JP2017189045A - Storage battery system and storage battery control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a performance in a whole power storage system and extend a storage battery life after eliminating restrictions on characteristics of a plurality of storage batteries.SOLUTION: A storage battery system comprises: a plurality of storage batteries 106A and 106B to which invertors 104A and 104B are individually connected and which can be individually charged and discharged; and a storage battery monitoring control device 103 that monitors a charging amount of the plurality of storage batteries and individually applies a charging command or a discharging command to the plurality of storage batteries. The storage battery monitoring control device 103 sets a first threshold value and a second threshold value, which is a charging amount smaller than the first threshold value, between an upper limit charging amount and a lower limit charging amount determined by a charging capacity of the storage battery as the charging amount of each storage battery. The storage battery monitoring control device 103 performs load distribution control in which the charge or discharge in the plurality of storage batteries are combined so that a charging amount between the first and second thresholds is preferentially set for each storage battery.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a storage battery system and a storage battery control method.

  Currently, most of the power supplied by electric power companies is generated by thermal power generation, hydroelectric power generation, and nuclear power generation. However, in recent years, the introduction of power generation systems that use renewable energy (solar power generation, wind power generation, etc.) is increasing from the viewpoint of reducing environmental impact.

  Systems that generate electricity using natural energy such as sunlight and wind power are susceptible to environmental changes, and output fluctuations are severe, causing the power system to become unstable. For this reason, a power generation system using renewable energy is provided with a large-capacity storage battery system in which a plurality of storage batteries are connected in series and parallel to stabilize the power system.

  In order to stabilize an electric power system using a storage battery, it is necessary to balance the demand and supply of the electric power system, and the storage battery provided side by side is charged and discharged as necessary. However, the ratio of charging and discharging is extremely rare, and usually tends to be biased to either one. Specifically, the state of charge (SOC) of the storage battery easily reaches an upper limit value or a lower limit value determined from the chargeable / dischargeable capacity of the storage battery. The output is limited or stopped so as not to be charged or overdischarged. In the following description, the upper limit value and the lower limit value set during actual operation are referred to as the SOC upper limit value and the SOC lower limit value.

The storage battery is charged to the SOC upper limit value when the battery is charged, and discharged to the SOC lower limit value when discharging. For example, in a certain storage battery system, assuming that the full charge capacity of the storage battery is 100%, the SOC upper limit value is 85%, the SOC lower limit value is 15%, and charging / discharging is performed between 85% and 15%. Is called. This is to prevent the storage battery from being deteriorated by full charge up to 100% or complete discharge up to 0%.
However, the above-described SOC upper limit value and SOC lower limit value are not values that can completely prevent deterioration due to the characteristics of the storage battery, but are set to values that balance economics and battery life in using the storage battery. That is, if the actual charge capacity of the storage battery determined between the SOC upper limit value and the SOC lower limit value is too small, the capacity that can be charged by the storage battery system will be very small. The values of 85% and 15% are set. Therefore, in actual operation, it is not preferable that the charging rate of the storage battery continues in a state where the SOC upper limit value or the SOC lower limit value is reached.

  Patent Document 1 discloses a technique in which a storage battery system includes a plurality of storage batteries having different characteristics and changes the distribution status to the plurality of storage batteries having different characteristics. According to the technology described in Patent Document 1, by preparing a plurality of storage batteries having different characteristics and performing control according to the characteristics of each storage battery, it is possible to improve the performance of the entire storage system. Has been.

WO2014 / 118903

  However, as described in Patent Document 1, when a system is constructed with a plurality of storage batteries having different characteristics, there is a problem that it cannot be applied to an existing storage battery system as it is. In general, a large-capacity storage battery system including a plurality of storage batteries is generally a system using a large number of storage batteries having the same characteristics. Therefore, it is difficult to apply the storage battery control technique described in Patent Document 1 to the existing storage battery system by changing the control software, and a large-scale modification such as replacement of the storage battery becomes necessary.

  An object of the present invention is to provide a storage battery system and a storage battery control method capable of improving the performance of the entire power storage system and extending the life of the storage battery while eliminating restrictions on characteristics of a plurality of storage batteries. There is.

