JP6904005B2 - Battery control method, battery system and uninterruptible power supply - Google Patents

Description

The present invention relates to a method for controlling an assembled battery having a configuration in which a plurality of secondary batteries are connected in series, an assembled battery system including the assembled battery, and an uninterruptible power supply.

An uninterruptible power supply that uses an assembled battery in which a plurality of secondary batteries (storage batteries) are connected in series is used.

Generally, in the case of an initial failure or a subsequent accidental failure in the assembled battery, the entire assembled battery is replaced with a non-defective product. Further, even if the expected life is about 10 years, the assembled battery may be renewed before 10 years have passed due to deterioration over time.

When the cause of the failure or the like occurring in the assembled battery is one or a small number of storage batteries in the storage battery group consisting of a plurality of storage batteries, the other storage batteries are normal. However, even in such a case, the entire assembled battery is generally replaced. Further, when the assembled battery is renewed, the entire assembled battery is replaced.

Japanese Unexamined Patent Publication No. 2009-21248 International Publication No. 2011/132311

In addition to the operating storage battery group, there is an assembled battery provided with a spare storage battery (see, for example, Patent Documents 1 and 2). In the assembled batteries described in Patent Documents 1 and 2, when an abnormality of a certain storage battery in the storage battery group is detected, the storage battery is separated from the storage battery group, and a spare storage battery is added to the storage battery group.

However, the deterioration of the spare storage battery is not taken into consideration with respect to the assembled batteries described in Patent Documents 1 and 2. In the invention described in Patent Document 1, when deterioration of the spare storage battery is detected, control is performed so that the spare storage battery is not added to the storage battery group. However, measures against deterioration of the spare storage battery are not considered.

An object of the present invention is to extend the overall life of an assembled battery including a spare storage battery.

The method for controlling an assembled battery according to the present invention is a method for controlling an assembled battery in which a larger number of storage batteries are arranged in series than for outputting a desired voltage, and is operated to output a desired voltage. By replacing the existing storage battery with the other storage batteries, all the storage batteries are given an opportunity to become a spare storage battery, and it is judged whether or not the storage battery is deteriorated. It is characterized in that the period of the storage battery as a spare is made longer than the period of the storage battery determined not to be deteriorated .

The assembled battery system according to the present invention is an assembled battery system including an assembled battery in which a larger number of storage batteries than the number for outputting a desired voltage are arranged in series, and a monitoring control unit for monitoring and controlling the assembled batteries. Therefore, the monitoring and control unit gives all the storage batteries an opportunity to become a spare storage battery by replacing the operating storage battery with the other storage batteries to output the desired voltage, and monitors and controls the storage battery. The unit includes a means for determining whether or not the storage battery is deteriorated, and the period during which the storage battery is used as a spare for the storage battery determined to be deteriorated is longer than the period of the storage battery determined to be not deteriorated. It is also characterized by making it longer.

The uninterruptible power supply according to the present invention is characterized by including the above-mentioned assembled battery system.

According to the present invention, the overall life of an assembled battery including a spare storage battery can be extended.

It is a block diagram which shows an example of an assembled battery system. It is a flowchart which shows the operation of the monitoring control unit in 1st Embodiment. It is explanatory drawing which shows the normal / abnormality of a storage battery, and the state of a bypass part. It is explanatory drawing for demonstrating the rotation of a storage battery. It is a flowchart which shows the operation of the monitoring control unit in 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1.
FIG. 1 is a block diagram showing an example of an assembled battery system. The assembled battery system includes an assembled battery 12 and a monitoring control unit 11 that monitors and controls the assembled battery 12.

The assembled battery 12 includes a storage battery group composed of storage batteries 121, 122, and 123, and a spare storage battery 124.

Further, FIG. 1 shows a charging / discharging device 13 for charging / discharging the storage batteries 121, 122, 123 and the spare storage battery 124. The charging / discharging device 13 is connected to, for example, a commercial AC power source. Further, the charging / discharging device 13 charges / discharges the storage batteries 121, 122, 123 and the spare storage battery 124 via the relay 14. The relay 14 is controlled by the monitoring control unit 11. In the present embodiment, the storage batteries 121, 122, 123 and the spare storage battery 124 can be charged separately.

