load device 20 has switched to an operating mode.

[0054] [System status monitoring] In another embodiment, the system control unit 140 monitors the state of the energy storage system 100. For example, the system control unit 140 monitors the state of at least one of the energy storage modules 110 and 130. The system control unit 140 may also monitor the individual states of the energy storage modules 110 and 130. The system control unit 140 may collect information about the battery characteristics of the energy storage units contained in each of the energy storage modules 110 and 130. The information about the battery characteristics of the energy storage units may be selected from at least one of the following: the voltage value of the energy storage unit, the current value flowing through the energy storage unit, the battery capacity of the energy storage unit, the temperature of the energy storage unit, the degradation state of the energy storage unit, and the SOC (State of Charge) of the energy storage unit.

[0055] Information regarding the battery characteristics of the energy storage unit (sometimes referred to as the battery characteristics of the energy storage module. The battery characteristics of the energy storage unit can be the battery characteristics of a single cell among the multiple individual cells constituting the energy storage module, or the battery characteristics of the combination of the multiple individual cells) may include at least one of the following: information about the specifications of the energy storage unit and information about the degradation status of the energy storage unit. Examples of specifications for the energy storage unit may include the type or model of the energy storage unit, the connection status of the energy storage unit, the types of charging methods that can charge the energy storage unit, the types of charging methods that cannot charge the energy storage unit, rated battery capacity (sometimes referred to as rated capacity), rated voltage, rated current, energy density, maximum charge / discharge current, charging characteristics, charging temperature characteristics, discharging characteristics, discharging temperature characteristics, self-discharge characteristics, charge / discharge cycle characteristics, equivalent series resistance in the initial state, battery capacity in the initial state, SOC [%] in the initial state, and storage voltage [V]. Examples of charging methods may include CCCV (Constant Current Constant Voltage), CC (Constant Current), and trickle charging.

[0056] As for the connection state of the energy storage unit, examples can be given of the type of unit battery constituting the energy storage unit, the number of such unit batteries, and the connection method of the unit batteries. As for the connection method of the unit batteries, examples can be given of the number of unit batteries connected in series, the number of unit batteries connected in parallel, etc. Energy density can be volumetric energy density [Wh / m³]. 3 It can also be the weight energy density [Wh / kg].

[0057] Information regarding the degradation state of the energy storage unit can include information about the energy storage unit at any point in time, and can include (i) battery capacity at a full charge; (ii) SOC under a predetermined temperature condition; (iii) SOH (State of Health); (iv) equivalent series resistance (DCR, sometimes also called internal resistance); and (v) accumulated usage time, number of charges, charge amount, discharge amount, number of charge / discharge cycles, temperature stress elements, and overcurrent stress elements from the initial state or a predetermined time sequence. Information regarding the battery characteristics of the energy storage unit can also establish a correspondence between information about the degradation state of the energy storage unit and information about the time at which that information was obtained, and store such information. Information regarding the battery characteristics of the energy storage unit can also store information about the degradation state of the energy storage unit at multiple points in time.

[0058] SOH [%] is expressed, for example, as the full capacity under degradation (e.g., the current full capacity) [Ah] ÷ the initial full capacity [Ah] × 100. There are no particular limitations on the method for calculating or estimating SOH; for example, the SOH of the battery can be calculated or estimated based on at least one of the DC resistance value and the open-circuit voltage value of the battery. SOH can also be a value obtained by converting it to a value under predetermined temperature conditions using any conversion formula.

[0059] There is no particular limitation on the method for determining the degradation state of the battery storage unit; currently known or future methods can be used. Generally speaking, as the battery storage unit deteriorates, the usable battery capacity decreases, while the equivalent series resistance increases. Therefore, for example, the battery degradation state can be determined by comparing the current battery capacity, state of charge (SOC), or equivalent series resistance with those in the initial state.

[0060] SOC [%] is expressed, for example, as remaining capacity [Ah] ÷ full charge capacity [Ah] × 100. There are no particular limitations on the method for calculating or estimating SOC. SOC can be calculated or estimated based on at least one of the following: (i) the measured voltage of the battery compartment, (ii) the IC characteristic data of the battery compartment voltage, and (iii) the cumulative value of the battery compartment current. SOC can also be a value obtained by converting it to a value under a predetermined temperature condition using any conversion formula.

[0061] Information about the battery characteristics of the energy storage unit can also include information about at least one of the charging and discharging times of the energy storage unit. The charging and discharging times of the energy storage unit can also be the charging and discharging times of the energy storage module containing the energy storage unit, respectively. Generally, as the energy storage unit deteriorates, the usable battery capacity decreases, and at least one of the charging and discharging times becomes shorter.

[0062] Information regarding the charging time of the energy storage unit may include information indicating the ratio of the charging time of the energy storage unit to the charging time of the energy storage system 100. The information regarding the charging time of the energy storage unit may include information indicating the charging time of the energy storage system 100 and information indicating the charging time of the energy storage unit. The charging time may be (i) the time during which current or voltage is applied to the energy storage system 100 or the energy storage unit in a single charging operation, or (ii) the sum of the times during which current or voltage is applied to the energy storage system 100 or the energy storage unit in one or more charging operations within a predetermined period.

[0063] Information regarding the charging time of the energy storage unit may include information indicating the ratio of the number of times the energy storage unit is charged within a predetermined period to the number of times the energy storage system 100 is charged within that period. Information regarding the charging time of the energy storage unit may also include information indicating the number of times the energy storage system 100 is charged within a predetermined period, and information indicating the number of times the energy storage unit is charged within that period.

[0064] Information regarding the discharge time of the energy storage unit may include information representing the ratio of the discharge time of the energy storage unit to the discharge time of the energy storage system 100. The information regarding the discharge time of the energy storage unit may include the discharge time of the energy storage system 100 and the discharge time of the energy storage unit itself. The discharge time may be (i) the time during which the energy storage system 100 or the energy storage unit has supplied current or voltage in a single discharge operation, or (ii) the sum of the times during which the energy storage system 100 or the energy storage unit has supplied current or voltage in one or more discharge operations within a predetermined period.

[0065] Information regarding the discharge time of the energy storage unit may include information about the ratio of the number of discharges of the energy storage unit to the number of discharges of the energy storage system 100 during a predetermined period. Information regarding the discharge time of the energy storage unit may also include the number of discharges of the energy storage system 100 during the predetermined period, and the number of discharges of the energy storage unit during that period.

[0066] The system control unit 140 can send at least one of the information regarding the battery characteristics of the energy storage unit included in the energy storage module 110 and the information regarding the battery characteristics of the energy storage unit included in the energy storage module 130 to an external machine. The external machine can then utilize the information regarding the battery characteristics of the energy storage unit. Examples of external machines include the charging device 14 and the load device 20. The external machine can also be an output device that outputs information to a user. Examples of output devices include display devices such as monitors and sound output devices such as microphones.

[0067] The system control unit 140 can determine the performance of the energy storage module based on information about its battery characteristics. The system control unit 140 can also output information indicating insufficient performance of the energy storage module if its battery characteristics do not meet predetermined determination conditions. The system control unit 140 can also determine the determination conditions based on the purpose of the energy storage system 100.

[0068] In this embodiment, the system control unit 140 has been described as collecting at least one of the battery characteristics of the energy storage unit included in the energy storage module 110 and the battery characteristics of the energy storage unit included in the energy storage module 130, and transmitting the collected information to an external machine. However, the energy storage system 100 is not limited to this embodiment. In another embodiment, both the energy storage module 110 and the energy storage module 130 may collect information on the battery characteristics of the energy storage units included in their respective energy storage modules and transmit the collected information to an external machine.

[0069] [Control of system actions] In another embodiment, the system control unit 140 controls the operation of each component of the energy storage system 100. For example, the system control unit 140 controls the operation of at least one of the energy storage modules 110 and 130. The system control unit 140 can switch the connection relationship between the energy storage section of the energy storage module 110 and the wiring 106. The system control unit 140 can switch the connection relationship between the energy storage section of the energy storage module 130 and the wiring 106.

[0070] The system control unit 140 can also control the operation of at least one of the charging device 14 and the charging switching unit 16. The system control unit 140 can control the start and stop of the power supply from the charging device 14 to the energy storage system 100. The system control unit 140 can adjust the set value of at least one of the charging voltage and the charging current. The system control unit 140 can also control the rate of increase or decrease of at least one of the charging voltage and the charging current.

[0071] The system control unit 140 can also control the operation of at least one of the load device 20 and the load switching unit 26. The system control unit 140 can control the start and stop of power supply from the energy storage system 100 to the load device 20. The system control unit 140 can adjust the set value of at least one of the output voltage and output current. The system control unit 140 can also control the rate of increase or decrease of at least one of the output voltage and output current.

[0072] The system control unit 140 can also determine the order in which the energy storage sections of each energy storage module are electrically connected to the wiring 106 based on the voltage of the energy storage section of each energy storage module. For example, when the operation of the energy storage system 100 begins and the state of the energy storage system 100 starts from the charging state, the system control unit 140 electrically connects the energy storage section of the energy storage module with the lower voltage to the wiring 106. On the other hand, when the operation of the energy storage system 100 begins and the state of the energy storage system 100 starts from the discharging state, the system control unit 140 electrically connects the energy storage section of the energy storage module with the higher voltage to the wiring 106. Furthermore, the system control unit 140 can also determine the order in which the energy storage sections of each energy storage module are electrically connected to the wiring 106 based on the inter-terminal voltage of each energy storage module.

[0073] In one embodiment, the system control unit 140 may also send signals for connecting the energy storage unit to the wiring 106 in a predetermined order to each energy storage module. In another embodiment, the system control unit 140 may also select the energy storage module with the lowest voltage or SOC, or the energy storage module with the highest voltage or SOC, and send the signal for connecting the energy storage unit to the wiring 106 only to the selected energy storage module.

[0074] The system control unit 140 can be implemented in hardware or software. Alternatively, it can be implemented using a combination of hardware and software. In one embodiment, the system control unit 140 can be implemented using analog circuits, digital circuits, or a combination of analog and digital circuits. In another embodiment, the system control unit 140 can be implemented by executing programs for controlling the various parts of the system control unit 140 in a general information processing device equipped with a data processing device, such as a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and a communication interface.

[0075] The program installed on the computer and which enables the computer to function as part of the system control unit 140 of this embodiment may include modules that limit the operation of each part of the system control unit 140. These programs or modules operate in the CPU or the like, enabling the computer to function as each part of the system control unit 140.

[0076] The information processing described in these programs is read into the computer, thereby functioning as a specific means of coordinating the software and the various hardware resources. Through these specific means, the computation or processing of information corresponding to the intended use of the computer in this embodiment is achieved, thereby enabling the construction of a device specific to that intended use. The programs may be stored on a computer-readable medium or on a network-connected storage device.

[0077] Furthermore, the term "electrical connection" is not limited to the direct connection between a specific component and other components. A third component may also exist between a specific component and other components. Additionally, the connection between a specific component and other components is not limited to a physical connection. For example, the input and output coils of a transformer are not physically connected, but electrically connected. Moreover, it includes not only cases where a specific component and other components are physically electrically connected, but also cases where a specific component and other components are electrically connected when the battery and the balance correction unit are electrically connected. Furthermore, the term "series connection" indicates that a specific component and other components are electrically connected in series, while the term "parallel connection" indicates that a specific component and other components are electrically connected in parallel.

[0078] [Parallel connection of energy storage module 110 and energy storage module 130] As described above, in the energy storage system 100, energy storage modules 110 and 130 of different specifications are connected in parallel. Therefore, in this embodiment, the power supply system 10 or the energy storage system 100 is constructed taking into account the differences in specifications between the energy storage modules 110 and 130.

[0079] In recent years, establishing methods for reusing batteries used in electric vehicles, hybrid vehicles, and other transportation equipment has become an urgent priority. However, there are significant differences in the specifications, ratings, and degradation conditions between batteries used in electric vehicles and those used in hybrid vehicles. For example, generally speaking, the inter-terminal voltage of electric vehicle batteries is higher than that of hybrid vehicle batteries. Additionally, the capacity of electric vehicle batteries is greater than that of hybrid vehicle batteries.

[0080] Therefore, for example, when the energy storage module 110 is manufactured using recycled materials (sometimes also called semi-used materials, reused materials, etc.) from electric vehicle batteries, and the energy storage module 130 is manufactured using recycled materials from hybrid vehicle batteries, and the two are connected in parallel to manufacture the energy storage system 100, the inter-terminal voltage of the energy storage module 110 is different from that of the energy storage module 130. Furthermore, when the electric vehicle battery is a lithium-ion battery or the like, the energy storage module 110 does not support trickle charging. On the other hand, when the hybrid vehicle battery is a nickel-metal hydride battery or the like, the energy storage module 130 supports trickle charging.

[0081] Here, based on the relationship between the number of batteries and the inter-terminal voltage in the energy storage module 110 and the number of batteries and the inter-terminal voltage in the energy storage module 130, the inter-terminal voltage of the energy storage module 130 is greater than that of the energy storage module 110. In this case, the set value of the charging end voltage of the energy storage module 110 is adjusted to a value lower than or less than the charging end voltage of the energy storage module 130.

[0082] In this case, when the energy storage module 110 supports trickle charging but the energy storage module 130 does not, trickle charging of the energy storage module 110 can continue until it reaches full charge voltage after charging is completed. However, depending on the type of battery included in the energy storage module 110 and the type of battery included in the energy storage module 130, it is also possible that the energy storage module 110 does not support trickle charging while the energy storage module 130 does. In this case, the operation and settings of the charging device 14 are determined with consideration of trickle charging of the energy storage module 130.

[0083] When the energy storage module 130 supports trickle charging, the charging termination voltage of the energy storage module 130 is below its full charge voltage. Furthermore, as described above, in this embodiment, the charging termination voltage of the energy storage module 130 is greater than the charging termination voltage of the energy storage module 110, which does not support trickle charging. Therefore, according to this embodiment, the charging voltage of the charging device 14 is set to a value greater than the charging termination voltage of the energy storage module 130.

[0084] Therefore, trickle charging of the energy storage module 130 can continue from the end of charging until it reaches full charge. Furthermore, the charging termination voltage of the energy storage module 130 depends, for example, on the number of batteries included in the energy storage module 130 and the inter-terminal voltage. The charging termination voltage of the energy storage module 110 also depends, for example, on the number of batteries included in the energy storage module 110 and the inter-terminal voltage.

[0085] Furthermore, the charging termination voltage of the energy storage module can be a voltage that allows the energy storage module to be charged in the constant current region. The set value of the charging termination voltage is, for example, specified by the manufacturer or seller of the energy storage module, or the designer of the energy storage system 100. Additionally, the full-charge voltage of the energy storage module can be a voltage at which the rate of increase in the charging rate becomes slower than a predetermined value after trickle charging. The value of the full-charge voltage of the energy storage module is greater than the value of its charging termination voltage.

[0086] For example, after the charging device 14 begins charging the energy storage module, it charges the module using relatively high-speed charging methods such as constant current charging, constant voltage charging, and constant current-constant voltage charging until the module's voltage or charge rate (sometimes referred to as SOC) reaches a first value. Afterward, the charging device 14 reduces the charging current and begins trickle charging. During trickle charging, the module's voltage increases slowly until it reaches a second value. When the module's voltage reaches the second value, it hardly increases further. For example, in the case where the energy storage module has multiple batteries and an equalization circuit that equalizes the voltages of these batteries, the voltages of the multiple batteries in the module are equalized during trickle charging. As a result, the module's voltage hardly increases further. In this case, the first value could be an example of the charging completion voltage. Alternatively, the second value could be an example of the full charge voltage.

[0087] Furthermore, as described above, by constructing the energy storage system 100 by connecting different types of secondary batteries in parallel, a power supply system can be constructed that excels in at least one of the following aspects: lifespan, reliability, charging performance, discharging performance, energy efficiency, temperature characteristics, and economy, compared to an energy storage system 100 containing a single type of secondary battery. For example, while lead-acid batteries operate over a relatively wide temperature range, their charging and discharging efficiency is relatively low. On the other hand, while lithium-ion batteries have high charging and discharging efficiency, they have operational problems in low-temperature and high-temperature regions. Therefore, by connecting an energy storage module having a storage section containing lead-acid batteries and an energy storage module having a storage section containing lithium-ion batteries in parallel, a power supply system that operates over a wider temperature range and has higher energy efficiency can be constructed.

[0088] Furthermore, compared to lithium-ion batteries, nickel-metal hydride (NiMH) batteries are better suited for operating at low temperatures and have a larger instantaneous power harvesting capacity. Therefore, by connecting an energy storage module having an energy storage section containing NiMH batteries and an energy storage module having an energy storage section containing lithium-ion batteries in parallel, a power supply system that operates over a wide temperature range, has a larger instantaneous power harvesting capacity, and can be constructed.

[0089] The power supply system 10 can be an example of an energy storage system. The energy storage system 100 can also be an example of an energy storage system. The energy storage module 110 can be an example of a second energy storage device. The energy storage section of the energy storage module 110 can also be an example of a second energy storage section. The energy storage module 130 can be an example of a first energy storage device. The energy storage section of the energy storage module 130 can also be an example of a second energy storage section. The system control unit 140 can be an example of a charging voltage control unit. The system control unit 140 can be an example of a current consumption control unit.

[0090] In this embodiment, the case where the energy storage system 100 has two energy storage modules connected in parallel has been described. However, the energy storage system 100 is not limited to this embodiment. In another embodiment, the energy storage system 100 may also have three or more energy storage modules connected in parallel.

[0091] In this embodiment, the user has described the operation of electrically connecting the storage section and wiring 106 of the new storage module 110 before installing the storage module 110 into the storage system 100. However, the installation or replacement method of the storage module 110 is not limited to this embodiment. In another embodiment, the user, for example, operates the input section (not shown) of the storage system 100 to input an instruction to start the replacement operation of the storage module 110. Examples of input sections include keyboards, pointing devices, touch panels, microphones, voice recognition systems, gesture input systems, etc.

[0092] When the system control unit 140 receives an instruction to begin replacing the energy storage module 110, it can also electrically disconnect the energy storage section and wiring 106 of the energy storage module (energy storage module 130 in this embodiment) connected in parallel with the energy storage module 110. At this time, the system control unit 140 can also electrically disconnect the energy storage section and wiring 106 of the energy storage module 110. For example, the system control unit 140 sends a signal to the switching element that disconnects the switching element located between the positive terminal and the energy storage section of each energy storage module.

[0093] When the system control unit 140 detects that an old energy storage module 110 has been retrieved and a new energy storage module 110 has been installed, it obtains the voltage of the energy storage section of each energy storage module. With the energy storage section of the new energy storage module 110 and the wiring 106 electrically connected, the system control unit 140, for example, uses only the energy storage module 110 to operate the energy storage system 100 until the voltage difference between the energy storage module 110 and the energy storage module 130 reaches an appropriate value. Furthermore, when the voltage difference between the energy storage module 110 and the energy storage module 130 reaches an appropriate value, the system control unit 140 performs an operation to electrically connect the energy storage module 130 and the wiring 106.

