Energy storage device control system and backup power supply system

Abstract

An electricity storage device control system comprising a plurality of electricity storage devices and a plurality of charging circuits. The plurality of electricity storage devices are charged by a main power supply. The plurality of charging circuits are connected between the main power supply and the plurality of electricity storage devices. A connection state of the plurality of electricity storage devices being charged is switched to a first connection state or a second connection state on the basis of a voltage difference between an input voltage Vin of the main power supply and a charging voltage based on the voltage of each of the plurality of electricity storage devices. The first connection state is a connection state in which the plurality of electricity storage devices are connected in series, and the second connection state is a connection state in which the plurality of electricity storage devices are connected in parallel to the main power supply.

Description

Technical Field

[0001] The present disclosure relates to a power storage device control system and a backup power supply system using the same, and more particularly, to a power storage device control system for controlling the charging of a plurality of power storage devices and a backup power supply system using this power storage device control system.

Background Art

[0002] The bank switching type capacitor power supply device described in Patent Document 1 switches the series-parallel connection of a plurality of capacitor banks based on the voltages of the plurality of capacitor banks. This bank switching type capacitor power supply device charges by connecting a plurality of capacitor banks in series, and then sequentially charges each of the plurality of capacitor banks individually. Then, after each of the plurality of capacitor banks is fully charged, this bank switching type capacitor power supply device connects the plurality of capacitor banks in parallel.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] An object of the present disclosure is to provide a power storage device control system and a backup power supply system capable of reducing energy loss during the charging of a plurality of power storage devices.

[0005] A control system for energy storage devices according to one aspect of the present disclosure comprises a plurality of energy storage devices and a plurality of charging circuits. The plurality of energy storage devices are charged by a main power supply. The plurality of charging circuits are connected between the main power supply and the plurality of energy storage devices. The connection state of the plurality of energy storage devices during charging is switched between a first connection state and a second connection state based on the voltage difference between the input voltage of the main power supply and the charging voltage based on the voltage of each of the plurality of energy storage devices. In the first connection state, the plurality of energy storage devices are connected in series, and in the second connection state, the plurality of energy storage devices are connected in parallel to the main power supply. The plurality of charging circuits are connected in parallel between the main power supply and the plurality of energy storage devices in the first connected state. The plurality of energy storage devices in the first connected state are charged by the current supplied from the plurality of charging circuits. A power storage device control system according to one aspect of the present disclosure comprises a plurality of power storage devices and a plurality of charging circuits. The plurality of power storage devices are charged by a main power supply. The plurality of charging circuits are connected between the main power supply and the plurality of power storage devices. The connection state of the plurality of power storage devices during charging is switched between a first connection state and a second connection state based on the voltage difference between the input voltage of the main power supply and the charging voltage based on the voltage of each of the plurality of power storage devices. In the first connection state, the plurality of power storage devices are connected in series, and in the second connection state, the plurality of power storage devices are connected in parallel to the main power supply. The connection state further includes a third connection state in which two or more power storage devices that are part of the plurality of power storage devices are connected in series. The connection state is switched in the order of the first connection state, the third connection state, and the second connection state.

[0006] A backup power supply system according to one aspect of the present disclosure comprises the energy storage device control system and the main power supply. According to this disclosure, it is possible to provide an energy storage device control system and a backup power supply system that can reduce energy loss during charging of multiple energy storage devices. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic circuit diagram showing the configuration of a first connection state of an energy storage device control system and a backup power supply system using the same, according to one embodiment of the present disclosure. [Figure 2] Figure 2 is a schematic circuit diagram showing the configuration of the energy storage device control system and the backup power supply system in the second connection state. [Figure 3] Figure 3 is a flowchart illustrating the charging operation of the energy storage device control system described above. [Figure 4] Figure 4 shows the voltage transitions of multiple energy storage devices in the same energy storage device control system. [Figure 5] Figure 5 is a schematic circuit diagram showing the configuration of the energy storage device control system of Modification 1 and the backup power supply system using it in the first connection state. [Figure 6] Figure 6 is a schematic circuit diagram showing the configuration of the energy storage device control system of Modification 1 and the backup power supply system using it in the third connection state. [Figure 7] Figure 7 is a schematic circuit diagram showing the configuration of the energy storage device control system of Modification 1 and the backup power supply system using it in the second connection state. [Figure 8] Figure 8 is a flowchart illustrating the charging operation of the energy storage device control system in Modification Example 1. [Figure 9] Figure 9 shows the voltage transitions of multiple energy storage devices in the energy storage device control system of Modified Example 2. [Modes for carrying out the invention]

[0008] A power storage device control system 1 and a backup power supply system 2 using the power storage device control system 1 according to the embodiments of this disclosure will be described in detail with reference to the drawings. The embodiments and modifications described below are merely examples of this disclosure, and this disclosure is not limited to these embodiments and modifications. Even outside of these embodiments and modifications, various modifications are possible depending on the design, etc., as long as they do not depart from the technical idea of ​​this disclosure.

[0009] (1) Overview First, an overview of the energy storage device control system 1 and backup power supply system 2 of this embodiment will be described with reference to Figures 1 and 2.

[0010] As shown in Figures 1 and 2, the energy storage device control system 1 is a control system that controls the charging of multiple energy storage devices 3. The energy storage device control system 1, together with the main power supply 4, constitutes the backup power supply system 2. In other words, the backup power supply system 2 comprises the energy storage device control system 1 and the main power supply 4. In this embodiment, the main power supply 4 is, for example, a DC power supply.

[0011] The energy storage device control system 1 and the backup power supply system 2 are installed in a mobile device such as an automobile and used as a backup power supply for a load 5 such as a brake system.

[0012] The energy storage device control system 1 comprises a plurality of (two in this embodiment) energy storage devices 3 and a plurality of (two in this embodiment) charging circuits 6.