Although three storage batteries 121, 122, and 123 are illustrated in FIG. 1, the number of storage batteries is not limited to three, and two or more storage batteries may be used. Further, although one spare storage battery 124 is illustrated in FIG. 1, there may be a plurality of spare storage batteries. In other words, the number may be any number as long as the number of storage batteries in the assembled battery 12 is larger than the number for outputting a desired voltage.

The storage battery 121 and the storage battery 122 are connected in series via a switch 141. The storage battery 122 and the storage battery 123 are connected in series via a switch 142. The storage battery 123 and the spare storage battery 124 are connected in series via a switch 143. Further, the spare storage battery 124 is disconnected by the switch 144.

When the common terminals of the switches 141, 142, 143, and 144 are connected to the OFF terminal side, the storage batteries 121, 122, 123 or the spare storage battery 124 are added to the operating storage battery group, and the common terminals are turned on (ON). When connected to the terminal side, the storage batteries 121, 122, 123 or the spare storage battery 124 are separated from the operating storage battery group. Hereinafter, since the spare storage battery 124 can also be an operating storage battery, the spare storage battery 124 may be simply referred to as a storage battery.

When the operating storage battery group is composed of storage batteries 121, 122, 123, the common terminals of the switches 141, 142, 143 are connected to the off terminal side. Further, the common terminal of the switch 144 is connected to the on terminal side.

The current path between the positive electrode side of the storage battery 121 and the on terminal of the switch 141 is used as the bypass portion 131. The current path between the common terminal of the switch 141 and the on terminal of the switch 142 is a bypass portion 132. The current path between the common terminal of the switch 142 and the on terminal of the switch 143 is the bypass portion 133. The current path between the common terminal of the switch 143 and the on terminal of the switch 144 is defined as the bypass portion 134.

Hereinafter, in each of the bypass portions 131, 132, 133, and 134, the state in which the current flows (the state in which the corresponding storage battery is disconnected) is "on state", and the state in which the current does not flow (the corresponding storage battery is not disconnected). The state) is called the "off state".

In FIG. 1, the dashed arrows to the switches 141, 142, 144, 144 indicate that the switches 141, 142, 144, 144 are controlled by the monitoring control unit 11. A broken line without an arrow indicates that a signal for monitoring is input / output between the storage batteries 121, 122, 123, 124 and the monitoring control unit 11.

Although the monitoring control unit 11 may be composed of a hardware circuit, it is an interface unit that inputs and outputs signals for monitoring and control of the microprocessor 121, 122, 123, 124 that operates according to the program. It may be realized by.

Next, the operation of the monitoring control unit 11 will be described with reference to the flowchart of FIG.

The monitoring control unit 11 first makes initial settings for the assembled battery 12 (step S201). FIG. 3 is an explanatory diagram showing the normal / abnormal (deteriorated) (○: normal, ×: abnormal (deteriorated)) of the storage batteries 121, 122, 123, 124, and the states of the bypass portions 131, 132, 133, 134. is there.

In the initial setting, the monitoring control unit 11 sets the state of the bypass units 131, 132, 133, 134 to the state shown in the "normal" column in FIG. That is, only the switch 144 is controlled so that the common terminal and the on terminal are connected (only the bypass portion 134 is turned on). As a result, the operating storage battery group is composed of storage batteries 121, 122, 123, and the storage battery 124 is positioned as a spare storage battery.

The monitoring control unit 11 monitors (checks the status) of the storage batteries 121, 122, 123 (step S202).

The monitoring process in step S202 is a process for monitoring whether or not the storage batteries 121, 122, and 123 are deteriorated. Any known method may be used as a method for determining whether or not the material has deteriorated. For example, the monitoring control unit 11 determines that the output voltage of a single unit has deteriorated when it is less than a predetermined threshold value. Further, the monitoring control unit 11 determines that the storage battery has deteriorated when the temperature exceeds the specified value, or determines that the storage battery has deteriorated when the internal resistance value exceeds the specified value (in the case of a lead storage battery). You may judge.

