JP2014191861A - Back-up power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a back-up power supply device capable of reducing wasteful power consumption due to self-discharge or the like of a secondary battery.SOLUTION: A secondary battery supplies electric power to a load driven by electric power supplied from a main power source. As a stand-by power supply which supplies electric power to the load, a plurality of metal-air batteries in a standby state where an electrolyte is not injected are prepared. The electrolyte injected into the metal-air battery is stored in a storage tank while being shut off from the atmosphere. An injection mechanism injects the electrolyte stored in the storage tank into the metal-air batteries by receiving command from a control device.

Description

  The present invention relates to a backup power supply apparatus for when a main power supply is lost.

  A secondary battery such as a lead storage battery is used as a backup power source during a power failure. Patent Document 1 discloses a backup power source that supplies a receiver with a sum of electrical energy from at least two dry batteries when a commercial power source is not available.

JP 2007-189813 A

  When a secondary battery such as a lead storage battery is used as a backup power source, the secondary battery is maintained in a fully charged state during a period in which power is normally supplied from the commercial power source. When the secondary battery is maintained in a charged state, power is wasted due to self-discharge even during periods when the secondary battery is not used. Furthermore, when the fully charged state is maintained, the secondary battery deteriorates, so the battery must be periodically replaced.

  When using a dry cell as a backup power source, the remaining amount of the dry cell may decrease due to self-discharge or the like. When the remaining amount of the dry battery decreases, a situation may occur in which the initial target operation time cannot be obtained. In order to guarantee the operating time according to the standard, the batteries must be replaced periodically.

  The objective of this invention is providing the backup power supply device which can reduce the useless power consumption resulting from the self-discharge etc. of a secondary battery.

According to one aspect of the invention,
A secondary battery for supplying power to a load driven by power supplied from a main power source;
As a backup power source for supplying power to the load, a plurality of metal-air batteries that wait in a state where no electrolyte is injected, and
A storage tank for storing the electrolyte injected into the metal-air battery in a state of being cut off from the atmosphere;
A control device;
By receiving a command from the control device, a backup power supply device having an injection mechanism for injecting the electrolyte stored in the storage tank into the metal-air battery is provided.

In the standby state, since the electrolyte is not injected into the metal-air battery, deterioration of the metal-air battery and self-discharge can be reduced. Moreover, since not only the secondary battery but also a metal-air battery is provided as a backup power source, the capacity of the secondary battery can be reduced. When the capacity of the secondary battery is reduced, unnecessary power consumption due to self-discharge is suppressed, and the volume of the secondary battery is reduced and the weight is reduced. Metal-air batteries have higher energy density than secondary batteries such as lead-acid batteries, so compared to the case where the backup power supply device is composed only of secondary batteries,
The entire backup power supply device can also be reduced in volume and weight.

FIG. 1 is a block diagram of a power supply device according to the first embodiment. FIG. 2 is a cross-sectional view of a primary battery used in the power supply device according to the first embodiment. FIG. 3 is an equivalent circuit diagram of the power supply device according to the first embodiment. FIG. 4 is a graph illustrating a change in voltage during backup of the power supply device according to the first embodiment. FIG. 5 is a block diagram during backup of the power supply device according to the first embodiment. FIG. 6 is a block diagram during backup of the power supply device according to the first embodiment. FIG. 7 is a block diagram during backup of the power supply device according to the first embodiment. FIG. 8 is a block diagram during backup of the power supply device according to the first embodiment. FIG. 9 is a schematic diagram of one primary battery unit. FIG. 10A is a schematic diagram of a primary battery unit 30 used in the backup power supply device according to the second embodiment. FIG. 10B is a schematic view of a primary battery unit in a state where an electrolytic solution is injected into a metal-air battery. FIG. 11 is a schematic diagram of a primary battery unit used in the backup power supply device according to the third embodiment. FIG. 12 is a schematic diagram of a primary battery unit used in the backup power supply device according to the fourth embodiment. FIG. 13 is a graph showing changes in internal impedance of two metal-air batteries among the plurality of metal-air batteries used in the backup power supply device according to Example 4, and changes in the open / close state of the on-off valves corresponding to the metal-air batteries. is there. FIG. 14 is a schematic diagram of a primary battery unit used in the backup power supply device according to the fifth embodiment. FIG. 15 is a graph showing changes in the weight of two metal-air batteries among the plurality of metal-air batteries used in the backup power supply device according to Example 5 and changes in the open / close state of the on-off valves corresponding to the metal-air batteries. . FIG. 16 is a schematic diagram of a primary battery unit used in the backup power supply device according to the sixth embodiment. FIG. 17 shows the change over time in the integral value of the flow rate of the electrolyte injected into two metal-air batteries among the plurality of metal-air batteries used in the backup power supply device according to Example 6, and the on-off valve corresponding to the metal-air batteries. It is a graph which shows the change of the opening-and-closing state of. FIG. 18 is a schematic diagram of a primary battery unit used in the backup power supply device according to the seventh embodiment. 19A to 19C are cross-sectional views of a sub tank used in the backup power supply device according to the seventh embodiment. 19D to 19G are cross-sectional views of a sub tank used in the backup power supply device according to the seventh embodiment. FIG. 20 is a schematic diagram of a primary battery unit used in the backup power supply device according to the eighth embodiment. 21A and 21B are cross-sectional views of a sub tank used in the backup power supply device according to the eighth embodiment. 21C and 21D are cross-sectional views of the sub tank used in the backup power supply device according to the eighth embodiment. FIG. 22 is a schematic diagram of a primary battery unit used in the backup power supply device according to the eighth embodiment. FIG. 23 is a schematic diagram of the primary battery unit when the electrolyte solution is filled in the sub tank in the backup power supply device according to the eighth embodiment. FIG. 24 is a schematic diagram of the primary battery unit when the electrolyte solution is filled in the sub tank in the backup power supply device according to the eighth embodiment. FIG. 25 is a schematic diagram of the primary battery unit in a state where the electrolyte is full in the sub tank in the backup power supply device according to the eighth embodiment. FIG. 26 is a schematic diagram of a primary battery unit when an electrolytic solution is injected from a sub tank into a metal-air battery in the backup power supply device according to the eighth embodiment.