[0094] On the other hand, when the energy storage section of the new energy storage module 110 is not electrically connected to the wiring 106, the system control unit 140 determines the order in which the energy storage sections of each energy storage module are electrically connected to the wiring 106 based on the voltage of the energy storage sections of each energy storage module. Then, the system control unit 140 connects the energy storage sections of each energy storage module to the wiring 106 in the determined order. Furthermore, when the energy storage section of the new energy storage module 110 is already electrically connected to the wiring 106, the system control unit 140 may first electrically disconnect the energy storage section of the new energy storage module 110 from the wiring 106. Then, it may determine the order in which the energy storage sections of each energy storage module are electrically connected to the wiring 106 based on the voltage of the energy storage sections of each energy storage module, and connect the energy storage sections of each energy storage module to the wiring 106 in the determined order.

[0095] Figure 2 This is a simplified example of the system configuration of the energy storage module 110. In this embodiment, the energy storage module 110 includes a positive terminal 202 and a negative terminal 204. Furthermore, the energy storage module 110 includes an energy storage section 210 having a positive terminal 212 and a negative terminal 214, and a switching section 230. In this embodiment, the energy storage section 210 includes a battery 222 and a battery 224. In this embodiment, the energy storage module 110 also includes a module control section 240, a protection section 250, and a balance correction section 260.

[0096] The impedance of the energy storage unit 210 can be less than 1Ω or less than 100mΩ. The impedance of the energy storage unit 210 can be less than 10mΩ, less than 1mΩ, less than 0.8mΩ, or less than 0.5mΩ. The impedance of the energy storage unit 210 can be greater than 0.1mΩ. The impedance of the energy storage unit 210 can be greater than 0.1mΩ and less than 1Ω, greater than 0.1mΩ and less than 100mΩ, greater than 0.1mΩ and less than 10mΩ, or greater than 0.1mΩ and less than 1mΩ.

[0097] According to the energy storage system 100 of this embodiment, for example, when replacing one of a plurality of parallel-connected energy storage modules, it is not necessary to ensure that the voltage of the newly added energy storage module matches the voltage of the remaining energy storage modules with high precision. Therefore, even when the impedance of the energy storage unit 210 is low, the energy storage module 110 can be replaced easily and quickly.

[0098] In this embodiment, battery 222 and battery 224 are connected in series. Battery 222 and battery 224 can be secondary batteries or capacitors. At least one of battery 222 and battery 224 may also contain multiple batteries connected in series, in parallel, or in a matrix configuration inside the battery.

[0099] In this embodiment, battery 222 and battery 224 are each composed of a secondary battery that cannot support trickle charging. At least one of battery 222 and battery 224 may be a lithium-ion battery.

[0100] Generally, when a secondary battery continues to be charged from a fully charged state, and no irreversible changes occur in the battery system (i.e., the chemical reaction of the battery system in an overcharged state is represented by a reaction formula without irreversible changes), the secondary battery can support trickle charging. Examples of secondary batteries that can support trickle charging include lead-acid batteries, nickel-metal hydride batteries, and nickel-cadmium batteries. The chemical reactions of the battery systems of lead-acid batteries, nickel-metal hydride batteries, and nickel-cadmium batteries during normal charging and discharging are represented by the following formulas (1) to (3), respectively. On the other hand, when the battery system of a secondary battery undergoes irreversible changes while it is being charged from a fully charged state (i.e., when the chemical reaction of the battery system of a secondary battery in an overcharged state is represented by a reaction formula accompanied by irreversible changes), the secondary battery cannot support trickle charging. Examples of secondary batteries that cannot support trickle charging include lithium batteries and lithium-ion batteries (including lithium-ion polymer batteries and solid-state batteries). In particular, the chemical reaction of the battery system of a lithium-ion battery during normal charging and discharging is represented by the following formula (4). Here, in the chemical reaction under overcharge conditions in a lithium-ion battery, the crystalline structure of lithium cobalt oxide, the positive electrode active material, deforms due to overcharging, thereby generating oxygen. This oxygen generated by overcharging causes oxidation of the lithium cobalt oxide (Li₂O₃) in the positive electrode. (1-x) The imbalance between CoO2 and cobalt dioxide (CoO2) prevents the original crystal structure from being restored, resulting in a decrease in the positive electrode capacity. Therefore, this change is considered irreversible. Trickle charging can be defined as a charging method in which a secondary battery that is fully charged or nearly fully charged is continuously or intermittently charged with a small current. In this embodiment, trickle charging is implemented as a charging method that continues to charge the battery module with a smaller current than the normal charging current after the charging of a battery module that supports trickle charging has ended, thereby bringing it closer to a fully charged state. Therefore, in this embodiment, the small current used for trickle charging is a current that can increase the charging amount of the target battery module, but when the charging state at the end of the charging is closer to full charge, it can also be a current that can compensate for the reduction in charging amount caused by the natural discharge of the target battery module.

[0101] In this embodiment, the positive terminal 212 of the energy storage unit 210 is electrically connected to the wiring 106 via the positive terminal 202 of the energy storage module 110 and the switching unit 230. Conversely, the negative terminal 214 of the energy storage unit 210 is electrically connected to the wiring 106 via the negative terminal 204 of the energy storage module 110. However, the energy storage module 110 is not limited to this embodiment. In another embodiment, the negative terminal 214 of the energy storage unit 210 is electrically connected to the wiring 106 via the negative terminal 204 of the energy storage module 110 and the switching unit 230. Conversely, the positive terminal 212 of the energy storage unit 210 is electrically connected to the wiring 106 via the positive terminal 202 of the energy storage module 110.

[0102] In this embodiment, the switching unit 230 is disposed between the wiring 106 and the energy storage unit 210. In this embodiment, the switching unit 230 switches the electrical connection between the wiring 106 and the energy storage unit 210 based on the voltage difference between them. For example, the switching unit 230 switches the connection state between the wiring 106 and the energy storage unit 210 based on a signal generated by the module control unit 240. Thus, the energy storage unit 210 can be electrically connected to the wiring 106, or the energy storage unit 210 can be electrically disconnected from the wiring 106.

[0103] When the energy storage module 110 is installed in the energy storage system 100, the energy storage module 110 can be installed in the energy storage system 100 after the energy storage unit 210 is electrically disconnected from the wiring 106 by the switching unit 230. As a result, damage or deterioration of the energy storage module 110 can be prevented.

[0104] The switching unit 230 can be implemented in hardware, software, or a combination of both. The switching unit 230 can also be implemented using analog circuits, digital circuits, or a combination of analog and digital circuits.

[0105] The switching unit 230 may have more than one component. The switching unit 230 may also have more than one switching component. Each of the more than one switching component may be configured between the positive terminal 202 and the positive terminal 212, or between the negative terminal 204 and the negative terminal 214. Examples of switching components include relays, thyristors, and transistors. The thyristor may also be a bidirectional thyristor (sometimes called a bidirectional silicon controlled rectifier). The transistor may also be a semiconductor transistor. The semiconductor transistor may be a bipolar transistor or a field-effect transistor. The field-effect transistor may also be a MOSFET.

[0106] The switching unit 230 may replace the switching assembly and have one or more DC-DC converters, or have a switching assembly and one or more DC-DC converters. The DC-DC converters may be isolated DC-DC converters. The DC-DC converters may be unidirectional DC-DC converters or bidirectional DC-DC converters. The switching unit 230 may also replace the switching assembly and have a transformer, or have both a switching assembly and a transformer.

[0107] The module control unit 240 controls the current flowing between the energy storage unit 210 of the energy storage module 110 and the wiring 106. In this embodiment, the module control unit 240 controls the switching unit 230 by electrically connecting the energy storage unit 210 and the wiring 106 when the voltage between the terminals of the switching unit 230 (in this embodiment, the voltage between the positive terminal 202 and the positive terminal 212) meets a predetermined condition. The switching unit 230 can electrically connect the energy storage unit 210 and the wiring 106 by electrically connecting the energy storage unit 210 and the positive terminal 202.

[0108] On the other hand, if the voltage between the terminals of the switching unit 230 does not meet the predetermined conditions, the switching unit 230 is controlled by electrically disconnecting the energy storage unit 210 from the wiring 106 or the positive terminal 202. The switching unit 230 can electrically disconnect the energy storage unit 210 from the wiring 106 by electrically disconnecting the energy storage unit 210 from the positive terminal 202.

[0109] The predetermined condition can be that the absolute value of the voltage between the terminals of the switching unit 230 is within a predetermined range. The predetermined range can be 3V or less, 1V or less, 0.1V or less, 10mV or less, or 1mV or less. Alternatively, the predetermined range can be 0.5mV or more, or 1mV or more. The predetermined range can also be 0.5mV or more and 3V or less. The predetermined range can also be 1mV or more and 3V or less, 1mV or more and 1V or less, 1mV or more and 0.1V or less, 1mV or more and 10mV or less, 10mV or more and 1V or less, or 0.1V or more and 1V or less. Furthermore, the voltage between the terminals of the switching unit 230 can be the voltage between the positive terminal 202 and the positive terminal 212, or the voltage between the wiring 106 and the energy storage unit 210.

[0110] The predetermined range can also be set based on the impedance of the energy storage unit 210. The predetermined range can be set based on the rated current or allowable current of the energy storage unit 210. The predetermined range can be set based on the impedance of the energy storage unit 210 and the rated current or allowable current of the energy storage unit 210. The predetermined range can be set based on the rated current or allowable current of the component with the smallest rated current or allowable current among the components constituting the energy storage module 110. The predetermined range can be set based on the impedance of the energy storage module 110 and the rated current or allowable current of the component with the smallest rated current or allowable current among the components constituting the energy storage module 110.

[0111] Therefore, when replacing a battery module, the state after the wiring 106 and the storage section 210 of the newly installed battery module are electrically disconnected can be maintained until the voltage difference between the newly installed battery module and the existing battery module is within a predetermined range. Furthermore, when the voltage difference between the newly installed battery module and the existing battery module is within a predetermined range due to charging or discharging of the existing battery module, the storage section of the newly installed battery module is electrically connected to the wiring 106. Thus, according to this embodiment, the newly installed battery module and other battery modules can be automatically connected.

[0112] In this embodiment, the module control unit 240 receives a signal from the system control unit 140 indicating that the inter-terminal voltage of the energy storage module 110 is lower than that of other energy storage modules. After receiving the signal when the energy storage system 100 transitions to a charging state, the module control unit 240 controls the switching unit 230 to electrically connect the energy storage module 210 to the wiring 106. This allows for efficient charging of multiple parallel-connected energy storage modules 110.

[0113] In this embodiment, the module control unit 240 receives a signal from the system control unit 140 indicating that the inter-terminal voltage of the energy storage module 110 is greater than that of other energy storage modules. After receiving the signal when the energy storage system 100 transitions to a discharge state, the module control unit 240 controls the switching unit 230 to electrically connect the energy storage unit 210 to the wiring 106. This allows for efficient discharge of the multiple parallel-connected energy storage modules 110.

[0114] In this embodiment, the module control unit 240 receives a signal from the protection unit 250 indicating that the inter-terminal voltage of the battery 222 or battery 224 is not within a predetermined range. When the module control unit 240 receives this signal, it controls the switching unit 230 to electrically disconnect the battery storage unit 210 from the wiring 106. This suppresses deterioration or damage to the battery storage unit 210 caused by overcharging or over-discharging.

[0115] In this embodiment, the module control unit 240 accepts user operations and receives instructions from the user to enable or disable the switching unit 230. When the module control unit 240 receives the user's instructions, it controls the switching unit 230 according to those instructions.

[0116] In this embodiment, the module control unit 240 can obtain information about the battery characteristics of the energy storage unit 210. The module control unit 240 can output the information about the battery characteristics of the energy storage unit 210 to an external device. Thus, the external device can utilize the information about the battery characteristics of the energy storage unit 210. Examples of external devices include the load device 20, the charging device 14, etc. The external device can also be an output device that outputs information to a user.

[0117] The module control unit 240 can be implemented in hardware or software. Alternatively, it can be implemented using a combination of hardware and software. In one embodiment, the module control unit 240 can be implemented using analog circuits, digital circuits, or a combination of analog and digital circuits. In another embodiment, the module control unit 240 can be implemented by executing a program for controlling the module control unit 240 in a general information processing device equipped with a data processing device, such as a CPU, ROM, RAM, and a communication interface.

[0118] The program installed on the computer and enabling the computer to function as part of the module control unit 240 of this embodiment may also include modules that limit the operation of each part of the module control unit 240. These programs or modules operate in the CPU or the like, enabling the computer to function as each part of the module control unit 240.

[0119] The information processing described in these programs is read into the computer, thereby functioning as a specific means of coordinating the software and the various hardware resources. Through these specific means, the computation or processing of information corresponding to the intended use of the computer in this embodiment is achieved, thereby enabling the construction of a device specific to that intended use. The programs may be stored on a computer-readable medium or on a network-connected storage device.

[0120] Protection unit 250 protects energy storage unit 210. In this embodiment, protection unit 250 protects energy storage unit 210 from overcharging or over-discharging damage. When protection unit 250 detects that the inter-terminal voltage of battery 222 or battery 224 is not within a predetermined range, it sends a signal indicating this intention to module control unit 240. Protection unit 250 can send information about the inter-terminal voltage of energy storage unit 210 to system control unit 140. Protection unit 250 can be implemented in hardware, software, or a combination of hardware and software. Protection unit 250 can also be implemented using analog circuits, digital circuits, or a combination of analog and digital circuits.

[0121] The balancing correction unit 260 equalizes the voltage of multiple batteries. The operating principle of the balancing correction unit 260 is not particularly limited, and any balancing correction device can be used. When the energy storage unit 210 has three or more batteries, the energy storage module 110 can have multiple balancing correction units 260. For example, when the energy storage unit 210 has n batteries (n being an integer of 2 or more), the energy storage module 110 has n-1 balancing correction units 260.

[0122] The balance correction unit 260 can be implemented in hardware, software, or a combination of both. It can also be implemented using analog circuits, digital circuits, or a combination of analog and digital circuits. In one embodiment, the balance correction unit 260 refers to an active balance correction device. An active balance correction unit can be one that moves charge between two batteries via an inductor, as described in Japanese Patent Application Publication No. 2006-067742, or one that uses a capacitor to move charge, as described in Japanese Patent Application Publication No. 2012-210109. In another embodiment, the balance correction unit 260 can also be a passive balance correction device. A passive balance correction device, for example, uses an external resistor to release excess charge.

[0123] In this embodiment, the case where the energy storage unit 210 has two batteries connected in series has been described. However, the energy storage unit 210 is not limited to this embodiment. In another embodiment, the energy storage unit 210 may also have three or more batteries connected in series. In addition, the energy storage unit 210 may have multiple batteries connected in parallel, or multiple batteries connected in a matrix.

[0124] The energy storage unit 210 of the energy storage module 110 can be an example of a second energy storage unit. The switching unit 230 of the energy storage module 110 can be an example of a second switching unit. The battery 222 and battery 224 of the energy storage module 110 can be examples of a second type of secondary battery.

[0125] Figure 3 This is a simplified example of the system configuration of the energy storage module 130. In this embodiment, the energy storage module 130 differs from the energy storage module 110 in that the plurality of batteries constituting the energy storage section 210 are each composed of a secondary battery capable of supporting trickle charging; and the energy storage module 130 includes a trickle charging section 320. Apart from the aforementioned differences, the energy storage module 130 may have the same features as the corresponding configuration of the energy storage module 110.

[0126] In this embodiment, the trickle charging unit 320 includes a direction limiting unit 322 and a flow limiting unit 324. The trickle charging unit 320 is connected in parallel with the switching unit 230 between the wiring 106 of the energy storage system 100 and the energy storage unit 210 of the energy storage module 130. The trickle charging unit 320 may have a larger resistance than the switching unit 230. That is, the resistance value when current flows through the trickle charging unit 320 between the wiring 106 and the energy storage unit 210 is greater than the resistance value when current flows through the switching unit 230.

[0127] In this embodiment, the trickle charging unit 320 allows current to flow in the direction from the wiring 106 to the energy storage unit 210. On the other hand, the trickle charging unit 320 inhibits current from flowing in the direction from the energy storage unit 210 to the wiring 106. For example, the trickle charging unit 320 prevents current from flowing in the direction from the energy storage unit 210 to the wiring 106.

[0128] In this embodiment, the flow limiting unit 324 limits the amount of current flowing through the trickle charging unit 320. The flow limiting unit 324 may have a resistance larger than that of the switching unit 230. The flow limiting unit 324 may have at least one of a fixed resistor, a variable resistor, a constant current circuit, and a constant power circuit. The flow limiting unit 324 may have a PTC (positive temperature coefficient) thermistor. During the trickle charging of the energy storage unit 210, the flow limiting unit 324 may sometimes heat up when current flows through it. In this case, according to this embodiment, because the flow limiting unit 324 has a PTC thermistor, the temperature of the flow limiting unit 324 increases, and the amount of current flowing through the flow limiting unit 324 decreases. Therefore, during the trickle charging of the energy storage unit 210, the temperature of the flow limiting unit 324 can be maintained within a specified range.

[0129] In this embodiment, the directional limiting part 322 and the flow limiting part 324 are connected in series. The directional limiting part 322 allows current to flow in the direction from the wiring 106 to the energy storage unit 210. On the other hand, the directional limiting part 322 prevents current from flowing in the direction from the energy storage unit 210 to the wiring 106. The directional limiting part 322 may have a diode. The diode may be configured such that the direction from the wiring 106 to the energy storage unit 210 is positive.

[0130] The energy storage unit 210 of the energy storage module 130 can be an example of a first energy storage unit. The switching unit 230 of the energy storage module 130 can be an example of a first switching unit. The battery 222 and battery 224 of the energy storage module 130 can be examples of a first type of secondary battery. The trickle charging unit 320 can be an example of a limiting unit. The direction limiting unit 322 can be an example of a current direction limiting unit. The flow limiting unit 324 can be an example of a current flow limiting unit.

[0131] Figure 4 This is a simplified representation of an example of the system configuration of the module control unit 240. In this embodiment, the module control unit 240 includes a determination unit 410, a receiving unit 420, and a signal generating unit 430. The module control unit 240 may also include a module information acquisition unit 440, a module information storage unit 450, and a module information transmission unit 460. The receiving unit 420 may be an example of a first signal receiving unit, a second signal receiving unit, and a third signal receiving unit. The module information acquisition unit 440 may be an example of a battery characteristic acquisition unit.

[0132] In this embodiment, the module control unit 240 is described as having a module information acquisition unit 440, a module information storage unit 450, and a module information transmission unit 460. However, the energy storage system 100 is not limited to this embodiment. In another embodiment, the system control unit 140 may also have at least one of the module information acquisition unit 440, the module information storage unit 450, and the module information transmission unit 460.

[0133] The determination unit 410 determines whether the voltage between the terminals of the switching unit 230 is within a predetermined range. The determination unit 410 sends a signal indicating the determination result to the signal generation unit 430. The determination unit 410 can also be any comparator or comparison circuit. The determination unit 410 can also be a window comparator.

[0134] The receiving unit 420 receives at least one of a signal from the system control unit 140, a signal from the protection unit 250, and an instruction from the user. The receiving unit 420 sends a signal corresponding to the received information to the signal generating unit 430.

[0135] The signal generating unit 430 receives signals from at least one of the determination unit 410 and the receiving unit 420. Based on the received signals, the signal generating unit 430 generates a signal for controlling the switching unit 230. The signal generating unit 430 sends the generated signal to the switching unit 230.

