charging and discharging device

Abstract

To provide a charge / discharge device capable of individually and appropriately controlling a plurality of battery modules in one communication control device even when reusing the plurality of battery modules having the same specifications installed in a vehicle.SOLUTION: The charge / discharge device comprises a plurality of battery modules 4, a connection path 5, an electric load 3, a first switch 6, a communication control device 8, and a power generation device 2. The battery module 4 has a storage battery 41 and a BMU 42. The BMU 42 of each battery module 4 has a common CAN_ID. A storage unit 81 for storing a voltage value or SOC of the storage battery 41 for each battery 4 is provided in the communication control unit 8. The communication control device 8 is configured to control each BMU 42 using the common CAN_ID. The first switch 6 of the battery module 4 is switched to an on state according to the voltage value or the SOC stored in the storage unit 81 when all the first switches 6 of the plurality of battery modules 4 are in an off state.SELECTED DRAWING: Figure 1

Description

Technical Field

[0006] , ,

[0005] , ,

[0001] The present invention relates to a charge-discharge device.

Background Art

[0002] Patent Document 1 discloses a power storage system that constitutes an independent drive system for supplying power to a base station (load) of a mobile phone installed in a remote area where a commercial power supply cannot be drawn, such as a mountainous area. This power storage system includes a plurality of battery units, a power generation unit, a power conversion unit, a charging power supply unit, and a control unit.

[0003] In this power storage system, when switching the battery unit to be discharged from the first battery unit to the second battery unit, backup is performed by the third battery unit, and even if the discharge from the second battery unit fails, power is supplied from the third battery unit to avoid the operation stop of the load.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, when using a reused product of a battery module mounted on a vehicle as the battery unit of the power storage system as described in Patent Document 1, there are the following problems.

[0006] The battery modules installed in vehicles have a controller (hereinafter referred to as "BMU (Battery Management Unit)") that manages the voltage value of each cell of the battery. This BMU sometimes uses CAN (Controller Area Network) as a standard for communicating with other controllers.

[0007] In CAN, each signal is assigned an ID. However, when using multiple reused battery modules of the same specifications, which are not intended for multiple use, the ID used in the BMUs of all these battery modules becomes the same. Therefore, if a single communication control device attempts to communicate with multiple BMUs of identical battery modules via CAN, signals will overlap, making it difficult to control multiple BMUs individually.

[0008] In this case, for example, if a separate communication control device is installed for each BMU, multiple battery modules with the same specifications can be controlled individually. However, since a communication control device is required for each battery module, the cost becomes high even when inexpensive reused parts are used.

[0009] The present invention has been made in view of the circumstances described above, and aims to provide a charging and discharging device that can individually and appropriately control multiple battery modules of the same specifications that were installed in a vehicle, using a single communication control device. [Means for solving the problem]

[0010] To achieve the above objective, the present invention provides a power supply device capable of supplying power, an electrical load, a connection path selectively connected to either the power supply device or the electrical load, and a connection path connected to the connection path. multiple The battery module group comprises the aforementioned multipleThe battery module group comprises a plurality of battery modules connected in parallel to each other with respect to the connection path, a plurality of first switches positioned between the battery modules and the connection path and capable of switching between an ON state to connect them and an OFF state to disconnect them, and a communication control device connected to the connection path that controls the switching of the plurality of first switches, each of the plurality of battery modules comprises a plurality of storage batteries and a plurality of BMUs that manage the state of the storage batteries and can communicate with the communication control device using a common identification signal, the communication control device has a storage unit that stores the voltage value or SOC of each storage battery in association with each of the battery modules, and when the connection path is connected to the power supply device, only one of the first switches corresponding to the battery module is turned ON according to the voltage value or SOC stored in the storage unit. Furthermore, if the supply voltage from the power supply device is less than the operating voltage of the BMU and the communication control device, the communication control device in one of the battery module groups to which the first switch that is turned ON belongs will, after the communication control device in the other battery module groups has turned ON one of the first switches belonging to it, switch the first switch and the other first switches to the OFF state and ON state, respectively. . [Effects of the Invention]