[Example 1]
FIG. 1 is a block diagram of a backup power supply device according to the first embodiment. AC power is supplied to the input terminal 10 from a commercial power source 12 (main power source). An electrical load 13 is connected to the output terminal 11. The electric load 13 is, for example, a transceiver of a radio base station of a mobile communication network. The AC-DC converter 20 converts AC power input to the input terminal 10 into DC power. The DC power is output to the output terminal 11 via the power transport circuit 21 and is supplied to the secondary battery 25 via the power transport circuit 21 and the switching element 26. Thereby, the secondary battery 25 is always maintained in a fully charged state. As the secondary battery 25, for example, a lead storage battery, a lithium ion secondary battery, a lithium ion capacitor, or the like is used.

  A plurality of primary battery units 30 are connected to the power transport circuit 21 via switching elements 31, respectively. Each of the primary battery units 30 includes a plurality of metal-air batteries 50 and a storage tank 55 connected in series or in parallel. The storage tank 55 stores an electrolytic solution used in the metal-air battery 50. For example, a zinc-air battery is used as the metal-air battery. Instead of the zinc-air battery, an aluminum air battery, a magnesium air battery, or the like may be used.

  The metal-air battery 50 included in each primary battery unit 30 includes a positive electrode current collector, a negative electrode current collector, and a negative electrode active material. During standby, the electrolytic solution is stored in the storage tank 55, the electrolytic solution is not injected into the metal-air battery 50, and the electrolytic solution is separated from the negative electrode active material. The state where the electrolytic solution is separated from the negative electrode active material is referred to as “standby state”. The primary battery unit 30 stands by as a standby power supply for supplying power to the electric load 13. When the electrolyte is injected into the metal-air battery and brought into contact with the negative electrode active material, an electromotive force is generated. A state in which an electromotive force is generated when the electrolytic solution is in contact with the negative electrode active material is referred to as an “operating state”.

  The measured value of the voltage applied to the input terminal 10, the voltage between the terminals of the secondary battery 25, and the voltage between the terminals of each of the plurality of primary battery units 30 is input to the control device 40. The control device 40 performs on / off control of the switching elements 26 and 31 and switching control of the primary battery unit 30 from the standby state to the operating state based on the input measurement value of the voltage.

  FIG. 2 shows a cross-sectional view of the metal-air battery 50 included in the primary battery unit 30 (FIG. 1) according to the first embodiment. A bag-shaped separator 36 is filled with a negative electrode current collector 33 and a negative electrode active material 34. For the negative electrode active material 34, for example, metal zinc particles are used. When an aluminum air battery or a magnesium air battery is used as the metal air battery 50, metal aluminum particles or metal magnesium particles are used as the negative electrode active material 34, respectively. For the negative electrode current collector 33, for example, a metal plate such as nickel is used. For the separator 36, for example, a porous film such as polyethylene or polypropylene, a resin nonwoven fabric, a glass fiber nonwoven fabric or the like is used.

A positive electrode current collector 32 is attached to the outer surface of the separator 36. Positive electrode current collector 32
Has a structure in which a conductive material such as carbon black is applied to a base such as carbon cloth or carbon paper. The conductive material includes a catalyst and a binder. For example, manganese dioxide is used as the catalyst. As the binder, for example, polyvinylidene fluoride is used. The positive electrode current collector 32 has a large number of fine holes that allow oxygen to pass therethrough. Oxygen in the atmosphere acts as a positive electrode active material. The negative electrode current collector 33 and the positive electrode current collector 32 are connected to the output terminal 37 of the metal-air battery 50.

  The electrolytic solution is injected into the space in the separator 36 from the electrolytic solution inlet 51 provided in the separator 36. For example, a potassium hydroxide (KOH) aqueous solution is used as the electrolytic solution. When the electrolytic solution is injected into the separator 36, a voltage is generated between the output terminals 37.

  FIG. 3 shows an equivalent circuit diagram of the backup power supply device according to the first embodiment. A voltmeter 24 measures the voltage of the commercial power supply 12 (FIG. 1) applied to the input terminal 10. The measurement result of the voltmeter 24 is input to the control device 40. The control device 40 monitors the measured value of the voltmeter 24 (the voltage of the commercial power supply 12 applied to the input terminal 10). The control device 40 compares the measured value of the voltmeter 24 with the specified voltage value, and when the measured value of the voltmeter 24 falls below the specified voltage value, normal power supply from the commercial power supply 12 (FIG. 1) is stopped. Is determined.

  The power transport circuit 21 includes a bus line 22 and a diode 23. The output DC voltage of the AC-DC converter 20 is applied to the bus line 22. The input / output terminal of the secondary battery 25 is connected to the bus line 22 via the switching element 26. The voltmeter 27 measures the voltage between the terminals of the secondary battery 25. The measurement result of the voltmeter 27 is input to the control device 40. Unless there are special circumstances, the switching element 26 is always turned on. For this reason, the voltage measured by the voltmeter 27 is equal to the voltage appearing on the bus line 22.

  The primary battery unit 30 is connected to the bus line 22 via the switching element 31. The diode 23 is disposed for each primary battery unit 30 and is connected in series with the primary battery unit 30. The diode 23 is connected so that the direction of the discharge current from the primary battery unit 30 is the forward direction. For this reason, inflow of the charging current to the primary battery unit 30 is prohibited. Note that when the potential of the positive electrode of the primary battery unit 30 becomes lower than the potential of the bus line 22, the switching element 31 may be turned off to perform control for preventing the charging current from flowing. When this control is performed, the diode 23 may be omitted.