[0136] In one embodiment, the signal generating unit 430 generates a signal to turn on the switching assembly of the switching unit 230 when the determination unit 410 has determined that the voltage between the terminals of the switching unit 230 is within a predetermined range. In another embodiment, the signal generating unit 430 generates a signal to turn off the switching assembly of the switching unit 230 when the determination unit 410 has determined that the voltage between the terminals of the switching unit 230 is not within a predetermined range.

[0137] The signal generation unit 430 can generate or send a signal after the determination unit 410 determines whether the voltage between the terminals of the switching unit 230 is within a predetermined range and after a predetermined time has elapsed. This prevents malfunctions caused by noise. In addition, it prevents the energy storage unit 210 from being electrically connected to the wiring 106 immediately after the energy storage module 110 is installed in the energy storage system 100.

[0138] In this embodiment, the signal generating unit 430 generates a signal for controlling the switching component of the switching unit 230 based on the signal received by the receiving unit 420. In one embodiment, when the receiving unit 420 has received a signal from the system control unit 140 to turn on the switching component of the switching unit 230, the signal generating unit 430 generates a signal to turn on the switching component of the switching unit 230.

[0139] In another embodiment, when the receiving unit 420 has received a signal from the protection unit 250 to disconnect the switching assembly of the switching unit 230, the signal generating unit 430 generates a signal to disconnect the switching assembly of the switching unit 230. In yet another embodiment, when the receiving unit 420 has received a user's instruction, the signal generating unit 430 generates a signal to operate the switching assembly of the switching unit 230 according to the user's instruction.

[0140] In this embodiment, the module information acquisition unit 440 acquires information about the battery characteristics of the energy storage unit 210. The module information acquisition unit 440 can also acquire information about the battery characteristics of the energy storage unit 210 by measuring its battery characteristics. The module information acquisition unit 440 can also acquire information about the battery characteristics of the energy storage unit 210 input by the manufacturer, seller, etc., at the time of shipment, inspection, or sale.

[0141] The module information acquisition unit 440 can store information about the battery characteristics of the energy storage unit 210 in the module information storage unit 450. The specific configuration of the module information acquisition unit 440 is not particularly limited; it can also be a controller that controls the reading and writing of data in the module information storage unit 450. In this embodiment, the module information storage unit 450 stores the battery characteristics of the energy storage unit 210 acquired by the module information acquisition unit 440.

[0142] In this embodiment, the module information sending unit 460 sends the battery characteristics information of the energy storage unit 210 obtained by the module information acquisition unit 440 to the system control unit 140. The module information sending unit 460 may also send the battery characteristics information of the energy storage unit 210 obtained by the module information acquisition unit 440 to an external machine. The module information sending unit 460 may send the battery characteristics information of the energy storage unit 210 upon request from an external machine, or it may send the battery characteristics information of the energy storage unit 210 at a predetermined time. The module information sending unit 460 may also refer to the module information storage unit 450 to send the battery characteristics information of the energy storage unit 210 to the system control unit 140 or an external machine.

[0143] Figure 5 This is a simplified illustration of an example of the circuit configuration of the energy storage module 110. Furthermore, for the sake of simplicity, Figure 5 The diagram does not show the protection unit 250 and the wiring associated with the protection unit 250.

[0144] In this embodiment, the switching unit 230 includes a transistor 510, a resistor 512, a resistor 514, a diode 516, a transistor 520, a resistor 522, a resistor 524, and a diode 526. Transistors 510 and 520 can be examples of switching components. In this embodiment, the case where transistors 510 and 520 are used as the switching components of the switching unit 230 is described. However, the switching components of the switching unit 230 are not limited to this embodiment. In another embodiment, a single switching component may also be used as the switching component of the switching unit 230.

[0145] In this embodiment, the module control unit 240 includes a determination unit 410, a signal generation unit 430, a switch 592, and a switch 594. In this embodiment, the determination unit 410 includes a transistor 530, a resistor 532, a transistor 540, a resistor 542, a resistor 552, and a resistor 554. The signal generation unit 430 includes a transistor 560, a capacitor 570, a resistor 572, and a transistor 580. Switches 592 and 594 can be examples of the receiving unit 420.

[0146] Next, detailed descriptions of each part of the switching unit 230 and the module control unit 240 will be provided. In the switching unit 230 of this embodiment, transistor 510 is a MOSFET. Even when transistor 510 is off, current can still flow from the positive terminal 212 to the positive terminal 202 through a parasitic diode (not shown) equivalently formed between the source and drain of transistor 510. Similarly, transistor 520 is a MOSFET. Even when transistor 520 is off, current can still flow from the positive terminal 202 to the positive terminal 212 through a parasitic diode (not shown) equivalently formed between the source and drain of transistor 520.

[0147] In this embodiment, transistors 510 and 520 are initially set to be off. When transistor 580 is turned on during charging of the energy storage system 100, current flows from the positive terminal 202 to the negative terminal 204 through resistors 512 and 514 and transistor 580. As a result, a voltage is applied to the gate of transistor 510, and transistor 510 is turned on. Thus, current can flow from the positive terminal 202 to the positive terminal 212 through the parasitic diode equivalently formed between the source and drain of transistor 520.

[0148] On the other hand, if transistor 580 is turned on when the energy storage system 100 is discharging, current will flow from the positive terminal 212 to the negative terminal 214 through resistors 522 and 524 and transistor 580. As a result, a voltage is applied to the gate of transistor 520, and transistor 520 is turned on. Thus, current can flow from the positive terminal 212 to the positive terminal 202 through the parasitic diode equivalently formed between the source and drain of transistor 510.

[0149] The voltage applied to the gate of transistor 510 or transistor 520 when transistor 580 is turned on can be an example of a signal used to turn on the switching assembly of switching unit 230. Similarly, the voltage applied to the gate of transistor 510 or transistor 520 when transistor 580 is turned off can also be an example of a signal used to turn off the switching assembly of switching unit 230.

[0150] In this embodiment, the values ​​of resistors 512 and 514 are set to enable transistor 510 to save power and reliably turn on / off. Similarly, the values ​​of resistors 522 and 524 are set to enable transistor 520 to save power and reliably turn on / off.

[0151] In this embodiment, a diode 516 is disposed between resistors 514 and 524. Diode 516 allows current to flow in the direction from resistor 514 to resistor 524, and prevents current from flowing in the direction from resistor 524 to resistor 514. By providing diode 516, when the switching unit 230 electrically disconnects the positive terminals 202 and 212, leakage of current from positive terminal 212 to positive terminal 202 is prevented from occurring through the path of resistors 522, 524, 514, and 512.

[0152] In this embodiment, a diode 526 is disposed between resistors 514 and 524. Diode 526 allows current to flow in the direction from resistor 524 to resistor 514, but prevents current from flowing in the direction from resistor 514 to resistor 524. By providing diode 526, when the switching unit 230 electrically disconnects the positive terminals 202 and 212, leakage of current from positive terminal 202 to positive terminal 212 is prevented from occurring through the path of resistors 512, 514, 524, and 522.

[0153] In the module control unit 240 of this embodiment, transistors 530 and 540 of the determination unit 410 are set to be off in the initial settings. In addition, transistors 560 and 580 of the signal generation unit 430 are set to be off in the initial settings.

[0154] According to this embodiment, the value of resistor 532 is set such that the transistor 530 is turned on when the voltage between the terminals of the switching unit 230 is smaller than a predetermined first value with the positive terminal 202 side as the positive side. The value of resistor 532 is preferably set such that the leakage current becomes minimal when the switching unit 230 is turned off. Furthermore, the value of resistor 542 is set such that the transistor 540 is turned on when the voltage between the terminals of the switching unit 230 is larger than a predetermined second value. The value of resistor 542 is preferably set such that the leakage current becomes minimal when the switching unit 230 is turned off. In addition, according to this embodiment, the voltage between the terminals of the switching unit 230 is equal to the voltage difference between the positive terminal 202 and the positive terminal 212.

[0155] When the voltage between the terminals of the switching unit 230 is lower than a predetermined first value, the transistor 530 is switched on. A voltage is applied from the energy storage unit 210 to the base of the transistor 560 via the positive terminal 212, the transistor 530, and the resistor 552, causing the transistor 560 to switch on. A voltage from the positive terminal 202 is applied to the base of the transistor 580, but this prevents the transistor 580 from switching on during the switching operation of the transistor 560. As a result, the transistor 580 is switched off.

[0156] On the other hand, if the voltage between the terminals of the switching unit 230 is greater than a predetermined second value, the transistor 540 is turned on, and a voltage is applied from the positive terminal 202 to the base of the transistor 560 via the transistor 540 and the resistor 554, causing the transistor 560 to be turned on. As a result, the transistor 580 is turned off.

[0157] In this embodiment, the value of resistor 552 is set within a range that allows transistor 560 to be turned on when transistor 530 is turned on, in order to reduce power consumption. The value of resistor 554 is set within a range that allows transistor 560 to be turned on when transistor 540 is turned on, in order to reduce power consumption.

[0158] The capacitance of capacitor 570 is set such that transistor 560 is turned on before transistor 580 is turned on, by applying a voltage from the positive terminal 202 to the base of transistor 580. Therefore, signal generation unit 430 can generate a signal after a predetermined time has elapsed after determination unit 410 determines whether the voltage between the terminals of the switching assembly is within a predetermined range.

[0159] Conversely, when the voltage between the terminals of the switching unit 230 is within the range specified by the first and second values, transistors 530 and 540 are in the off state, and transistor 560 is also in the off state. Therefore, a voltage is applied to the base of transistor 580 from the positive terminal 202 via resistor 572, and transistor 580 is turned on.

[0160] Switches 592 and 594 can be manual switches, or they can be switching components such as relays, thyristors, or transistors. Switch 592 can be input with a signal 52 indicating that the switching unit 230 is turned on. Switch 594 can be input with a signal 54 indicating that the switching unit 230 is turned off.

[0161] When switch 592 is turned on, switching unit 230 is turned on regardless of whether transistor 580 is turned on or off. When switch 594 is turned on, transistor 580 is turned off regardless of whether transistor 560 is turned on or off. As a result, switching unit 230 can be turned off.

[0162] Figure 6 This is a simplified illustration of the system configuration of the system control unit 140. (Using...) Figure 6This section outlines the information processing between the charging device 14, the load device 20, and the system control unit 140. In this embodiment, the system control unit 140 includes a status management unit 622, a module selection unit 624, and a signal generation unit 626. In this embodiment, the charging device 14 includes a charging switching unit 16, a charging control unit 642, and a charging unit 644. In this embodiment, the load device 20 includes a load switching unit 26, a load control unit 662, and a load unit 664.

[0163] [Overview of the various sections of the System Control Unit 140] In this embodiment, the state management unit 622 manages the state of the energy storage system 100. The state management unit 622 can manage the state of energy storage modules 110 and 130. The state management unit 622 can monitor the respective states of energy storage modules 110 and 130. The state management unit 622 can monitor energy storage modules 110 and 130 and obtain information about the battery characteristics of each energy storage module 110 and 130. The state management unit 622 can also send the information obtained from monitoring energy storage modules 110 and 130 to an external machine.

[0164] The status management unit 622 can measure the battery characteristics of each energy storage module while using the energy storage system 100. If the battery characteristics of a energy storage module do not meet predetermined conditions, the status management unit 622 can output information indicating insufficient performance of that module to an output device for user information. The status management unit 622 can also output identification information of the energy storage module and information indicating insufficient performance of that module.

[0165] Therefore, users can easily identify and replace energy storage modules with insufficient performance. According to this embodiment, for example, when constructing an energy storage system 100 using recycled energy storage modules, the inspection of at least a portion of the recycled energy storage modules can be omitted.

[0166] In one embodiment, when the energy storage system 100 transitions to a charging state, the module selection unit 624 selects the energy storage module with the lowest inter-terminal voltage among the plurality of energy storage modules included in the energy storage system 100. For example, the module selection unit 624 compares the inter-terminal voltages of energy storage module 110 and energy storage module 130, and selects the energy storage module with the lower inter-terminal voltage. The module selection unit 624 sends a signal indicating the selected energy storage module to the signal generation unit 626.

[0167] In another embodiment, when the energy storage system 100 transitions to a discharge state, the module selection unit 624 selects the energy storage module with the highest inter-terminal voltage among the plurality of energy storage modules included in the energy storage system 100. For example, the module selection unit 624 compares the inter-terminal voltages of energy storage module 110 and energy storage module 130, and selects the energy storage module with the larger inter-terminal voltage. The module selection unit 624 sends a signal indicating the selected energy storage module to the signal generation unit 626.

[0168] In this embodiment, the signal generating unit 626 generates a signal for the energy storage module selected by the module selection unit 624 to turn on the switching component of the switching unit 230 of that energy storage module. The signal generating unit 626 sends the generated signal to the module control unit 240. In another embodiment, the signal generating unit 626 may also generate a signal for the energy storage module selected by the module selection unit 624 to turn off the switching component of the switching unit 230 of that energy storage module.

[0169] In this embodiment, the signal generating unit 626 may also generate a signal for controlling the charging device 14. For example, the signal generating unit 626 generates a signal for adjusting the set value of at least one of the charging voltage and charging current of the charging device 14. The signal generating unit 626 can send the signal for controlling the charging device 14 to the charging device 14. Thus, the charging of the energy storage system 100 is controlled.

[0170] In this embodiment, the signal generation unit 626 generates a signal for setting the charging voltage of the charging device 14. For example, the signal generation unit 626 obtains information about the battery characteristics of each energy storage module installed in the energy storage system 100 from the status management unit 622. Based on the information about the battery characteristics, the signal generation unit 626 identifies the energy storage module with the highest charging end voltage among the energy storage modules installed in the energy storage system 100. Based on the information about the battery characteristics, the signal generation unit 626 determines whether the energy storage module with the highest charging end voltage supports trickle charging.

[0171] When the energy storage module with the highest charging end voltage supports trickle charging, the signal generation unit 626 can generate a signal to set the charging voltage of the charging device 14 to a value greater than or equal to the full-charge voltage of the energy storage module. Conversely, when the energy storage module with the highest charging end voltage does not support trickle charging, the signal generation unit 626 can generate a signal to set the charging voltage of the charging device 14 to a value greater than or equal to the charging end voltage of the energy storage module.

[0172] As described above, even if the energy storage modules installed in the energy storage system 100 include energy storage modules capable of supporting trickle charging, the ability to implement trickle charging may still depend on the specifications of other energy storage modules. However, according to this embodiment, when the energy storage modules installed in the energy storage system 100 include energy storage modules capable of supporting trickle charging, trickle charging of that energy storage module can be reliably implemented.

[0173] In this embodiment, the signal generating unit 626 can generate a signal for controlling the operation of the charging switching unit 16. The signal generating unit 626 can send the signal for controlling the operation of the charging switching unit 16 to the charging device 14 or the charging switching unit 16. For example, the signal generating unit 626 generates a signal for controlling the ON / OFF operation of the charging switching unit 16. This allows, for example, switching the electrical connection between the charging device 14 and the energy storage system 100. If the charging switching unit 16 has a function to adjust the current amount, the signal generating unit 626 can also generate a signal for controlling the current amount of the charging current. This allows control of the current amount of the charging current. Details regarding the operation control of the charging switching unit 16 will be described below.

[0174] In this embodiment, the signal generating unit 626 may also generate a signal for controlling the load device 20. For example, the signal generating unit 626 may generate a signal for adjusting a set value of the current consumption of the load device 20. As a result, the discharge of the energy storage system 100 can be controlled.

[0175] For example, the signal generation unit 626 generates a signal to control the load device 20 in such a way that the current consumption of the load device 20 increases continuously or in stages after the power storage system 100 supplies power to the load device 20. As a result, the rate of increase of the output current supplied from the power supply system 10 to the load device 20 can be controlled.

[0176] In the energy storage system 100 of this embodiment, if the rate of decrease of the voltage (sometimes referred to as line voltage, output voltage, etc.) of the wiring 106 is greater than the operating speed of the switching unit 230, it may be impossible to connect the energy storage module installed in the energy storage system 100 to the wiring 106, resulting in unstable power supply from the power supply system 10. However, by controlling the rate of increase of the output current supplied from the power supply system 10 to the load device 20 within a range that the switching unit 230 can handle, the power supply system 10 can stably supply power.

[0177] In this embodiment, the signal generating unit 626 can generate a signal for controlling the operation of the load switching unit 26. The signal generating unit 626 can send the signal for controlling the operation of the load switching unit 26 to the load device 20 or the load switching unit 26. For example, the signal generating unit 626 generates a signal for controlling the on / off operation of the load switching unit 26. This allows switching the electrical connection between the load device 20 and the energy storage system 100. If the load switching unit 26 has a function to adjust the current amount, the signal generating unit 626 can also generate a signal for controlling the current amount of the load switching unit 26. This allows control of the discharge current (sometimes also called the output current). Details of the operation control of the load switching unit 26 will be described below.

[0178] In this embodiment, the signal generation unit 626 may also generate a signal for controlling the operation of components or circuits (not shown) included in the energy storage system 100, which control at least one of the output voltage and output current. The signal generation unit 626 may send the signal to the components or circuits. For example, the signal generation unit 626 generates a signal for controlling the magnitude of at least one of the output voltage and output current supplied from the power supply system 10 to the load device 20.

[0179] In one embodiment, the signal generating unit 626 receives from the load device 20 a signal (sometimes called a request signal) indicating the magnitude of the current to be supplied to the load device 20. The signal generating unit 626 generates a signal to control the operation of the component or circuit so as to output a current of the magnitude indicated by the request signal. This allows control of the output current supplied from the power supply system 10 to the load device 20. In another embodiment, the signal generating unit 626 generates a signal to control the magnitude of the output current so that the output current increases continuously or in stages after the energy storage system 100 begins supplying power. This also allows control of the output current supplied from the power supply system 10 to the load device 20.

[0180] In this embodiment, the signal generating unit 626 may also generate signals for controlling each energy storage module of the energy storage system 100. The signal generating unit 626 may send these signals to the energy storage modules that are the objects of its control. For example, the signal generating unit 626 may generate a signal to warn that the load device 20 will operate. It may also generate a signal to notify that the load device 20 has already started operating.

[0181] [Overview of the components of charging device 14] In this embodiment, the charging control unit 642 controls the charging unit 644. Specifically, the charging control unit 642 controls the magnitude of at least one of the voltage (sometimes referred to as charging voltage) and the current (sometimes referred to as charging current) output by the charging unit 644. The charging control unit 642 may also control the rate of change of at least one of the charging voltage and the charging current.

[0182] The charging control unit 642 can receive signals from the signal generation unit 626 of the system control unit 140 and control the charging unit 644 based on these signals. The charging control unit 642 can also control the charging unit 644 according to instructions input by the user to the input device (not shown).