[0011] According to the present invention, even when multiple battery modules of the same specifications that were installed in a vehicle are reused, a charging and discharging device can be provided that can individually and appropriately control these reused battery modules with a single communication control device. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a schematic diagram of a charge / discharge device according to a first embodiment of the present invention. [Figure 2] Figure 2 shows an example of the voltage values ​​stored in the memory unit of the charge / discharge device according to the first embodiment of the present invention. [Figure 3] Figure 3 is a schematic diagram of a charge / discharge device according to a second embodiment of the present invention. [Figure 4] Figure 4 shows an example of a timing chart for battery module switching in a charge / discharge device according to a second embodiment of the present invention. [Modes for carrying out the invention]

[0013] A charge / discharge device according to one embodiment of the present invention comprises a power supply device capable of supplying power, an electrical load, a connection path selectively connected to either the power supply device or the electrical load, and at least one group of battery modules connected to the connection path. The at least one group of battery modules comprises a plurality of battery modules connected in parallel to each other with respect to the connection path, a plurality of first switches positioned between the battery modules and the connection path and capable of switching between an ON state to connect them and an OFF state to disconnect them, and a communication control device connected to the connection path that controls the switching of the plurality of first switches. Each of the plurality of battery modules comprises a plurality of storage batteries and a plurality of BMUs that manage the state of the storage batteries and can communicate with the communication control device using a common identification signal. The communication control device has a storage unit that stores the voltage value or SOC of each storage battery in association with each battery module, and when the connection path is connected to the power supply device, the device has a configuration that turns on only one of the first switches corresponding to a battery module according to the voltage value or SOC stored in the storage unit. [Examples]

[0014] Hereinafter, a charge / discharge device according to one embodiment of the present invention will be described with reference to the drawings.

[0015] (First example) As shown in Figure 1, the charge / discharge device 1 according to the first embodiment includes a power generator 2 as a power supply device, an electrical load 3, a plurality of battery modules 4, a connection path 5, a plurality of first switches 6, a second switch 7, and a communication control device 8. Note that the charge / discharge device 1 according to this embodiment corresponds to the case in the charge / discharge device 101 according to the second embodiment described later, where there is one group of battery modules.

[0016] In the charging and discharging device 1 according to this embodiment, n battery modules 4 are provided. That is, the number of the plurality of battery modules 4 is a natural number n of 2 or more. In this embodiment, in order to distinguish each of the plurality of battery modules 4, the plurality of battery modules 4 are respectively denoted as battery modules 4(1) to 4(n). When indicating one battery module without specifying any of the battery modules 4(1) to 4(n), it is simply denoted as "battery module 4".

[0017] The power generation device 2 is connected to the connection path 5 via the second switch 7 so as to be able to supply power to the plurality of battery modules 4 and the communication control device 8.

[0018] The power generation device 2 is constituted by a power generation device that generates power using renewable energy such as a solar power generation device or a wind power generation device. The power generation device that generates power using renewable energy is not limited to a solar power generation device or a wind power generation device, and power generation devices using renewable energy such as hydro, geothermal, biomass, etc. are also applicable.

[0019] The electrical load 3 is constituted by a device having a light emitter as a load, such as lighting or an electric bulletin board. The electrical load 3 is not limited to a device having a light emitter as a load.

[0020] The battery modules 4(1) to 4(n) are connected to the connection path 5 in parallel with each other. Each battery module 4 has a storage battery 41 and a BMU (Battery Management Unit) 42, respectively. In the battery module 4 of this embodiment, a reused battery module is used. That is, in the charging and discharging device 1, the battery module mounted on the vehicle is reused as the battery module 4.

[0021] In this embodiment, in order to distinguish which of the battery modules 4(1) to 4(n) a particular battery 41 and BMU 42 it is, a reference numeral corresponding to the battery module 4(1) to 4(n) is assigned to the battery 41 and BMU 42, and they are referred to as battery 41(1) to 41(n) and BMU 42(1) to 42(n). When referring to a single battery and BMU without specifying which of the battery modules 4(1) to 4(n) it belongs to, they are simply written as "battery 41" and "BMU 42," respectively.