  A plurality of voltmeters 38 each measure a voltage between terminals of the primary battery unit 30. The measurement result is input to the control device 40. The switch 30A described in the broken line indicating the primary battery unit 30 means that the primary battery unit 30 has two states, a standby state and an operation state. The off state and on state of the switch 30A correspond to the standby state and the operating state, respectively.

  The secondary battery 25 outputs a necessary voltage by connecting in series the number of lead storage batteries corresponding to the voltage required by the electric load 13. The primary battery unit 30 includes a plurality of metal-air batteries connected in series so that the open circuit voltage is slightly higher than the open circuit voltage of the secondary battery 25.

The operation of the backup power supply apparatus according to the first embodiment will be described with reference to FIGS.
FIG. 4 shows an example of the time change of the voltage of the bus line 22 (FIG. 3) and the voltage between the terminals of the primary battery unit 30 (FIG. 1). 4, the upper solid line v1 indicates the voltage of the bus line 22 (FIG. 3), the middle solid line v2 indicates the voltage between the terminals of the primary battery unit 30 (FIG. 1) that operates first, and the lower solid line v3 indicates The inter-terminal voltage of the primary battery unit 30 (FIG. 1) that operates second is shown. Since the switching element 26 (FIG. 3) is always on, the voltage v1 of the bus line 22 can be measured by the voltmeter 27 (FIG. 3).

  It is assumed that the supply of power from the commercial power supply 12 (FIG. 1) is stopped at time t0. When the measured value of the voltmeter 24 (FIG. 3) is equal to or less than the specified voltage value, the control device 40 detects the stop of the power supply from the commercial power supply 12. At time t0, as shown in FIG. 5, discharging from the secondary battery 25 is started, and power is supplied to the electrical load 13 via the power transport circuit 21. As the secondary battery 25 is discharged, the inter-terminal voltage v1 of the secondary battery 25 decreases with time as shown in FIG.

  At time t1 shown in FIG. 4, the voltage v1 of the bus line 22 (FIG. 3) drops to the voltage threshold Va. When the control device 40 (FIG. 1) detects that the voltage v1 has decreased to the voltage threshold Va, the control device 40 electrolyzes each metal-air battery 50 (FIG. 2) of the primary battery unit 30 to be operated first. Inject liquid. When the electrolytic solution is injected into the primary battery unit 30, the inter-terminal voltage v2 of the primary battery unit 30 starts to rise. When the discharge current of the secondary battery 25 is within the rated value range, the voltage between the terminals of the secondary battery 25 corresponds to the state of charge (SOC) of the secondary battery 25, so the voltage of the bus line 22 (FIG. 3). Monitoring v1 is substantially equivalent to monitoring the SOC of the secondary battery 25.

  At time t2, the inter-terminal voltage v2 of the primary battery unit 30 into which the electrolytic solution has been injected reaches the rated open circuit voltage Vb. When the control device 40 (FIG. 1) detects that the inter-terminal voltage v2 has reached the rated open circuit voltage Vb (that is, the primary battery unit 30 has changed from the standby state to the operating state), the primary into which the electrolyte has been injected. The switching element 31 (FIGS. 1 and 3) connected to the battery unit 30 is turned on. A discharge current starts to flow from the primary battery unit 30, and the voltage v1 of the bus line 22 (FIG. 3) increases. Since the voltage drop ΔVb caused by the internal resistance of the primary battery unit 30 occurs, the voltage v1 after the rise of the bus line 22 (FIG. 3) becomes Vb−ΔVb.

  As shown in FIG. 6, electric power is supplied from the primary battery unit 30 in the operating state to the electric load 13. When the voltage v1 of the bus line 22 (FIG. 3) is higher than the open circuit voltage between the terminals of the secondary battery 25, that is, the positive electrode potential of the bus line 22 (FIG. 3) is higher than the positive electrode potential of the secondary battery 25. When it is high, the secondary battery 25 is charged by the discharge power from the primary battery unit 30 in the operating state. When the power consumption of the electric load 13 increases, the discharge current of the primary battery unit 30 increases. Thereby, the voltage drop resulting from the internal resistance of the primary battery unit 30 increases, and the voltage v1 of the bus line 22 decreases. When the voltage v1 of the bus line 22 (FIG. 3) becomes lower than the open circuit voltage between the terminals of the secondary battery 25, the secondary battery 25 is discharged as shown in FIG. For this reason, electric power is supplied to the electric load 13 from both the primary battery unit 30 and the secondary battery 25. The secondary battery 25 is charged / discharged according to the power consumption of the electric load 13, and as a whole, the voltage v1 of the bus line 22 decreases with time. The charging and discharging of the secondary battery 25 are also switched by an instantaneous change in power consumption due to the electric load 13.

When the voltage v1 of the bus line 22 decreases to the voltage threshold Va at time t3 in FIG. 4, the control device 40 (FIG. 1) starts injecting electrolyte into the primary battery unit 30 to be operated second. As a result, the inter-terminal voltage v3 of the primary battery unit 30 that operates second increases. When the inter-terminal voltage v3 reaches the rated open circuit voltage Vb, the control device 40 (FIG. 1) turns on the switching element 31 (FIGS. 1 and 3) connected to the primary battery unit 30 to be operated second. Then, the switching element 31 (FIG. 1) connected to the primary battery unit 30 operated first is turned off. Since the discharge current from the primary battery unit 30 operated first does not flow, the inter-terminal voltage v2 of the primary battery unit 30 maintains a substantially constant value.