[0183] The charging control unit 642 can control the set value of the charging voltage of the charging unit 644. For example, the charging control unit 642 adjusts the set value of the charging voltage so that the charging voltage of the charging device 14 is greater than the full-charge voltage of the energy storage module 130. As a result, the full-charge voltage of the energy storage module 130 is less than the charging voltage of the charging device 14. As described above, in this embodiment, the energy storage section 210 of the energy storage module 130 supports trickle charging. In addition, the charging end voltage of the energy storage module 130 is the highest among the multiple energy storage modules installed in the energy storage system 100. In this case, by setting the charging voltage of the charging device 14 in the above manner, after the voltage of the energy storage module 130 reaches the charging end voltage, the full-charge voltage of the energy storage module 130 can be maintained by trickle charging.

[0184] The charging control unit 642 can control the charging mode of the charging unit 644. Examples of charging modes include constant voltage charging, constant current charging, constant voltage and constant current charging, and trickle charging.

[0185] For example, during at least a portion of the charging period of the energy storage modules 110 and 130, the charging control unit 642 controls the charging unit 644 to charge both energy storage modules 110 and 130 using a constant current charging method. Afterwards, the charging control unit 642 can control the charging unit 644 to charge the energy storage module 130 using a constant voltage charging method. For example, after the charging of the energy storage module 110 is complete, the charging control unit 642 can control the charging unit 644 to charge the energy storage module 130 using a constant voltage charging method. Furthermore, after the voltage of the energy storage module 130 reaches the charging completion voltage of the energy storage module 130, the charging control unit 642 can control the charging unit 644 to charge the energy storage module 130 using a trickle charging method.

[0186] Therefore, when the voltage of the energy storage module 130 is below the charging end voltage, the charging device 14 charges the energy storage module 130 using either constant current charging or constant voltage charging. Conversely, when the voltage of the energy storage module 130 is above the charging end voltage, the charging device 14 charges the energy storage module 130 using trickle charging.

[0187] In this embodiment, the charging unit 644 receives power from the system power supply. Additionally, the charging unit 644 supplies power to the energy storage system 100 via the charging switching unit 16. The charging unit 644 can output power using a current set by the charging control unit 642. The charging unit 644 can also output power using a voltage set by the charging control unit 642.

[0188] [Overview of the components of load device 20] In this embodiment, the load control unit 662 controls the load unit 664. Specifically, the load control unit 662 controls the magnitude of at least one of the voltage (sometimes referred to as the consumed voltage) and the current (sometimes referred to as the consumed current) of the power consumed by the load unit 664. The load control unit 662 may also control the rate of change of at least one of the consumed voltage and consumed current. For example, after the energy storage system 100 supplies power to the load device 20, the load control unit 662 controls the load unit 664 in a manner that the consumed current of the load device 20 increases continuously or in stages.

[0189] The load control unit 662 can receive signals from the signal generation unit 626 of the system control unit 140 and control the load unit 664 based on these signals. The load control unit 662 can also control the load unit 664 according to instructions input by the user into the input device (not shown).

[0190] The charging control unit 642 can be an example of a charging voltage control unit. The load control unit 662 can be an example of a current consumption control unit.

[0191] use Figure 7 , Figure 8 and Figure 9 This section provides a summary of the charging operation of the energy storage system 100. Figure 7 This section briefly illustrates an example of the voltage variation 730 between the terminals of the energy storage module 130 and an example of the voltage variation 710 between the terminals of the energy storage module 110 during charging. Additionally, Figure 7 This is a simplified example of the variation 740 of the current through the energy storage section 210 of the energy storage module 130. Figure 8 This is a brief example of the variation 814 in the charging voltage of the charging device 14. Figure 9 An example of the output characteristics 914 of the charging device 14 is shown in general.

[0192] like Figure 7 As shown, according to this embodiment, charging of the energy storage system 100 begins at time t1. The maximum value of the charging voltage of the charging device 14 is set to Vcv. Furthermore, at the time point t1 when charging of the energy storage system 100 begins, the terminal voltages of the energy storage module 110 and the energy storage module 130 are Vai and Vbi, respectively. At this time, the energy storage section 210 of the energy storage module 110 is electrically connected to the wiring 106, and the energy storage section 210 of the energy storage module 130 is electrically disconnected from the wiring 106.

[0193] Afterwards, the energy storage module 110 is charged. When the voltage between the terminals of the energy storage module 110 becomes Vai at time t2, the switching part 230 of the energy storage module 130 is switched on, and the energy storage part 210 of the energy storage module 130 is electrically connected to the wiring 106.

[0194] Afterwards, the energy storage module 110 and the energy storage module 130 are charged. When the voltage between the terminals of the energy storage module 110 reaches the charging end voltage Vbc of the energy storage module 110 at time t3, the protection unit 250 of the energy storage module 110 detects overcharging and controls the switching unit 230, thereby disconnecting the energy storage unit 210 of the energy storage module 110 from the wiring 106.

[0195] Then, the energy storage module 130 is charged. At time t4, after the voltage between the terminals of the energy storage module 130 reaches the charging end voltage Vac of the energy storage module 130, the protection unit 250 of the energy storage module 110 detects overcharging and controls the switching unit 230. As a result, the energy storage unit 210 of the energy storage module 130 is electrically disconnected from the wiring 106.

[0196] At this time, as Figure 8 As shown, by electrically disconnecting the energy storage section 210 of the energy storage module 130 from the wiring 106, the voltage of the wiring 106 is equal to the output voltage Vcv of the charging device 14. Additionally, as... Figure 9 As shown, by disconnecting the energy storage section 210 of the energy storage module 130 from the wiring 106, the charging current is reduced sharply.

[0197] Then, trickle charging of the energy storage module 130 is performed. As a result, the inter-terminal voltage of the energy storage module 130 reaches the full-charge voltage Vaf of the energy storage module 130. In addition, trickle charging is used to maintain the full-charge state of the energy storage module 130.

[0198] use Figure 7 , Figure 8 and Figure 9 The charging operation, as described above, can be controlled by the charging control unit 642. (Use...) Figure 7 , Figure 8 and Figure 9The charging operation described herein can be implemented by the system control unit 140 controlling the charging control unit 642.

[0199] [Energy storage module with interlocking mechanism] Next, use Figure 10 , Figure 11 and Figure 12 Another example of the energy storage module 110 will be described. To the extent that there is no technical inconsistency, the matters described for the energy storage module 110 and its components can also be applied to another example of the energy storage module 110 and its components. Furthermore, the matters described for another example of the energy storage module 110 and its components can also be applied to the energy storage module 110 and its components. Figures 10-12 In the description, the details concerning the various parts of the energy storage module 110 are sometimes omitted.

[0200] Figure 10 This section outlines a schematic example of the system configuration of the energy storage module 1010. In this embodiment, the energy storage module 1010 includes a positive terminal 202, a negative terminal 204, and an energy storage unit 210. The energy storage module 1010 may include a switching unit 230. The energy storage module 1010 may include a protection unit 250. The energy storage module 1010 may include a balance correction unit 260. In this embodiment, the energy storage module 1010 includes a current detection component 1020 and a module control unit 1040.

[0201] In this embodiment, the switching unit 230 adjusts the current flowing between the wiring 106 and the energy storage unit 210. In one embodiment, the switching unit 230 electrically connects the wiring 106 and the energy storage unit 210, or electrically disconnects the wiring 106 and the energy storage unit 210. In another embodiment, the switching unit 230 increases or decreases the current, for example, by changing the resistance value of the path between the wiring 106 and the energy storage unit 210.

[0202] In this embodiment, one end of the switching unit 230 is electrically connected to the wiring 106 via the positive terminal 202 and the current detection component 1020. The other end of the switching unit 230 is electrically connected to the positive terminal 212 of the energy storage unit 210. Information indicating the voltage between the terminals of the switching unit 230 can be used to represent the difference between the potential of the wiring 106 or the voltage applied to the wiring 106 (sometimes simply referred to as the voltage of the wiring 106) and the potential of the terminal of the energy storage unit 210 (e.g., the positive terminal 212) or the voltage applied to that terminal (sometimes simply referred to as the voltage of the energy storage unit 210, the voltage of the terminal, etc.).

[0203] In one embodiment, the switching unit 230 adjusts at least the magnitude of the current flowing between the wiring 106 and the energy storage unit 210 in the direction from the positive terminal 212 of the energy storage unit 210 toward the positive terminal 202 (sometimes referred to as the discharge direction). In another embodiment, the switching unit 230 adjusts at least the magnitude of the current flowing between the wiring 106 and the energy storage unit 210 in the direction from the positive terminal 202 toward the positive terminal 212 of the energy storage unit 210 (sometimes referred to as the charging direction). In yet another embodiment, the switching unit 230 adjusts both the magnitude of the current flowing in the discharge direction between the wiring 106 and the energy storage unit 210 and the magnitude of the current flowing in the charging direction between the wiring 106 and the energy storage unit 210.

[0204] In this embodiment, the energy storage module 1010 includes a current detection component 1020, which differs from the energy storage module 110. The energy storage module 1010 also includes a module control unit 1040 instead of a module control unit 240, which differs from the energy storage module 110. Aside from the aforementioned differences, the energy storage module 1010 may have the same features as the corresponding configuration of the energy storage module 110.

[0205] In this embodiment, the current detection component 1020 is used to obtain information indicating the current flowing between the wiring 106 and the energy storage unit 210. Examples of current information include the presence or absence of the current, the magnitude of the current, and the direction of the current. In this embodiment, the energy storage module 1010 obtains information about the current flowing between the wiring 106 and the energy storage unit 210 by measuring the voltage between the terminals of the current detection component 1020.

[0206] In this embodiment, the current detection component 1020 is disposed between the positive terminal 202 and the switching unit 230. More specifically, one end of the current detection component 1020 is electrically connected to the switching unit 230. The other end of the current detection component 1020 is electrically connected to the wiring 106 via the positive terminal 202. Alternatively, the current detection component 1020 may also be disposed between the switching unit 230 and the positive terminal 212 of the energy storage unit 210. Furthermore, the switching unit 230 or a part of the components constituting the switching unit 230 may also be used as the current detection component 1020.

[0207] The current sensing component 1020 can be any component with any resistance value, and its type is not particularly limited. For example, the current sensing component 1020 has an appropriate resistance value corresponding to the maximum allowable current of the energy storage unit 210. Examples of current sensing components 1020 include resistors, Hall effect sensors, etc. Passive or active components with appropriate resistance values ​​can also be used as the resistor.

[0208] In this embodiment, the module control unit 1040 detects the current flowing between the wiring 106 and the energy storage unit 210, which differs from the module control unit 240. In this embodiment, the module control unit 1040 controls the operation of the switching unit 230 based on (i) the voltage or state of charge (SOC) of the energy storage unit 210 and (ii) the current flowing between the wiring 106 and the energy storage unit 210, which differs from the module control unit 240. The module control unit 1040 may also control the operation of the switching unit 230 based on (i) the voltage or SOC of the energy storage unit 210, (ii) the current flowing between the wiring 106 and the energy storage unit 210, and (iii) the inter-terminal voltage of the switching unit 230. Apart from the aforementioned differences, the module control unit 1040 may have the same features as the corresponding configuration of the module control unit 240.

[0209] The method by which the module control unit 1040 detects the current flowing between the wiring 106 and the energy storage unit 210 is not particularly limited. In this embodiment, the module control unit 1040 obtains information representing the inter-terminal voltage of the current detection component 1020 disposed between the positive terminal 202 and the positive terminal 212, and detects the current flowing between the wiring 106 and the energy storage unit 210 based on this information. Thus, the module control unit 1040 can monitor the current flowing between the wiring 106 and the energy storage unit 210. The module control unit 1040 can determine the magnitude and direction of the current flowing between the wiring 106 and the energy storage unit 210.

[0210] In one embodiment, when the switching unit 230 at least adjusts or controls the magnitude of the current flowing in the discharge direction between the wiring 106 and the energy storage unit 210, the module control unit 1040 monitors or detects the current flowing in the charging direction between the wiring 106 and the energy storage unit 210. When the switching unit 230 disconnects the electrical connection in the discharge direction between the wiring 106 and the energy storage unit 210 (sometimes referred to as "electrical disconnection in the discharge direction"), the module control unit 1040 monitors or detects the current flowing between the wiring 106 and the energy storage unit 210. Furthermore, in this case, the current result detected by the module control unit 1040 is the current flowing in the charging direction between the wiring 106 and the energy storage unit 210.

[0211] In another embodiment, when the switching unit 230 at least adjusts or controls the magnitude of the current flowing in the charging direction between the wiring 106 and the energy storage unit 210, the module control unit 1040 monitors or detects the current flowing in the discharging direction between the wiring 106 and the energy storage unit 210. When the switching unit 230 disconnects the electrical connection in the charging direction between the wiring 106 and the energy storage unit 210 (sometimes referred to as "electrical disconnection in the charging direction"), the module control unit 1040 can also monitor or detect the current flowing between the wiring 106 and the energy storage unit 210. Furthermore, in this case, the current detected by the module control unit 1040 is the current flowing in the discharging direction between the wiring 106 and the energy storage unit 210.

[0212] The method by which the module control unit 1040 controls the operation of the switching unit 230 is not particularly limited. As described above, the module control unit 1040 detects the current flowing between the wiring 106 and the energy storage unit 210. The module control unit 1040 can control the operation of the switching unit 230 based on information indicating the current flowing between the wiring 106 and the energy storage unit 210. Therefore, when the energy storage module 1010 is hot-swapped, the interlock of the switching unit 230 can be safely released.

[0213] Similar to module control unit 240, module control unit 1040 can acquire information indicating the inter-terminal voltage of switching unit 230. Module control unit 1040 can control the operation of switching unit 230 based on the information indicating the inter-terminal voltage of switching unit 230. This reduces the time required for hot-swapping the energy storage module 1010.

[0214] Similar to the module control unit 240, the module control unit 1040 can obtain information acquired or generated by the protection unit 250. For example, the module control unit 1040 obtains information from the protection unit 250 indicating that the overcharge protection function is active, that the overcharge protection function is inactive, that the over-discharge protection function is active, and that the over-discharge protection function is inactive. The module control unit 1040 can control the operation of the switching unit 230 based on the information acquired or generated by the protection unit 250. Therefore, the switching unit 230 can be appropriately controlled according to the state of the energy storage unit 210.

[0215] For example, if the voltage or SOC of the energy storage unit 210 is less than or below the threshold for over-discharge protection, the over-discharge protection function becomes active. If the voltage or SOC of the energy storage unit 210 is greater than or above the threshold for over-discharge protection, the over-discharge protection function becomes inactive. Similarly, if the voltage or SOC of the energy storage unit 210 is greater than or above the threshold for overcharge protection, the overcharge protection function becomes active. If the voltage or SOC of the energy storage unit 210 is less than or below the threshold for overcharge protection, the overcharge protection function becomes inactive.

[0216] Similar to the module control unit 240, the module control unit 1040 can obtain information acquired or generated by the system control unit 140. For example, the module control unit 1040 obtains information from the system control unit 140 indicating the battery characteristics of the energy storage unit 210. The module control unit 1040 can control the operation of the switching unit 230 based on the information acquired or generated by the system control unit 140. Therefore, the switching unit 230 can be appropriately controlled according to the state of the energy storage unit 210.

[0217] [Specific example of the sequence of actions of the control switching unit 230] In one embodiment, the module control unit 1040 controls the operation of the switching unit 230 based on the charging state of the energy storage unit 210. In another embodiment, the module control unit 1040 controls the operation of the switching unit 230 based on the inter-terminal voltage of the switching unit 230. In yet another embodiment, the module control unit 1040 controls the operation of the switching unit 230 based on the current flowing between the wiring 106 and the energy storage unit 210. The module control unit 1040 may control the operation of the switching unit 230 based on at least one of the magnitude and direction of the current.

[0218] More specifically, the module control unit 1040 controls the operation of the switching unit 230 based on (i) the voltage or state of charge (SOC) of the energy storage unit 210, and (ii) the current flowing between the wiring 106 and the energy storage unit 210. The module control unit 1040 may also control the operation of the switching unit 230 based on (i) the voltage or SOC of the energy storage unit 210, (ii) the current flowing between the wiring 106 and the energy storage unit 210, and (iii) the inter-terminal voltage of the switching unit 230.

[0219] For example, when the voltage or SOC of the energy storage unit 210 meets predetermined conditions, the module control unit 1040 controls the switching unit 230 to electrically connect the wiring 106 to the energy storage unit 210. Regarding the battery characteristics of the energy storage unit 210, the voltage or SOC of the energy storage unit 210 can be an example of its battery characteristics. The predetermined conditions can be conditions using a predetermined numerical range or threshold, or conditions using a numerical range or threshold calculated according to a predetermined sequence of steps. Thus, for example, it is possible to prevent deterioration or damage to the energy storage unit 210 caused by overcharging or over-discharging.

[0220] The predetermined conditions can be conditions used to protect the battery storage unit 210. Examples of predetermined conditions include: (i) conditions indicating that the voltage or SOC of the battery storage unit 210 is within a specific numerical range; (ii) conditions indicating that the voltage or SOC of the battery storage unit 210 is greater than or above a specific threshold; and (iii) conditions indicating that the voltage or SOC of the battery storage unit 210 is less than or below a specific threshold; and (v) conditions obtained by combining these conditions, etc.

[0221] A condition indicating that the voltage or SOC of the energy storage unit 210 is within a specific numerical range can also be a condition indicating that at least one of the overvoltage protection function and over-discharge protection function of the energy storage module 1010 is invalid. A condition indicating that the voltage or SOC of the energy storage unit 210 is within a specific numerical range can also be a condition indicating that the overvoltage protection function and over-discharge protection function of the energy storage module 1010 are invalid. A condition indicating that the voltage or SOC of the energy storage unit 210 is greater than or above a specific threshold can also be a condition indicating that the over-discharge protection function of the energy storage module 1010 is invalid. A condition indicating that the voltage or SOC of the energy storage unit 210 is less than or below a specific threshold can also be a condition indicating that the overcharge protection function of the energy storage module 1010 is invalid.

[0222] According to this embodiment, the module control unit 1040 controls the switching unit 230 to electrically connect the energy storage unit 210 and the wiring 106 when the voltage between the terminals of the switching unit 230 meets a predetermined condition. More specifically, when the voltage difference between the wiring 106 and the energy storage unit 210 is relatively large, the energy storage unit 210 and the wiring 106 are electrically disconnected. On the other hand, when the difference is relatively small, the energy storage unit 210 and the wiring 106 are electrically connected. This enables rapid hot-swapping.

[0223] The predetermined conditions can be conditions used to achieve rapid hot-swapping. Examples of predetermined conditions include: (i) a condition indicating that the voltage between the terminals of the switching unit 230 is within a specific numerical range; (ii) a condition indicating that the voltage between the terminals of the switching unit 230 is greater than or above a specific threshold; (iii) a condition indicating that the voltage between the terminals of the switching unit 230 is less than or below a specific threshold; and (v) a condition obtained by combining these conditions, etc.

[0224] (Specific example of the sequence of steps to disengage the over-discharge protection interlock) When the energy storage unit 210 of the energy storage module 1010 is electrically connected to the wiring 106 of the energy storage system 100, and the energy storage system 100 discharges, for example, if the voltage or state of charge (SOC) of the energy storage unit 210 is less than the threshold for over-discharge protection, the protection unit 250 sends a signal to the module control unit 1040 to activate the over-discharge protection function. At this time, current flows in the discharge direction between the wiring 106 and the energy storage unit 210. In this case, the discharge direction can be an example of a first direction. Alternatively, the charging direction can be an example of a second direction. Furthermore, in this embodiment, the discharge direction and the charging direction are opposite to each other.