[0022] The storage battery 41 is composed of a rechargeable secondary battery, such as a lithium-ion battery. For example, a lithium-ion battery that was previously installed in a vehicle can be reused as the storage battery 41.

[0023] The BMU42 monitors and manages the state of the battery 41, including its voltage and remaining capacity (SOC: state of charge). The BMU42 calculates the SOC based on the charging and discharging current of the battery 41.

[0024] Each BMU 42 is connected to the communication control device 8 in a communication manner and is configured to transmit various information such as the voltage value of the battery 41 and the SOC to the communication control device 8 at predetermined timings, along with a common identification signal described later. The BMU 42 uses CAN (Controller Area Network) as the communication standard for communicating with the communication control device 8.

[0025] Each of the BMUs 42(1) through 42(n) has a CAN_ID as an identification signal to identify itself when communicating with the communication control device 8. In this embodiment, the CAN_IDs of BMUs 42(1) through 42(n) are common to each other because the BMUs 42 have the same specifications. That is, BMUs 42(1) through 42(n) use the same CAN_ID.

[0026] This is because the vehicle has only one battery module installed, eliminating the need for individual identification, and all modules have the same specifications and CAN_ID. Furthermore, the charge / discharge device 1 in this embodiment reuses these battery modules.

[0027] Each first switch 6 is provided between the battery module 4 and the connection path 5, and is a switch that can switch between an ON state, which connects the battery module 4 and the connection path 5, and an OFF state, which disconnects them.

[0028] In this embodiment, in order to distinguish whether a switch 6 corresponds to a battery module 4(1) to 4(n), the first switches 6 corresponding to each of the battery modules 4(1) to 4(n) are indicated as first switches 6(1) to 6(n). When referring to a single first switch 6(1) to 6(n) without specifying which of the battery modules 4(1) to 4(n) it belongs to, it is simply written as "first switch 6".

[0029] The switching between the on and off states of each first switch 6 is controlled by the communication control device 8. In other words, each of the multiple first switches 6 is electrically connected to the communication control device 8 and can be controlled individually.

[0030] Battery modules 4(1) to 4(n) are connected in parallel to each other in connection path 5. A second switch 7 is connected to one end of connection path 5.

[0031] The second switch 7 is provided between the connection path 5 and the power generator 2 and the electrical load 3, and is a switch that can switch between an ON state, which connects the connection path 5 to the power generator 2 or the electrical load 3, and an OFF state, which disconnects it.

[0032] In other words, the second switch 7 can be switched between an ON state, which is either a power generation ON state where the connection path 5 is connected to the power generator 2, or a discharge ON state where the connection path 5 is connected to the electrical load 3, and an OFF state, which is not connected to either the power generator 2 or the electrical load 3.

[0033] The switching of the second switch 7 between the power generation ON state, the discharge ON state, and the OFF state is controlled by the communication control device 8. When the communication control device 8 is not powered on, for example when the charge / discharge device 1 is OFF, it is preferable that the second switch 7 is switched to the power generation ON state from the viewpoint of securing the power necessary to start the charge / discharge device 1.

[0034] The communication control device 8 is composed of a computer unit comprising a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), an input port, and an output port. The ROM of the computer unit stores various constants and other data, along with a program that enables the computer unit to function as the communication control device 8. In other words, the CPU executes the program stored in the ROM using the RAM as a working area, thereby enabling the computer unit to function as the communication control device 8 in this embodiment.

[0035] The communication control device 8 is connected to the connection path 5, and power is supplied to it from the power generator 2 or from at least one of the battery modules 4(n) 4(1) via the connection path 5. The communication control device 8 controls the switching between the on and off states of the first switch 6 and the second switch 7.

