Control device for power storage system, power storage system, method for controlling the same, and program

Abstract

To quickly reach a target temperature by efficiently performing temperature control for a plurality of storage batteries.SOLUTION: A control device for a power storage system in which a plurality of storage battery units having storage batteries and DC / DC converters for converting a voltage of charging / discharging power for the storage batteries are connected in parallel comprises: an acquisition unit that acquires limit value information on an input power limit value and an output power limit value set in each of the storage batteries of the storage battery units; and a charging / discharging control unit that, on the basis of the input power limit value and the output power limit value set in each of the storage batteries, charges the storage batteries of the other remaining storage battery units by power charged / discharged from at least one storage battery unit among the storage battery units.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a control device for a power storage system, a power storage system, a control method for a power storage system, and a program. [Background technology]

[0002] Energy storage systems are used in various facilities such as power generation facilities and factories that use renewable energy. The energy storage system includes a plurality of storage battery units each having a storage battery and a DC / DC converter. The output of the storage battery tends to decrease when the temperature is low. For this reason, Patent Document 1 discloses a control device that controls the temperature caused by heat generation due to the internal resistance of a first energy storage device by controlling the conduction rate of a bidirectional DC / DC converter provided between a first energy storage device and a second energy storage device based on the SOC (State Of Charge) of the energy storage device in a power storage system including a plurality of energy storage devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-125880 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a power storage system having a plurality of storage battery units, the performance and capacity of the storage batteries (hereinafter, this may be referred to as the characteristics of the storage battery) used may differ among the plurality of storage batteries, for example, due to the degree of deterioration from a new state, or due to a combination with a used battery having different performance and capacity. For this reason, even if the same storage battery has the same SOC indicating the charging rate or charging state of the storage battery among the plurality of storage batteries, if the characteristics of the storage battery are different, the input / output power of the storage battery will differ. For this reason, the difference between the target temperature of the storage battery commanded by the control device and the actual temperature of the storage battery may vary depending on the state of the storage battery. Therefore, even when a plurality of storage batteries with different characteristics are used in combination, it is desired to efficiently adjust the temperature.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a control device for a power storage system, a power storage system, a control method for a power storage system, and a program that are capable of efficiently controlling the temperatures of multiple storage batteries and quickly reaching a target temperature. [Means for solving the problem]

[0006] In order to solve the above problems, the control device for a power storage system, the power storage system, and the control method and program for a power storage system disclosed herein are a control device for a power storage system in which multiple storage battery units, each having a storage battery and a DC / DC converter that converts the voltage of charging and discharging power to the storage battery, are connected in parallel, and include an acquisition unit that acquires limit value information regarding an input power limit value and an output power limit value set for each of the storage batteries of the multiple storage battery units, and a charge / discharge control unit that charges the storage battery of the remaining storage battery units of the multiple storage battery units with power discharged from the storage battery of at least one of the multiple storage battery units based on the input power limit value and output power limit value set for each of the storage batteries.

[0007] The power storage system according to the present disclosure includes a plurality of storage battery units each having a storage battery and a DC / DC converter that converts the voltage of charging / discharging power for the storage battery, and the control device for the power storage system as described above.

[0008] The control method for a power storage system according to the present disclosure is a control method for a power storage system in which multiple storage battery units, each having a storage battery and a DC / DC converter that converts the voltage of charging / discharging power to the storage battery, are connected in parallel, and includes the steps of acquiring limit value information regarding an input power limit value and an output power limit value set for each of the storage batteries of the multiple storage battery units, and charging the storage battery of the remaining storage battery units among the multiple storage battery units with power discharged from the storage battery of at least one of the multiple storage battery units based on the input power limit value and output power limit value set for each of the storage batteries.

[0009] The program of the present disclosure causes a control device of a power storage system in which multiple storage battery units, each having a storage battery and a DC / DC converter that converts the voltage of charging and discharging power to the storage battery, are connected in parallel to execute the steps of acquiring limit value information regarding an input power limit value and an output power limit value set for each of the storage batteries of the multiple storage battery units, and charging the storage battery of the remaining storage battery units among the multiple storage battery units with power discharged from the storage battery of at least one of the multiple storage battery units based on the input power limit value and output power limit value set for each of the storage batteries. Effect of the Invention