[0013] As shown in Figures 1 and 2, the multiple (two) energy storage devices 3 are charged by the main power supply 4 that supplies power to the load 5. Furthermore, the multiple (two) energy storage devices 3 supply power to the load 5 in the event of a failure of the main power supply 4. In this embodiment, when supplying power to the load 5, the multiple (two) energy storage devices 3 are connected in series, and the combined voltage of the multiple (two) energy storage devices 3 is applied to the load 5. However, the voltage of each of the multiple (two) energy storage devices 3 may be applied to separate loads.

[0014] Multiple (two) charging circuits 6 are connected between the main power supply 4 and multiple (two) energy storage devices 3. In the charging circuit 6, heat is generated in proportion to the difference between the input and output voltages. The heat generated in the charging circuit 6 is the energy that is lost from the energy supplied from the main power supply 4 to the charging circuit 6 without being charged into the energy storage devices 3. Therefore, in this embodiment, in order to reduce energy loss, the connection state M0 of the multiple (two) energy storage devices 3 during charging is switched. This makes it possible to extend the charging period in which the difference between the input and output voltages of the charging circuit 6 is small compared to when charging with a single connection state M0, thereby reducing the amount of heat generated in the charging circuit 6 and reducing energy loss during charging.

[0015] In this embodiment, the connection state M0 during charging of a plurality (two) of power storage devices 3 is switched to the first connection state M1 or the second connection state M2 based on the voltage difference dV between the input voltage Vin of the main power supply 4 and the charging voltage Vout based on the voltage of each of the plurality (two) of power storage devices 3. Here, in the first connection state M1, as shown in FIG. 1, the plurality (two) of power storage devices 3 are connected in series, and in the second connection state M2, as shown in FIG. 2, the plurality (two) of power storage devices 3 are connected in parallel to the main power supply 4.

[0016] (2) Details Hereinafter, the power storage device control system 1 and the backup power supply system 2 according to this embodiment will be described in detail with reference to FIGS. 1 to 4.

[0017] (2.1) Overall configuration As shown in FIGS. 1 and 2, the power storage device control system 1 includes a plurality (two) of power storage devices 3 (first power storage device 31, second power storage device 32) and a plurality (two) of charging circuits 6 (first charging circuit 61, second charging circuit 62). Further, in this embodiment, the power storage device control system 1 further includes two voltage detection units 71 and 72, switches S1 to S4, a charging control unit 8, and a storage unit 9.

[0018] The backup power supply system 2 includes the power storage device control system 1 and a main power supply 4 that supplies power to the load 5. Further, in this embodiment, the backup power supply system 2 further includes switches S5 and S6. Note that a reverse current prevention unit for preventing the flow of current from the first power storage device 31 and the second power storage device 32 into the main power supply 4 is provided between the main power supply 4 and the load 5, and the reverse current prevention unit is, for example, a diode D1.

[0019] The first power storage device 31 and the second power storage device 32 are, for example, electric double layer capacitors. Note that the first power storage device 31 and the second power storage device 32 may be other components capable of storing electricity, such as lead-acid batteries or the like.

[0020] In this embodiment, switch S5 is connected between the load 5 and the positive terminal of the first energy storage device 31. When the main power supply 4 fails, switch S5 is turned on, and the first energy storage device 31 and the second energy storage device 32 supply power to the load 5. When power is supplied to the load 5, the first energy storage device 31 and the second energy storage device 32 are connected in series in a first connection state M1. Here, switch S5 is, for example, a semiconductor switch, and its on / off state is controlled by the drive control unit 10. The drive control unit 10 is connected to the main power supply 4 and receives a signal SigVin from the main power supply 4 indicating the input voltage Vin of the main power supply 4. As a result, the drive control unit 10 detects the input voltage Vin of the main power supply 4 and controls switch S5 to off when the main power supply 4 is not failing, and controls switch S5 to on when it detects a failure of the main power supply 4.

[0021] The first energy storage device 31 and the second energy storage device 32 are charged by the main power supply 4. In this embodiment, the switch S6 is connected between the main power supply 4 and the first charging circuit 61 and the second charging circuit 62. Here, the switch S6 is, for example, a semiconductor switch, and its on / off state is controlled by the drive control unit 10. When the drive control unit 10 controls the switch S6 to the ON position, an input voltage Vin is input from the main power supply 4 to the first charging circuit 61 and the second charging circuit 62. As a result, current is supplied from the first charging circuit 61 and the second charging circuit 62 to the first energy storage device 31 and the second energy storage device 32, and the first energy storage device 31 and the second energy storage device 32 are charged. In this embodiment, the drive control unit 10 is provided separately from the backup power supply system 2, but it may be included in the backup power supply system 2.

[0022] The first charging circuit 61 and the second charging circuit 62 are dropper circuits, which are dropper-type stabilization circuits. The first charging circuit 61 and the second charging circuit 62 may also include circuits other than dropper circuits, such as circuits composed only of resistors. In other words, the first charging circuit 61 and the second charging circuit 62 are two circuits that include dropper circuits. As shown in Figures 1 and 2, the first charging circuit 61 is provided between the main power supply 4 and the positive terminal of the first energy storage device 31, and supplies a current of a predetermined value or less to the first energy storage device 31. The second charging circuit 62 is provided between the main power supply 4 and the positive terminal of the second energy storage device 32, and supplies a current of a predetermined value or less to the second energy storage device 32. That is, the first charging circuit 61 and the second charging circuit 62 are provided in parallel with respect to the main power supply 4.

[0023] Voltage detection units 71 and 72 detect the voltages of the first energy storage device 31 and the second energy storage device 32, respectively. Voltage detection unit 71 is connected to the positive and negative terminals of the first energy storage device 31 and detects the voltage V1 of the first energy storage device 31. Voltage detection unit 72 is connected to the positive and negative terminals of the second energy storage device 32 and detects the voltage V2 of the second energy storage device 32. Voltage detection units 71 and 72 also output signals SigV1 and SigV2, representing the detected voltages V1 and V2 of the first energy storage device 31 and the second energy storage device 32, respectively, to the charge control unit 8, which will be described later.