[0036] Various sensors 9 are connected to the communication control device 8. In this embodiment, the necessary sensors 9 are connected according to the type of power generation device 2 and the type of electrical load 3. For example, sensors capable of detecting changes in the external environment, such as wind sensors, illuminance sensors, and temperature sensors, are connected. Furthermore, if the electrical load 3 is lighting, the communication control device 8 may be equipped with a timer to manage lighting time and lighting schedule.

[0037] In this embodiment, the communication control device 8 is provided with a storage unit 81. The storage unit 81 may be composed of, for example, the RAM described above, or it may be composed of a storage device other than the RAM described above.

[0038] The storage unit 81 of the communication control device 8 stores the voltage value or SOC of each battery module 4 of the storage battery 41. Specifically, as shown in Figure 2, the storage unit 81 has pre-stored the voltage value or SOC of each storage battery 41(1) to 41(n), associated with each of the battery modules 4(1) to 4(n) that have a common CAN_ID. Note that Figure 2 shows an example in which the storage unit 81 stores voltage values. The storage unit 81 may also store both the voltage value and SOC of each storage battery 41(1) to 41(n), associated with each of the battery modules 4(1) to 4(n).

[0039] These voltage values ​​or SOCs pre-stored in the memory unit 81 are the voltage values ​​or SOCs measured and transmitted by the BMU 42 at the timing when each first switch 6 is switched from the ON state to the OFF state, for example, when it is necessary to know each voltage value at once, such as when the charge / discharge device 1 is started up for the first time. Specifically, the BMU 42 is configured to repeatedly transmit its own information (the voltage value and SOC of the corresponding storage battery 41, etc.) to the communication control device 8 while the corresponding first switch 6 is ON. In other words, the BMU 42 does not transmit this information when the corresponding first switch 6 is OFF.

[0040] The communication control device 8, at the timing when it sends an instruction to one of the first switches 6(1) to 6(n) to be turned ON while the other first switches remain OFF, and then to be turned OFF, stores information from the BMU 42 of the battery module 4 corresponding to the first switch 6 to which the instruction was sent, associating it with the BMU 42 (identifying the BMU 42 that sent the information based on the first switch 6 that sent the instruction).

[0041] At this time, the communication control device 8 receives information transmitted from the first switch 6 as it changes from the ON state to the OFF state, but ultimately stores the information received at the time the instruction is sent (the last information sent from the BMU 42) in the storage unit 81.

[0042] For example, when the first switch 6(1) is ON and the other first switches 6(2) through 6(n) are OFF, the communication control device 8 sends an instruction to the first switch 6(1) to turn it OFF. At the same time, it acquires the voltage value or SOC of the storage battery 41(1) transmitted from the BMU 42(1) of the corresponding battery module 4(1) and stores it in the storage unit 81 in association with the battery module 4(1) (identified as the voltage value or SOC of the battery module 4(1)). By performing the same process for each of the remaining first switches 6(2) through 6(n), the voltage value or SOC of each storage battery 41 can be stored in association with the battery modules 4(1) through 4(n) that have a common CAN_ID, as shown in Figure 2.

[0043] As described above, the communication control device 8 controls BMUs 42(1) through 42(n) that have a common CAN_ID. Therefore, if the communication control device 8 attempts to control BMUs 42(1) through 42(n) simultaneously, it cannot control them individually due to the duplication of CAN_IDs. In other words, in this case, the communication control device 8 cannot distinguish which battery 41's voltage value or SOC is transmitted from each BMU 42, and as a result, it is difficult to determine which of the first switches 6(1) through 6(n) should be switched based on the acquired battery 41 voltage value or SOC.

[0044] Therefore, in this embodiment, the communication control device 8 employs the following configuration so that it can individually control BMUs 42(1) to 42(n) even when a common CAN_ID is used for BMUs 42(1) to 42(n).

[0045] In other words, the communication control device 8 is configured to acquire information from the BMU 42 corresponding to one of the multiple first switches 6(1) to 6(n) that has a different state (on or off state) from the other switches, while identifying which battery module it is.