[0010] According to the power storage system control device, the power storage system, the power storage system control method, and the program disclosed herein, it is possible to efficiently control the temperatures of a plurality of storage batteries, and quickly achieve a target temperature. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating an overall configuration of a power storage system according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a block diagram showing a functional configuration of a control device of the power storage system. [Diagram 3] 10A and 10B are diagrams illustrating examples of input power limit values ​​and output power limit values ​​set for a plurality of storage batteries in the embodiment of the present disclosure. [Figure 4] FIG. 11 is a diagram showing an example of a combination selected based on the sum of the input power limit value of the first storage battery group and the sum of the output power limit value of the second storage battery group when multiple storage batteries are divided into a first storage battery group and a second storage battery group in an embodiment of the present disclosure. [Diagram 5] FIG. 11 is a diagram showing an example of a storage battery that serves as a discharge side and a storage battery that serves as a charge side based on a selected combination in an embodiment of the present disclosure. [Figure 6] 5 is a flowchart showing an example of processing by a control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments for carrying out a control device for a power storage system, a power storage system, a control method for a power storage system, and a program according to the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to the embodiments. (Overall configuration of the energy storage system) FIG. 1 is a diagram showing an overall configuration of a power storage system according to an embodiment. As shown in FIG. 1, the power storage system 1 includes a control device 3, a DC bus 4, and a plurality of storage battery units 5.

[0013] The power storage system 1 is connected to an external power supply source 7 and an external power supply target 8. The power supply source 7 is, for example, a solar power generation system, a generator, etc. The power supply source 7 is not limited to a solar power generation system, a generator, etc., and may be an external power system. The external power supply target 8 is, for example, a device that consumes power supplied from the power storage system 1. The external power supply target 8 may be an external power system.

[0014] The power storage system 1 may include a PCS (Power Conditioning System) 2 between the external power supply source 7 and the power supply target 8. The PCS is a power conditioner that is connected to the power supply source 7 and the power supply target 8. The PCS has a bidirectional inverter that converts AC power and DC power. The PCS converts DC power discharged from each storage battery unit 5 into AC power and outputs it to the external power supply target 8. The PCS 2 also converts AC power supplied from the external power supply target 8 into DC power and outputs it to each storage battery unit 5.

[0015] The control device 3 controls charging and discharging of each storage battery unit. A specific functional configuration of the control device 3 will be described later.

[0016] The DC bus 4 is a bus for connecting an external power supply source 7, a power supply target 8, and the multiple storage battery units 5.

[0017] The multiple storage battery units 5 are connected in parallel via the DC bus 4. In this embodiment, for example, four storage battery units 5 are provided in parallel. The number of storage battery units 5 is not limited to four and can be changed as appropriate.

[0018] Each storage battery unit 5 includes a DC / DC converter 51 , a storage battery 52 , and a storage battery controller 55 .

[0019] The DC / DC converter 51 converts the voltage of the charging / discharging power for the storage battery 52 in accordance with a command from the control device 3. The DC / DC converter 51 converts the power supplied from the external power supply source 7 to a predetermined voltage and charges the storage battery 52. ​​The DC / DC converter 51 also converts the discharging power of the storage battery 52 to a predetermined voltage and supplies it to the external power supply target 8.

[0020] The storage batteries 52 included in each of the multiple storage battery units 5 may have different degrees of deterioration from a new state of the storage batteries 52 between the multiple storage battery units 5. Specifically, for example, the characteristics of each storage battery 52, such as the usage time from a new state, capacity, and performance, may be different.

[0021] The battery controller 55 monitors the state of each storage battery 52. ​​The battery controller 55 monitors, for example, the terminal output (output voltage, output current) of each storage battery 52 and the temperature of each storage battery 52. ​​The battery controller 55 outputs information indicating the state of each storage battery 52 to the control device 3.

[0022] The battery controller 55 also sets an input power limit value and an output power limit value for each battery 52. ​​Here, the input power limit value is the maximum power (kW) that can be input (charged) to each battery 52. ​​The output power limit value is the maximum power (kW) that can be output (discharged) from each battery 52. ​​The battery controller 55 sets the input power limit value and the output power limit value of the battery 52 from preset map information or the like based on the terminal output of each battery 52 and the temperature of each battery 52. ​​The battery controller 55 sets the input power limit value and the output power limit value at a specified time interval. The battery controller 55 outputs the set input power limit value and output power limit value to the control device 3.

[0023] (Functional configuration of the control device) FIG. 2 is a block diagram illustrating a functional configuration of a control device according to an embodiment. As shown in FIG. 2, the control device 3 includes a processor 31, a memory 32, a storage 33, and a communication interface .

[0024] The processor 31 operates according to a predetermined program to thereby fulfill the functions of an acquisition unit 311 and a charge / discharge control unit 312 .

[0025] The acquisition unit 311 acquires, from the storage battery controller 55, storage battery-related information D1 (see FIG. 2 ) indicating the state of each storage battery 52 of the multiple storage battery units 5. The storage battery-related information D1 includes limit value information, terminal voltage, temperature, etc. of the storage battery 52. ​​The limit value information of the storage battery 52 is information on the input power limit value and output power limit value set for each storage battery 52 of the multiple storage battery units 5. In this embodiment, the information on the input power limit value and output power limit value may be the input power limit value and output power limit value themselves. Furthermore, the information on the input power limit value and output power limit value may be information on which the control device 3 calculates the input power limit value and output power limit value, for example, limit values ​​of current input to and output from the storage battery 52.