[0024] Switches S1 to S4 are, for example, semiconductor switches, and their on / off state is controlled by the charge control unit 8, which will be described later. Switch S1 is provided between the output terminal of the second charging circuit 62 and the positive terminal of the second energy storage device 32. Switch S2 is provided between the negative terminal of the first energy storage device 31 and the positive terminal of the second energy storage device 32. Switch S3 is provided between the negative terminal of the first energy storage device 31 and the reference potential. Switch S3 is also provided in parallel with switches S2 and the second energy storage device 32, which are connected in series. In other words, the negative terminal of the second energy storage device 32 is connected to the reference voltage. Switch S4 is provided between the output terminal of the first charging circuit 61 and the output terminal of the second charging circuit 62. A reverse current prevention switch may also be provided between the output terminal of the first charging circuit 61 and the positive terminal of the first energy storage device 31. By controlling the reverse current prevention switch to the OFF position, it is possible to prevent reverse current flow from the first energy storage device 31 and the second energy storage device 32 to the first charging circuit 61 and the second charging circuit 62 when power is supplied from the first energy storage device 31 and the second energy storage device 32 to the load.

[0025] The charging control unit 8 is connected to the main power supply 4, and receives a signal SigVin from the main power supply 4, which indicates the input voltage Vin of the main power supply 4. The charging control unit 8 is also connected to voltage detection units 71 and 72, and receives signals SigV1 and SigV2 from the voltage detection units 71 and 72, respectively, which represent the voltages V1 and V2 of the first energy storage device 31 and the second energy storage device 32. Furthermore, the charging control unit 8 is connected to switches S1 to S4, and controls the on / off state of switches S1 to S4 based on the input voltage Vin, voltages V1 and V2, using control signals Sig1 to Sig4.

[0026] The charging control unit 8 primarily consists of a computer system including, for example, memory and a processor. That is, the functions of the charging control unit 8 are realized by the processor executing a program stored in the computer system's memory. The program may be pre-stored in memory, provided via telecommunication lines such as the Internet, or stored and provided on a non-temporary storage medium such as a memory card.

[0027] The memory unit 9 is connected to the charge control unit 8 and stores the set voltages and other information that the charge control unit 8 refers to when controlling the on / off state of switches S1 to S4 based on the input voltage Vin, voltages V1 and V2.

[0028] The memory unit 9 includes rewritable non-volatile memory such as EEPROM (Electrically Erasable Programmable Read-Only Memory) and flash memory. Note that the set voltage and other settings may be stored in the charge control unit 8, and the memory unit 9 is not an essential component of the energy storage device control system 1 and can be omitted as appropriate.

[0029] (2.2) Charging operation The charging operation of the first energy storage device 31 and the second energy storage device 32 by the energy storage device control system 1 of this embodiment will be described in detail with reference to Figures 1 to 4.

[0030] (2.2.1) Charging operation in the first connection state As shown in Figure 1, the first charging circuit 61 and the second charging circuit 62 start charging the first energy storage device 31 and the second energy storage device 32 in a first connection state M1 in which the first energy storage device 31 and the second energy storage device 32 are connected in series (Figure 3ST1).

[0031] Specifically, the charge control unit 8 controls switches S1 and S3 to be off and switches S2 and S4 to be on, so that the first energy storage device 31 and the second energy storage device 32 enter the first connection state M1. Then, when the drive control unit 10 turns on switch S6, the first charging circuit 61 and the second charging circuit 62 start charging the first energy storage device 31 and the second energy storage device 32 in the first connection state M1.

[0032] In the first connection state M1, as shown in Figure 1, the first charging circuit 61 and the second charging circuit 62 are connected in parallel between the main power supply 4 and the first and second energy storage devices 31 and 32, which are connected in series. In other words, the input terminals of the first charging circuit 61 and the second charging circuit 62 are connected to the main power supply 4, and the output terminals of the first charging circuit 61 and the second charging circuit 62 are connected to the positive terminal of the first energy storage device 31. Then, in the first connection state M1, the first and second energy storage devices 31 and 32 are charged by the current supplied from the first and second charging circuits 62. Here, if the voltage difference dV between the input voltage Vin and the charging voltage Vout(V1+V2), which is the combined voltage of voltages V1 and V2, is greater than the first set value E1 (Figure 3ST2:NO), the first and second charging circuits 61 and 62 continue charging in the first connection state M1.

[0033] (2.2.2) Charging operation in the second connection state As shown in Figure 4, when charging progresses in the first connection state M1 and the voltage difference dV between the input voltage Vin and the charging voltage Vout(V1+V2), which is the combined voltage of voltages V1 and V2, falls below the first set value E1 (Figure 3ST2:YES), the first charging circuit 61 and the second charging circuit 62 perform charging in the second connection state M2 (Figure 3ST3).

[0034] In this embodiment, for example, when E1 = 0.5V and Vin = 12V, when the charging voltage Vout becomes 11.5V or higher, the voltage difference dV becomes 0.5V or less, and the connection state M0 of the first energy storage device 31 and the second energy storage device 32 is switched from the first connection state M1 to the second connection state M2.

[0035] The switch from the first connection state M1 to the second connection state M2 is performed by the charge control unit 8. The charge control unit 8 derives the voltage difference dV between the input voltage Vin and the charging voltage Vout at predetermined intervals (for example, every 1 second), and when the voltage difference dV becomes 0.5V or less, it controls the on / off state of switches S1 to S4 to switch the first energy storage device 31 and the second energy storage device 32 to the second connection state M2. Specifically, as shown in Figure 2, the charge control unit 8 controls switches S1 and S3 to be on and switches S2 and S4 to be off, so that the first energy storage device 31 and the second energy storage device 32 enter the second connection state M2.