[0046] Specifically, the communication control device 8 first stores the voltage value or SOC of each battery 41 in the memory unit 81 in association with the battery modules 4(1) to 4(n) using the method described above. Then, when the connection path 5 is connected to the power generator 2, such as during charging, the communication control device 8 turns on one of the first switches 6 of the battery module 4 having the battery 41 with the lowest voltage value or SOC among the batteries 41(1) to 41(n) stored in the memory unit 81, and turns off all the remaining first switches 6.

[0047] In other words, the communication control device 8 turns on only one of the first switches 6. As a result, the state of one of the first switches 6(1) to 6(n) will be different from the state of the other first switches, so the communication control device 8 can identify the BMU 42 corresponding to that one first switch and communicate with this BMU 42 on a one-to-one basis. Therefore, the voltage value or SOC already stored in the memory unit 81 can be updated with the voltage value or SOC sent from the BMU 42 as needed, so the communication control device 8 can appropriately control the battery module 4 based on the latest information (voltage value or SOC) (for example, prioritizing charging the battery with the lowest voltage value or SOC, and prioritizing discharging the battery with the highest voltage value or SOC).

[0048] As described above, the charge / discharge device 1 according to this embodiment is configured to communicate one-to-one with the BMU 42 corresponding to the first switch 6 by utilizing a first switch 6 with different states.

[0049] With this configuration, the charge / discharge device 1 according to this embodiment can manage each voltage value or each SOC of the storage battery 41(1) to 41(n) in association with the corresponding battery module 4, even when a common CAN_ID is used for each BMU 42 of the battery modules 4(1) to 4(n).

[0050] Furthermore, the charging and discharging device 1 according to this embodiment is configured to switch only the first switch 6 of one battery module 4 to the ON state when the connection path 5 is connected to the power generation device 2, according to the voltage values ​​or states of charge (SOC) of each battery 41(1) to 41(n) stored in the memory unit 81.

[0051] With this configuration, the charge / discharge device 1 according to this embodiment can, for example, charge battery modules 4 having a lower voltage value or state of charge (SOC) prioritizing their charging over other battery modules 4, while enabling one-to-one communication between the communication control device 8 and the BMU 42. Furthermore, it can discharge battery modules having a higher voltage value prioritizing their discharge over other battery modules, while enabling one-to-one communication between the communication control device 8 and the BMU. This allows for the individual and appropriate control of multiple battery modules 4, even when using multiple reused battery modules 4 of the same specifications that were previously installed in a vehicle, using a single communication control device 8.

[0052] If multiple batteries 41 have the same voltage value or state of charge (SOC), it is sufficient to switch the first switch 6 corresponding to any one of these batteries 41 to the ON position.

[0053] Furthermore, the charge / discharge device 1 according to this embodiment can control multiple BMUs 42 with a single communication control device 8 without requiring specification changes such as changing the CAN_ID for each BMU 42, thus contributing to cost reduction and taking advantage of the benefits of using reused battery modules 4.

[0054] Furthermore, the charging and discharging device 1 according to this embodiment is provided between the connection path 5 and the power generation device 2 and the electrical load 3, and includes a second switch 7 that can switch between an ON state, which connects the connection path 5 to the power generation device 2 or the electrical load 3, and an OFF state, which disconnects the connection.

[0055] With this configuration, the charge / discharge device 1 according to this embodiment can, for example, switch the power source to the electrical load 3 between the power generator 2 and the battery module 4 as needed, and also ensure power supply to the communication control device 8 when there is neither charging from the power generator 2 nor discharging to the electrical load 3. As a result, the charge / discharge device 1 according to this embodiment can function as an independent charge / discharge device.

[0056] Furthermore, the charge / discharge device 1 according to this embodiment is composed of a power generation device 2 that generates electricity using renewable energy. This allows the charge / discharge device 1 according to this embodiment to be installed independently outdoors.

[0057] Furthermore, the charge / discharge device 1 according to this embodiment is configured as a device in which the electrical load 3 has a light-emitting element as the load. As a result, the charge / discharge device 1 according to this embodiment can be used for lighting or electronic display boards that are independently installed outdoors.