[0026] FIG. 3 is a diagram showing an example of input power limit value and output power limit value set for a plurality of storage batteries. The information D1 about the storage batteries acquired by the acquisition unit 311 includes, for example, the input power limit value and the output power limit value of each storage battery 52 set by the storage battery controller 55 as shown in FIG. 3. In the example of FIG. 3, of the four storage battery units 5 shown in FIG. 1, the storage battery 52A (indicated as "A" in FIGS. 3 to 5) of the first storage battery unit 5A has an input power limit value of 25 kW and an output power limit value of 25 kW. The storage battery 52B (indicated as "B" in FIGS. 3 to 5) of the second storage battery unit 5B has an input power limit value of 20 kW and an output power limit value of 15 kW. The storage battery 52C (indicated as "C" in FIGS. 3 to 5) of the third storage battery unit 5C has an input power limit value of 20 kW and an output power limit value of 25 kW. The storage battery 52D (denoted as "D" in Figs. 3 to 5) of the fourth storage battery unit 5D has an input power limit value of 15 kW and an output power limit value of 30 kW.

[0027] Here, when at least one of the multiple storage battery units 5 is outputting power to an external power supply target 8, the acquisition unit 311 acquires the amount of power being output from the storage battery 52 to the outside. Also, when at least one of the multiple storage battery units 5 is receiving power input from an external power supply source 7, the acquisition unit 311 acquires the amount of power being input to the storage battery 52 from the outside.

[0028] The charge / discharge control unit 312 adjusts the temperature of the storage batteries 52 by performing charging and discharging between the storage batteries 52 of the multiple storage battery units 5. The charge / discharge control unit 312 charges the power discharged from the storage battery 52 of at least one storage battery unit 5 among the multiple storage battery units 5 to the storage batteries 52 of the remaining storage battery units 5 among the multiple storage battery units 5.

[0029] The charge / discharge control unit 312 performs charging / discharging between the storage batteries 52 of the multiple storage battery units 5 based on the input power limit value and the output power limit value set for each of the storage batteries 52. Based on the input power limit value and the output power limit value set for each of the storage batteries 52, the charge / discharge control unit 312 selects, among the multiple storage battery units 5, the storage battery 52 of at least one storage battery unit 5 that will be the charging side and the storage batteries 52 of the remaining storage battery units 5 that will be the discharging side.

[0030] FIG. 4 is a diagram showing an example of a combination selected based on the sum of the input power limit value of the first storage battery group G1 and the sum of the output power limit value of the second storage battery group G2 when multiple storage batteries are divided into a first storage battery group G1 and a second storage battery group G2. As shown in Fig. 4, the charge / discharge control unit 312 generates a plurality of combinations into a first storage battery group G1 including the storage batteries 52 of at least one storage battery unit 5 and a second storage battery group G2 including the storage batteries 52 of the remaining storage battery units 5. Here, the first storage battery group G1 is a group of one or more candidate storage batteries to be the charging side. The second storage battery group G2 is a group of the remaining candidate storage batteries to be the discharging side. The storage batteries 52 of all the storage battery units 5 are divided so as to belong to either the first storage battery group G1 or the second storage battery group G2. In this embodiment, the charge / discharge control unit 312 divides, for example, the storage batteries 52 of the four storage battery units 5 in this embodiment into a first storage battery group G1 and a second storage battery group G2, two batteries per group.

[0031] The number of storage batteries 52 belonging to the first storage battery group G1 and the number of storage batteries 52 belonging to the second storage battery group G2 may be the same or different. For example, in this embodiment, four storage battery units 5 are provided. For example, the first storage battery group G1 may include the storage battery 52 of one storage battery unit 5 among the four storage battery units 5, and the second storage battery group G2 may include the storage batteries 52 of the remaining three storage battery units 5 among the four storage battery units 5. Also, for example, the first storage battery group G1 may include the storage batteries 52 of two storage battery units 5 among the four storage battery units 5, and the second storage battery group G2 may include the storage batteries 52 of the remaining two storage battery units 5 among the four storage battery units 5. Also, for example, the storage batteries 52 of three of the four storage battery units 5 may belong to the first storage battery group G1, and the storage battery 52 of the remaining storage battery unit 5 may belong to the second storage battery group G2. The charge / discharge control unit 312 may generate the first storage battery group G1 and the second storage battery group G2 using all of the combinations described above.