[0036] In this embodiment, the first charging circuit 61 and the second charging circuit 62 are provided corresponding to the first energy storage device 31 and the second energy storage device 32, respectively. In the second connection state M2, the first energy storage device 31 and the second energy storage device 32 are each charged by the current supplied from the corresponding first charging circuit 61 and the second charging circuit 62. As a result, in the second connection state M2, at least a portion of the charging periods of the first energy storage device 31 and the second energy storage device 32 overlap. In other words, in the second connection state M2, the first energy storage device 31 and the second energy storage device 32 can be charged simultaneously, and the charging time can be shortened compared to sequentially charging the first energy storage device 31 and the second energy storage device 32 using a single charging circuit.

[0037] The first charging circuit 61 and the second charging circuit 62 terminate charging of the first and second energy storage devices 31 and 32 when the voltage differences dV1 and dV2 between the input voltage Vin and the voltages V1 and V2 of the first and second energy storage devices 31 and 32, respectively, become less than or equal to the second setpoint E2 (Figure 3ST4:YES, ST6:YES) (Figure 3ST5, ST7). More specifically, the charging control unit 8 derives the voltage difference dV1 between the input voltage Vin and the voltage V1 of the first energy storage device 31, and the voltage difference dV2 between the input voltage Vin and the voltage V2 of the second energy storage device 32 at predetermined intervals (e.g., 1-second intervals). As shown in Figure 4, when the voltage differences dV1 and dV2 become less than or equal to the second setpoint E2, the charging control unit 8 controls the on / off state of switches S1 to S4 to terminate charging of the energy storage devices 31 and 32 by the first charging circuit 61 and the second charging circuit 62, respectively. In this embodiment, the second setting value E2 is set to different values ​​E21 and E22 corresponding to the energy storage devices 31 and 32, respectively. Alternatively, the second setting value E2 may be set to the same value for each energy storage device.

[0038] In this embodiment, for example, if the second setting value E21 corresponding to the first energy storage device 31 is E21=2V and Vin=12V, when the voltage V1 becomes 10V or higher, the voltage difference dV1 becomes 2V or less, and the first charging circuit 61 terminates charging of the first energy storage device 31. Specifically, the first charging circuit 61 stops supplying current to the first energy storage device 31 by controlling switch S3 to the OFF position by the charging control unit 8, thereby terminating the charging of the first energy storage device 31. Also, for example, if the second setting value E22 corresponding to the second energy storage device 32 is E22=4.5V, as shown in Figure 4, when the voltage V2 becomes 7.5V or higher, the voltage difference dV2 becomes 4.5V or less, and the second charging circuit 62 terminates charging of the second energy storage device 32. Specifically, the second charging circuit 62 terminates charging of the second energy storage device 32 by controlling switch S1 to the OFF position by the charging control unit 8.

[0039] (3) Variation 1 Hereinafter, a modified example 1 of the above embodiment, specifically the energy storage device control system 1, will be described with reference to Figures 5 to 8. However, components common to the energy storage device control system 1 of the above embodiment will be given the same reference numerals, and their descriptions will be omitted as appropriate. Furthermore, each configuration of the modified example 1 described below can be appropriately combined with each configuration described in the above embodiment.

[0040] The energy storage device control system 1 of the above embodiment includes a plurality (two) of energy storage devices 3 (a first energy storage device 31 and a second energy storage device 32), and can be switched between a first connection state M1 in which the first energy storage device 31 and the second energy storage device 32 are connected in series, or a second connection state M2 in which the first energy storage device 31 and the second energy storage device 32 are connected in parallel to the main power supply 4.

[0041] In this modified example 1, the energy storage device control system 1 includes a plurality (3) of energy storage devices 3 (a first energy storage device 31, a second energy storage device 32, and a third energy storage device 33). Furthermore, the connection state M0 during charging of the first to third energy storage devices 31 to 33 differs from the above embodiment in that it further includes a third connection state M3 in which the first energy storage device 31 and the second energy storage device 32, which are part of the first to third energy storage devices 31 to 33, are connected in series. In this modified example 1, the first connection state M1 is the connection state M0 in which the first to third energy storage devices 31 to 33 are connected in series, and the second connection state M2 is the connection state M0 in which the first to third energy storage devices 31 to 33 are connected in parallel to the main power supply 4.

[0042] In this modified example 1, the connection state M0 of the first energy storage device 31 to the third energy storage device 33 is switched in the order of first connection state M1, third connection state M3, and second connection state M2.

[0043] (3.1) Overall structure of modified example 1 As shown in Figures 5 to 7, the modified energy storage device control system 1 comprises a first energy storage device 31 to a third energy storage device 33, a first charging circuit 61, a second charging circuit 62, a third charging circuit 63, voltage detection units 71 to 73, switches S11 to S18, and a charging control unit 8.

[0044] The first charging circuits 61 to the third charging circuits 63 are connected in parallel to the main power supply 4.

[0045] Voltage detection units 71 to 73 detect the voltages V1 to V3 of the first energy storage device 31 to the third energy storage device 33, respectively. The voltage detection units 71 to 73 also transmit signals SigV1 to SigV3, representing the detected voltages V1 to V3, to the charging control unit 8.

[0046] Switches S11 to S18 are switches whose on / off state is controlled by the charge control unit 8. Here, switches S11 to S18 are, for example, semiconductor switches. Switch S11 is provided between the output terminal of the second charge circuit 62 and the positive terminal of the second energy storage device 32. Switch S12 is provided between the output terminal of the third charge circuit 63 and the positive terminal of the third energy storage device 33. Switch S13 is provided between the negative terminal of the first energy storage device 31 and the positive terminal of the second energy storage device 32. Switch S14 is provided between the negative terminal of the second energy storage device 32 and the positive terminal of the third energy storage device 33. Switch S15 is provided between the negative terminal of the first energy storage device 31 and the reference potential. Switch S15 is also provided in parallel with switches S13, the second energy storage device 32, switches S14 and the third energy storage device 33, which are connected in series. In other words, the negative terminal of the third energy storage device 33 is connected to a reference voltage. Switch S16 is provided between the negative terminal of the second energy storage device 32 and the reference potential. Switch S16 is also provided in parallel with the switch S14 and the third energy storage device 33, which are connected in series. Switch S17 is provided between the output terminal of the first charging circuit 61 and the output terminal of the second charging circuit 62. Switch S18 is provided between the output terminal of the second charging circuit 62 and the output terminal of the third charging circuit 63. A reverse current prevention switch may also be provided between the output terminal of the first charging circuit 61 and the positive terminal of the first energy storage device 31. By controlling the reverse current prevention switch to the OFF position, when power is supplied to the load by the first energy storage devices 31 to the third energy storage devices 33, reverse current flow from the first energy storage devices 31 to the third energy storage devices 33 to the first charging circuit 61 to the third charging circuit 63 can be prevented.