  As shown in FIG. 8, after time t4, the primary battery unit 30 in the second operating state is discharged. The secondary battery 25 is charged and discharged according to the power consumption of the electric load 13. Also after time t4, whenever the voltage v1 of the bus line 22 (FIG. 3) falls to the voltage threshold Va, injection of the electrolyte into the primary battery unit 30 to be operated next is started. Thereby, electric power can be continuously supplied to the electric load 13.

  FIG. 9 shows a schematic diagram of one primary battery unit 30. The primary battery unit 30 includes a plurality of metal-air batteries 50, a storage tank 55, and an injection mechanism 60. An open valve 56 is attached to the upper part of the storage tank 55. With the open valve 56 closed, the storage tank 55 stores the electrolyte 70 injected into the metal-air battery 50 in a state where it is cut off from the atmosphere. The injection mechanism 60 injects the electrolytic solution 70 stored in the storage tank 55 into the metal-air battery 50 by receiving a command from the control device 40. During the period in which the electrolytic solution 70 is injected into the metal-air battery 50, the control device 40 keeps the release valve 56 open.

  The injection mechanism 60 includes a flow path 62 that connects each of the metal-air batteries 50 and the storage tank 55, and an on-off valve 61 that is inserted into the flow path 62. The control device 40 controls the opening / closing operation of the opening / closing valve 61. When the on-off valve 61 is opened, the electrolytic solution 70 in the storage tank 55 falls due to gravity and is injected into the metal-air battery 50.

  The storage tank 55 includes a plurality of storage chambers 57 prepared for the metal-air battery 50. The plurality of storage chambers 57 are separated from each other by a partition wall 58. In the upper part of the internal space of the storage tank 55, the storage chambers 57 are connected. In each of the storage chambers 57, the volume of electrolyte 70 to be injected into the corresponding metal-air battery 50 (the volume to be targeted) is stored. The electrolytic solution 70 stored in the storage chamber 57 is injected into the corresponding metal-air battery 50.

  When the storage tank 55 is not partitioned into the plurality of storage chambers 57, the flow rate of the electrolyte injected into the metal air battery 50 is not necessarily the same for each metal air battery 50. When the flow rate varies, the volume injected into the metal-air battery 50 varies. There is a concern that the electrolyte 70 overflows from the metal-air battery 50 into which the electrolyte is injected at a relatively large flow rate.

  In the first embodiment, since the volume of the electrolyte 70 to be injected into the corresponding metal-air battery 50 is stored in the storage chamber 57 prepared corresponding to the metal-air battery 50, The electrolyte 70 having a volume to be injected can be injected.

  In the method in which the electrolyte is dissolved in the solvent immediately before the electrolytic solution is injected into the metal-air battery 50, the temperature of the electrolytic solution may increase before being injected into the metal-air battery 50 due to the generation of heat of dissolution. . In Example 1, an electrolyte is previously dissolved in a solvent and prepared as an electrolytic solution. For this reason, it is possible to inject the electrolytic solution at substantially room temperature into the metal-air battery 50. Since the electrolytic solution 70 is stored in the storage tank 55 in a state of being cut off from the atmosphere, the deterioration of the electrolytic solution can be suppressed.

  In Example 1, the negative electrode active material 34 (FIG. 2) and the electrolytic solution are not in contact with each other during the period when the primary battery unit 30 (FIG. 1) is in the standby state. For this reason, self-discharge and deterioration of a battery can be prevented. During the period (time t0 to t2 in FIG. 4) from when the electrolytic solution is injected into the primary battery unit 30 to generate the rated open circuit voltage Vb (FIG. 4), power is supplied to the electrical load 13 by the secondary battery 25. . For this reason, the continuity of power supply is guaranteed.

  The capacity of the secondary battery 25 may be set to such an extent that power can be supplied to the electric load 13 until the primary battery unit 30 starts operating. For this reason, the capacity | capacitance of the secondary battery 25 can be made small compared with the case where it backs up only with the secondary battery 25. FIG. When the capacity of the secondary battery 25 is reduced, power loss due to self-discharge can be reduced.

[Example 2]
FIG. 10A is a schematic diagram of a primary battery unit 30 used in the backup power supply device according to the second embodiment. Hereinafter, differences from the first embodiment will be described, and description of the same configuration will be omitted.

  In the second embodiment, the injection mechanism 60 includes a flow path 62, an elevating mechanism 63, and a stop cock 64. The stop cock 64 is disposed for each storage chamber 57 and can close the opening formed on the bottom surface of the storage chamber 57. The upper end of the flow path 62 is connected to this opening. The elevating mechanism 63 raises and lowers the storage tank 55 with respect to the stop cock 64. For example, the stop cock 64 is fixed to the metal-air battery 50. When the storage tank 55 is moved up and down, the length of the flow path 62 varies according to the amount of movement of the storage tank 55.

  The control device 40 controls the lifting mechanism 63. When the primary battery unit 30 is in the standby state, the stop cock 64 blocks the opening provided in the bottom surface of the storage chamber 57. For this reason, the electrolyte solution 70 in the storage tank 55 maintains the state stored in the storage tank 55.

  FIG. 10B shows a schematic diagram of the primary battery unit 30 in a state where the electrolytic solution 70 is injected into the metal-air battery 50. The control device 40 controls the elevating mechanism 63 to lower the storage tank 55 with respect to the stop cock 64 and open the release valve 56. When the storage tank 55 is lowered, the stop cock 64 is separated from the bottom surface of the storage chamber 57, and the electrolytic solution 70 is injected into the metal-air battery 50 through the opening provided in the bottom surface of the storage chamber 57 and the flow path 62. Is done.

  Also in the second embodiment, as in the first embodiment, the volume of the electrolytic solution 70 to be injected can be injected into each metal-air battery 50.

[Example 3]
FIG. 11 shows a schematic diagram of the primary battery unit 30 used in the backup power supply device according to the third embodiment. Hereinafter, differences from the first embodiment will be described, and description of the same configuration will be omitted.