[0058] (Second example) Next, with reference to Figures 3 and 4, the charge / discharge device 101 according to the second embodiment will be described.

[0059] As shown in Figure 3, the charge / discharge device 101 of this embodiment includes a plurality of battery module groups 104, each corresponding to the configuration of the plurality of battery modules 4, the first switch 6, and the communication control device 8 in the first embodiment described above.

[0060] In this embodiment, there are two battery module groups 104, and to distinguish between them, one is referred to as battery module group 104A and the other as battery module group 104B. Battery module 4A of battery module group 104A and battery module 4B of battery module group 104B are installed in different types of vehicles and therefore have different common CAN_IDs. That is, the common CAN_ID of battery module 4A is different from that of battery module 4B.

[0061] In this embodiment, an example with two battery module groups 104 is described, but a configuration with three or more battery module groups 104 with different common CAN_IDs is also possible.

[0062] Furthermore, in this embodiment, to clarify which of the two battery module groups 104 a battery module 4, the first switch 6, and the communication control device 8 belong to, those belonging to battery module group 104A are denoted with "A" and those belonging to battery module group 104B are denoted with "B" to distinguish them. Similarly, the storage battery 41, BMU 42, and memory unit 81 are also distinguished by denoting "A" or "B" in their designations.

[0063] In the charge / discharge device 101 of this embodiment, the communication control device 8A and the communication control device 8B are connected in a bidirectional manner. The storage unit 81A of the communication control device 8A is configured to store in advance the voltage value or SOC of each battery module 4A(1) to 4A(n) belonging to the battery module group 104A, similar to the first embodiment. Similarly, the storage unit 81B of the communication control device 8B is configured to store in advance the voltage value or SOC of each battery module 4B(1) to 4B(n) belonging to the battery module group 104B.

[0064] In the charge / discharge device 101 of this embodiment configured as described above, when the communication control device 8A and the communication control device 8B charge the battery module 4 with power supplied from the power generator 2, they switch on only the first switch 6 of the battery module 4 having the lowest voltage value or SOC among all the battery modules 4 stored in the storage units 81A and 81B. That is, among all the battery modules 4 belonging to the two battery module groups 104A and 104B, the battery module 4 with the lowest voltage value or SOC is selected, and only the first switch 6 corresponding to the selected battery module 4 is turned on.

[0065] For example, the communication control devices 8A and 8B compare the voltage value or SOC of each battery 41A stored in the memory unit 81A with the voltage value or SOC of each battery 41B stored in the memory unit 81B, and switch the first switch 6 of the battery module 4 to the ON state according to the voltage value or SOC. The following describes an example in which the first switch 6 is switched according to the voltage value.

[0066] Furthermore, in this embodiment, if the voltage supplied from the power generator 2 is less than the voltage required for the operation of the BMU 42 and the communication control device 8 (hereinafter referred to as the "operating voltage"), the charge / discharge device 101 supplies power from the battery module 4, which currently has the first switch 6 turned ON, to the BMU 42 and the communication control device 8.

[0067] At this time, if the voltage value of the battery 41 of the battery module 4 falls below a predetermined value obtained by adding a predetermined margin to the operating voltage, there is a risk that the operation of the BMU 42 and the communication control device 8 will not be able to be maintained. In other words, there is a risk that the power necessary for operation of the BMU 42 and the communication control device 8 will not be supplied.

[0068] Therefore, in this embodiment, if the supply voltage from the power generator 2 is less than the operating voltage, and the voltage value of the battery 41 currently connected to the connection path 5 via the first switch 6 which is in the ON state is less than a predetermined value, the charge / discharge device 101 will replace this battery 41 with another battery 41 having a voltage value of the predetermined value or higher and connect it to the connection path 5. Specifically, the first switch 6 which is currently in the ON state is switched to the OFF state, and another first switch 6 corresponding to a battery module 4 having a voltage value of the predetermined value or higher is switched to the ON state.