[0047] The charging control unit 8 is connected to the main power supply 4 and receives a signal SigVin from the main power supply 4 indicating the input voltage Vin of the main power supply 4. The charging control unit 8 is also connected to voltage detection units 71 to 73 and receives signals SigV1 to SigV3 from the voltage detection units 71 to 73, respectively, representing the voltages V1 to V3 of the first energy storage device 31 to the third energy storage device 33. Furthermore, the charging control unit 8 is connected to switches S11 to S18 and controls the on / off state of switches S11 to S18 based on the input voltage Vin and voltages V1 to V3 using control signals Sig11 to Sig18.

[0048] (3.2) Charging operation of modified example 1 The charging operation of the first energy storage device 31 to the third energy storage device 33 by the energy storage device control system 1 of this modified example 1 will be explained in detail with reference to Figures 5 to 8.

[0049] (3.2.1) Charging operation in the first connection state of the modified example 1 As shown in Figure 5, the first charging circuits 61 to the third charging circuits 63 start charging the first energy storage devices 31 to the third energy storage devices 33 in a first connection state M1 in which the first energy storage devices 31 to the third energy storage devices 33 are connected in series (Figure 8ST10).

[0050] Specifically, the charge control unit 8 controls switches S11, S12, S15, and S16 to be turned off, and switches S13, S14, S17, and S18 to be turned on, so that the first to third energy storage devices 31 to 33 enter the first connection state M1. Then, when the drive control unit 10 turns on switch S6, the first to third charging circuits 61 to 33 begin charging the first to third energy storage devices 31 to 33.

[0051] In the first connection state M1, as shown in Figure 5, the first charging circuits 61 to the third charging circuits 63 are connected in parallel between the series-connected first energy storage devices 31 to the third energy storage devices 33 and the main power supply 4. In other words, the input terminals of the first charging circuits 61 to the third charging circuits 63 are connected to the main power supply 4, and the output terminals of the first charging circuits 61 to the third charging circuits 63 are connected to the positive terminal of the first energy storage device 31. In the first connection state M1, the first energy storage devices 31 to the third energy storage devices 33 are charged by the current supplied from the first charging circuits 61 to the third charging circuits 63.

[0052] (3.2.2) Charging operation in the third connection state of the modified example 1 As charging progresses in the first connection state M1, when the voltage difference dVa between the input voltage Vin and the first charging voltage Vout1(V1+V2+V3), which is the combined voltage of voltages V1 to V3, falls below the first setpoint E1 (Figure 8ST11:YES), the first charging circuits 61 to the third charging circuits 63 perform charging in the third connection state M3 (Figure 8ST12). In this modified example 1, as shown in Figure 6, the third connection state M3 is a connection state M0 in which the first energy storage device 31 and the second energy storage device 32 are connected in series, and the third energy storage device 33 is connected in parallel with the first energy storage device 31 and the second energy storage device 32 which are connected in series. Also, in the third connection state M3, the first charging circuit 61 and the second charging circuit 62 are connected in parallel. In other words, the input terminals of the first charging circuit 61 and the second charging circuit 62 are connected to the main power supply 4, and the output terminals of the first charging circuit 61 and the second charging circuit 62 are connected to the positive terminals of the first energy storage device 31. As a result, the first energy storage device 31 and the second energy storage device 32, which are connected in series, are charged by the current supplied from the first charging circuit 61 and the second charging circuit 62, which are connected in parallel. In addition, the third energy storage device 33 is charged by the current supplied from the third charging circuit 63.

[0053] In this modified example 1, for example, if E1 = 0.5V and Vin = 12V, when the charging voltage Vout1 becomes 11.5V or higher, the voltage difference dVa becomes 0.5V or less, and the connection state M0 of the first energy storage device 31 to the third energy storage device 33 is switched from the first connection state M1 to the third connection state M3.

[0054] The switching from the first connection state M1 to the third connection state M3 is performed by the charging control unit 8. The charging control unit 8 derives the voltage difference dVa between the input voltage Vin and the charging voltage Vout1 at predetermined intervals (for example, every 1 second), and when the voltage difference dVa becomes 0.5V or less, it controls the on / off state of switches S11 to S18 to switch the first energy storage device 31 to the third energy storage device 33 to the third connection state M3. Specifically, as shown in Figure 6, the charging control unit 8 controls switches S12, S13, S16 and S17 to be on and switches S11, S14, S15 and S18 to be off, so that the first energy storage device 31 to the third energy storage device 33 enter the third connection state M3.

[0055] In the third connection state M3, the first energy storage device 31 and the second energy storage device 32, which are connected in series, are charged by the current supplied from the first charging circuit 61 and the second charging circuit 62, and the third energy storage device 33 is charged by the current supplied from the third charging circuit 63. In this modified example 1, the first energy storage device 31 and the second energy storage device 32 are connected in series in the third connection state M3, but the second energy storage device 32 and the third energy storage device 33 may be connected in series. In this case, the first energy storage device 31 is connected in parallel with the second energy storage device 32 and the third energy storage device 33, which are connected in series.

[0056] (3.2.3) Charging operation in the second connection state of the modified example 1 As charging progresses in the third connection state M3, when the voltage difference dVb between the input voltage Vin and the second charging voltage Vout2(V1+V2), which is the combined voltage of voltages V1 and V2, falls below the third set value E3 (Figure 8ST13:YES), the first charging circuit 61 to the third charging circuit 63 perform charging in the second connection state M2 (Figure 8ST14).