  In the third embodiment, the injection mechanism 60 includes one open / close valve 75 and a flow path 62 prepared for each metal-air battery 50. A plurality of flow paths 62 are connected to one on-off valve 75. The opening / closing operation of the opening / closing valve 75 is controlled by the control device 40. The storage tank 55 stores an electrolytic solution 70 having a volume corresponding to the total volume to be injected into the plurality of metal-air batteries 50.

  When the on-off valve 75 is opened, the electrolytic solution 70 in the storage tank 55 is branched into a plurality of flow paths 62 and injected into the metal-air battery 50. The shape and dimensions of the flow paths 62 are set so that the flow rates of the electrolytes 70 flowing through the flow paths 62 are equal. For example, the channel cross section of the relatively long channel 62 is thicker than the channel cross section of the relatively short channel 62. Since the flow rate of the electrolytic solution 70 flowing through each flow path 62 becomes equal, the volume of the electrolytic solution 70 injected into each metal-air battery 50 becomes substantially equal.

  Also in the third embodiment, as in the first embodiment, the volume of electrolyte solution 70 to be injected can be injected into each metal-air battery 50.

[Example 4]
FIG. 12 shows a schematic diagram of the primary battery unit 30 used in the backup power supply device according to the fourth embodiment. Hereinafter, differences from the first embodiment will be described, and description of the same configuration will be omitted.

  One flow path led out from the storage tank 55 is branched into a plurality of flow paths 62. The plurality of flow paths 62 are prepared corresponding to the metal-air battery 50. An opening / closing valve 77 is inserted into each of the flow paths 62. A plurality of internal impedance measuring devices 78 are respectively connected to the output terminal 37 of the metal-air battery 50. The internal impedance measuring device 78 measures the internal impedance of the metal-air battery 50. The measurement result of the internal impedance is input to the control device 40. The on-off valve 77, the flow path 62, and the internal impedance measuring device 78 constitute an injection mechanism 60.

  With reference to FIG. 13, the process of the control apparatus 40 when inject | pouring electrolyte solution into the metal air battery 50 of the backup power supply device by Example 4 is demonstrated. FIG. 13 shows time-dependent changes in internal impedances ZA and ZB of two metal air batteries 50A and 50B (FIG. 12) among a plurality of metal air batteries 50, and on-off valves 77A and 77B corresponding to the metal air batteries 50A and 50B (FIG. The graph of the change of the open / close state of 12) is shown.

  At time t11, the control device 40 opens all the on-off valves 77. The time t11 corresponds to the electrolyte injection start time such as the times t1 and t3 shown in FIG. When the injection of the electrolytic solution into the metal-air battery 50 is started, the internal impedance of the metal-air battery 50 gradually decreases. The internal impedance depends on the volume of the electrolyte injected into the metal-air battery 50. When a predetermined amount of electrolyte is injected, the internal impedance drops to a specified value. The internal impedances ZA and ZB of the metal-air batteries 50A and 50B decrease to the specified value Zt at times t12 and t13, respectively.

  Since the metal-air battery 50 varies in the flow rate of electrolyte injection, the time t12 and the time t13 do not necessarily match. When the control device 40 detects that the internal impedance ZA of the metal-air battery 50A has decreased to the specified value Zt at time t12, the control device 40 closes the on-off valve 77A. Similarly, at time t13, the on-off valve 77B is closed.

  In the fourth embodiment, in order to control the injection amount of the electrolyte based on the internal impedance of the metal-air battery 50, a predetermined amount (volume to be injected) of the electrolyte is applied to each of the metal-air batteries 50. Can be injected.

[Example 5]
In FIG. 14, the schematic of the primary battery unit 30 used for the backup power supply device by Example 5 is shown. Hereinafter, differences from the fourth embodiment will be described, and description of the same configuration will be omitted. In the fifth embodiment, a weight scale 80 is prepared in place of the internal impedance measuring device 78 (FIG. 12) of the fourth embodiment. The weigh scale 80 is prepared for the metal-air battery 50 and measures the weight of the corresponding metal-air battery 50. A flexible tube or the like is used as the flow path 62 so that the weight of the parts upstream from the flow path 62 does not affect the measurement result obtained by the weighing scale 80. A measurement result by the weight scale 80 is input to the control device 40.

With reference to FIG. 15, the process of the control apparatus 40 when inject | pouring electrolyte solution into the metal air battery 50 of the backup power supply device by Example 5 is demonstrated. FIG. 15 shows the time changes of the weights WA and WB of two metal air batteries 50A and 50B (FIG. 14) among the plurality of metal air batteries 50, and on-off valves 77A and 77B (FIG. 14) corresponding to the metal air batteries 50A and 50B. ) Shows a graph of changes in the open / close state.

  At time t21, the control device 40 opens all the on-off valves 77. The time t21 corresponds to the electrolyte injection start time such as the times t1 and t3 shown in FIG. When the injection of the electrolytic solution into the metal-air battery 50 is started, the weight of the metal-air battery 50 gradually increases. The weight of the metal-air battery depends on the volume of the injected electrolyte. When a predetermined amount of electrolyte is injected, the weight of the metal-air battery 50 rises to a specified value. The weights WA and WB of the metal-air batteries 50A and 50B reach the specified value Wt at times t22 and t23, respectively.

  Since the flow rate of the electrolyte injection varies depending on the metal-air battery 50, the time t22 and the time t23 do not necessarily match. When detecting that the weight of the metal-air battery 50A has increased to the specified value Wt at time t22, the control device 40 closes the on-off valve 77A. Similarly, at time t23, the on-off valve 77B is closed.

  In Example 5, in order to stop the injection of the electrolyte when the weight of the metal-air battery 50 reaches the specified value, a predetermined amount of the electrolyte is injected into each of the metal-air batteries 50. Can do.