In order to solve the above problems, for example, the configuration described in the claims is adopted.
The present application includes a plurality of means for solving the above-mentioned problems. For example, a plurality of storage batteries that are individually connected to an inverter and can be charged and discharged individually, and a charge amount of the plurality of storage batteries are monitored. And it applies to a storage battery system provided with the storage battery monitoring control apparatus which gives a charge command or a discharge command separately with respect to a some storage battery.
Then, the storage battery monitoring and control device sets the charge amount of each storage battery between the upper limit charge amount determined from the charge capacity of the storage battery and the lower limit charge amount, and a second threshold value with a charge amount smaller than the first threshold value. Is set, and each storage battery performs load distribution control that combines charging or discharging with a plurality of storage batteries so that the charge amount between the first threshold value and the second threshold value is set preferentially.

According to the present invention, among a plurality of installed storage batteries, when the charge amount of a specific storage battery reaches the first threshold value, the charge amount of another storage battery is adjusted to prevent reaching the SOC upper limit value. Thus, it is possible to reduce the number of times the SOC upper limit value or SOC lower limit value is reached. Therefore, according to the present invention, it is possible to improve the performance of the storage battery system while preventing the deterioration of the storage battery.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a block diagram which shows the example of the whole storage battery system of one embodiment of this invention. It is a characteristic view which shows the example of a response | compatibility with the inverter load factor of one embodiment of this invention, and power conversion efficiency. It is a flowchart which shows the control processing example of the storage battery by one embodiment of this invention. It is a control state figure showing an example of operation of a plurality of storage batteries by one example of an embodiment of the present invention. It is a flowchart which shows the example of control processing changed with the conversion efficiency by one embodiment of this invention. It is a flowchart which shows the example of a control process changed with the accumulation charge / discharge time by the example of 1 embodiment of this invention. It is a flowchart which shows the example of control processing which changes a threshold value with the change of the supply-and-demand balance by the example of 1 embodiment of this invention.

Hereinafter, an example of an embodiment of the present invention (hereinafter referred to as “this example”) will be described with reference to FIGS.
[1. Configuration example of storage battery system]
FIG. 1 shows a configuration example of a storage battery system 100 of this example.
Storage battery system 100 is connected to AC line 107 provided in power system 101. The storage battery system 100 includes a plurality of inverters 104A and 104B connected to a power supply line 107, and storage batteries 106A and 106B are connected to the inverters 104A and 104B via DC lines 105A and 105B, respectively. Each of the storage batteries 106A and 106B provided in the storage battery system 100 of this example may be either a case where batteries having the same characteristics and capacity are used or a case where batteries having different characteristics or capacities are used. Moreover, the example provided with two storage batteries 106A and 106B is an example, and the storage battery system 100 may be configured to include more storage batteries.

Charging and discharging of the inverters 104A and 104B and the storage batteries 106A and 106B are individually controlled by the storage battery monitoring control device 103. That is, the storage battery monitoring and control device 103 acquires the charge amounts of the respective storage batteries 106A and 106B as SOC information SOC1 and SOC2, and sends charge / discharge commands P1 and P2 to the inverters 104A and 104B to control charging or discharging individually. To do.
The storage battery monitoring control device 103 individually controls charging / discharging of the storage batteries 106A, 106B, and performs load distribution processing so that excessive charging / discharging loads are not applied to the storage batteries 106A, 106B.

  The storage battery monitoring control device 103 is supplied with charging / discharging command information PX from the external remote monitoring control device 102. The remote monitoring control device 102 supplies charge / discharge command information PX to the storage battery monitoring control device 103 based on the state of the power system 101. For example, the remote monitoring and control apparatus 102 issues a charging command based on the amount of power generated at a solar power plant connected to the power system 101. Alternatively, a discharge command is issued according to the operating status of the load connected to the power system 101. The storage battery monitoring control device 103 determines the charging amount or discharging amount of the entire storage battery system 100 based on the charging / discharging command information PX supplied from the remote monitoring control device 102, and performs individual charging / discharging of each storage battery 106A, 106B. Set.

  When the storage battery monitoring control device 103 controls charging / discharging of each storage battery 106A, 106B, the storage battery 106A, 106B is combined with charging or discharging so that the remaining charge of each storage battery 106A, 106B is optimized. Perform load balancing control. The load distribution control by the storage battery monitoring and control device 103 here includes, for example, the process of charging one storage battery 106A and stopping the charging of the other storage battery 106B, as well as the charging status of the one storage battery 106A and the other storage battery. There is a process of changing the charging status at 106B. Alternatively, as load distribution control by the storage battery monitoring control device 103, distributed control combining charging and discharging, such as charging one storage battery 106A and discharging the other storage battery 106B, may be performed.