[0057] In this modified example 1, for example, if E3 = 0.5V and Vin = 12V, when the charging voltage Vout2 becomes 11.5V or higher, the voltage difference dVb becomes 0.5V or less, and the connection state M0 of the first energy storage device 31 to the third energy storage device 33 is switched from the third connection state M3 to the second connection state M2.

[0058] The switch from the third connection state M3 to the second connection state M2 is performed by the charge control unit 8. The charge control unit 8 derives the voltage difference dVb between the input voltage Vin and the charging voltage Vout2 at predetermined intervals (for example, every 1 second), and when the voltage difference dVb becomes 0.5V or less, it controls the on / off state of switches S11 to S18 to switch the first energy storage device 31 to the third energy storage device 33 to the second connection state M2. Specifically, as shown in Figure 7, the charge control unit 8 controls switches S11, S12, S15 and S16 to be on and switches S13, S14, S17 and S18 to be off, so that the first energy storage device 31 to the third energy storage device 33 enter the second connection state M2.

[0059] In this modified example 1, the first charging circuit 61 to the third charging circuit 63 are provided corresponding to the energy storage devices 31 to 33, and in the second connection state M2, each of the energy storage devices 31 to 33 is charged by the current supplied from the corresponding charging circuit 61 to 63.

[0060] The charging circuits 61 to 63 terminate charging of the first to third energy storage devices 31 to 33 when the voltage difference dV1 to dV3 between the input voltage Vin and the respective voltages V1 to V3 of the first to third energy storage devices 31 to 33 falls below the second setpoint E2 (Figure 8 ST15: YES, ST17: YES, ST19: YES) (Figure 8 ST16, ST18, ST20). More specifically, the charging control unit 8 derives the voltage difference dV1 to dV3 at predetermined intervals (e.g., 1-second intervals), and when the voltage difference dV1 to dV3 falls below the second setpoint E2, it controls the on / off state of switches S11 to S18 to terminate charging of the first to third energy storage devices 31 to 33 by the first to third charging circuits 61 to 33. In this modified example 1, the second setting value E2 is set to different values ​​E21 to E23 corresponding to the first energy storage device 31 to the third energy storage device 33, respectively. Alternatively, the second setting value E2 may be set to the same value for each energy storage device.

[0061] In this modified example 1, for example, if the second setting value E21 corresponding to the first energy storage device 31 is E21 = 7.2V and Vin = 12V, when the voltage V1 becomes 4.8V or higher, the voltage difference dV1 becomes 7.2V or lower, and the first charging circuit 61 terminates charging of the first energy storage device 31. Specifically, the first charging circuit 61 stops supplying current to the first energy storage device 31 by controlling the switch S15 to the OFF position by the charging control unit 8, thereby terminating the charging of the first energy storage device 31. Similarly, for example, if the second setting value E22 corresponding to the second energy storage device 32 is E22 = 4.8V, when the voltage V2 becomes 7.2V or higher, the voltage difference dV2 becomes 4.8V or lower, and the second charging circuit 62 terminates charging of the second energy storage device 32. Specifically, the second charging circuit 62 terminates charging of the second energy storage device 32 when the charging control unit 8 controls at least one of switches S11 and S16 to the OFF position. Also, for example, if the second set value E23 corresponding to the third energy storage device 33 is E23 = 2.4V, when the voltage V3 becomes 9.6V or higher, the voltage difference dV3 becomes 2.4V or lower, and the third charging circuit 63 terminates charging of the third energy storage device 33. Specifically, the third charging circuit 63 terminates charging of the third energy storage device 33 when the charging control unit 8 controls switch S12 to the OFF position. Note that if dV3 becomes 2.4V or lower when in the third connection state M3, the third charging circuit 63 terminates charging of the third energy storage device 33 while in the third connection state M3.

[0062] (4) Modification 2 Hereinafter, a modified example 2 of the above embodiment of the energy storage device control system 1 will be described with reference to Figure 9. However, components common to the energy storage device control system 1 of the above embodiment will be given the same reference numerals, and their descriptions will be omitted as appropriate. Furthermore, each configuration of the modified example 2 described below can be applied in appropriate combination with each configuration described in the above embodiment and modified example 1.

[0063] In the energy storage device control system 1 of the above embodiment, the switching between the first connection state M1 and the second connection state M2 is performed based on the voltage difference dV between the input voltage Vin of the main power supply 4 and the charging voltage Vout based on the voltages V1 and V2 of the multiple (two) energy storage devices 3 (first energy storage device 31, second energy storage device 32).

[0064] In this modified example 2, the switching between the first connection state M1 and the second connection state M2 is performed based on the voltage difference dV between the input voltage Vin and the charging voltage Vout, and the voltages V1 and V2 of the multiple (two) energy storage devices 3 (first energy storage device 31, second energy storage device 32), which differs from the above embodiment and modified example 1. This will be explained in detail below.

[0065] In this modified example 2, set voltages VL1 and VL2 are set corresponding to the voltages V1 and V2 of the first energy storage device 31 and the second energy storage device 32, respectively. Then, the connection state M0 is switched from the first connection state M1 to the second connection state M2 depending on whether the voltage difference dV between the input voltage Vin and the charging voltage Vout becomes less than or equal to the first set value E1, whether the voltage V1 becomes greater than or equal to the set voltage VL1, or whether the voltage V2 becomes greater than or equal to the set voltage VL2. For example, as shown in Figure 9, even if the voltage difference dV between the input voltage Vin and the charging voltage Vout(V1+V2) is greater than the first set value E1, the connection state M0 is switched from the first connection state M1 to the second connection state M2 when the voltage V2 reaches the set voltage VL2.

[0066] In other words, in this modified example 2, if the voltage difference dV is greater than the first set value E1, and voltages V1 and V2 are smaller than the set voltages VL1 and VL2, respectively, the first charging circuit 61 and the second charging circuit 62 continue charging in the first connection state M1.