[0225] The case where the voltage or SOC of the energy storage unit 210 is less than the threshold for over-discharge protection may be an example of a situation where the conditions for protecting the energy storage unit 210 are not met. In another embodiment, when the voltage or SOC of the energy storage unit 210 is below the threshold for over-discharge protection, the protection unit 250 may send a signal to the module control unit 1040 to enable the over-discharge protection function.

[0226] When the module control unit 1040 receives the signal, it controls the switching unit 230 to disconnect the wiring 106 and the energy storage unit 210. When the energy storage system 100 continues to discharge after the wiring 106 and the energy storage unit 210 are disconnected, a voltage difference is generated between the wiring 106 and the energy storage unit 210.

[0227] After the discharge of the energy storage system 100 ends, when charging of the energy storage system 100 begins, a voltage difference is generated between the wiring 106 and the energy storage unit 210. In this case, if the absolute value of the voltage difference is greater than the threshold for achieving rapid hot-swapping, the module control unit 1040 determines that the voltage between the terminals of the switching unit 230 does not meet the conditions for achieving rapid hot-swapping. As a result, the energy storage system 100 begins charging while the wiring 106 between the energy storage unit 210 of the energy storage module 1010 and the energy storage system 100 is electrically disconnected.

[0228] On the other hand, (i) when the absolute value of the voltage difference at the start of charging of the energy storage system 100 is less than or below the threshold for achieving rapid hot-swapping, or (ii) when the absolute value of the voltage difference is less than or below the threshold for achieving rapid hot-swapping during charging of the energy storage system 100, the module control unit 1040 will control the switching unit 230 to connect the wiring 106 and the energy storage unit 210. However, during this stage, the voltage or SOC of the energy storage unit 210 is less than the threshold for over-discharge protection. Therefore, the interlocking mechanism of the module control unit 1040 is activated. As a result, the module control unit 1040 cannot control the switching unit 230 to connect the wiring 106 and the energy storage unit 210.

[0229] In order for the module control unit 1040 to control the switching unit 230 to connect the wiring 106 and the energy storage unit 210, the interlock must be released using some kind of logic. The method for releasing the interlock is not particularly limited. In this embodiment, the module control unit 1040 determines whether to release the interlock based on the current flowing between the wiring 106 and the energy storage unit 210 or information about that current, and controls the operation of the switching unit 230 accordingly.

[0230] Here, as Figure 5 As explained in the related description, the switching unit 230 includes a transistor 520 that adjusts or controls the magnitude of the current flowing in the discharge direction between the wiring 106 and the energy storage unit 210. Examples of transistors 520 include Si-MOSFETs, insulated-gate bipolar transistors (IGBTs), SiC-MOSFETs, and GaN-MOSFETs.

[0231] When the rated voltage of the energy storage unit 210 is relatively high, the transistor 520 is preferably a SiC-MOSFET. For example, when the maximum rated voltage of the energy storage unit 210 is 100V or higher, preferably 200V or higher, more preferably 300V or higher, even more preferably 500V or higher, even more preferably 800V or higher, and even more preferably 1000V, a SiC-MOSFET is used as the transistor 520. This allows the advantages of SiC-MOSFETs, such as their excellent voltage withstand characteristics and low losses, to be fully utilized. When the maximum rated voltage of the energy storage unit 210 is 300V or higher or 500V or higher, the effect of using a SiC-MOSFET as the transistor 520 becomes clearly apparent.

[0232] Furthermore, a parasitic diode is formed between the source and drain of transistor 520. This parasitic diode allows current flowing in the charging direction between wiring 106 and the energy storage unit 210. On the other hand, the parasitic diode also suppresses current flowing in the discharging direction between wiring 106 and the energy storage unit 210 via this parasitic diode.

[0233] Transistor 520 may be an example of a first current regulating section or a second current regulating section. The parasitic diode of transistor 520 may be an example of a first bypass section or a second bypass section. Furthermore, switching section 230 may also have a rectifier separate from the parasitic diode of transistor 520, the rectifier having the same function as the parasitic diode, and connected in parallel with transistor 520 between wiring 106 and energy storage section 210. Examples of such rectifiers include: (i) rectifier components such as diodes, and (ii) rectifier circuits comprising multiple components.

[0234] As described above, according to this embodiment, the switching unit 230 includes: (i) a transistor 520 that adjusts the current in the discharge direction; and (ii) a parasitic diode that is configured in parallel with the transistor 520 to allow current in the charging direction to pass through while preventing current in the discharge direction from passing through. Therefore, when the energy storage system 100 is further charged, and the voltage of the wiring 106 is greater than the voltage of the positive terminal 212 of the energy storage unit 210, current flows in the charging direction between the wiring 106 and the energy storage unit 210 via the parasitic diode of the transistor 520.

[0235] To prevent deterioration or damage to the energy storage unit 210 caused by over-discharge, the module control unit 1040 must prevent current from flowing in the discharge direction, but may not prevent current from flowing in the charging direction. Therefore, according to this embodiment, the module control unit 1040 monitors the current flowing between the wiring 106 and the energy storage unit 210.

[0236] In one embodiment, the module control unit 1040 detects the current flowing in the charging direction between the wiring 106 and the energy storage unit 210. In another embodiment, the module control unit 1040 may also detect the current flowing between the wiring 106 and the energy storage unit 210 when the switching unit 230 electrically disconnects the wiring 106 and the energy storage unit 210 in the discharging direction.

[0237] From the start of charging of the energy storage system 100 until the current is detected, the module control unit 1040 maintains the interlock for over-discharge protection. On the other hand, when the current is detected, the module control unit 1040 releases the interlock for over-discharge protection.

[0238] In one embodiment, the module control unit 1040 controls the switching unit 230 to connect the power supply wiring 106 and the energy storage unit 210. Generally, the on-resistance of the transistor 520 is less than the resistance of the parasitic diode, so according to this embodiment, the charging and discharging efficiency of the energy storage unit 210 is improved.

[0239] When the current is detected when the voltage difference does not meet the conditions for achieving rapid hot-swapping, the module control unit 1040 can control the switching unit 230 in the following manner: At least until the voltage difference meets the conditions for achieving rapid hot-swapping, the switching unit 230 electrically connects the wiring 106 and the energy storage unit 210. Furthermore, during the period when the voltage difference meets the conditions for achieving rapid hot-swapping, the module control unit 1040 can control the switching unit 230 by electrically connecting the wiring 106 and the energy storage unit 210.

[0240] In another embodiment, when the current is detected, the module control unit 1040 may also send a signal to the protection unit 250 to reset the over-discharge protection function. Furthermore, when the protection unit 250 receives the signal to reset the over-discharge protection function, it may control the switching unit 230 to connect the wiring 106 and the energy storage unit 210.

[0241] When the energy storage system 100 is further charged after the wiring 106 is electrically connected to the energy storage unit 210, the voltage or state of charge (SOC) of the energy storage unit 210 exceeds the threshold for over-discharge protection. If the voltage or SOC of the energy storage unit 210 exceeds the over-discharge protection threshold, the protection unit 250 may also send a signal to the module control unit 1040 to reset the over-discharge protection function. When the module control unit 1040 receives the signal to reset the over-discharge protection function, it can control the switching unit 230 by electrically connecting the energy storage unit 210 to the wiring 106.

[0242] Furthermore, as described above, when it is determined that the over-discharge protection function is enabled, the module control unit 1040, for example (i) electrically disconnects the wiring 106 and the energy storage unit 210, or (ii) reduces the current that can flow in the discharge direction between the wiring 106 and the energy storage unit 210. Therefore, when the over-discharge protection function is enabled, the current that can flow in the discharge direction is smaller compared to when the over-discharge protection function is disabled. On the other hand, when it is determined that the over-discharge protection interlock is deactivated (sometimes referred to as disabling the over-discharge protection function), the module control unit 1040, for example (i) electrically connects the wiring 106 and the energy storage unit 210, or (ii) increases the current that can flow in the discharge direction between the wiring 106 and the energy storage unit 210.

[0243] The module control unit 1040 adjusts or controls the magnitude of the current flowing in the discharge direction between the wiring 106 and the energy storage unit 210 by adjusting the resistance value or conduction ratio (sometimes called duty cycle) of the switching unit 230. In one embodiment, when the switching unit 230 includes a transistor 520 and the transistor 520 is a field-effect transistor, the module control unit 1040 can adjust or control the magnitude of the current flowing in the discharge direction between the wiring 106 and the energy storage unit 210 by adjusting the gate voltage (sometimes called input voltage) of the transistor 520. The module control unit 1040 can also adjust or control the magnitude of the current flowing in the discharge direction between the wiring 106 and the energy storage unit 210 by controlling the operation of components configured in the circuit used to adjust the input voltage of the transistor 520.

[0244] In another embodiment, when the switching unit 230 includes a transistor 520 and the transistor 520 is a bipolar transistor, the module control unit 1040 can adjust or control the magnitude of the current flowing in the discharge direction between the wiring 106 and the energy storage unit 210 by adjusting the base current (sometimes referred to as the input current) of the transistor 520. The module control unit 1040 can also adjust or control the magnitude of the current flowing in the discharge direction between the wiring 106 and the energy storage unit 210 by controlling the operation of components configured in the circuit used to adjust the input current of the transistor 520.

[0245] The resistance value or conduction ratio of the switching unit 230 may be the same or different when the over-discharge protection function is active and when the over-discharge protection function is inactive. When the switching unit 230 has a switching assembly, the on-resistance of the switching assembly may be the same or different when the over-charge protection function is active and when the over-charge protection function is inactive. When the switching unit 230 has a variable resistor, the resistance value of the variable resistor may be the same or different when the over-charge protection function is active and when the over-charge protection function is inactive. The module control unit 1040 may also control the switching unit 230 in the following manner: when the over-discharge protection function is active, the resistance value of the switching unit 230 increases compared to when the over-discharge protection function is inactive. The module control unit 1040 may also control the switching unit 230 in the following manner: when the over-discharge protection function is active, the conduction ratio of the switching unit 230 decreases compared to when the over-discharge protection function is inactive.

[0246] For the sake of simplicity, this embodiment describes the steps of the module control unit 1040 in releasing the over-discharge protection interlock using the following example: (i) when it is determined that the over-discharge protection function is enabled, the module control unit 1040 electrically disconnects the wiring 106 from the energy storage unit 210, and (ii) when it is determined that the over-discharge protection function is disabled, the module control unit 1040 electrically connects the wiring 106 to the energy storage unit 210. However, those skilled in the art who have accessed this specification will understand that in other embodiments where (i) when it is determined that the over-discharge protection function is enabled, the module control unit 1040 reduces the current flowing in the discharge direction between the wiring 106 and the energy storage unit 210, and (ii) when it is determined that the over-discharge protection function is disabled, the module control unit 1040 can also release the over-discharge protection interlock using the same steps as in this embodiment.

[0247] Specifically, when the over-discharge protection function is enabled, in this embodiment, the series of actions by which the module control unit 1040 electrically disconnects the wiring 106 and the energy storage unit 210 are equivalent to a series of actions by which the module control unit 1040 reduces the current flowing between the energy storage unit 210 and the wiring 106, as described in other embodiments. Similarly, when the over-discharge protection function is disabled, in this embodiment, the series of actions by which the module control unit 1040 electrically connects the wiring 106 and the energy storage unit 210 are equivalent to a series of actions by which the module control unit 1040 increases the current flowing between the energy storage unit 210 and the wiring 106, as described in other embodiments.

[0248] (Specific example of the steps to release the overcharge protection interlock) When the energy storage unit 210 of the energy storage module 1010 is electrically connected to the wiring 106 of the energy storage system 100, and the energy storage system 100 is charging, for example, if the voltage or state of charge (SOC) of the energy storage unit 210 exceeds the threshold for overcharge protection, the protection unit 250 sends a signal to the module control unit 1040 to activate the overcharge protection function. At this time, current flows between the wiring 106 and the energy storage unit 210 in the charging direction. In this case, the charging direction can be an example of a first direction. Alternatively, the discharging direction can be an example of a second direction. Furthermore, in this embodiment, the discharging direction and the charging direction are opposite to each other.

[0249] If the voltage or SOC of the energy storage unit 210 is greater than the threshold for overcharge protection, it could be an example of a situation where the conditions for protecting the energy storage unit 210 are not met. In another embodiment, if the voltage or SOC of the energy storage unit 210 is above the threshold for over-discharge protection, the protection unit 250 may send a signal to the module control unit 1040 to enable the overcharge protection function.

[0250] When the module control unit 1040 receives the signal, it controls the switching unit 230 to disconnect the wiring 106 and the energy storage unit 210. When the energy storage system 100 continues to charge after the wiring 106 and the energy storage unit 210 are disconnected, a voltage difference is generated between the wiring 106 and the energy storage unit 210.

[0251] After the charging of the energy storage system 100 is completed, when the discharge of the energy storage system 100 begins, a voltage difference is generated between the wiring 106 and the energy storage unit 210. In this case, if the absolute value of the voltage difference is greater than the threshold for achieving rapid hot-swapping, the module control unit 1040 determines that the voltage between the terminals of the switching unit 230 does not meet the conditions for achieving rapid hot-swapping. As a result, the energy storage system 100 discharges while the wiring 106 between the energy storage unit 210 of the energy storage module 1010 and the energy storage system 100 is electrically disconnected.

[0252] On the other hand, (i) when the absolute value of the voltage difference at the start of discharge of the energy storage system 100 is less than or below the threshold for achieving rapid hot-swapping, or (ii) when the energy storage system 100 is charging and the absolute value of the voltage difference is less than or below the threshold for achieving rapid hot-swapping, the module control unit 1040 will control the switching unit 230 to connect the wiring 106 and the energy storage unit 210. However, during this stage, the voltage or SOC of the energy storage unit 210 is greater than the threshold for overcharge protection. Therefore, the interlocking mechanism of the module control unit 1040 is activated. As a result, the module control unit 1040 cannot control the switching unit 230 to connect the wiring 106 and the energy storage unit 210.

[0253] In order for the module control unit 1040 to control the switching unit 230 to connect the wiring 106 and the energy storage unit 210, the interlock must be released using some kind of logic. The method for releasing the interlock is not particularly limited. In this embodiment, the module control unit 1040 determines whether to release the interlock based on the current flowing between the wiring 106 and the energy storage unit 210 or information about that current, and controls the operation of the switching unit 230 accordingly.

[0254] Here, as Figure 5As explained in the related description, the switching unit 230 includes a transistor 510 that adjusts or controls the magnitude of the current flowing in the charging direction between the wiring 106 and the energy storage unit 210. Examples of transistors 510 include Si-MOSFETs, insulated-gate bipolar transistors (IGBTs), SiC-MOSFETs, and GaN-MOSFETs.

[0255] When the rated voltage of the energy storage unit 210 is relatively high, the transistor 510 is preferably a SiC-MOSFET. For example, when the maximum rated voltage of the energy storage unit 210 is 100V or higher, preferably 200V or higher, more preferably 300V or higher, even more preferably 500V or higher, even more preferably 800V or higher, and even more preferably 1000V, a SiC-MOSFET is used as the transistor 510. This allows the advantages of SiC-MOSFETs, such as their excellent voltage withstand characteristics and low losses, to be fully utilized. When the maximum rated voltage of the energy storage unit 210 is 300V or higher or 500V or higher, the effect of using a SiC-MOSFET as the transistor 510 becomes clearly apparent.

[0256] Furthermore, a parasitic diode is formed between the source and drain of transistor 510. This parasitic diode allows current flowing in the discharge direction between wiring 106 and the energy storage unit 210. On the other hand, the parasitic diode also suppresses current flowing in the charging direction between wiring 106 and the energy storage unit 210 via this parasitic diode.

[0257] Transistor 510 may be an example of a first current regulating section or a second current regulating section. The parasitic diode of transistor 510 may be an example of a first bypass section or a second bypass section. Furthermore, the switching section 230 may also have a rectifier separate from the parasitic diode of transistor 510, the rectifier having the same function as the parasitic diode, and connected in parallel with transistor 510 between wiring 106 and the energy storage section 210. Examples of such rectifiers include (i) rectifier components such as diodes, and (ii) rectifier circuits comprising multiple components.

[0258] As described above, according to this embodiment, the switching unit 230 includes: (i) a transistor 510 that adjusts the current in the charging direction; and (ii) a parasitic diode configured in parallel with the transistor 510 to allow the current in the discharging direction to pass through while preventing the current in the charging direction from passing through. Therefore, when the energy storage system 100 further discharges, and the voltage of the wiring 106 is less than the voltage of the positive terminal 212 of the energy storage unit 210, current flows through the parasitic diode of the transistor 510 in the discharging direction between the wiring 106 and the energy storage unit 210.

[0259] To prevent deterioration or damage to the energy storage unit 210 caused by overcharging, the module control unit 1040 must prevent current from flowing in the charging direction, but may not prevent current from flowing in the discharging direction. Therefore, according to this embodiment, the module control unit 1040 monitors the current flowing between the wiring 106 and the energy storage unit 210.

[0260] In one embodiment, the module control unit 1040 detects the current flowing in the discharge direction between the wiring 106 and the energy storage unit 210. In another embodiment, the module control unit 1040 may also detect the current flowing between the wiring 106 and the energy storage unit 210 when the switching unit 230 disconnects the wiring 106 and the energy storage unit 210 in the charging direction.

[0261] During the period from the start of discharge of the energy storage system 100 until the current is detected, the module control unit 1040 maintains the interlock for overcharge protection. On the other hand, when the current is detected, the module control unit 1040 releases the interlock for overcharge protection.

[0262] In one embodiment, the module control unit 1040 controls the switching unit 230 to connect the power supply wiring 106 and the energy storage unit 210. Generally, the on-resistance of the transistor 510 is less than the resistance of the parasitic diode, so according to this embodiment, the charging and discharging efficiency of the energy storage unit 210 is improved.

[0263] When the current is detected when the voltage difference does not meet the conditions for achieving rapid hot-swapping, the module control unit 1040 can control the switching unit 230 in the following manner: At least until the voltage difference meets the conditions for achieving rapid hot-swapping, the switching unit 230 electrically connects the wiring 106 and the energy storage unit 210. Furthermore, during the period when the voltage difference meets the conditions for achieving rapid hot-swapping, the module control unit 1040 can control the switching unit 230 by electrically connecting the wiring 106 and the energy storage unit 210.

[0264] In another embodiment, when the current is detected, the module control unit 1040 may also send a signal to the protection unit 250 to reset the over-discharge protection function. Furthermore, when the protection unit 250 receives the signal to reset the over-discharge protection function, it may control the switching unit 230 to connect the wiring 106 and the energy storage unit 210.

[0265] When the energy storage system 100 further discharges after the wiring 106 is electrically connected to the energy storage unit 210, the voltage or state of charge (SOC) of the energy storage unit 210 is less than the threshold for overcharge protection. If the voltage or SOC of the energy storage unit 210 is less than the threshold for overcharge protection, the protection unit 250 may also send a signal to the module control unit 1040 to reset the overcharge protection function. When the module control unit 1040 receives the signal to reset the over-discharge protection function, it can control the switching unit 230 by electrically connecting the switching unit 230 to the energy storage unit 210 and the wiring 106.