In addition, when the storage battery monitoring control device 103 controls charging / discharging, the charge amount of each storage battery 106A, 106B is between the SOC upper limit value and the SOC lower limit value in addition to the SOC upper limit value and the SOC lower limit value. Two threshold values (first threshold value and second threshold value) are set and managed. The SOC upper limit value and the SOC lower limit value are values of the maximum charge remaining amount and the minimum charge remaining amount determined from the characteristics of the storage batteries 106A and 106B.
As specific examples of the first threshold value and the second threshold value, for example, when the SOC upper limit value and the SOC lower limit value are 85% and 15% of the battery capacity, the first threshold value is 60% and the second threshold value is 40%. (See FIG. 4 described later). When the amount of charge of each storage battery 106A, 106B is between the first threshold value and the second threshold value, the storage battery is least deteriorated. However, the deterioration of the storage battery occurs due to various factors such as the number of times of charging / discharging and the cumulative usage time, and setting the remaining charge amount between the first threshold value and the second threshold value suppresses the deterioration of the storage battery 1 This is one factor.

  The charging and discharging of the storage batteries 106A and 106B are performed by the operation of the inverters 106A and 106B as described above. However, in the following description, the operation control of the inverter is omitted unless particularly necessary, and the storage batteries are simply stored. Is referred to as charging or discharging.

[2. Example of inverter conversion efficiency]
FIG. 2 shows an example of a change characteristic of the power conversion efficiency depending on the load factor of the inverters 104A and 104B. The horizontal axis in FIG. 2 indicates the inverter load factor, and the vertical axis indicates the power conversion efficiency. However, only the tendency is shown about power conversion efficiency.
As shown in FIG. 2, the power conversion efficiency is low when the inverter load factor is very low, 10% or less, and the power conversion efficiency increases as the inverter load factor increases until the inverter load factor reaches about 30%. Become. The peak of the power conversion efficiency is in the range where the inverter load factor is about 30% to about 40%, and the power conversion efficiency gradually decreases as the inverter load factor becomes higher than 40%.

Therefore, when paying attention to the power conversion efficiency, it is preferable that the inverters 104A and 104B avoid the inverter load factor of 10% or less. When operating with higher efficiency, the load factor is preferably in the range of about 30% to about 40%. However, this range is an example, and the range of the load factor at which the power conversion efficiency is highest differs depending on the inverter type.
When the storage battery monitoring control device 103 performs load distribution control that combines charging or discharging of the storage batteries 106A and 106B, attention is paid to the power conversion efficiency as one of the control factors. Other control factors of interest when the storage battery monitoring control device 103 performs load distribution control will be described later.

[3. Example of control processing by storage battery monitoring and control device]
The flowchart of FIG. 3 shows a processing example for controlling charging / discharging of the plurality of storage batteries 106 </ b> A and 106 </ b> B by the storage battery monitoring control device 103.
First, the storage battery monitoring control device 103 determines whether there is an instruction for charging or discharging based on the charging / discharging command information PX from the remote monitoring control device 102 (step S11). If there is no charge or discharge instruction (NO in step S11), the process waits until the charge / discharge command information PX is supplied.

When there is an instruction for charging or discharging (YES in step S11), the storage battery monitoring control device 103 determines whether the current charge amount of the storage batteries 106A and 106B can be managed between the first threshold value and the second threshold value. Is determined (step S12). The state that can be managed between the first threshold value and the second threshold value here is, for example, when there is a charge instruction, when there is a storage battery with a remaining charge exceeding the first threshold value, or there is a discharge instruction. Sometimes this corresponds to the case where there is a storage battery with a remaining charge less than the second threshold.
Here, when the state is not manageable between the first threshold value and the second threshold value (NO in step S12), the storage battery monitoring control device 103 performs charging to the SOC upper limit value or discharging to the SOC lower limit value. Then, the storage batteries 106A and 106B are charged and discharged (step S13). When the charge state or the discharge state has changed after the start of the charge or discharge in step S13, the storage battery monitoring control device 103 returns to the determination in step S11.