When a deteriorated storage battery is detected as a result of the monitoring process in step S202 (step S203), the monitoring control unit 11 replaces the storage battery with the spare storage battery 124 (step S204).

For example, when the deterioration of the storage battery 121 is detected, the monitoring control unit 11 changes from the state of the "normal" state to the common terminal and the off terminal of the switch 144, as shown in the line of "deterioration of the storage battery 121" in FIG. (The bypass unit 134 is set to the "off state") and the switch 141 is changed so that the common terminal and the on terminal are connected (the bypass unit 131 is set to the "on state"). To.).

Further, the monitoring control unit 11 rotates the storage batteries constituting the operating storage battery group.

That is, when the rotation condition (replacement condition) is satisfied, the monitoring control unit 11 disconnects one of the storage batteries constituting the operating storage battery group from the storage battery group, and replaces the storage battery reserved at that time with the storage battery. Add to the group. Battery replacement (disconnection and addition) switches 141, 142, 144, so that the bypass section changes from "on state" to "off state" or from "off state" to "on state". It is realized by controlling 144 by the monitoring control unit 11.

FIG. 4 is an explanatory diagram for explaining the rotation (replacement) of the storage battery. In FIG. 4, “◯” indicates that it constitutes an operating storage battery group, and “x” indicates that it is separated from the storage battery group. FIG. 4 also shows the states of the corresponding bypass portions 131, 132, 133, 134. In the present embodiment, for example, the state shown in the first row in FIG. 4 is sequentially transitioned to the state shown in the fourth row. Therefore, the storage batteries 121, 122, 123, and 124 are sequentially used as spare storage batteries.

The rotation conditions are, for example, 24 hours, 1 week, 1 month, and the like, but other conditions may be used. Further, the rotation condition may be changed according to the elapsed time since the assembled battery 12 is newly operated (for example, when the elapsed time becomes long, the rotation condition may be changed from one month to one week).

Further, the monitoring control unit 11 controls the charge rate of the spare storage battery (step S207). For example, the monitoring control unit 11 drives the relay 14 to connect the charging / discharging device 13 to the storage battery, and trickle charges the storage battery so that the charging rate becomes a predetermined value (for example, 100%). Further, the monitoring control unit 11 determines the upper limit threshold value and the lower limit threshold value of the sufficiency rate in advance, and when the charging rate of the storage battery exceeds the threshold value range, the monitoring control unit 11 drives the relay 14. At the same time, the charging / discharging device 13 may be controlled to charge / discharge the storage battery so as to fall within the threshold range. In that case, the threshold range is, for example, 80 to 100%, but it is preferable to select a range in which the storage battery is less likely to deteriorate depending on the type of the storage battery.

As described above, in the present embodiment, since the storage battery that operates by rotation and the spare storage battery are replaced, for example, periodically, the usage status of all the storage batteries constituting the assembled battery becomes equal. As a result, the life of the assembled battery as a whole is extended. That is, the frequency of replacement of the assembled battery can be reduced, and the maintenance cost of the uninterruptible power supply using the assembled battery can be reduced.

Embodiment 2.
In the first embodiment, the storage batteries 121, 122, 123, 124 constituting the assembled battery are treated evenly and rotated. However, the storage batteries 121, 122, 123, and 124 may be rotated in consideration of the deterioration of each special battery.

FIG. 5 is a flowchart showing the operation of the monitoring control unit 11 in the second embodiment of performing such control.

In the second embodiment, when the rotation condition is satisfied (step S205), the monitoring control unit 11 replaces the storage batteries (from the operating storage battery group) in consideration of the deterioration of the storage batteries 121, 122, 123, 124. (Detachment and addition to the storage battery group) is determined (step S216).

The monitoring control unit 11 can identify the deteriorated storage battery in the process of step S202. Therefore, when such a storage battery is to be separated from the storage battery group one after another, the storage battery is separated from the storage battery group at the next replacement. That is, it will shift to the position as a spare storage battery as soon as possible.