[0069] Here, when switching one of the first switches 6 of battery module group 104A and battery module group 104B to the OFF state while switching the other first switch 6 to the ON state, that is, when connecting the other storage battery 41 to the connection path 5 in place of the one storage battery 41, the communication control device 8 of one and the communication control device 8 of the other will be different (non-identical communication control devices 8A and 8B will be used for switching the switches of each battery module group). For this reason, in each of battery module group 104A and battery module group 104B, duplicate CAN_IDs will not be used simultaneously for multiple BMUs 42. In other words, in each battery module group, a common CAN_ID will be used for a single BMU 42.

[0070] Therefore, for example, when switching the connection to the connection path 5 from the battery 41A of battery module group 104A to the battery 41B of battery module group 104B, the first switch 6A is switched from the ON state to the OFF state and the first switch 6B is switched from the OFF state to the ON state simultaneously, or the first switch 6A is switched after the first switch 6B is switched.

[0071] In contrast, when switching the first switch 6 to the ON state within one of the battery module groups 104A and 104B, that is, for example, when switching the first switch 6A(1) which is ON to the OFF state and the first switch 6A(2) which is OFF to the ON state within battery module group 104A, it is desirable to switch the first switch 6A(1) first and then the first switch 6A(2) in order to prevent the CAN_ID from being duplicated in the communication control device 8A (so that duplicate CAN_IDs are not used simultaneously in battery module group 104A).

[0072] However, in this case, when the first switch 6A(1), which is currently in the ON state, is switched to the OFF state, all first switches 6 will be in the OFF state, which will interrupt the power supply to the communication control device 8, making it impossible to switch the first switch 6A(2) to the ON state.

[0073] Therefore, in this embodiment, when switching a battery module 4 in one of the battery module groups 104A and 104B in which the first switch 6 is turned ON, the battery 41 of one of the battery module 4s in the other battery module groups is connected to the connection path 5 until the switching of the battery module 4 in that battery module group is completed, so as to prevent interruption of power supply to the communication control device 8.

[0074] Specifically, for example, when switching a battery module 4A in the battery module group 104A that has the first switch 6A turned ON, the first switch 6B of any of the battery modules 4B in the battery module group 104B is switched ON first, and then the battery module 4A in the battery module group 104A that has the first switch 6A turned ON is switched.

[0075] In this case, after the battery module 4A is switched within the battery module group 104A, the first switch 6B, which was switched to the ON state within the battery module group 104B, is switched back to the OFF state.

[0076] An example of switching between storage batteries 41 connected to the connection path 5 within the same battery module group (by switching the first switch 6 on and off) will be explained with reference to Figure 4.

[0077] Figure 4 is a timing chart illustrating the case where the battery module connected to the connection path 5 within the battery module group 104A is switched from battery module 4A(1) to battery module 4A(2). In this example, it is assumed that the supply voltage from the power generator 2 is less than the operating voltage of the BMU 42 and the communication control device 8.

[0078] As shown in Figure 4, before time t1, the first switch 6A(1) corresponding to the battery module 4A(1) is turned ON, and this state is maintained at time t1, so that power is supplied from the battery module 4A(1) belonging to the battery module group 104A to the BMU42A(1) and the communication control device 8A.

[0079] At time t1, if the voltage value of the battery 41 of battery module 4A(1) falls below a predetermined value, the first switch 6B(1) corresponding to battery module 4B(1) belonging to battery module group 104B is switched to the ON state.

[0080] Subsequently, at time t2, the first switch 6A(1) corresponding to battery module 4A(1) is switched to the OFF state. This temporarily disconnects the battery module group 104A from the connection path 5. At this time, the first switch 6B(1) corresponding to battery module 4B(1) has already been switched to the ON state, so the battery module group 104B is connected to the connection path 5. Therefore, even while the connection between the battery module group 104A and the connection path 5 is temporarily disconnected, power supply to the communication control device 8A is maintained by the battery module group 104B.

[0081] Subsequently, at time t3, the first switch 6A(2) corresponding to the battery module 4A(2) is switched to the ON state. As a result, the battery module group 104A is connected to the connection path 5, and power can be supplied from the battery module group 104A to the communication control device 8A.