If it is determined in step S12 that the state can be managed between the first threshold value and the second threshold value (YES in step S12), the charge / discharge loads of the plurality of storage batteries 106A and 106B are dispersed. Then, charging or discharging is performed between the first threshold value and the second threshold value (step S14). An example of charge / discharge load distribution control will be described later, but in addition to simply distributing charge and discharge to a plurality of storage batteries, control for discharging some storage batteries during charging and charging some storage batteries during discharging In some cases, control is performed.
After starting charging or discharging in the state where the load distribution control is performed in step S14, the storage battery monitoring control device 103 determines whether or not the combination of storage batteries according to the current load distribution control state is appropriate (step S15). ). Here, when a situation where the combination is not appropriate occurs (NO in step S15), the storage battery monitoring control device 103 changes the combination of charging / discharging of the plurality of storage batteries 106A and 106B (step S16), and step S14. Return to the load balancing control state.
If the combination is appropriate (YES in step S15), the storage battery monitoring control device 103 returns to the determination in step S11.

  In the control example shown in the flowchart of FIG. 3, the storage battery monitoring control device 103 performs load distribution control in step S14 when the remaining charge amount of each of the storage batteries 106A and 106B is between the first threshold value and the second threshold value. I did it. On the other hand, the storage battery monitoring control device 103 may perform load distribution control when performing charging to the SOC upper limit value or discharging to the SOC lower limit value in Step S13.

[4. Specific charge / discharge example]
FIG. 4 shows an example in which load distribution control is performed using two storage batteries 106A and 106B.
Here, the two storage batteries 106A and 106B have the same characteristics and capacity, and are an example in which the SOC upper limit value is set to 85%, the SOC lower limit value is set to 15%, the first threshold value is set to 60%, and the second threshold value is set to 40%. . In FIG. 4, the vertical axis represents the remaining charge of each of the storage batteries 106A and 106B, and the horizontal axis represents time. In FIG. 4, a solid-line characteristic SOC1 indicates the remaining charge of one storage battery 106A, and a broken-line characteristic SOC2 indicates the remaining charge of the other storage battery 106B. In addition, discharge amounts IV1 and IV2 indicated by two-point difference lines in FIG. 4 indicate integrated amounts of electric power converted by the inverters 104A and 104B.

  FIG. 4 shows a state in which a discharge command has arrived from the remote monitoring control device 102 to the storage battery monitoring control device 103, and each of the storage batteries 106A, 106B is in a standby state with the remaining charge remaining at the first threshold (60%). Is shown. The necessary amount of discharge can be secured by discharging one storage battery 106A, and it is preferable to discharge only the storage battery 106A from the viewpoint of load distribution control. In this case, the storage battery monitoring control device 103 sends a charge / discharge command P1 to the inverter 104A so as to discharge the storage battery 106A. With this charge / discharge command P1, discharge IV1 is performed in the period t1 in FIG. 4, and the remaining charge SOC1 of the storage battery 106A gradually decreases as shown by the solid line.

  Then, it is assumed that the remaining charge SOC1 of the storage battery 106A has decreased to less than the second threshold (40%) by continuing the discharge for a predetermined period (period t1 in FIG. 4) from the start of discharge. At this time, the storage battery monitoring controller 103 stops discharging the storage battery 106A and starts discharging another storage battery 106B. In order to start the discharge of the storage battery 106B, the storage battery monitoring control device 103 sends a charge / discharge command P2 to the inverter 104B. With this charge / discharge command P2, discharge IV2 shown in period t2 in FIG. 4 is performed, and as shown by the broken line, the remaining charge SOC2 of storage battery 106B gradually decreases.

  Here, the storage battery monitoring control device 103 sends a charge / discharge command P1 so that the inverter 104A operates for charging when the storage battery 106B is discharged, and charges the storage battery 106A with the current discharged from the storage battery 106B. As a result of this charging, the remaining charge SOC1 of the storage battery 106A that has dropped below the second threshold value returns to the range between the first threshold value and the second threshold value.

When the remaining charge SOC1 of the storage battery 106A reaches a certain value (for example, 50%), the storage battery monitoring control device 103 sends a charge / discharge command P1 so that the inverter 104A operates for discharging, and discharges the storage battery 106A. . By this charge / discharge command P1, the discharge IV1 is performed in the period t3 in FIG.
In this way, the storage battery monitoring control device 103 controls the load distribution process that alternately operates the two storage batteries 106A and 106B.