[Example 6]
FIG. 16 is a schematic diagram of a primary battery unit 30 used in the backup power supply device according to the sixth embodiment. Hereinafter, differences from the fourth embodiment will be described, and description of the same configuration will be omitted. In the sixth embodiment, a flow meter 83 is prepared in place of the internal impedance measuring device 78 (FIG. 12) of the fourth embodiment. The flow meter 83 is prepared for the metal-air battery 50 and measures the flow rate of the electrolyte injected into the corresponding metal-air battery 50. A measurement result by the flow meter 83 is input to the control device 40.

  With reference to FIG. 17, the process of the control apparatus 40 when inject | pouring electrolyte solution into the metal air battery 50 of the backup power supply device by Example 6 is demonstrated. FIG. 17 shows the time variation of the integral values VA and VB of the flow rate of the electrolyte injected into two metal air batteries 50A and 50B (FIG. 16) among the plurality of metal air batteries 50, and the metal air batteries 50A and 50B. The graph of the change of the opening-and-closing state of corresponding opening-and-closing valve 77A and 77B (Drawing 16) is shown.

  At time t31, the control device 40 opens all the on-off valves 77. The time t31 corresponds to the electrolyte injection start time such as the times t1 and t3 shown in FIG. When injection of the electrolytic solution into the metal-air battery 50 is started, the integral values VA and VB of the flow rate of the electrolytic solution monotonously increase. The integral value of the flow rate of the electrolytic solution corresponds to the volume of the electrolytic solution injected into the metal-air battery 50. The integrated values VA and VB of the electrolyte injected into the metal-air batteries 50A and 50B increase to the volume (specified value) Vf of the electrolyte to be filled in the metal-air battery 50 at times t32 and t33, respectively.

  Since the metal-air battery 50 varies in the flow rate of electrolyte injection, the time t32 and the time t33 do not necessarily match. When detecting that the integral value of the flow rate of the electrolyte injected into the metal-air battery 50A has increased to the specified value Vf at time t32, the control device 40 closes the on-off valve 77A. Similarly, at time t33, the on-off valve 77B is closed.

  In Example 6, in order to stop the injection of the electrolytic solution when the volume of the electrolytic solution injected into the metal-air battery 50 reaches the specified value Vf, a predetermined injection is performed to each of the metal-air batteries 50. An electrolyte of a desired volume can be injected.

[Example 7]
FIG. 18 is a schematic diagram of a primary battery unit 30 used in the backup power supply device according to the seventh embodiment. Hereinafter, differences from the first embodiment will be described, and description of the same configuration will be omitted.

  The injection mechanism 60 of the backup power supply device according to the seventh embodiment will be described. The electrolyte flows out from the storage tank 55 through the on-off valve 84 into one common flow path 85. A plurality of metal-air batteries 50 are connected to a common flow path 85 via subtanks 86 and on-off valves 87, respectively. The electrolyte flowing out of the storage tank 55 flows into the sub tank 86 through the common flow path 85. The sub tank 86 temporarily stores the electrolytic solution. The electrolytic solution temporarily stored in the sub tank 86 is injected into the metal-air battery 50 through the opening / closing valve 87. The opening / closing operation of the opening / closing valve 84 and the plurality of opening / closing valves 87 is controlled by the control device 40.

  FIG. 19A shows a cross-sectional view of the sub tank 86. A sub tank 86 is connected to the common flow path 85 via the accumulation amount limiting mechanism 90. The accumulation amount limiting mechanism 90 accumulates more electrolyte in the sub tank when the electrolyte of the volume (specified value) of the electrolyte to be injected into the corresponding metal-air battery 50 is accumulated in the sub tank 86. Restrict. In the seventh embodiment, the accumulation amount limiting mechanism 90 is configured by a float valve. The float valve includes a float 91, a lid 92, and an opening 93. The space in the common flow path 85 and the space in the sub tank 86 are connected via an opening 93. The float 91 moves up and down in accordance with the level of the electrolytic solution accumulated in the sub tank 86. The lid 92 rises together with the float 91 to close the opening 93.

  The operation of the accumulation amount limiting mechanism 90 will be described with reference to FIGS. 19B to 19G. When the control device 40 opens the on-off valve 84 (FIG. 18), the electrolyte 70 flows through the common flow path 85 as shown in FIG. 19B. The electrolytic solution 70 in the common flow path 85 flows into the sub tank 86 through the opening 93. If the inflow of the electrolytic solution 70 into the sub tank 86 continues, the liquid level of the electrolytic solution 70 rises and reaches the height of the bottom surface of the float 91 as shown in FIG. 19C.

  When the electrolytic solution 70 further flows into the sub tank 86, the float 91 rises and the lid 92 closes the opening 93 as shown in FIG. 19D. Thereby, the inflow of the electrolytic solution 70 into the sub tank 86 is stopped. When the lid 92 closes the opening 93, the filling of the electrolyte into the sub tank 86 is completed.

  The storage tank 55 (FIG. 18) stores a sufficient amount of electrolyte 70 necessary to fill all the subtanks 86 with the electrolyte. When the filling of the electrolyte solution 70 into all the sub tanks 86 is completed, the storage tank 55 and the common flow path 85 are emptied as shown in FIG. 19E. The time from when the on-off valve 84 (FIG. 18) is opened to when the electrolyte solution 70 is completely filled in all the sub tanks 86 (required filling time) is measured in advance. This filling time is stored in the control device 40 in advance.

  The control device 40 (FIG. 18) opens the on-off valve 87 as shown in FIG. 19F when the required filling time has elapsed after opening the on-off valve 84 (FIG. 18). As a result, the electrolytic solution 70 in the sub tank 86 is injected into the metal-air battery 50. As shown in FIG. 19G, when the sub tank 86 is emptied, the injection of the electrolytic solution 70 into the metal-air battery 50 is stopped.