[0032] As shown in the example of Figure 4, the charge / discharge control unit 312 calculates the sum of the input power limit values ​​of the batteries 52 of the storage battery units 5 belonging to the first storage battery group G1 and the sum of the output power limit values ​​of the storage batteries 52 of the storage battery units 5 belonging to the second storage battery group G2.

[0033] Furthermore, the charge / discharge control unit 312 selects a combination of the first storage battery group G1 to be the charging side and the second storage battery group G2 to be the discharging side from among multiple combinations based on the calculated sum of the input power limit value of the first storage battery group G1 and the calculated sum of the output power limit value of the second storage battery group G2.

[0034] For example, the greater the power that can be discharged from the discharging storage battery 52, the more sufficiently charged the storage battery 52 can be. For this reason, it is preferable for the charge / discharge control unit 312 to select, from among a plurality of combinations, the combination that maximizes the sum of the output power limit values ​​of the second discharging storage battery group G2.

[0035] Furthermore, if there is a large difference between the amount of power that can be discharged from the discharging battery 52 and the amount of power that can be charged into the charging battery 52, sufficient discharging or charging may not be possible. Therefore, it is preferable for the charge / discharge control unit 312 to select, for example, from among a plurality of combinations, a combination in which the difference between the sum of the input power limit value of the first storage battery group G1 and the sum of the output power limit value of the second storage battery group G2 is the smallest. Furthermore, for example, from among a plurality of combinations, the charge / discharge control unit 312 may select, for example, a combination in which the sum of the input power limit value of the first storage battery group G1 and the sum of the output power limit value of the second storage battery group G2 are the same.

[0036] In addition, it is preferable that the charge / discharge control unit 312 selects, from among multiple combinations, a combination in which the sum of the output power limit values ​​of the second storage battery group G2, which is the discharging side, is greater than the sum of the input power limit values ​​of the first storage battery group G1, which is the charging side.

[0037] Furthermore, it is preferable that the charge / discharge control unit 312 selects, from among multiple combinations, a combination in which the difference between the sum of the output power limit values ​​of the second storage battery group G2 and the sum of the input power limit values ​​of the first storage battery group G1 is greater than the amount of power being output from the storage system 1 to the outside at that time. For example, it is preferable for the charge / discharge control unit 312 to select from among multiple combinations one in which the difference between the sum of the output power limit values ​​of the second storage battery group G2 and the sum of the input power limit values ​​of the first storage battery group G1 is greater than the power being input to the storage system 1 from outside at that time.

[0038] The charge / discharge control unit 312 selects a combination of the first storage battery group G1 that is the charging side and the second storage battery group G2 that is the discharging side from among the multiple combinations based on the selection criteria described above. The charge / discharge control unit 312 may, for example, select a combination that satisfies all of the selection criteria described above. Furthermore, the charge / discharge control unit 312 may, for example, select a combination that satisfies the largest number of selection criteria described above from among the multiple combinations. For example, in the example of FIG. 4, the storage battery 52A and the storage battery 52B are selected as the first storage battery group G1 that is the charging side, and the storage battery 52C and the storage battery 52D are selected as the second storage battery group G2 that is the discharging side. Fig. 5 is a diagram showing an example of a storage battery that becomes a discharge side and a storage battery that becomes a charge side based on the selected combination. As shown in Fig. 5, in this embodiment, for example, the storage battery 52A of the first storage battery unit 5A and the storage battery 52B of the two storage battery units 5B are selected as the charge side, and the storage battery 52C of the third storage battery unit 5C and the storage battery 52D of the fourth storage battery unit 5D are selected as the discharge side.

[0039] The charge / discharge control unit 312 charges the storage batteries 52 of the storage battery units 5 belonging to the first storage battery group G1 with power discharged from the storage batteries 52 of the storage battery units 5 belonging to the selected second storage battery group G2. To this end, the charge / discharge control unit 312 outputs a discharge command D2h to the DC / DC converter 51 of the selected first storage battery group G1 to discharge power from the storage batteries 52 of the storage battery units 5 belonging to the selected first storage battery group G1. The charge / discharge control unit 312 outputs a power receiving command D2j to the DC / DC converter 51 of the selected second storage battery group G2.

[0040] Here, the charge / discharge control unit 312 may output a command to the DC / DC converter 51 to perform droop control of each storage battery unit 5. The droop control changes the droop slope while fixing the droop intercept of each storage battery unit 5 to an initial value (zero) so as to keep the voltage of the DC bus 4 constant and suppress variations in the state (SOC, etc.) of each storage battery unit 5. In addition, when charging / discharging a desired amount of power to a target unit, which is at least one storage battery unit 5 among the multiple storage battery units 5, the charge / discharge control unit 312 may perform a process of changing the droop intercept of the target unit as part of the droop control.