The monitoring control unit 11 may replace the storage battery earlier than usual when the storage battery to be separated from the storage battery group is deteriorated (rotation condition is set). If it is a period).

By executing the above control, the storage battery determined to be deteriorated becomes a spare storage battery during the period in which the storage battery determined to be deteriorated becomes a spare storage battery. It will be longer than the period you are in.

Further, the monitoring control unit 11 may rank the degree of deterioration and determine the replacement of the storage battery according to the rank. For example, in order to know the degree of deterioration of each storage battery 121, 122, 123, 124, the monitoring control unit 11 also ranks the deterioration in the process of step S202. As an example, for an observation target (output voltage, temperature, internal resistance value, etc.) that is a specific target for determining deterioration, a plurality of different reference values (a plurality of different values with respect to a decrease in output voltage and an increase in temperature or internal resistance value) The value) is provided, and the monitoring control unit 11 ranks the deterioration by comparing the actually detected value with the reference value.

Then, for example, when the rotation condition is a period and the storage battery to be separated from the storage battery group is a storage battery having a high degree of deterioration, the storage battery is replaced as soon as possible.

By performing the above control, the chance that the deteriorated storage battery becomes an actually operating storage battery (non-spare storage battery) is reduced, and further extension of the life of the assembled battery as a whole can be expected.

In each of the above embodiments, the assembled battery and the monitoring control unit 11 are separately provided, but the battery including the assembled battery and the monitoring control unit 11 shown in FIG. 1 is combined with one assembled battery. It may be defined.

Further, the assembled battery of each of the above embodiments is suitably incorporated in the uninterruptible power supply device. However, the assembled battery of each of the above embodiments can be incorporated in other than the uninterruptible power supply.

1 set battery system 11 monitoring control unit 12 set battery 13 charge / discharge device 14 relay 121, 122, 123, 124 storage battery 131, 132, 133, 134 bypass part 141, 142, 143, 144 switches

Claims (9)

It is a control method of an assembled battery in which a larger number of storage batteries than the number for outputting a desired voltage are arranged in series.
By replacing the operating storage battery with the other storage batteries to output the desired voltage, all storage batteries are given the opportunity to become spare storage batteries.
Determine if the storage battery is deteriorated and
A method for controlling an assembled battery, which comprises making the period of a storage battery as a spare of a storage battery determined to be deteriorated longer than the period of the storage battery determined to be not deteriorated. The method for controlling an assembled battery according to claim 1, wherein a storage battery that is operating to output a desired voltage is periodically replaced with another storage battery. The shift is executed at a predetermined cycle, and the cycle is changed according to the operating period of the assembled battery.
The method for controlling an assembled battery according to claim 2. The method for controlling an assembled battery according to any one of claims 1 to 3, wherein trickle charge is performed so that the charge rate of the spare storage battery becomes a predetermined value. An assembled battery system including an assembled battery in which a larger number of storage batteries than the number for outputting a desired voltage are arranged in series, and a monitoring control unit for monitoring and controlling the assembled battery.
The monitoring control unit gives all the storage batteries an opportunity to become a spare storage battery by replacing the operating storage battery with the other storage batteries to output the desired voltage .
The monitoring control unit includes a means for determining whether or not the storage battery is deteriorated, and the storage battery determined not to be deteriorated during the period of being a spare storage battery for the storage battery determined to be deteriorated. An assembled battery system characterized in that it is longer than the relevant period. The assembled battery system according to claim 5, wherein the monitoring and control unit periodically controls to switch between a storage battery that is operating to output a desired voltage and a storage battery other than the storage battery. The monitoring and control unit executes the change in a predetermined cycle, and changes the cycle according to the operating period of the assembled battery.
The assembled battery system according to claim 6. The assembled battery system according to any one of claims 5 to 7, wherein the monitoring control unit controls trickle charging so that the charging rate of the spare storage battery becomes a predetermined value. An uninterruptible power supply including the assembled battery system according to any one of claims 5 to 8.

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