[5. Example of judgment factors during load balancing processing]
Next, an example of a determination factor when the storage battery monitoring control device 103 executes the load distribution process will be described.
FIG. 5 is a flowchart illustrating a processing example for determining the load distribution processing state from the conversion efficiency of the inverters 104A and 104B.
First, the storage battery monitoring control device 103 determines whether there is another storage battery (inverter) combination that has a higher conversion efficiency than the currently operating state (step S21). Here, if it is determined that there is no other combination that has higher conversion efficiency than the currently operating combination (NO in step S21), the storage battery monitoring control device 103 continues the current combination and determines in step S21. Repeat.

And when there exists another combination whose conversion efficiency becomes higher than the combination currently actuated (YES of step S21), the storage battery monitoring control apparatus 103 changes the combination of the storage battery to charge or discharge (step S22). . The change of the combination here includes the change of the load factor of each of the inverters 104A and 104B in operation.
After changing the combination of storage batteries to be charged or discharged in step S22, the process returns to the determination in step S21.
By doing in this way, charging and discharging are performed in a state where the conversion efficiency is always high.

FIG. 6 is a flowchart showing a processing example in which the load distribution processing state is determined from the cumulative charge / discharge times of the inverters 104A and 104B, and the cumulative charge / discharge times of the inverters 104A and 104B are made substantially equal.
First, the storage battery monitoring control device 103 determines whether or not there is a bias in the current cumulative charge / discharge time of the inverters 104A and 104B (step S31). If it is determined that there is no bias in the current cumulative charge / discharge time of the inverters 104A and 104B (NO in step S31), the storage battery monitoring control device 103 continues the current combination and determines in step S31. repeat.

  If there is a bias in the current accumulated charge / discharge time (YES in step S31), the storage battery monitoring control device 103 determines the storage battery to be charged or discharged so as to preferentially use an inverter having a short accumulated charge / discharge time. The combination is changed (step S32). After changing the combination of storage batteries to be charged or discharged in step S32, the process returns to the determination in step S31. By doing in this way, the accumulation charge / discharge time of an inverter or a storage battery becomes substantially equal.

  The storage battery monitoring control device 103 comprehensively determines the optimum load distribution state for each of these factors, and determines the load distribution state to be actually set. At this time, the storage battery monitoring control device 103 may determine the priority for each factor, for example, and perform a load distribution state that more reflects the factor having a higher priority. Note that the use of two factors of conversion efficiency and cumulative charge / discharge time is merely an example, and the storage battery monitoring control device 103 may determine the load distribution state by adding other factors.

  As described above, according to the storage battery system 100 of this example, the storage batteries 106A and 106B and the inverters 104A and 104B are appropriately dispersed and used, and the remaining charge of the storage batteries 106A and 106B is appropriately managed. Therefore, it is possible to improve the performance of the entire power storage system and extend the life of the storage battery. For example, when the amount of charge of the storage battery 106A reaches the first threshold, it becomes possible to adjust the amount of charge of another storage battery 106B to prevent the SOC upper limit value from being reached, and the SOC upper limit value or SOC lower limit value Operation to reduce the number of times to reach is possible. In addition, it is possible to prevent a bias in the accumulated charge / discharge time of the plurality of storage batteries 106A and 106B, and it is possible to improve the performance of the entire power storage system and extend the life of the storage battery.

  In addition, in the case of the storage battery system 100 of this example, it can be applied to any combination of characteristics and capacities of the plurality of storage batteries 106A and 106B, and can be applied to various storage battery systems including a plurality of storage batteries. become able to. Specifically, the plurality of storage batteries 106A and 106B can be applied to the storage battery system 100 of this example regardless of whether the characteristics and capacity are the same or different. Therefore, it can be applied to a newly created storage battery system, but it can also be applied by adding a control function performed by the storage battery monitoring control device 103 to an existing storage battery system.

[6. Example of changing threshold]
In the description so far, the first threshold value and the second threshold value set between the SOC upper limit value and the SOC lower limit value are set to 60% and 40%. On the other hand, the first threshold value and the second threshold value may be variably set according to the situation at that time.
FIG. 7 is a flowchart illustrating a processing example in which the storage battery monitoring control device 103 variably sets the first threshold value and the second threshold value.