[0082] Subsequently, at time t4, the first switch 6B(1) corresponding to the battery module 4B(1) is switched to the OFF state.

[0083] Thus, in the example shown in Figure 4, while the first switch 6B(1) corresponding to battery module 4B(1) is in the ON state, the battery module 4 connected to the connection path 5 within the battery module group 104A is switched from battery module 4A(1) to battery module 4A(2). Therefore, the voltage value of the connection path 5 is maintained above the operating voltage even during this switching.

[0084] As described above, the charge / discharge device 101 according to this embodiment is configured such that, when the supply voltage from the power generator 2 is less than the operating voltage of the BMU 42 and the communication control device 8, and when switching a battery module 4 in one battery module group that has its first switch 6 turned ON, the first switch 6 of any battery module 4 in another battery module group is switched ON first, and then the battery module 4 in the same battery module group that has its first switch 6 turned ON is switched.

[0085] With this configuration, the charge / discharge device 101 according to this embodiment can switch between battery modules 4 in a group of battery modules, in which the first switch 6 is in the ON state, while maintaining the operating voltage of the BMU 42 and the communication control device 8, even when the supply voltage from the power generator 2 is insufficient.

[0086] Furthermore, the charge / discharge device 101 according to this embodiment is configured such that after a battery module 4 is switched within one battery module group, the first switch 6, which was switched to the ON state within another battery module group, is switched to the OFF state.

[0087] With this configuration, the charging and discharging device 101 according to this embodiment can individually and appropriately control multiple battery modules 4 of the same specifications that were installed in a vehicle, using a single communication control device 8.

[0088] While embodiments of the present invention have been disclosed, it will be apparent to those skilled in the art that modifications can be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims. [Explanation of symbols]

[0089] 1, 101 Charging and discharging equipment 2. Power generation equipment (power supply equipment) 3. Electrical load 4 Battery Modules 5 Connections 6. First switch 7. The second switch 8. Communication control device 9 Various Sensors 41 Storage Battery 42 BMU 81 Storage section 104 Battery Module Group

Claims

1. A power supply device capable of supplying electricity, Electrical load and A connection path selectively connected to either the power supply unit or the electrical load, The system comprises a group of battery modules connected to the aforementioned connection path, The aforementioned group of battery modules is A plurality of battery modules connected in parallel to each other with respect to the aforementioned connection path, A plurality of first switches are disposed between the battery module and the connection path, and are capable of switching between an ON state to connect them and an OFF state to disconnect them. A communication control device connected to the aforementioned connection path and controlling the switching of the plurality of first switches, It has, Each of the aforementioned battery modules is: Multiple storage batteries, It has a plurality of BMUs that manage the state of the storage battery and can communicate with the communication control device using a common identification signal, The communication control device is It has a storage unit that stores the voltage value or SOC of each of the storage batteries in association with each of the battery modules, When the connection path is connected to the power supply device, of all the first switches, only one of the first switches corresponding to the battery module is turned ON according to the voltage value or SOC stored in the memory unit. A charge / discharge device characterized in that, when the supply voltage from the power supply device is less than the operating voltage of the BMU and the communication control device, the communication control device in one of the plurality of battery module groups to which the one first switch that is turned ON belongs switches the one first switch and the other first switches to the OFF state and ON state, respectively, after the communication control device of the other battery module group switches one of the first switches belonging to it to the ON state.

2. The charging and discharging device according to claim 1, characterized in that the communication control device of the other battery module group switches the first switch, which was switched to the ON state, to the OFF state after the switching has been performed by the communication control device of the first battery module group.

3. The charge / discharge device according to claim 1 or 2, further comprising a second switch provided between the connection path and the power supply and the electrical load, for selectively connecting the connection path to either the power supply or the electrical load.

4. The charging and discharging device according to claim 1 or 2, characterized in that the power supply device is comprised of a power generation device that generates electricity using renewable energy.

5. The charge / discharge device according to claim 1 or 2, characterized in that the electrical load is configured by a device having a light-emitting element as a load.

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