[0041] The predetermined program executed by the processor 31 is stored in a computer-readable recording medium. The computer-readable recording medium refers to a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, etc. The computer program may be distributed to a computer via a communication line, and the computer that receives the program may execute the program. The program may be for realizing part of the above-mentioned functions. The program may be a so-called difference file (difference program) that can realize the above-mentioned functions in combination with a program already recorded in the computer system.

[0042] The memory 32 has a memory area necessary for the operation of the processor 31 .

[0043] The storage 33 is a so-called auxiliary storage device, such as a hard disk drive (HDD), a solid state drive (SSD), etc. The storage 33 stores data that each part of the processor 31 acquires, generates, and refers to during processing.

[0044] The communication interface 34 is an interface for transmitting and receiving various data and control signals (information D1 relating to the storage battery, a discharge command D2h, a power receiving command D2j) between each storage battery unit.

[0045] (Control device processing flow) FIG. 6 is a flowchart illustrating an example of processing by the control device according to an embodiment. Here, a process flow in a case where the control device 3 operates some of the storage battery units 5 with a desired charge / discharge power will be described with reference to Fig. 6. The control device 3 repeatedly executes the process flow shown in Fig. 6 at preset time intervals.

[0046] First, the charge / discharge control unit 312 acquires information on preset charge / discharge conditions from each part of the power storage system 1 in order to determine whether or not to perform a charge / discharge operation for charging / discharging between the storage batteries 52 of the multiple storage battery units 5 (step S11). The information on the charge / discharge conditions acquired here includes, for example, the temperature of each storage battery 52, information indicating the occurrence of a failure in each part, and the like.

[0047] The charge / discharge control unit 312 determines whether or not a predetermined charge / discharge condition is satisfied based on the information on the charge / discharge condition acquired in step S11 (step S12). If the predetermined charge / discharge condition is satisfied (step S12: Yes), the charge / discharge control unit 312 proceeds to step S13 and onward and performs a charge / discharge operation. If the charge / discharge condition is not satisfied (step S12: No), the charge / discharge control unit 312 does not perform a charge / discharge operation and ends the process. Specifically, for example, when the temperature of the storage battery 52 is lower than a predetermined threshold, it is determined that the charge / discharge condition is satisfied. This is because if the temperature of the storage battery 52 is sufficiently high, there is no need to increase the temperature by charging from another storage battery 52. Also, for example, if some kind of failure occurs in the power storage system 1, it is determined that the charge / discharge conditions are not satisfied, and the process is terminated.

[0048] Next, the acquisition unit 311 acquires the information D1 about the storage battery from each storage battery unit 5 at each predetermined timing (step S13).

[0049] Next, the charge / discharge control unit 312 judges whether the input power limit value and the output power limit value set for each of the storage batteries 52 of the storage battery units 5, which are included in the information D1 about the storage battery, satisfy a preset limit value condition (step S14). For example, the charge / discharge control unit 312 judges whether the input power limit value of each storage battery 52 is equal to or less than a preset first threshold value. As a result, if the input power limit value is greater than the first threshold value (step S14: No), the charge / discharge operation is not performed and the process ends. If the input power limit value is equal to or less than the first threshold value (step S14: Yes), the charge / discharge control unit 312 proceeds to step S15. The input power limit value being equal to or less than the first threshold value, i.e., the input power limit value being small, means that the capacity that can be input to the storage battery 52 is small. In other words, the temperature of the storage battery 52 is lower than the threshold value, and the power that can be input is small. For this reason, the temperature of the storage battery 52 is increased in steps S15 and thereafter. Also, for example, the charge / discharge control unit 312 determines whether the output power limit value of each storage battery 52 is equal to or less than a preset second threshold value. As a result, if the output power limit value is greater than the second threshold value (step S14: No), the charge / discharge operation is not performed and the process ends. If the output power limit value is equal to or less than the second threshold value (step S14: Yes), the charge / discharge control unit 312 proceeds to step S15. In this case, the temperature of the storage battery 52 is lower than the threshold value, and the power that can be output is small. For this reason, the temperature of the storage battery 52 is increased in steps S15 and thereafter.

[0050] Next, the charge / discharge control unit 312 generates multiple combinations into a first storage battery group G1 including the storage batteries 52 of at least one storage battery unit 5 and a second storage battery group G2 including the storage batteries 52 of the other remaining storage battery units 5 (step S15).

[0051] Next, the charge / discharge control unit 312 calculates the sum of the input power limit values ​​of the batteries 52 of the storage battery units 5 belonging to the first storage battery group G1 and the sum of the output power limit values ​​of the batteries 52 of the storage battery units 5 belonging to the second storage battery group G2.