[0266] Furthermore, as described above, when it is determined that the over-discharge protection function is enabled, the module control unit 1040, for example (i) electrically disconnects the wiring 106 and the energy storage unit 210, or (ii) reduces the current flowing in the charging direction between the wiring 106 and the energy storage unit 210. Therefore, when the over-charge protection function is enabled, the current flowing in the charging direction is smaller compared to when the over-charge protection function is disabled. On the other hand, when it is determined that the over-charge protection interlock is deactivated (sometimes referred to as disabling the over-charge protection function), the module control unit 1040, for example (i) electrically connects the wiring 106 and the energy storage unit 210, or (ii) increases the current flowing in the charging direction between the wiring 106 and the energy storage unit 210.

[0267] The module control unit 1040 adjusts or controls the magnitude of the current flowing in the charging direction between the wiring 106 and the energy storage unit 210 by adjusting the resistance value or conduction ratio (sometimes referred to as the duty cycle) of the switching unit 230. In one embodiment, when the switching unit 230 includes a transistor 510 and the transistor 510 is a field-effect transistor, the module control unit 1040 can adjust or control the magnitude of the current flowing in the charging direction between the wiring 106 and the energy storage unit 210 by adjusting the gate voltage (sometimes referred to as the input voltage) of the transistor 510. The module control unit 1040 can also adjust or control the magnitude of the current flowing in the charging direction between the wiring 106 and the energy storage unit 210 by controlling the operation of components configured in the circuit used to adjust the input voltage of the transistor 510.

[0268] In another embodiment, when the switching unit 230 includes a transistor 510 and the transistor 510 is a bipolar transistor, the module control unit 1040 can adjust or control the magnitude of the current flowing in the charging direction between the wiring 106 and the energy storage unit 210 by adjusting the base current (sometimes referred to as the input current) of the transistor 510. The module control unit 1040 can also adjust or control the magnitude of the current flowing in the charging direction between the wiring 106 and the energy storage unit 210 by controlling the operation of components configured in the circuit used to adjust the input current of the transistor 510.

[0269] The resistance value or conduction ratio of the switching unit 230 may be the same or different when the overcharge protection function is active and when the overcharge protection function is inactive. When the switching unit 230 has a switching assembly, the on-resistance of the switching assembly may be the same or different when the overcharge protection function is active and when the overcharge protection function is inactive. When the switching unit 230 has a variable resistor, the resistance value of the variable resistor may be the same or different when the overcharge protection function is active and when the overcharge protection function is inactive. The module control unit 1040 may also control the switching unit 230 in the following manner: when the overcharge protection function is active, the resistance value of the switching unit 230 increases compared to when the overcharge protection function is inactive. The module control unit 1040 may also control the switching unit 230 in the following manner: when the overcharge protection function is active, the conduction ratio of the switching unit 230 decreases compared to when the overcharge protection function is inactive.

[0270] For the sake of simplicity, this embodiment describes the steps by which the module control unit 1040 releases the overcharge protection interlock using the following example: (i) when it is determined that the overcharge protection function is enabled, the module control unit 1040 electrically disconnects the wiring 106 from the energy storage unit 210, and (ii) when it is determined that the overcharge protection function is disabled, the module control unit 1040 electrically connects the wiring 106 to the energy storage unit 210. However, anyone skilled in the art who has accessed this specification will understand that in other embodiments where (i) when it is determined that the overcharge protection function is enabled, the module control unit 1040 reduces the current flowing in the charging direction between the wiring 106 and the energy storage unit 210, and (ii) when it is determined that the overcharge protection function is disabled, the module control unit 1040 increases the current flowing in the charging direction between the wiring 106 and the energy storage unit 210, the module control unit 1040 can also release the overcharge protection interlock using the same steps as in this embodiment.

[0271] Specifically, when the overcharge protection function is enabled, in this embodiment, the series of actions by which the module control unit 1040 electrically disconnects the wiring 106 and the energy storage unit 210 are equivalent to a series of actions by which the module control unit 1040 reduces the current flowing between the energy storage unit 210 and the wiring 106, as described in other embodiments. Similarly, when the overcharge protection function is disabled, in this embodiment, the series of actions by which the module control unit 1040 electrically connects the wiring 106 and the energy storage unit 210 are equivalent to a series of actions by which the module control unit 1040 increases the current flowing between the energy storage unit 210 and the wiring 106, as described in other embodiments.

[0272] As described above, according to this embodiment, the module control unit 1040 can, for example, prevent a significant reduction in the charging and discharging efficiency of the energy storage module 1010 while simultaneously providing hot-swappable functionality and protection functionality for the energy storage unit 210.

[0273] In this embodiment, the current detection component 1020 and the switching unit 230 are arranged between the positive terminal 202 of the energy storage module 1010 and the positive terminal 212 of the energy storage unit 210, and the positive terminal 212 of the energy storage unit 210 is electrically connected to the wiring 106 via the switching unit 230. However, the arrangement of the current detection component 1020 and the switching unit 230 is not limited to this embodiment. In another embodiment, the current detection component 1020 and the switching unit 230 are arranged between the negative terminal 204 of the energy storage module 1010 and the negative terminal 214 of the energy storage unit 210, and the negative terminal 214 of the energy storage unit 210 is electrically connected to the wiring 106 via the switching unit 230.

[0274] The energy storage module 1010 may be an example of a second energy storage device. The switching unit 230 of the energy storage module 1010 may be an example of a second switching unit.

[0275] Figure 11 This is a simplified example of the system configuration of the module control unit 1040. In this embodiment, the module control unit 1040 includes a determination unit 410, a receiving unit 420, and a signal generation unit 430. The module control unit 1040 may also include a module information acquisition unit 440, a module information storage unit 450, and a module information transmission unit 460. In this embodiment, the module control unit 1040 includes a current monitoring unit 1120. In this embodiment, the current monitoring unit 1120 includes a current detection unit 1122 and a direction determination unit 1124. The signal generation unit 430 may be an example of an action control unit.

[0276] In this embodiment, the module control unit 1040 includes a current monitoring unit 1120, which differs from the module control unit 240. Aside from the aforementioned differences, the module control unit 1040 may have the same features as the corresponding configuration of the module control unit 240.

[0277] In this embodiment, the current monitoring unit 1120 monitors the current flowing between the wiring 106 of the energy storage system 100 and the energy storage unit 210 of the energy storage module 1010. For example, the current monitoring unit 1120 monitors the current flowing between the positive terminal 202 and the positive terminal 212 of the energy storage module 1010.

[0278] In this embodiment, the current detection unit 1122 detects the current flowing between the wiring 106 of the energy storage system 100 and the energy storage unit 210 of the energy storage module 1010. The current detection unit 1122 can also determine the magnitude of the current. The current detection unit 1122 may include any analog circuit or any digital circuit.

[0279] In this embodiment, the direction determination unit 1124 determines the direction of the current flowing between the wiring 106 of the energy storage system 100 and the energy storage section 210 of the energy storage module 1010. The direction determination unit 1124 may include any analog circuit or any digital circuit.

[0280] Figure 12 Here is a simplified example of the circuit configuration of the module control unit 1040. Figure 12 Here is a simplified example of the circuit configuration of the switching unit 230. Figure 12 Examples of the positive terminal 202, negative terminal 204, energy storage unit 210, protection unit 250, current detection component 1020, switching unit 230, and module control unit 1040 are shown.

[0281] [Specific example of the circuit of switching unit 230] In this embodiment, one end of transistor 510 is electrically connected to wiring 106, and the other end is electrically connected to the energy storage unit 210. Transistor 510 is connected in series with transistor 520 and parasitic diode 1244 between wiring 106 and energy storage unit 210. In this embodiment, transistor 510 adjusts the magnitude of the current flowing in the charging direction between wiring 106 and energy storage unit 210.

[0282] In this embodiment, one end of transistor 520 is electrically connected to wiring 106, and the other end is electrically connected to the energy storage unit 210. Transistor 520 is connected in series with transistor 510 and parasitic diode 1242 between wiring 106 and energy storage unit 210. In this embodiment, transistor 520 adjusts the magnitude of the current flowing in the discharge direction between wiring 106 and energy storage unit 210.

[0283] One end of the parasitic diode 1242 is electrically connected to wiring 106, and the other end is electrically connected to the energy storage unit 210. The parasitic diode 1242 is connected in parallel with transistor 510 between wiring 106 and the energy storage unit 210. The parasitic diode 1242 is also connected in series with transistor 520 and parasitic diode 1244 between wiring 106 and the energy storage unit 210.

[0284] The parasitic diode 1242 allows current flowing in the discharge direction between the wiring 106 and the energy storage unit 210 to pass through. On the other hand, the parasitic diode 1242 suppresses current flowing in the charging direction between the wiring 106 and the energy storage unit 210 through the parasitic diode 1242.

[0285] One end of the parasitic diode 1244 is electrically connected to wiring 106, and the other end is electrically connected to the energy storage unit 210. The parasitic diode 1244 is connected in parallel with transistor 520 between wiring 106 and the energy storage unit 210. The parasitic diode 1244 is also connected in series with transistor 510 and parasitic diode 1242 between wiring 106 and the energy storage unit 210.

[0286] Parasitic diode 1242 allows current flowing in the charging direction between wiring 106 and energy storage unit 210 to pass through. On the other hand, parasitic diode 1244 inhibits current flowing in the discharging direction between wiring 106 and energy storage unit 210 through parasitic diode 1244.

[0287] Transistor 510 can be an example of one of the first current adjustment section and the second current adjustment section. Transistor 520 can be an example of the other of the first current adjustment section and the second current adjustment section. Parasitic diode 1242 can be an example of one of the first bypass section and the second bypass section. Parasitic diode 1244 can be an example of the other of the first bypass section and the second bypass section. The discharge direction can be an example of one of the first direction and the second direction. The charging direction can be an example of the other of the first direction and the second direction.

[0288] [Specific example of the circuit of module control unit 1040] In this embodiment, the module control unit 1040 includes a determination unit 410, a signal generation unit 430, and a current monitoring unit 1120. The determination unit 410 may be an example of a first determination unit, a second determination unit, and a third determination unit.

[0289] In this embodiment, the signal generation unit 430 includes an OR circuit 1260, an AND circuit 1272, an AND circuit 1274, an OR circuit 1282, and an OR circuit 1284. Additionally, in this embodiment, a resistor with an appropriate resistance value is disposed between the positive terminal 202 and the switching unit 230 as a current detection component 1020. The resistance value of the current detection component 1020 is determined, for example, in a manner that allows the current monitoring unit 1120 to reliably determine the direction of the current flowing between the wiring 106 and the energy storage unit 210.

[0290] In this embodiment, the determination unit 410 determines whether the voltage between the terminals of the switching unit 230 is within a predetermined range. The determination unit 410 sends a signal indicating the determination result to the signal generation unit 430. The determination unit 410 may include any analog circuit or any digital circuit. The determination unit 410 may include a window comparator. The window comparator can be implemented, for example, using two comparators.

[0291] In this embodiment, the determination unit 410 has two input terminals. The voltage of one end of the switching unit 230 (e.g., the end on the positive terminal 202 side) is input to one input terminal of the determination unit 410 (shown as the - terminal in the figure). The voltage of the other end of the switching unit 230 (e.g., the end on the energy storage unit 210 side) is input to the other input terminal of the determination unit 410 (shown as the + terminal in the figure).

[0292] In this embodiment, the determination unit 410 has two output terminals. The determination unit 410 outputs a signal from one output terminal (shown as terminal L in the figure) indicating that the inter-terminal voltage of the switching unit 230 is less than a first threshold, as a signal indicating the determination result. For example, when the inter-terminal voltage of the switching unit 230 is less than the first threshold, the determination unit 410 outputs H logic from terminal L. On the other hand, when the inter-terminal voltage of the switching unit 230 is greater than or equal to the first threshold, the determination unit 410 outputs L logic from terminal L.

[0293] Additionally, the determination unit 410 outputs a signal from another output terminal (shown as terminal H in the figure) indicating that the inter-terminal voltage of the switching unit 230 is greater than a second threshold as a signal indicating the determination result. In this embodiment, the absolute value of the second threshold is set to a value larger than the absolute value of the first threshold. For example, when the inter-terminal voltage of the switching unit 230 is greater than the second threshold, the determination unit 410 outputs H logic from terminal H. On the other hand, when the inter-terminal voltage of the switching unit 230 is less than or equal to the second threshold, the determination unit 410 outputs L logic from terminal H.

[0294] In one embodiment, the determination unit 410 can, for example, determine whether the voltage or SOC of the energy storage unit 210 meets a first condition. Examples of the first condition include: (i) a condition indicating that the voltage or SOC of the energy storage unit is outside a predetermined first numerical range; (ii) a condition indicating that the voltage or SOC of the energy storage unit is greater than a predetermined first threshold; and (iii) a condition indicating that the voltage or SOC of the energy storage unit is above the first threshold. For example, the first condition could be a condition indicating that the energy storage unit 210 is overcharged.

[0295] In another embodiment, the determination unit 410 can, for example, determine whether the voltage or SOC of the energy storage unit 210 meets a second condition. Examples of the second condition include: (i) a condition indicating that the voltage or SOC of the energy storage unit is outside a predetermined second numerical range; (ii) a condition indicating that the voltage or SOC of the energy storage unit is less than a predetermined second threshold; and (iii) a condition indicating that the voltage or SOC of the energy storage unit is below the second threshold, etc. Furthermore, the second condition can be a condition different from the first condition. For example, the second condition could be a condition indicating that the energy storage unit 210 is over-discharged.

[0296] In another embodiment, the determination unit 410 may determine, for example, whether the inter-terminal voltage of the switching unit 230 meets a third condition. Examples of the third condition include: (i) a condition indicating that the inter-terminal voltage of the switching unit 230 is within a predetermined third numerical range; (ii) a condition indicating that the inter-terminal voltage of the switching unit 230 is less than a predetermined third threshold; and (iii) a condition indicating that the inter-terminal voltage of the switching unit 230 is below the third threshold, etc.

[0297] In another embodiment, the determination unit 410 can, for example, determine whether the inter-terminal voltage of the switching unit 230 meets a fourth condition. Examples of the fourth condition include: (i) a condition indicating that the inter-terminal voltage of the switching unit 230 is outside a predetermined fourth numerical range; (ii) a condition indicating that the inter-terminal voltage of the switching unit 230 is greater than a predetermined fourth threshold; (iii) a condition indicating that the inter-terminal voltage of the switching unit 230 is greater than or equal to the fourth threshold, etc. The fourth numerical range may also be the same as the third numerical range. The upper limit of the fourth numerical range may also be greater than the upper limit of the third numerical range. The fourth threshold may also be the same as the third threshold. The fourth threshold may also be greater than the third threshold.

[0298] In this embodiment, the current monitoring unit 1120 may include a comparator. The current monitoring unit 1120, for example, has two input terminals and one output terminal. The voltage of one end of the current detection component 1020 (e.g., the end on the positive terminal 202 side) is input to one input terminal of the current monitoring unit 1120 (shown as the + terminal in the figure). The voltage of the other end of the current detection component 1020 (e.g., the end on the switching unit 230 side) is input to the other input terminal of the current monitoring unit 1120 (shown as the - terminal in the figure).

[0299] For example, when the voltage input to the + terminal is greater than the voltage input to the - terminal, the current monitoring unit 1120 outputs an H logic signal from the output terminal. On the other hand, when the voltage input to the + terminal is less than the voltage input to the - terminal, the current monitoring unit 1120 outputs an L logic signal from the output terminal. Furthermore, when the voltage input to the + terminal is equal to or considered equal to the voltage input to the - terminal, the current monitoring unit 1120 does not output a signal from the output terminal.

[0300] In this embodiment, the current monitoring unit 1120 detects the current flowing between the wiring 106 and the energy storage unit 210 when at least one of the transistors 510 and 520 electrically disconnects the wiring 106 and the energy storage unit 210. In one embodiment, the current monitoring unit 1120 detects the current flowing in the discharge direction between the wiring 106 and the energy storage unit 210 when the overcharge protection function is activated. In another embodiment, the current monitoring unit 1120 detects the current flowing in the charging direction between the wiring 106 and the energy storage unit 210 when the over-discharge protection function is activated.

[0301] In this embodiment, the signal generating unit 430 may also function as the receiving unit 420. For example, the signal generating unit 430 receives a signal 86 from the protection unit 250 to activate the over-discharge protection function. Additionally, the signal generating unit 430 receives a signal 88 from the protection unit 250 to activate the overcharge protection function. The signal generating unit 430 receives information from the determination unit 410 regarding the inter-terminal voltage of the switching unit 230. The signal generating unit 430 receives information from the current monitoring unit 1120 regarding the current between the wiring 106 and the energy storage unit 210.

[0302] In this embodiment, the signal generation unit 430 can control the operation of at least one of the transistors 510 and 520 based on (i) the voltage or SOC of the energy storage unit 210 and (ii) the detection result of the current monitoring unit 1120. The signal generation unit 430 can control the operation of at least one of the transistors 510 and 520 based on (i) the voltage or SOC of the energy storage unit 210, (ii) the detection result of the current monitoring unit 1120, and (iii) the determination result of the determination unit 410. The signal generation unit 430 can control at least one of the transistors 510 and 520 by outputting a signal used to control the operation of at least one of the transistors 510 and 520 to the transistor that is the target of the signal control.

[0303] In this embodiment, when the determination unit 410 determines that the inter-terminal voltage of the switching unit 230 meets the fourth condition, the signal generation unit 430 can output a signal to at least one of the transistors 510 and 520 to perform an operation of electrically disconnecting the wiring 106 from the energy storage unit 210, or to reduce the current flowing between the wiring 106 and the energy storage unit 210. Therefore, the determination unit 410 can also be used as an overcurrent protection function for the energy storage unit 210.

[0304] In this embodiment, the OR circuit 1260 has two input terminals and one output terminal. One input terminal of the OR circuit 1260 receives the output from the H terminal of the determination unit 410. The other input terminal of the OR circuit 1260 receives the output from the L terminal of the determination unit 410.

[0305] The OR circuit 1260 outputs the logical sum of its two inputs. For example, when the voltage between the terminals of the switching unit 230 converges to a specific numerical range, the OR circuit 1260 outputs L logic. On the other hand, when the voltage between the terminals of the switching unit 230 deviates from the specific numerical range, the OR circuit 1260 outputs H logic. For example, as an example of the case where the switching unit 230 meets the fourth condition, when the voltage between the terminals of the switching unit 230 is greater than a specific value, H logic is output from the H terminal of the determination unit 410. In this case, the OR circuit 1260 outputs H logic.

[0306] In this embodiment, the AND circuit 1272 has two input terminals and one output terminal. One input terminal of the AND circuit 1272 receives a signal obtained by inverting the output of the OR circuit 1260. The other input terminal of the AND circuit 1272 receives a signal obtained by inverting the signal 88 used to activate the overcharge protection function.

[0307] The AND circuit 1272 outputs the logic product of its two inputs. For example, when the voltage between the terminals of the switching unit 230 converges to a specific value range (specifically, when the absolute value of the difference between the voltage of the wiring 106 and the voltage of the energy storage unit 210 is less than a specific threshold or is below that threshold), and when the voltage or SOC of the energy storage unit 210 is less than a threshold for overcharge protection, the AND circuit 1272 outputs an H logic value. On the other hand, in other cases, the AND circuit 1272 outputs an L logic value.