[0067] Furthermore, when at least one of the following conditions is met, the voltage difference dV becomes less than or equal to the first set value E1, the voltage V1 becomes greater than the set voltage VL1, or the voltage V2 becomes greater than the set voltage VL2, the first charging circuit 61 and the second charging circuit 62 perform charging in the second connection state M2.

[0068] (5) Other variations The following are other modifications of the embodiment. These modifications may be implemented in appropriate combinations.

[0069] The energy storage device control system 1 in this disclosure includes a computer system. The computer system mainly consists of a processor and memory as hardware. The functions of the energy storage device control system 1 in this disclosure are realized by the processor executing a program recorded in the memory of the computer system. The program may be pre-recorded in the memory of the computer system, provided via a telecommunication line, or provided on a non-temporary recording medium such as a memory card, optical disk, or hard disk drive that can be read by the computer system. The processor of the computer system consists of one or more electronic circuits including semiconductor integrated circuits (ICs) or large-scale integrated circuits (LSIs). The integrated circuits such as ICs or LSIs referred to here are named differently depending on the degree of integration, and include integrated circuits called system LSIs, VLSIs (Very Large Scale Integration), or ULSIs (Ultra Large Scale Integration). Furthermore, FPGAs (Field-Programmable Gate Arrays) that are programmed after the manufacture of LSIs, or logic devices that allow for the reconfiguration of junction relationships or circuit compartments within LSIs, can also be used as processors. Multiple electronic circuits may be integrated onto a single chip or distributed across multiple chips. Multiple chips may be integrated onto a single device or distributed across multiple devices. The computer system referred to here includes a microcontroller having one or more processors and one or more memories. Therefore, the microcontroller also consists of one or more electronic circuits, including semiconductor integrated circuits or large-scale integrated circuits.

[0070] Furthermore, it is not essential for the energy storage device control system 1 to have multiple functions integrated into a single enclosure; the components of the energy storage device control system 1 may be distributed across multiple enclosures. Moreover, at least some of the functions of the energy storage device control system 1, for example, the functions of the charge control unit 8, may be implemented by the cloud (cloud computing), etc.

[0071] In the above embodiment, when comparing the voltage of the energy storage device 3 with a set value, etc., the term "less than or equal to" may be replaced with "less than". In other words, whether or not the case where the two values ​​are equal is included in the comparison of the two values ​​can be arbitrarily changed depending on the setting of the reference value, etc., so there is no technical difference between "less than or equal to" and "less than". Similarly, the term "greater than or equal to" may be replaced with "greater than".

[0072] (6) Summary As described above, the first embodiment of the energy storage device control system (1) comprises a plurality of energy storage devices (3) and a plurality of charging circuits (6). The plurality of energy storage devices (3) are charged by a main power supply (4). The plurality of charging circuits (6) are connected between the main power supply (4) and the plurality of energy storage devices (3). The connection state (M0) of the plurality of energy storage devices (3) during charging is switched between a first connection state (M1) or a second connection state (M2) based on the voltage difference between the input voltage (Vin) of the main power supply (4) and the charging voltage (Vout) based on the respective voltages of the plurality of energy storage devices (3). In the first connection state (M1), the plurality of energy storage devices (3) are connected in series, and in the second connection state (M2), the plurality of energy storage devices (3) are connected in parallel to the main power supply (4).

[0073] According to this embodiment, energy loss during charging of multiple energy storage devices (3) can be reduced.

[0074] In the second embodiment of the energy storage device control system (1), in the first embodiment, the connection state (M0) is switched between a first connection state (M1) or a second connection state (M2) based on the voltage difference between the input voltage (Vin) of the main power supply (4) and the charging voltage (Vout) based on the respective voltages of the multiple energy storage devices (3), and the respective voltages of the multiple energy storage devices (3).

[0075] According to this embodiment, energy loss during charging of multiple energy storage devices (3) can be reduced.

[0076] In the third embodiment of the energy storage device control system (1), in the first or second embodiment, a plurality of charging circuits (6) are connected in parallel between the main power supply (4) and a plurality of energy storage devices (3) in a first connection state (M1). The plurality of energy storage devices (3) in the first connection state (M1) are charged by the current supplied from the plurality of charging circuits (6).

[0077] According to this embodiment, the charging speed of multiple energy storage devices (3) can be increased compared to when charging with a single charging circuit (6).

[0078] In the fourth embodiment of the energy storage device control system (1), in the first or second embodiment, a plurality of charging circuits (6) are provided corresponding to a plurality of energy storage devices (3). Each of the plurality of energy storage devices (3) is charged by the current supplied from the corresponding charging circuit (6) in the second connection state (M2).

[0079] According to this embodiment, an appropriate current can be supplied to each of the multiple energy storage devices (3).

[0080] In the fifth embodiment of the energy storage device control system (1), in any one of the first to fourth embodiments, at least a portion of the charging periods of each of the multiple energy storage devices (3) overlap.

[0081] According to this embodiment, multiple energy storage devices (3) can be charged simultaneously, and the charging time can be shortened compared to charging each energy storage device (3) sequentially.

[0082] In the sixth embodiment of the energy storage device control system (1), in any one of the first to fifth embodiments, the multiple charging circuits (6) start charging the multiple energy storage devices (3) in a first connection state (M1). The multiple charging circuits (6) perform charging in a second connection state (M2) when the voltage difference between the input voltage (Vin) and the charging voltage (Vout), which is the combined voltage of the voltages of the multiple energy storage devices (3), falls below a first setpoint (E1). The multiple charging circuits (6) terminate charging when the voltage difference between the input voltage (Vin) and the voltage of each of the multiple energy storage devices (3) falls below a second setpoint (E2).

[0083] According to this embodiment, the charging of the multiple energy storage devices (3) can be controlled based on the input voltage (Vin) and the voltage of each of the multiple energy storage devices (3).