[0052] Furthermore, the charge / discharge control unit 312 selects a combination of the first storage battery group G1 to be the charging side and the second storage battery group G2 to be the discharging side from among multiple combinations based on the calculated sum of the input power limit value of the first storage battery group G1 and the calculated sum of the output power limit value of the second storage battery group G2 (step S16).

[0053] The charge / discharge control unit 312 charges the power discharged from the storage batteries 52 of the storage battery units 5 belonging to the selected second storage battery group G2 into the storage batteries 52 of the storage battery units 5 belonging to the first storage battery group G1 (step S17).

[0054] (Action, effect) As described above, in the control device 3 of the power storage system 1, the power storage system 1, and the control method of the power storage system 1 according to the present embodiment, the storage battery 52 of at least one of the storage battery units 5 is discharged and the storage battery 52 of the remaining storage battery units 5 is charged based on the input power limit value and the output power limit value set for each of the storage batteries 52 of the storage battery units 5. As a result, the storage battery 52 on the charging side is charged with power supplied from the discharging side, so that the temperature of the storage battery 52 rises and the efficiency of the storage battery 52 is improved. Here, the higher the temperature of the storage battery 52 rises, and the efficiency of the charge / discharge operation also increases accordingly. As a result, the temperature of the storage battery 52 due to the charge / discharge operation can be efficiently increased. By repeatedly executing the above-mentioned process at preset time intervals, the temperature increase efficiency of the storage battery 52 due to the charge / discharge operation increases at an accelerated rate, so that the temperature adjustment in the power storage system 1 can be efficiently performed. Here, the input power limit value and the output power limit value are set based on the terminal voltage of the storage battery 52, the temperature of the storage battery 52, and the like. Even if the characteristics of the storage batteries 52, such as the degree of deterioration, capacity, and performance, are different, the actual values ​​of the terminal voltage and temperature of each storage battery 52 can be directly acquired. As a result, the input power limit value and the output power limit value reflect the terminal voltage and temperature of each storage battery 52 at that time. Therefore, unlike the SOC, even if the numerical values ​​are the same, the actual output does not differ depending on the characteristics of the storage batteries 52, such as the degree of deterioration, capacity, and performance. As a result, even if the actual amounts of electricity stored in the storage batteries 52 differ among the multiple storage batteries 52 in the multiple storage battery units 5, the input power limit value and the output power limit value are set based on the actual amounts of electricity stored in the storage batteries 52. Therefore, the temperature control of the multiple storage batteries 52 constituting the electricity storage system 1 can be performed efficiently, allowing the target temperature to be reached quickly.

[0055] The control device 3 divides the batteries 52 of the multiple battery units 5 into a first battery group G1 and a second battery group G2, and selects the batteries 52 of the first battery group to be the charging side and the batteries 52 of the second battery group G2 to be the discharging side based on the sum of the input power limit value of the first battery group G1 and the sum of the output power limit value of the second battery group G2. This makes it possible to efficiently control the temperatures of the multiple batteries 52 constituting the power storage system 1 and quickly reach a target temperature.

[0056] Furthermore, the control device 3 selects a combination of the first storage battery group G1 as the charging side and the second storage battery group G2 as the discharging side from among multiple combinations based on the amount of power output to or input from the outside, the sum of the input power limit value of the first storage battery group G1, and the sum of the output power limit value of the second storage battery group G2. This makes it possible to efficiently control the temperatures of the multiple storage batteries 52 constituting the power storage system 1 and quickly reach a target temperature while ensuring the amount of power output to or input from the outside.

[0057] As described above, the embodiments according to the present disclosure have been described, but the above-mentioned embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and gist of the invention.

[0058] <Additional Notes> The control device 3 of the power storage system 1, the power storage system 1, the control method for the power storage system 1, and the program described in the embodiment can be understood as follows, for example.

[0059] (1) The control device 3 of the energy storage system 1 in the first aspect is a control device 3 of the energy storage system 1 in which a plurality of storage battery units 5, each having a storage battery 52 and a DC / DC converter 51 that converts the voltage of charging and discharging power to the storage battery 52, are connected in parallel via a DC bus 4, and the control device 311 is provided with an acquisition unit 311 that acquires limit value information regarding an input power limit value and an output power limit value set for each of the storage batteries 52 of the plurality of storage battery units 5, and a charge / discharge control unit 312 that charges the storage battery 52 of the remaining storage battery units 5 of the plurality of storage battery units 5 with power discharged from the storage battery 52 of at least one of the plurality of storage battery units 5 based on the input power limit value and output power limit value set for each of the storage batteries 52.