[0308] In this embodiment, the AND circuit 1274 has two input terminals and one output terminal. One input terminal of the AND circuit 1274 receives a signal obtained by inverting the output of the OR circuit 1260. The other input terminal of the AND circuit 1274 receives a signal obtained by inverting the signal 86 used to activate the over-discharge protection function.

[0309] The AND circuit 1274 outputs the logic product of its two inputs. For example, when the voltage between the terminals of the switching unit 230 converges to a specific value range (specifically, when the absolute value of the difference between the voltage of the wiring 106 and the voltage of the energy storage unit 210 is less than a specific threshold or is below that threshold), and when the voltage or SOC of the energy storage unit 210 is greater than a threshold for over-discharge protection, the AND circuit 1274 outputs an H logic value. On the other hand, in other cases, the AND circuit 1274 outputs an L logic value.

[0310] In this embodiment, the OR circuit 1282 has two input terminals and one output terminal. One input terminal of the OR circuit 1282 receives a signal obtained by inverting the output of the current monitoring unit 1120. The other input terminal of the OR circuit 1282 receives the output of the AND circuit 1272.

[0311] The OR circuit 1282 outputs the logic sum of its two inputs. For example, when the output of the OR circuit 1282 is H logic, the transistor 510 is turned on; when the output of the OR circuit 1282 is L logic, the transistor 510 is turned off. In one embodiment, the OR circuit 1282 outputs H logic when current flows in the discharge direction between the wiring 106 and the energy storage unit 210. In another embodiment, the OR circuit 1282 outputs H logic when the voltage between the terminals of the switching unit 230 converges to a specific numerical range, and when the voltage or SOC of the energy storage unit 210 is less than a threshold for overcharge protection.

[0312] In this embodiment, the OR circuit 1284 has two input terminals and one output terminal. The output of the current monitoring unit 1120 is input to one input terminal of the OR circuit 1284. The output of the AND circuit 1274 is input to the other input terminal of the OR circuit 1284.

[0313] The OR circuit 1284 outputs the logical sum of its two inputs. For example, when the output of the OR circuit 1284 is H logic, the transistor 520 is turned on; when the output of the OR circuit 1284 is L logic, the transistor 520 is turned off. In one embodiment, the OR circuit 1284 outputs H logic when current flows in the charging direction between the wiring 106 and the energy storage unit 210. In another embodiment, the OR circuit 1284 outputs H logic when the voltage between the terminals of the switching unit 230 converges to a specific numerical range, and when the voltage or SOC of the energy storage unit 210 is less than a threshold for overcharge protection.

[0314] [Specific example of the operation of the signal generation unit 430] In one embodiment, when the determination unit 410 determines that the voltage or SOC of the energy storage unit 210 meets the first condition, the signal generation unit 430 outputs a signal to the transistor 510, for example, to perform an operation to electrically disconnect the wiring 106 from the energy storage unit 210, or to reduce the current flowing in the charging direction between the wiring 106 and the energy storage unit 210. Furthermore, depending on the content of the first condition, the signal generation unit 430 may also output a signal to the transistor 520.

[0315] In another embodiment, when the determination unit 410 determines that the voltage or SOC of the energy storage unit 210 meets the second condition, the signal generation unit 430 outputs a signal to the transistor 520, for example, to perform an operation to electrically disconnect the wiring 106 from the energy storage unit 210, or to reduce the current flowing in the discharge direction between the wiring 106 and the energy storage unit 210. Furthermore, depending on the content of the second condition, the signal generation unit 430 may also output a signal to the transistor 510.

[0316] In another embodiment, when the determination unit 410 determines that the inter-terminal voltage of the switching unit 230 meets the third condition, the signal generation unit 430 outputs signals to the transistors 510 and 520 to perform operations such as electrically connecting the wiring 106 to the charging unit 210 or increasing the current flowing between the wiring 106 and the charging unit 210, regardless of whether the voltage or SOC of the energy storage unit 210 meets the first and second conditions. On the other hand, when the determination unit 410 determines that the inter-terminal voltage of the switching unit 230 does not meet the third condition, the signal generation unit 430 may output a signal corresponding to the detection result of the current monitoring unit 1120. For example, the signal generation unit 430 outputs a signal in the following manner.

[0317] [(a) If the determination unit 410 determines that the inter-terminal voltage of the switching unit 230 does not meet the third condition, (b) if the current monitoring unit 1120 detects (i) the current flowing in the discharge direction between the wiring 106 and the energy storage unit 210 when the overcharge protection function is activated, or (ii) the current flowing between the wiring 106 and the energy storage unit 210 when the transistor 510 electrically disconnects the wiring 106 and the energy storage unit] In this case, regardless of whether the voltage or SOC of the energy storage unit 210 meets the first condition, the signal generation unit 430 outputs a signal to the transistor 510 to perform the operation of electrically connecting the wiring 106 and the energy storage unit 210, or to increase the current flowing between the wiring 106 and the energy storage unit 210.

[0318] [(a) If the determination unit 410 determines that the inter-terminal voltage of the switching unit 230 does not meet the third condition, (c) if the current monitoring unit 1120 detects (i) the current flowing in the charging direction between the wiring 106 and the energy storage unit 210 when the over-discharge protection function is activated, or (ii) the current flowing between the wiring 106 and the energy storage unit 210 when the transistor 520 electrically disconnects the wiring 106 and the energy storage unit] In this case, regardless of whether the voltage or SOC of the energy storage unit 210 meets the second condition, the signal generation unit 430 outputs a signal to the transistor 520 to perform the operation of electrically connecting the wiring 106 and the energy storage unit 210, or to increase the current flowing between the wiring 106 and the energy storage unit 210.

[0319] In another embodiment, the module control unit 1040 can suppress the deterioration or damage of the energy storage unit 210 due to overcurrent. As described above, as an example of the case where the switching unit 230 meets the fourth condition, when the voltage between the terminals of the switching unit 230 is greater than a specific value, the OR circuit 1260 outputs H logic.

[0320] Therefore, when current flows in the discharge direction between wiring 106 and the energy storage unit 210 and the voltage between the terminals of the switching unit 230 is greater than a specific value, L logic can be output from the OR circuit 1282. As a result, transistor 510 is disconnected. Similarly, when current flows in the charging direction between wiring 106 and the energy storage unit 210 and the voltage between the terminals of the switching unit 230 is greater than a specific value, L logic can be output from the OR circuit 1284. As a result, transistor 520 is disconnected.

[0321] According to this embodiment, it is possible to suppress the constant flow of current through parasitic diodes 1242 and 1244. As a result, the voltage between the terminals of the switching unit 230 can be considered to be proportional to the current flowing through transistors 510 and 520. Therefore, by appropriately setting the resistance value of the current detection component 1020, or by connecting a resistor with an appropriate resistance value in series with the current detection component 1020 between the wiring 106 and the energy storage unit 210, the determination unit 410 and the signal generation unit 430 can be used as an overcurrent protection circuit.

[0322] Next, use Figure 13 and Figure 14 Another example of the energy storage module 130 will be described. To the extent that there is no technical contradiction, the matters described for the energy storage module 130 and its components can also be applied to another example of the energy storage module 130 and its components. Furthermore, the matters described for another example of the energy storage module 130 and its components can also be applied to the energy storage module 130 and its components. Figures 13-14 In the description, the details concerning the various parts of the energy storage module 130 are sometimes omitted.

[0323] like Figure 13 As shown, the difference between energy storage module 1330 and energy storage module 1010 is that energy storage module 1330 has a trickle charging section 320. Apart from the aforementioned differences, energy storage module 1330 may have the same configuration as energy storage module 1010.

[0324] like Figure 14 As shown, the difference between energy storage module 1430 and energy storage module 1330 is that when module control unit 1040 determines to release at least one of the over-discharge protection interlock and over-charge protection interlock, it sends at least one of the over-discharge protection reset signal and over-charge protection reset signal to protection unit 250. Furthermore, the difference between energy storage module 1430 and energy storage module 1330 is that when protection unit 250 receives the reset signal, it controls switching unit 230 to release at least one of the over-discharge protection interlock and over-charge protection interlock. Apart from the aforementioned differences, energy storage module 1430 may have the same features as its counterpart in energy storage module 1330.

[0325] Energy storage module 1330 may be an example of a first energy storage device. Energy storage module 1430 may also be an example of a first energy storage device.

[0326] In each of the embodiments described above, the details of the energy storage system 100 are explained using the case where the switching unit is disposed inside the energy storage module as an example. However, the energy storage system 100 is not limited to the embodiments described above. In another embodiment, the switching unit may also be disposed outside the energy storage module. For example, the switching unit may be disposed between the connection terminal 102 of the energy storage system 100 and the positive terminal 202 of each energy storage module. The switching unit may also be disposed between the connection terminal 104 of the energy storage system 100 and the negative terminal 204 of each energy storage module. Regardless of its location, the switching unit disposed inside or outside each energy storage module is sometimes referred to as the switching unit of each energy storage module.

[0327] [Another example of a power supply system] use Figure 15 and Figure 16 This illustrates another example of power supply system 10. Figure 15 This is a simplified representation of the system configuration of the power supply system 10. Figure 16 Here is a simplified example of the system configuration of the energy storage module 1630.

[0328] Figure 15 The power supply system 10 and related Figure 1 The difference in the power supply system 10 described herein is that it includes a storage system 1500 instead of a storage system 100. Regarding features other than the aforementioned differences, Figure 15 The power supply system 10 may have associated Figure 1 The power supply system 10 described herein has the same configuration.

[0329] To the extent that there is no technical inconsistency, the matters described regarding the energy storage system 100 and its components can also be applied to the energy storage system 1500 and its components. Furthermore, the matters described regarding the energy storage system 1500 and its components can also be applied to the energy storage system 100 and its components. Figure 15 and Figure 16 In the description, some details about the various parts of the energy storage system 100 are omitted.

[0330] like Figure 15 As shown, the difference between the energy storage system 1500 and the energy storage system 100 is that the energy storage system 1500 has an energy storage module group 1510 instead of the energy storage module 110; and the energy storage module group 1530 has an energy storage module group 1530 instead of the energy storage module 130.

[0331] In this embodiment, the energy storage module group 1510 has one or more energy storage modules 110 connected in parallel. In this embodiment, the energy storage module group 1530 has one or more energy storage modules 130 connected in parallel. Furthermore, at least one of the plurality of energy storage modules 130 constituting the energy storage module group 1530 may also be... Figure 16 The energy storage module 1630 shown. At least two of the plurality of energy storage modules 130 constituting the energy storage module group 1530 may also be Figure 16 The energy storage module 1630 is shown. Among the multiple energy storage modules 130 constituting the energy storage module group 1530, the energy storage module with the largest set value of the charging end voltage can be the energy storage module 1630.

[0332] like Figure 16 As shown, the energy storage module 1630 differs from the energy storage module 1430 in that it includes a short-circuit switch 1632 and a module control unit 1640 instead of a module control unit 1040. Apart from the aforementioned differences, the energy storage module 1630 may have the same configuration as the energy storage module 1430.

[0333] In this embodiment, the short-circuit switch 1632 is disposed between the wiring 106 and the energy storage unit 210. The short-circuit switch 1632 is connected in parallel with the switching unit 230 between the wiring 106 and the energy storage unit 210. In this embodiment, the short-circuit switch 1632 short-circuits the switching unit 230. For example, the closing action of the short-circuit switch 1632 causes the short-circuit switch 1632 to switch to a state where the switching unit 230 is short-circuited.

[0334] In this embodiment, the short-circuit switch 1632 switches between a state where the switching section 230 is short-circuited and a state where the switching section 230 is not short-circuited. The short-circuit switch 1632 can switch between the state where the switching section 230 is short-circuited and the state where the switching section 230 is not short-circuited based on an instruction from the module control unit 1640. Therefore, the short-circuit switch 1632 can short-circuit the switching section 230 as needed. Furthermore, the short-circuit switch 1632 can switch its state based on signals from components or circuits other than the module control unit 1640.

[0335] In one embodiment, when it is detected that the output current of the energy storage system 100 is greater than the charging current of the energy storage system 100, or when it is predicted that the output current of the energy storage system 100 will be greater than the charging current of the energy storage system 100, the short-circuit switch 1632 receives an instruction to short-circuit the switching unit 230. For example, when the system control unit 140 obtains information (sometimes called a warning signal) from the load device 20 indicating that the load device 20 has started using power, the short-circuit switch 1632 receives an instruction to turn on the short-circuit switch 1632. The instruction to turn on the short-circuit switch 1632 can be an example of an instruction to short-circuit the switching unit 230.

[0336] In another embodiment, the short-circuit switch 1632 receives an instruction to disconnect the short-circuit switch 1632 in at least one of the following situations: (i) a predetermined time has elapsed after the short-circuit switch 1632 short-circuited the switching section 230; and (ii) it is detected that the output current of the power supply system 10 is less than the charging current of the power supply system 10, or it is predicted that the output current of the power supply system 10 will be less than the charging current of the power supply system 10. The instruction to disconnect the short-circuit switch 1632 may be an example of an instruction to switch the state of the short-circuit switch 1632 from a state where the short-circuit switch 1632 short-circuits the switching section 230 to a state where the short-circuit switch 1632 does not short-circuit the switching section 230.

[0337] In this embodiment, the module control unit 1640 differs from the module control unit 1040 in that it controls the operation of the short-circuit switch 1632. Apart from the aforementioned differences, the module control unit 1640 may have the same configuration as the module control unit 1040.

[0338] In one embodiment, if the output current of the power supply system 10 is detected to be greater than the charging current of the power supply system 10, or if the output current of the power supply system 10 is greater than the charging current of the power supply system 10, the module control unit 1640 determines to short-circuit the switching unit 230. For example, if the system control unit 140 receives information from the load device 20 indicating that the load device 20 has started using power (sometimes called a warning signal), the module control unit 1640 determines to short-circuit the switching unit 230. After the module control unit 1640 determines to short-circuit the switching unit 230, the module control unit 1640 generates an instruction to turn on the short-circuit switch 1632 and sends the instruction to the short-circuit switch 1632.

[0339] In another embodiment, the module control unit 1640 determines not to short-circuit the switching unit 230 under at least one of the following conditions: (i) a predetermined time has elapsed since the short-circuit switch 1632 short-circuited the switching unit 230; and (ii) it is detected that the output current of the power supply system 10 is less than the charging current of the power supply system 10, or the output current of the power supply system 10 is less than the charging current of the power supply system 10. Additionally, the module control unit 1640 generates an instruction to disconnect the short-circuit switch 1632 and sends the instruction to the short-circuit switch 1632.

[0340] The energy storage system 1500 can be an example of an energy storage system. The energy storage module group 1510 can be an example of a second energy storage device. The energy storage module group 1530 can be an example of a first energy storage device. The energy storage module 1630 can be an example of a first energy storage device. The short-circuit switch 1632 can be an example of a short-circuit section and a short-circuit state switching section.

[0341] In this embodiment, the details of the energy storage module 1630 are described using the example where a portion of the energy storage module 1430 and the energy storage module 1630 differ. However, the energy storage module 1630 is not limited to this embodiment. In another embodiment, the energy storage module 1630 can be manufactured by modifying a portion of the energy storage module 1330 in a manner that relates to the differences between the energy storage modules 1430 and 1630.

[0342] Next, use Figure 17 and Figure 18 This illustrates an example of the operation of a power supply system 10 equipped with a group of energy storage modules 1530, which includes at least one energy storage module 1630. (In related...) Figure 17 and Figure 18 In order to simplify the explanation, an example of the operation of the power supply system 10 will be given by taking the case where the energy storage module 1630 is the energy storage module with the largest set value of the charging end voltage among the multiple energy storage modules 130 constituting the energy storage module group 1530.

[0343] Figure 17 This is a simplified representation of an example of the control of the module control unit 1640. Figure 17 Examples of variations in the on / off state of the warning signal 1722, variations in the output current of the power supply system 10 1724, variations in the on / off state of the short-circuit switch 1632 1732, variations in the state of the switching unit 230 1734, and variations in the output voltage of the power supply system 10 1740 are briefly shown.

[0344] Figure 18 This is a rough example of the current variations in various parts of the power supply system 10. Figure 18 This example briefly illustrates a variation 1822 in the charging current of the energy storage system 1500, and a variation 1824 in the current of the energy storage module with the highest voltage in the energy storage module group 1530. Furthermore, in this embodiment, the energy storage module is energy storage module 1630.

[0345] like Figure 17 and Figure 18As shown, according to this embodiment, trickle charging of the energy storage module group 1530 is performed during the period before time t1. At this time, a voltage of Vcv [V] is applied to the energy storage module 1630, and a current of Ict [A] flows through it. In this embodiment, at this time, the switching unit 230 of all energy storage modules installed in the energy storage system 150 electrically disconnects the wiring 106 of each energy storage module from the energy storage unit 210. In addition, the current supplied from the charging device 14 to each energy storage module flows into the energy storage unit 210 via the trickle charging unit 320.

[0346] Here, at time t1, the module control unit 1640 detects that the warning signal has been activated. When the warning signal is activated, the module control unit 1640 activates the short-circuit switch 1632 of the energy storage module 1630. When the short-circuit switch 1632 is activated, the inter-terminal voltage of the power supply system 10 is approximately equal to the inter-terminal voltage Von[V] of the energy storage module 1630. Furthermore, after the warning signal is activated or the short-circuit switch 1632 is activated, the charging device 14 can increase the electrical force or current supplied to the energy storage system 1500 to Icc.

[0347] Subsequently, at time t2, the switching unit 230 is turned on. According to one embodiment, when the inter-terminal voltage of the power supply system 10 is approximately equal to the inter-terminal voltage Von[V] of the energy storage module 1630, at time t2, the module control unit 1640 causes the switching unit 230 to turn on. According to another embodiment, the module control unit 1640 sends a reset signal to the protection unit 250. As a result, the overcharge protection function of the protection unit 250 becomes ineffective, and at time t2, the switching unit 230 is turned on.

[0348] Through the above actions, preparations are completed for the power supply system 10 to stably supply power. Then, at time t3, the load device 20 begins to consume power. At this time, the output current of the power supply system 1910 is Iout [A]. Iout can be a value larger than a predetermined value.

[0349] Generally, a delay occurs between the activation of the warning signal and the activation of the switching unit 230. Therefore, for example, if all the energy storage modules installed in the energy storage system 150 are electrically disconnected from the wiring 106, and the load device 20 consumes a lot of power, the voltage between the terminals of the power supply system 10 may decrease sharply, and the activation action of the switching unit 230 may not be timely.

[0350] To address this issue, according to this embodiment, at least one energy storage module 1630 is connected to the wiring 106 of the energy storage system 1500 before the load device 20 begins to consume power. As a result, the power supply system 10 can supply power stably. Furthermore, in this embodiment, the length of the warning signal's on-time ts can be set to a value greater than the length of the period tb between the moment the warning signal is on and the moment the load device 20 begins consuming power. Additionally, the length of the period tb can be set to a value greater than the length of the delay time td of the switching unit 230.