  First, the storage battery monitoring and control apparatus 103 determines whether or not there is a change in the current supply / demand balance from the status of the power system 101 and the status of the storage battery system 100 (step S41). Here, when it is determined that there is no change in the supply-demand balance (NO in step S41), the process stands by without changing each threshold value.

  When determining that there is a change in the supply-demand balance, the storage battery monitoring control device 103 sets the first threshold value and the second threshold value based on the current (or expected) supply-demand balance to the SOC upper limit value and the SOC lower limit value. A threshold setting process is performed to reset the interval (step S42). And the storage battery monitoring control apparatus 103 performs load distribution control with the reset 1st threshold value and 2nd threshold value. Thereafter, the storage battery monitoring control device 103 returns to the determination process in step S41.

The change in the supply and demand balance in step S41 is, for example, when a large number of load devices connected to the power system 101 are activated to increase power consumption, or when a power plant connected to the power system 101 (solar It is assumed that the amount of power generated by light, wind power, etc. increases.
Moreover, as an expected supply and demand balance, there is a case where there is a device that operates at a specific time, and a case where a change in power generation amount is predicted from a weather forecast or the like.

  Thus, by variably setting the first threshold value and the second threshold value based on the change in the supply and demand balance, the range in which each storage battery 106A, 106B can be appropriately subjected to load distribution control is varied, and the appropriate value based on the supply and demand balance at that time Operation becomes possible.

[7. Modified example]
Note that the present invention is not limited to the above-described embodiments, and includes various modifications and application examples. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to the one having all the configurations described in FIG.

  Further, in the configuration shown in FIG. 1, two sets of storage batteries 106A and 106B and two sets of inverters 104A and 104B are provided for the sake of simplicity. However, the present invention is not limited to three sets of storage batteries. And can be applied to power storage systems equipped with inverters.

Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function can be stored in a recording device such as a memory, a hard disk, an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.
Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

  DESCRIPTION OF SYMBOLS 100 ... Storage battery system, 101 ... Electric power system, 102 ... Remote monitoring control apparatus, 103 ... Storage battery monitoring control apparatus, 104A, 104B ... Inverter, 105A, 105B ... DC line, 106A, 106B ... Storage battery, 107 ... AC line

Claims (6)

A plurality of storage batteries that are individually connected to each other and can be charged and discharged individually, and a storage battery monitor that individually monitors a charge amount of the plurality of storage batteries and gives a charge command or a discharge command to the plurality of storage batteries individually A storage battery system comprising a control device,
The storage battery monitoring and control device has a first threshold value and a second charge amount smaller than the first threshold value between the upper limit charge amount and the lower limit charge amount determined from the charge capacity of the storage battery as the charge amount of each storage battery. Load balancing control combining charging or discharging of a plurality of the storage batteries so that a threshold value is set and each of the storage batteries is preferentially set with a charge amount between the first threshold value and the second threshold value Do a storage battery system. The storage battery system according to claim 1, wherein the load distribution control by the storage battery monitoring control device is charged by the specific storage battery and simultaneously discharged by the storage battery other than the specific storage battery. The said storage battery monitoring control apparatus performs control which preferentially uses the load factor in the predetermined range with high power conversion efficiency in the said inverter combining the charge or discharge in the said some storage battery. Storage battery system. The storage battery system according to claim 1, wherein the storage battery monitoring and control device performs control such that cumulative charge / discharge times in the plurality of inverters are substantially equal by combining charging or discharging in the plurality of storage batteries. The said storage battery monitoring control apparatus acquires the information regarding the supply-and-demand balance of the connected electric power grid | system, and variably sets the said 1st threshold value and the said 2nd threshold value based on the information regarding the acquired supply-and-demand balance. The storage battery system according to any one of the above. A storage battery control method that individually gives a charge command or a discharge command to a plurality of storage batteries that can be individually charged and discharged by being individually connected to an inverter.
Threshold setting processing for setting a first threshold value and a second threshold value with a charge amount smaller than the first threshold value between the upper limit charge amount and the lower limit charge amount determined from the charge capacity of the storage battery as the charge amount of each storage battery When,
Load balancing control that performs load balancing control that combines charging or discharging of the plurality of storage batteries so that each of the storage batteries is preferentially set with a charge amount between the first threshold value and the second threshold value. A storage battery control method including processing.

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