[0060] The control device 3 of this power storage system 1 discharges the battery 52 of at least one of the storage battery units 5 and charges the battery 52 of the remaining storage battery units 5 based on the input power limit value and the output power limit value set for each of the storage batteries 52 of the storage battery units 5. As a result, the storage battery 52 on the charging side is charged with power supplied from the discharging side, thereby increasing the temperature of the storage battery 52 and easing the output limit value of the storage battery 52. Here, the input power limit value and the output power limit value are set based on the terminal voltage of the storage battery 52, the temperature of the storage battery 52, and the like. Therefore, even if the deterioration degree of the storage battery 52 differs, the actual values ​​of the terminal voltage and temperature of each storage battery 52 can be directly acquired. As a result, the input power limit value and the output power limit value reflect the terminal voltage and temperature of each storage battery 52 at that time. Therefore, unlike the SOC, even if the numerical value is the same, the actual output does not differ depending on the deterioration degree of the storage battery 52, and the like. As a result, even if the actual amounts of electricity stored in the storage batteries 52 differ among the multiple storage batteries 52 in the multiple storage battery units 5, the input power limit value and the output power limit value are set based on the actual amounts of electricity stored in the storage batteries 52. Therefore, the temperature control of the multiple storage batteries 52 constituting the electricity storage system 1 can be performed efficiently, allowing the target temperature to be reached quickly.

[0061] (2) A control device 3 of a power storage system 1 according to a second aspect is the control device 3 of the power storage system 1 of (1), in which the charge / discharge control unit 312 generates a plurality of combinations in which the storage batteries 52 of the plurality of storage battery units 5 are divided into a first storage battery group G1 and a second storage battery group G2, and calculates a sum of input power limit values ​​of the storage batteries 52 of the storage battery units 5 belonging to the first storage battery group G1 and a sum of output power limit values ​​of the storage batteries 52 of the storage battery units 5 belonging to the second storage battery group G2. Based on the calculated sum of the input power limit value of the first storage battery group G1 and the calculated sum of the output power limit value of the second storage battery group G2, a combination of the first storage battery group G1 to be the charging side and the second storage battery group G2 to be the discharging side is selected from the multiple combinations, and the storage battery 52 of the storage battery unit 5 belonging to the selected second storage battery group G2 is charged with the power discharged from the storage battery 52 of the storage battery unit 5 belonging to the first storage battery group G1.

[0062] As a result, the storage batteries 52 of the multiple storage battery units 5 are divided into a first storage battery group G1 and a second storage battery group G2, and the storage batteries 52 of the first storage battery group G1 to be the charging side and the storage batteries 52 of the second storage battery group G2 to be the discharging side are selected based on the sum of the input power limit value of the first storage battery group G1 and the sum of the output power limit value of the second storage battery group G2. As a result, the temperature of the multiple storage batteries 52 constituting the power storage system 1 can be efficiently controlled and can be made to reach a target temperature quickly.

[0063] (3) A control device 3 of a storage system 1 according to a third aspect is the control device 3 of the storage system 1 of (1) or (2), wherein the acquisition unit 311 acquires the amount of power output to the outside or input from the outside in each of the storage batteries 52 of the multiple storage battery units 5, and the charge / discharge control unit 312 selects a combination of the first storage battery group G1 to be the charging side and the second storage battery group G2 to be the discharging side from among the multiple combinations based on the amount of power, the sum of the input power limit value of the first storage battery group G1, and the sum of the output power limit value of the second storage battery group G2.

[0064] According to this configuration, the amount of power output to or input from the outside is excluded, and a combination of the first storage battery group G1 to be the charging side and the second storage battery group G2 to be the discharging side is selected from the multiple combinations based on the sum of the input power limit value of the first storage battery group G1 and the sum of the output power limit value of the second storage battery group G2. This makes it possible to efficiently control the temperatures of the multiple storage batteries 52 constituting the power storage system 1 and quickly reach a target temperature while ensuring the amount of power exchanged between the storage battery 52 and the outside.

[0065] (4) A fourth aspect of the energy storage system 1 includes a plurality of storage battery units 5 each having a storage battery 52 and a DC / DC converter 51 that converts the voltage of the charging / discharging power for the storage battery 52, and a control device 3 of any one of the energy storage systems 1 (1) to (3).

[0066] This makes it possible to efficiently control the temperatures of the multiple storage batteries 52 constituting the power storage system 1, and to quickly reach the target temperature.

[0067] (5) A control method for a storage system 1 according to a fifth aspect is a control method for a storage system 1 in which a plurality of storage battery units 5, each having a storage battery 52 and a DC / DC converter 51 that converts the voltage of charging and discharging power to and from the storage battery 52, are connected in parallel via a DC bus 4, and includes a step S13 of acquiring limit value information regarding an input power limit value and an output power limit value set for each of the storage batteries 52 of the plurality of storage battery units 5, and a step S17 of charging the storage battery 52 of the remaining storage battery units 5 of the plurality of storage battery units 5 with power discharged from the storage battery 52 of at least one of the plurality of storage battery units 5 based on the input power limit value and output power limit value set for each of the storage batteries 52.