[0351] [Another example of a power supply system] use Figure 19 , Figure 20 and Figure 21 Let's take another example to illustrate the power supply system. Figure 19 This is a simplified representation of the system configuration of the power supply system in 1910. Figure 20 This is a simplified representation of an example of the control of the module control unit 1640. Figure 21 This is a rough illustration of the current variations in various parts of the 1910 power supply system.

[0352] like Figure 19 As shown, the power supply system 1910 and its associated systems Figure 15 and Figure 16 The difference in the power supply system 10 described is that it also includes a capacitor 1920; and the switching unit 230 does not need to be short-circuited before the power supply system 1910 outputs current.

[0353] According to the association Figure 17 and Figure 18 The control method of the power supply system 10, as described above, involves short-circuiting the switching section 230 using the short-circuit switch 1632 before the power supply system 10 outputs current, thereby stabilizing the power supply from the power supply system 10 to the load device 20. On the other hand, according to this embodiment, by connecting the capacitor 1920 in parallel with the load device 20, abrupt fluctuations in the output voltage of the power supply system 1910 can be suppressed. This, in turn, stabilizes the power supply from the power supply system 10 to the load device 20.

[0354] For example, because it can suppress drastic fluctuations in the output voltage of the power supply system 1910, the switching unit 230 can easily cope with a decrease in the output voltage of the power supply system 1910. Furthermore, even if the switching unit 230 cannot cope with a decrease in the output voltage of the power supply system 1910, the short-circuit switch 1632 can short-circuit the switching unit 230 upon receiving a notification signal from the system control unit 140 indicating that the load device 20 has begun to consume power. As a result, the power supply from the power supply system 10 to the load device 20 can be stabilized. Moreover, in this embodiment, the short-circuit switch 1632 can short-circuit the switching unit 230 before or after the power supply system 10 outputs current.

[0355] According to this embodiment, for example, one end of capacitor 1920 is electrically connected to connection terminal 102, and the other end of capacitor 1920 is electrically connected to connection terminal 104. Thus, when the load device 20 is electrically connected to the power supply system 1910, capacitor 1920 is connected in parallel with the load device 20. This suppresses fluctuations in the output voltage of the power supply system 1910. Therefore, even when all energy storage modules installed in the energy storage system 150 are electrically disconnected from the wiring 106, and the load device 20 consumes a large amount of power, the switching operation of the switching unit 230 can cope with the voltage drop in the wiring 106.

[0356] The power supply system 1910 can be an example of an energy storage system. The capacitor 1920 can be an example of a fluctuation suppression unit.

[0357] Figure 20 This section briefly illustrates an example of a change in the on / off state of a notification signal 2022, a change in the output current of the power supply system 10 2024, a change in the on / off state of a short-circuit switch 1632 2032, a change in the state of a switching unit 230 2034, and a change in the output voltage of the power supply system 10 2040.

[0358] The notification signal can be a signal indicating that the load device 20 has started consuming current or that the load device 20 is consuming current. The notification signal can also be a signal indicating that the current consumed by the load device 20 is above or greater than a predetermined value. For example, the notification signal is sent from the load device 20 to the system control unit 140.

[0359] Figure 21This example illustrates, in general terms, a variation 2122 in the charging current of the energy storage system 1500 and a variation 2124 in the current of the energy storage module with the highest voltage in the energy storage module group 1530. Furthermore, as described above, the energy storage module group 1530 includes one or more energy storage modules 1630. In this embodiment, the energy storage module with the highest voltage may be energy storage module 1630.

[0360] like Figure 20 and Figure 21 As shown, according to this embodiment, trickle charging of the energy storage module group 1530 is performed during the period before time t1. At this time, a voltage of Vcv [V] is applied to the energy storage module 1630, and a current of Ict [A] flows through it. In this embodiment, at this time, the switching unit 230 of all energy storage modules installed in the energy storage system 150 electrically disconnects the wiring 106 of each energy storage module from the energy storage unit 210. In addition, the current supplied from the charging device 14 to each energy storage module flows into the energy storage unit 210 via the trickle charging unit 320.

[0361] Here, at time t1, the load device 20 begins to consume power. At this time, the output current of the power supply system 1910 is Iout[A]. Iout can be a value larger than a predetermined value. Furthermore, when the load device 20 begins to consume power, the output voltage of the power supply system 1910 decreases. Additionally, after the load device 20 begins to consume power, the charging device 14 can increase the electrical force or current supplied to the energy storage system 1500 to Icc. At this time, if the capacitance of the capacitor 1920 is set to C, and the output current of the power supply system 1910 is set to I2, then... Figure 20 In this context, the slope of (I2-Icc) / C represents the rate of decrease of the output voltage.

[0362] Next, at time t2, the module control unit 1640 detects that a notification signal has been activated. After the notification signal is activated, the module control unit 1640 activates the short-circuit switch 1632 of the energy storage module 1630. As described above, among the energy storage modules included in the energy storage module group 1530 of the energy storage module 1630, the inter-terminal voltage is the highest. Therefore, after the short-circuit switch 1632 is activated, the inter-terminal voltage of the power supply system 10 is approximately equal to the inter-terminal voltage Von[V] of the energy storage module 1630.

[0363] Additionally, at this time, a large battery current I flows instantaneously through the energy storage module 1630. A As a result, capacitor 1920 is charged. As a result, the voltage between the terminals of the power supply system 10 increases.

[0364] Then, after a delay time td from time t2, when time t3 is reached, the switching unit 230 of the energy storage module 1630 is turned on. At this time, the output voltage of the power supply system 1910 becomes Vout[V]. The magnitude of Vout[V] depends, for example, on the energy storage module group 1530.

[0365] In this embodiment, the length of the notification signal's on-time ts can be set to a value greater than the length of the delay time td of the switching unit 230. The length of the period tb between the start time of power consumption of the load device 20 and the time when the notification signal has been on can be determined based on the capacitance of the capacitor 1920.

[0366] [Another example of a power supply system] use Figure 22 , Figure 23 and Figure 24 This illustrates another example of a power supply system. Figure 22 This is a simplified representation of the system configuration of the power supply system 2210. Figure 23 This is a simplified representation of an example of the control of the module control unit 1640. Figure 24 This is a rough illustration of the current variations in various parts of the power supply system 2210.

[0367] like Figure 22 As shown, the power supply system 2210 and its associated systems... Figure 15 and Figure 16 The difference in the power supply system 10 described herein is that it also includes a current detection component 2220; and a short-circuit switch 1632 that short-circuits the switching unit 230 based on the detection result of the current detection component 2220. Regarding other features, the power supply system 2210 may have related... Figure 15 and Figure 16 The power supply system 10 described herein has the same configuration.

[0368] In this embodiment, the current detection component 2220 detects that the power supply system 2210 is supplying power to the load device 20. Furthermore, the current detection component 2220 sends information indicating this detection result to the system control unit 140.

[0369] In one embodiment, the current detection component 2220 detects whether the output current of the power supply system 2210 is greater than a predetermined value. If the output current of the power supply system 2210 is detected to be greater than the predetermined value, the current detection component 2220 sends information indicating the detection result to the system control unit 140. In another embodiment, the current detection component 2220 measures the current value of the output current of the power supply system 2210. The current detection component 2220 sends information indicating the measurement result to the system control unit 140.

[0370] In this embodiment, when the system control unit 140 detects that the power supply system 2210 is supplying power to the load device 20, it sends (i) a signal indicating that the power supply system 2210 is supplying power to the load device 20 (sometimes called a detection signal) or (ii) a signal used to turn on the short-circuit switch 1632.

[0371] In this embodiment, when the module control unit 1640 receives a detection signal or a signal to turn on the short-circuit switch 1632, it sends a signal to the short-circuit switch 1632 to turn it on. This causes the switching unit 230 to short-circuit. When the current detection component 2220 detects that the power supply system 2210 is supplying power to the load device 20, it also short-circuits the switching unit 230.

[0372] Figure 23 This section briefly illustrates an example of a change in the on / off state of a detection signal 2322, a change in the output current of the power supply system 10 2324, a change in the on / off state of a short-circuit switch 1632 2332, a change in the state of a switching unit 230 2334, and a change in the output voltage of the power supply system 10 2340.

[0373] Figure 24 This section provides a simplified example of the variation 2422 in the charging current of the energy storage system 1500 and an example of the variation 2424 in the current of the energy storage module with the highest voltage in the energy storage module group 1530. Furthermore, as described above, the energy storage module group 1530 includes one or more energy storage modules 1630. In this embodiment, the energy storage module with the highest voltage may be energy storage module 1630.

[0374] like Figure 23 and Figure 24 As shown, according to this embodiment, trickle charging of the energy storage module group 1530 is performed during the period before time t1. At this time, a voltage of Vcv [V] is applied to the energy storage module 1630, and a current of Ict [A] flows through it. In this embodiment, at this time, the switching units 230 of all energy storage modules installed in the energy storage system 150 electrically disconnect the wiring 106 of each energy storage module from the energy storage unit 210. In addition, the current supplied from the charging device 14 to each energy storage module flows into the energy storage unit 210 via the trickle charging unit 320.

[0375] On the other hand, at time t0, the load device 20 begins to consume power. In this embodiment, after the power supply system 2210 supplies power to the load device 20, the current consumed by the load device 20 increases continuously or in stages. According to this embodiment, the value of the output current of the power supply system 2210 increases continuously as time passes.

[0376] Then, when time t1 is reached, the current value of the power supply system 2210 reaches Isp[A]. Isp can be a predetermined value. When the current value of the power supply system 2210 reaches Isp[A], the current detection component 2220 detects the output current of the power supply system 2210. Thus, it is detected that the power supply system 2210 has supplied power to the load device 20.

[0377] When the detection signal is activated, the module control unit 1640 activates the short-circuit switch 1632 of the energy storage module 1630. When the short-circuit switch 1632 is activated, the inter-terminal voltage of the power supply system 10 is approximately equal to the inter-terminal voltage Von[V] of the energy storage module 1630. Furthermore, after the short-circuit switch 1632 is activated, the charging device 14 can increase the electrical force or current supplied to the energy storage system 1500 to Icc.

[0378] Subsequently, when time t2 arrives after a delay time td from time t1, the switching unit 230 is turned on. In this embodiment, after the short-circuit switch 1632 is turned on, after a time ta, the module control unit 1640 causes the short-circuit switch 1632 of the energy storage module 1630 to perform an open operation. The length of time ta can be set to a value greater than the length of the delay time td of the switching unit 230.

[0379] The power supply system 2210 can be an example of an energy storage system. The current detection component 2220 can be an example of a detection unit.

[0380] The present invention has been described above using embodiments, but the scope of the present invention is not limited to the scope described in the embodiments. Those skilled in the art will understand that various modifications or improvements can be made to the embodiments. Furthermore, to the extent that there is no technical inconsistency, matters described for a particular embodiment can be applied to other embodiments. As can be seen from the claims, such modifications or improvements can also be included within the scope of the present invention.

[0381] It should be noted that the execution order of actions, steps, procedures, and stages in the apparatus, systems, programs, and methods shown in the claims, description, and drawings can be implemented in any order unless specifically stated as "before," "prior to," etc., or unless the output of a previous process is used in a later process. Although terms such as "firstly" and "next" are used to describe the flow of actions in the claims, description, and drawings for convenience, this does not mean that they must be implemented in that order. [Explanation of Symbols]

[0382] 10. Power Supply System 14 Charging device 16 Charging Switching Unit 20 Load devices 26 Load Switching Unit 52 signals 54 signal 86 signal 88 signal 100 energy storage system 102 Connection Terminal 104 Connection Terminals 106 wiring 110 Energy Storage Module 130 Energy Storage Module 140 System Control Department 150 energy storage system 202 Positive Extreme Particles 204 Negative extremes 210 Battery Storage Department 212 Positive extremes 214 Negative extremes 222 storage battery 224 storage battery 230 Switching Unit 240 Module Control Unit 250 Protection Department 260 Balance Correction Unit 320 Trickle Charge Unit 322 Directional Restriction Section 324 Flow Control Department 410 Judgment Department 420 Receiving Section 430 Signal Generation Unit Module 440 Information Acquisition Department 450 Module Information Storage Department 460 Module Information Sending Department 510 transistors 512 resistor 514 resistor 516 diode 520 transistors 522 resistor 524 resistor 526 diode 530 transistors 532 resistor 540 transistors 542 resistor 552 resistor 554 resistor 560 transistors 570 capacitor 572 resistor 580 transistors 592 switch 594 switch 622 Status Management Department 624 Module Selection Section 626 Signal Generation Unit 642 Charging Control Unit 644 Charging Unit 662 Load Control Unit 664 Load Section 710 Changes 730 Changes 740 changes 814 Changes 914 Output Characteristics 1010 Energy Storage Module 1020 Current Detection Component 1040 Module Control Unit 1120 Current Monitoring Department 1122 Current Detection Unit 1124 Direction Determination Department 1242 Parasitic Diode 1244 Parasitic Diode 1260 OR circuit 1272 AND circuit 1274 AND circuit 1282 OR circuit 1284 OR circuit 1330 Energy Storage Module 1430 Energy Storage Module 1500 Energy Storage System 1510 Battery Storage Module Group 1530 Battery Storage Module Group 1630 Energy Storage Module 1632 Short-circuit switch 1640 Module Control Section 1722 Changes Changes in 1724 Changes in 1732 1734 Changes 1740 Change 1822 Changes 1824 Change 1910 Electricity Supply System 1920 Capacitor 2022 Changes 2024 Changes Changes in 2032 Changes in 2034 2040 Changes 2122 Changes 2124 Changes 2210 Power Supply System 2220 Current Detection Component 2322 Changes 2324 Changes 2332 Changes 2334 Changes 2340 Changes 2422 Changes 2424 Changes

Claims

1. An energy storage system, comprising: The first energy storage device has a first energy storage section; A second energy storage device, comprising a second energy storage section; and Wiring is provided to connect the first energy storage device and the second energy storage device in parallel; and The first energy storage device has a first switching unit. The first switching unit is disposed between the wiring and the first energy storage unit, and switches the electrical connection between the wiring and the first energy storage unit based on the voltage difference between the wiring and the first energy storage unit. The second energy storage device has a second switching unit. The second switching unit is disposed between the wiring and the second energy storage unit, and switches the electrical connection between the wiring and the second energy storage unit based on the voltage difference between them. The first energy storage unit includes a first type of secondary battery and a short-circuit section. The second energy storage unit includes a second type of secondary battery. The battery system of the first type of secondary battery is represented by a reaction formula that, in principle, will not undergo irreversible changes even when the overcharge state continues. The short-circuit section is disposed between the wiring and the first energy storage unit, and is connected in parallel with the first switching unit between the wiring and the first energy storage unit, for the purpose of short-circuiting the first switching unit. The battery system of the second type of secondary battery is represented by a reaction formula that, in principle, causes an irreversible change when the overcharged state persists. The charging termination voltage of the first energy storage unit, The voltage is below the full charge voltage of the first energy storage unit, and Greater than the charging termination voltage of the second energy storage unit; The full-charge voltage of the first energy storage unit is less than the charging voltage of the charging device that charges the first energy storage unit and the second energy storage unit connected in parallel. The charging device, When the voltage of the first energy storage unit is below the charging end voltage, the first energy storage device is charged using a constant current method. When the voltage of the first energy storage unit is greater than the charging end voltage, the first energy storage device is charged by trickle charging. The short-circuit section includes a short-circuit state switching section, which causes the short-circuit section to switch to a state in which the short-circuit section short-circuits the first switching section. The short-circuit switching unit short-circuits the first switching unit when it detects that the output current of the energy storage system is greater than the charging current of the energy storage system, or when it predicts that the output current of the energy storage system will be greater than the charging current of the energy storage system. The short-circuit switching unit short-circuites when the energy storage system receives information indicating that a load device using power supplied from the energy storage system has started using power.

2. The energy storage system according to claim 1, further comprising a charging voltage control unit, The charging voltage control unit controls the set value of the charging voltage of the charging device.

3. The energy storage system according to claim 2, wherein... During at least a portion of the charging period of the first and second energy storage devices, the charging device charges the first and second energy storage devices in a constant current manner.

4. The energy storage system according to claim 1, wherein The first energy storage device also has a limiting part. The limiting part is connected in parallel with the first switching part between the wiring and the first energy storage part, and has a larger resistance than the first switching part, so that the current flows in the direction from the wiring to the first energy storage part, while suppressing the current from the first energy storage part to the wiring.

5. The energy storage system according to claim 4, wherein... The limiting part includes: A current limiting section that limits the amount of current flowing through the limiting section; and The current direction limiting part is connected in series with the current quantity limiting part, so that the current passes through in the direction from the wiring to the first energy storage part, while the current is suppressed from passing through in the direction from the first energy storage part to the wiring.

6. The energy storage system according to claim 1, wherein The short-circuit state switching unit operates in at least one of the following situations: The state of the short-circuit section is switched from a state where the short-circuit section causes the first switching section to short-circuit to a state where the short-circuit section does not short-circuit the first switching section. This refers to the following situation: (i) a predetermined time has elapsed after the short-circuit state switching unit short-circuits the first switching unit; and (ii) it is detected that the output current of the energy storage system is less than the charging current of the energy storage system, or it is predicted that the output current of the energy storage system is less than the charging current of the energy storage system.

7. The energy storage system according to claim 1, wherein... Before the energy storage system outputs current, the short-circuit switching unit short-circuits the first switching unit if it detects that the output current of the energy storage system is greater than the charging current of the energy storage system, or if it predicts that the output current of the energy storage system is greater than the charging current of the energy storage system.

8. The energy storage system according to claim 1, further comprising a fluctuation suppression unit, The fluctuation suppression unit is used to suppress fluctuations in the output voltage of the energy storage system.

9. The energy storage system according to claim 8, wherein The short-circuit switching unit short-circuits the first switching unit after the energy storage system outputs current, either when it detects that the output current of the energy storage system is greater than the charging current of the energy storage system, or when it predicts that the output current of the energy storage system is greater than the charging current of the energy storage system.

10. The energy storage system according to claim 9, wherein The fluctuation suppression unit is configured such that, when a load device using power supplied from the energy storage system is electrically connected to the energy storage system, the fluctuation suppression unit is connected in parallel with the load device.

11. The energy storage system according to claim 1, further comprising a detection unit, The testing department detects the power supply of the energy storage system to the load device. The short-circuit state switching unit When the detection unit detects that the energy storage system has supplied power to the load device, If the output current of the energy storage system is detected to be greater than the charging current of the energy storage system, or if it is predicted that the output current of the energy storage system will be greater than the charging current of the energy storage system, the first switching unit is short-circuited.

12. The energy storage system according to claim 11, wherein After the energy storage system supplies power to the load device, the current consumption of the load device increases continuously or in stages.

13. The energy storage system according to claim 12, wherein The energy storage system, Receive a request signal from the load device indicating the magnitude of the current that should be supplied to the load device. Output a current of the magnitude indicated by the requested signal.

14. The energy storage system according to claim 12, wherein The load device includes a current consumption control unit that controls the amount of current consumed by the load device.

15. The energy storage system according to claim 1, wherein The energy storage system has multiple first energy storage devices connected in parallel. At least two of the plurality of first energy storage devices have the short-circuit section.

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