  In the seventh embodiment, the electrolytic solution 70 is temporarily accumulated in the sub tank 86 before the electrolytic solution 70 is injected into the metal-air battery 50. The volume of the electrolytic solution 70 temporarily accumulated in the sub tank 86 is limited by the capacity of the sub tank 86. The capacity of the sub tank 86 is made equal to the volume of the electrolyte 70 to be injected into the metal-air battery 50. For this reason, it is possible to inject an amount (specified amount) of the electrolytic solution 70 to be injected into each metal-air battery 50.

  The electrolytic solution 70 is strongly alkaline and exhibits strong corrosiveness to proteins. For this reason, the storage tank for storing the electrolyte solution 70 for a long period is required to have high leakage resistance and corrosion resistance. In the seventh embodiment, since the electrolyte solution 70 is stored in one storage tank 55 for a long period of time, it is desired to increase the leakage resistance and corrosion resistance of the storage tank 55. On the other hand, the electrolytic solution 70 is only temporarily stored in the plurality of sub tanks 86. For this reason, the sub-tank 86 is not required to be as leaky and corrosion resistant as the storage tank 55. Compared with the configuration in which the electrolytic solution 70 is distributed and stored in the plurality of sub tanks 86, the safety of the backup power supply device is easily ensured in the seventh embodiment.

[Example 8]
FIG. 20 shows a schematic diagram of a primary battery unit 30 used in the backup power supply device according to the eighth embodiment. Hereinafter, differences from the seventh embodiment will be described, and description of the same configuration will be omitted.

  In the seventh embodiment, the open / close valve 84 is attached to the common flow path 85 (FIG. 18). However, in the eighth embodiment, the open / close valve 84 is attached between the common flow path 85 and the sub tank 86. In the eighth embodiment, a liquid level sensor 95 is used in place of the float 91 (FIG. 19A). The liquid level sensor 95 transmits a detection signal to the control device 40 when the liquid level of the electrolyte in the sub tank 86 reaches a specified height (level).

  As the liquid level sensor 95, for example, a pair of electrodes and a detection circuit for detecting a conduction state between the electrodes can be used. When the liquid level of the electrolytic solution rises and the electrolytic solution contacts the pair of electrodes, the electrodes are electrically connected. The conduction between the electrodes is detected by the detection circuit, and a detection signal is transmitted to the control device 40.

  With reference to FIG. 21A-FIG. 21D, the procedure which inject | pours electrolyte solution into the metal air battery 50 is demonstrated. When the metal-air battery 50 is in a standby state, the on-off valve 84 is closed (FIG. 21A). At this time, the common flow path 85 is filled with the electrolytic solution 70. When the electrolytic solution 70 is injected into the metal-air battery 50, the control device 40 (FIG. 20) opens the on-off valve 84. When the on-off valve 84 is opened, the electrolyte 70 flows from the common flow path 85 into the sub tank 86 (FIG. 21B). When the liquid level of the electrolytic solution 70 reaches a specified height, a detection signal is transmitted from the liquid level sensor 95 to the control device 40 (FIG. 20) (FIG. 21C).

  When the control device 40 (FIG. 20) receives the detection signal from the liquid level sensor 95, the control device 40 (FIG. 20) closes the on-off valve 84 that causes the electrolyte to flow into the sub tank 86 to which the liquid level sensor 95 is attached. Thereby, the inflow of the electrolyte solution to the sub tank 86 is stopped.

  After closing the on-off valve 84, the on-off valve 87 inserted between the sub tank 86 and the metal-air battery 50 is opened (FIG. 21D). As a result, the electrolytic solution 70 is poured from the sub tank 86 to the metal-air battery 50.

  In the eighth embodiment, the liquid level sensor 95 and the opening / closing valve 84 serve as the accumulation amount limiting mechanism 90. In the eighth embodiment, similarly to the seventh embodiment, since the specified amount of the electrolyte 70 is temporarily stored in the sub tank 86, the specified amount of the electrolyte 70 can be injected into each metal-air battery 50.

[Example 9]
FIG. 22 is a schematic diagram of the primary battery unit 30 used in the backup power supply device according to the ninth embodiment. Hereinafter, differences from the seventh embodiment will be described, and description of the same configuration will be omitted.

  The common flow path 85 is inclined so as to become lower as the distance from the on-off valve 84 increases. A plurality of sub tanks 86 are connected to the common flow path 85 in order from upstream to downstream. In the seventh embodiment, the float valve is attached to the connection portion between the common flow path 85 and the sub tank 86. However, in the ninth embodiment, a mechanism such as a float valve for stopping the inflow of the electrolytic solution is not attached.

  As shown in FIG. 23, when the on-off valve 84 is opened, the electrolytic solution 70 flows out from the storage tank 55 to the common flow path 85. The electrolyte 70 flowing through the common flow path 85 flows into the sub tank 86 arranged on the most upstream side. As the inflow of the electrolyte 70 continues, the most upstream sub-tank 86 is filled with the electrolyte 70. As shown in FIG. 24, when the relatively upstream sub tank 86 is filled with the electrolyte 70, the electrolyte 70 overflowing from the upstream sub tank 86 passes through the common flow path 85 and is relatively downstream. Flows into the sub-tank 86 on the side.

  As shown in FIG. 25, finally, all the sub tanks 86 are filled with the electrolytic solution 70. Before the injection of the electrolyte solution 70 is started, the storage tank 55 stores the electrolyte solution 70 necessary and sufficient to fill all the sub-tanks 86. For this reason, when all the sub tanks 86 are full, the storage tank 55 is emptied. The time from when the on-off valve 84 is opened until all the sub-tanks 86 are full (required filling time) is obtained in advance and stored in the control device 40.