[0068] This makes it possible to provide a control method that can efficiently control the temperatures of the multiple storage batteries 52 that constitute the power storage system 1 and quickly reach a target temperature.

[0069] (6) A program relating to a sixth aspect causes a control device 3 of a power storage system 1 in which multiple storage battery units 5, each having a storage battery 52 and a DC / DC converter 51 that converts the voltage of charging and discharging power to and from the storage battery 52, are connected in parallel via a DC bus 4 to execute the following steps: a step S13 of acquiring limit value information regarding an input power limit value and an output power limit value set for each of the storage batteries 52 of the multiple storage battery units 5; and a step S17 of charging the storage battery 52 of the remaining storage battery units 5 of the multiple storage battery units 5 with power discharged from the storage battery 52 of at least one of the multiple storage battery units 5 based on the input power limit value and output power limit value set for each of the storage batteries 52.

[0070] This makes it possible to provide a control device 3 that can efficiently control the temperatures of the multiple storage batteries 52 that constitute the power storage system 1 and quickly reach a target temperature. [Explanation of symbols]

[0071] 1. Energy storage system 3. Control device 5, 5A~5D…Battery unit 51...DC / DC converter 52, 52A~52D…Storage battery 311…Acquisition Department 312…Charge / discharge control unit G1: First battery group G2: Second battery group

Claims

1. A control device for a power storage system in which a plurality of storage battery units, each of which has a storage battery and a DC / DC converter that converts a voltage of charging / discharging power for the storage battery, are connected in parallel, an acquisition unit that acquires limit value information related to an input power limit value and an output power limit value set for each of the storage batteries of the plurality of storage battery units; a charge / discharge control unit that charges the power discharged from the storage battery of at least one of the plurality of storage battery units to the storage battery of the remaining storage battery units among the plurality of storage battery units based on an input power limit value and an output power limit value set for each of the storage batteries; A control device for a power storage system comprising:

2. The charge / discharge control unit is generating a plurality of combinations in which the storage batteries of the plurality of storage battery units are divided into a first storage battery group and a second storage battery group; calculating a sum of input power limit values ​​of the storage batteries of the storage battery units belonging to the first storage battery group and a sum of output power limit values ​​of the storage batteries of the storage battery units belonging to the second storage battery group; selecting, from the plurality of combinations, a combination of the first storage battery group to be a charging side and the second storage battery group to be a discharging side based on the calculated sum of the input power limit values ​​of the first storage battery group and the calculated sum of the output power limit values ​​of the second storage battery group; charging the storage battery of the storage battery unit belonging to the first storage battery group with electric power discharged from the storage battery of the storage battery unit belonging to the selected second storage battery group; The control device for the power storage system according to claim 1 .

3. The acquisition unit acquires an amount of power output to an outside source or input from an outside source in each of the storage batteries of the plurality of storage battery units, the charge / discharge control unit selects, from the plurality of combinations, a combination of the first storage battery group to be a charge side and the second storage battery group to be a discharge side, based on the amount of power, a sum of an input power limit value of the first storage battery group, and a sum of an output power limit value of the second storage battery group; The control device for the power storage system according to claim 2 .

4. A plurality of storage battery units each including a storage battery and a DC / DC converter that converts a voltage of charging / discharging power for the storage battery; The control device for the power storage system according to any one of claims 1 to 3; A power storage system comprising:

5. A control method for a power storage system in which a plurality of storage battery units, each of which has a storage battery and a DC / DC converter that converts a voltage of charging / discharging power for the storage battery, are connected in parallel, comprising: acquiring limit value information regarding an input power limit value and an output power limit value set for each of the storage batteries of the plurality of storage battery units; and charging the power discharged from the storage battery of at least one of the plurality of storage battery units to the storage battery of the remaining storage battery units among the plurality of storage battery units based on an input power limit value and an output power limit value set for each of the storage batteries. A method for controlling an energy storage system.

6. A control device for a power storage system in which a plurality of storage battery units, each having a storage battery and a DC / DC converter that converts the voltage of charging / discharging power for the storage battery, are connected in parallel, acquiring limit value information regarding an input power limit value and an output power limit value set for each of the storage batteries of the plurality of storage battery units; charging the power discharged from the storage battery of at least one of the plurality of storage battery units to the storage battery of the remaining storage battery units among the plurality of storage battery units based on an input power limit value and an output power limit value set for each of the storage batteries; A program that executes the following.

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