[0084] In the seventh embodiment of the energy storage device control system (1), in any one of the first to sixth embodiments, the connection state (M0) is set to a first connection state (M1) when power is supplied to the load (5), and power is supplied to the load (5) from multiple energy storage devices (3).

[0085] According to this embodiment, the combined voltage of the voltages of each of the multiple energy storage devices (3) can be applied to the load (5).

[0086] In the energy storage device control system (1) of the eighth embodiment, in any one of the first to seventh embodiments, the connection state (M0) further includes a third connection state (M3) in which two or more energy storage devices (3) that are part of a plurality of energy storage devices (3) are connected in series. The connection state (M0) is switched in the order of first connection state (M1), third connection state (M3), and second connection state (M2).

[0087] According to this embodiment, energy loss during charging of multiple energy storage devices (3) can be reduced.

[0088] In the ninth embodiment of the energy storage device control system (1), in the eighth embodiment, in the third connection state (M3), two or more charging circuits (6) that are part of a plurality of charging circuits (6) are connected in parallel. Two or more energy storage devices (3) are charged by the current supplied from two or more charging circuits (6). Energy storage devices (3) other than two or more of the plurality of energy storage devices (3) are charged by the current supplied from two or more of the charging circuits (6) other than the plurality of charging circuits (6).

[0089] According to this embodiment, the charging speed of two or more energy storage devices (3) can be increased compared to when charging with a single charging circuit (6).

[0090] In the tenth embodiment of the energy storage device control system (1), in any one of the first to ninth embodiments, the plurality of charging circuits (6) include dropper circuits.

[0091] According to this embodiment, the multiple charging circuits (6) can supply a current of a predetermined value or less.

[0092] The backup power supply system (2) of the 11th embodiment comprises a power storage device control system (1) of any one of the first to tenth embodiments and a main power supply (4).

[0093] According to this embodiment, energy loss during charging of multiple energy storage devices (3) can be reduced.

[0094] Furthermore, the second to tenth embodiments are not essential components of the energy storage device control system (1) and can be omitted as appropriate. [Explanation of Symbols]

[0095] 1. Energy Storage Device Control System 2. Backup power system 3. Energy storage devices 4 Main power 5 load 6 Charging circuit E1 First setting value E2 Second setting value M0 Connection Status M1 First connection state M2 Second Connection State M3 Third Connection State Vin Input Voltage Vout charging voltage

Claims

1. Multiple energy storage devices that are charged by the main power supply, The system comprises a plurality of charging circuits connected between the main power supply and the plurality of energy storage devices, The connection state of the plurality of energy storage devices during charging is switched between a first connection state and a second connection state based on the voltage difference between the input voltage of the main power supply and the charging voltage based on the voltage of each of the plurality of energy storage devices. In the first connection state, the plurality of energy storage devices are connected in series. In the second connection state, the plurality of energy storage devices are connected in parallel to the main power supply. The plurality of charging circuits are connected in parallel between the main power supply and the plurality of energy storage devices in the first connected state. The plurality of energy storage devices in the first connected state are charged by the current supplied from the plurality of charging circuits. Energy storage device control system.

2. Multiple energy storage devices that are charged by a main power supply, The system comprises a plurality of charging circuits connected between the main power supply and the plurality of energy storage devices, The connection state of the plurality of energy storage devices during charging is switched between a first connection state and a second connection state based on the voltage difference between the input voltage of the main power supply and the charging voltage based on the voltage of each of the plurality of energy storage devices. In the first connection state, the plurality of energy storage devices are connected in series. In the second connection state, the plurality of energy storage devices are connected in parallel to the main power supply. The aforementioned connection state further includes a third connection state in which two or more energy storage devices, which are part of the plurality of energy storage devices, are connected in series. The connection state is switched in the order of the first connection state, the third connection state, and the second connection state. Energy storage device control system.

3. The connection state is switched between the first connection state and the second connection state based on the voltage difference between the input voltage of the main power supply and the charging voltage based on the voltage of each of the plurality of energy storage devices, and the voltage of each of the plurality of energy storage devices. A power storage device control system according to claim 1 or 2.

4. The plurality of charging circuits are connected in parallel between the main power supply and the plurality of energy storage devices in the first connected state, The plurality of energy storage devices in the first connected state are charged by the current supplied from the plurality of charging circuits. The energy storage device control system according to claim 2.

5. The plurality of charging circuits are provided in correspondence with each of the plurality of energy storage devices, Each of the plurality of energy storage devices is charged by the current supplied from the corresponding charging circuit in the second connection state. A power storage device control system according to any one of claims 1 to 4.

6. In the second connection state, at least a portion of the charging periods of each of the plurality of energy storage devices overlap, A power storage device control system according to any one of claims 1 to 5.

7. The plurality of charging circuits start charging the plurality of energy storage devices in the first connection state, The plurality of charging circuits perform charging in the second connection state when the voltage difference between the input voltage and the charging voltage, which is the combined voltage of the voltages of the plurality of energy storage devices, falls below the first set value. The plurality of charging circuits terminate charging when the voltage difference between the input voltage and the voltage of each of the plurality of energy storage devices falls below a second set value. A power storage device control system according to any one of claims 1 to 6.

8. When supplying power to a load, the connection state is set to the first connection state, and power is supplied to the load from the plurality of energy storage devices. A power storage device control system according to any one of claims 1 to 7.

9. In the third connection state described above, Two or more charging circuits, which are part of the aforementioned plurality of charging circuits, are connected in parallel. The two or more energy storage devices are charged by the current supplied from the two or more charging circuits. Of the plurality of energy storage devices, the energy storage devices other than the two or more energy storage devices are charged by current supplied from the charging circuits other than the two or more charging circuits among the plurality of charging circuits. The energy storage device control system according to claim 2.

10. The aforementioned multiple charging circuits include a dropper circuit. A power storage device control system according to any one of claims 1 to 9.

11. A power storage device control system according to any one of claims 1 to 10, The main power supply and, Backup power supply system.

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