  As shown in FIG. 26, the control device 40 opens the on-off valve 87 when the required filling time has elapsed after opening the on-off valve 84. The electrolytic solution 70 temporarily stored in the sub tank 86 is injected into the metal-air battery 50 through the on-off valve 87.

  The volume of the sub tank 86 corresponds to the volume of the electrolytic solution 70 to be injected into the corresponding metal-air battery 50. Thereby, it is possible to inject the electrolyte solution 70 of a volume (specified amount) to be injected into each metal-air battery 50. In the ninth embodiment, after the sub tank 86 is filled with the electrolytic solution 70, the structure in which the electrolytic solution 70 overflows from the sub tank 86 to the inclined common flow path 85 plays a role as an accumulation amount limiting mechanism.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

DESCRIPTION OF SYMBOLS 10 Input terminal 11 Output terminal 12 Commercial power supply 13 Electric load 20 AC-DC converter 21 Power transport circuit 22 Bus line 23 Diode 24 Voltmeter 25 Secondary battery 26 Switching element 27 Voltmeter 30 Primary battery unit 31 Switching element 32 Positive electrode current collection Body 33 Negative electrode current collector 34 Negative electrode active material 35 Electrolyte solution 36 Separator 37 Output terminal 38 Voltmeter 40 Control device 41 Storage device 50 Metal-air battery 51 Electrolyte injection port 55 Storage tank 56 Release valve 57 Storage chamber 58 Bulkhead 60 Injection mechanism 61 On-off valve 62 Channel 63 Elevating mechanism 64 Stop cock 70 Electrolyte 75 On-off valve 77 On-off valve 78 Internal impedance measuring device 80 Weigh scale 83 Flow meter 84 On-off valve 85 Common channel 86 Sub tank 87 On-off valve 90 Accumulated amount limiting mechanism 91 Float 92 Lid 93 Opening 95 Liquid Level Level Sensor S

Claims (12)

A secondary battery for supplying power to a load driven by power supplied from a main power source;
As a backup power source for supplying power to the load, a plurality of metal-air batteries that wait in a state where no electrolyte is injected, and
A storage tank for storing the electrolyte injected into the metal-air battery in a state of being cut off from the atmosphere;
A control device;
A backup power supply device having an injection mechanism for injecting the electrolyte stored in the storage tank into the metal-air battery by receiving a command from the control device. The injection mechanism is
A flow path connecting each of the metal-air batteries and the storage tank;
An on-off valve inserted into the flow path,
The backup power supply device according to claim 1, wherein the control device controls an opening / closing operation of the opening / closing valve. Furthermore, it has an open valve that is attached to the storage tank and introduces air into the storage tank,
The backup power supply device according to claim 2, wherein the control device opens the open valve during a period of injecting an electrolyte into the metal-air battery. The storage tank includes a plurality of storage chambers prepared for the metal-air batteries,
The plurality of storage chambers are partitioned from each other by a partition, and each of the storage chambers stores a volume of electrolyte to be injected into the corresponding metal-air battery,
The backup power supply device according to claim 2, wherein the injection mechanism injects an electrolyte stored in the storage chamber into the corresponding air battery. Furthermore, it has a measuring device for measuring the internal impedance of each of the plurality of metal-air batteries,
The on-off valve is prepared for each of the metal-air batteries,
4. The backup according to claim 2, wherein when the control device detects that the internal impedance is equal to or less than a specified value, the control device closes the on-off valve corresponding to the metal-air battery whose internal impedance is equal to or less than the specified value. Power supply. Furthermore, it has a weighing scale for measuring the weight of each of the metal-air batteries,
The on-off valve is prepared for each of the metal-air batteries,
The said control apparatus closes the said on-off valve corresponding to the said metal air battery in which the weight became more than a regulation value, if it detects that the weight measured with the said weighing scale became more than a regulation value. The backup power supply unit described in 1. Furthermore, it has a flow meter for measuring the flow rate of the electrolyte injected into each of the metal-air batteries,
The on-off valve is prepared for each of the metal-air batteries,
When the control device detects that the integrated value of the flow rate measured by the flow meter is equal to or higher than a specified value, the control device opens the on-off valve corresponding to the metal-air battery whose integrated value of the flow rate is equal to or higher than the specified value. The backup power supply device according to claim 2 or 3 to be closed. The injection mechanism is
A plurality of sub-tanks that are prepared corresponding to the plurality of metal-air batteries and temporarily store the electrolyte flowing out of the storage tank and inject the temporarily stored electrolyte into the corresponding metal-air batteries When,
An accumulation amount limiting mechanism for restricting the accumulation of more electrolyte in the sub tank when the volume of the electrolyte corresponding to the volume of the electrolyte to be injected into the corresponding metal-air battery is accumulated in the sub tank; The backup power supply device according to claim 1, comprising:   The backup power supply device according to claim 8, wherein the accumulation amount limiting mechanism is realized by setting the volume of the sub tank to a volume corresponding to the volume of the electrolyte to be injected into the corresponding metal-air battery. The accumulation amount limiting mechanism includes an inclined channel through which an electrolyte flowing out from the storage tank flows,
The plurality of sub-tanks are connected to the flow path;
10. The backup power supply device according to claim 9, wherein when the relatively upstream sub-tank is filled with electrolyte, the electrolyte overflowing from the upstream sub-tank flows into the relatively downstream sub-tank.   9. The backup power supply device according to claim 8, wherein when the specified amount of electrolyte is stored in the corresponding sub tank, the accumulation amount limiting mechanism stops the inflow of a specified amount or more of the electrolyte into the sub tank.   The backup power supply device according to claim 9, wherein the accumulation amount limiting mechanism includes a float valve that closes when a liquid level of the electrolyte accumulated in the sub tank reaches a predetermined level.

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