JP2016093057A - Power storage system, power storage control method, and power storage control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage system capable of preventing a storage battery from reaching the state of full-charge or complete discharge, and to provide a power storage control method, and a power storage control program.SOLUTION: A power storage system is connected with an external power supply, supply power of which varies. The power storage system has a first storage battery, a second storage battery, a generation unit, and a correction unit. The second storage battery has a charge/discharge rate per capacity that is lower compared with that of the first storage battery. The generation unit generates a primary charge/discharge command for the first and second storage batteries, respectively, on the basis of the supply power. The correction unit calculates an expected charging rate of the first storage battery when the primary charge/discharge command is given thereto, and generates a secondary charge/discharge command for correcting the charging rate of the first storage battery in a direction not deviating from a set range, on the basis of an expected charging rate of the first storage battery thus calculated.SELECTED DRAWING: Figure 4

Description

  Embodiments described herein relate generally to a power storage system, a power storage control method, and a power storage control program.

  The power generation means using natural energy such as sunlight, wind power, and geothermal power varies in power generation according to the environment. For this reason, in order to suppress a fluctuation | variation, storage batteries, such as a secondary battery, may be attached. Storage batteries include those with a high charge / discharge rate and those with a low charge / discharge rate, and those with a high charge / discharge rate are generally expensive. Therefore, a technique for increasing the overall storage capacity while improving output characteristics by using a storage battery having a high charge / discharge rate and an inexpensive storage battery having a low charge / discharge rate but a large capacity is known. However, in the conventional technology, when one of the storage batteries reaches a fully charged or completely discharged state, the subsequent control may be difficult.

JP 2011-205824 A JP 2011-234563 A

  The problem to be solved by the present invention is to provide a power storage system, a power storage control method, and a power storage control program capable of suppressing a storage battery from reaching a fully charged or fully discharged state.

  The power storage system of the embodiment is connected to an external power source whose supply power varies. The power storage system includes a first storage battery, a second storage battery, a generation unit, and a correction unit. The second storage battery has a lower charge / discharge rate per capacity than the first storage battery. The generation unit generates a primary charge / discharge command for each of the first storage battery and the second storage battery based on the supplied power. The correction unit calculates an expected charging rate of the first storage battery when the primary charge / discharge command is given to the first storage battery, and based on the calculated expected charging rate of the first storage battery, A secondary charge / discharge command is generated so that the charging rate of the storage battery of 1 is corrected so as not to fall outside the set range.

It is a figure which shows the structural example of the electrical storage system 1 of 1st Embodiment. 1 is a diagram illustrating a storage battery employed in a power storage system 1. FIG. It is a figure which shows the structure of each storage battery unit, and the connection relationship with PCS. 3 is a block diagram illustrating an example of a functional configuration of a control controller 50. FIG. It is a figure which shows a simulation result. It is a figure which shows a simulation result. It is a flowchart which shows the flow of the process performed by the control controller 50 which concerns on 1st Embodiment. It is a figure which shows a simulation result. It is a block diagram which shows the function structural example of 50 A of control controllers which concern on 2nd Embodiment. It is a flowchart which shows the flow of the process performed by 50 A of control controllers which concern on 2nd Embodiment. It is a flowchart which shows the flow of the process performed by the controller 50 which concerns on 3rd Embodiment. It is the figure which illustrated correction coefficient Gc at the time of charge of large capacity side storage battery unit 10 # 2. It is the figure which illustrated correction coefficient Gd at the time of large capacity side storage battery unit 10 # 2 discharging. It is a figure which shows a simulation result.

  Hereinafter, a power storage system, a power storage control method, and a power storage control program according to embodiments will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram illustrating a configuration example of a power storage system 1 according to the first embodiment. In the figure, a solid line indicates a power line, and a broken line indicates a communication line. The power storage system 1 is connected to a power generation device G that uses natural energy such as sunlight, wind power, and geothermal heat. Electric power supplied from the power generation device G and the power storage system 1 is connected to a power system including a commercial power source and a load via a transformer T. Since the power supply of the power generator G fluctuates, the power that is suppressed by the power storage system 1 is supplied to the power system including the commercial power supply and the load. The power generation device G is an example of an “external power source”.

  The power storage system 1 includes, for example, a wattmeter 5, a high output storage battery unit 10 # 1, a large capacity storage battery unit 10 # 2, a high output side PCS (Power Conditioning System) 40 # 1, and a large capacity side PCS 40. # 2 and a controller 50 are provided. The wattmeter 5 measures the power supplied from the power generation device G and outputs it to the controller 50. The controller 50 outputs a charge / discharge command to each of the high output side PCS 40 # 1 and the large capacity side PCS 40 # 2 based on the value of the electric power input from the wattmeter 5, thereby providing high output having different output characteristics. Type storage battery unit 10 # 1 and large capacity storage battery unit 10 # 2 are charged and discharged.

  The high-power storage battery unit 10 # 1 is a storage battery having a higher maximum charge / discharge rate per capacity than the large-capacity storage battery unit 10 # 2. The charge / discharge rate indicates the power that can be charged / discharged per unit time. If the voltage is assumed to be constant, it can be regarded as a chargeable / dischargeable current. The high power storage battery unit 10 # 1 is an example of a “first storage battery”, and the large capacity storage battery unit 10 # 2 is an example of a “second storage battery”. Examples of the storage battery employed in the power storage system 1 include those illustrated in FIG. FIG. 2 is a diagram illustrating a storage battery employed in the power storage system 1. As shown in the figure, the capacitor, flywheel battery, lithium ion battery using LMO (lithium manganate) for the positive electrode and LTO (lithium titanate) for the negative electrode, in order from the highest maximum charge / discharge rate per capacity, positive electrode LNCMO (lithium nickel cobalt manganese oxide), lithium ion battery using LTO for negative electrode, LNCMO for positive electrode, lithium ion battery using carbon material for negative electrode, nickel metal hydride battery, sodium / sulfur battery (NAS battery), lead A storage battery or the like can be used.

  In the power storage system 1, any two types of storage batteries illustrated in FIG. 2 are selected, the one with a higher charge / discharge rate is used as the high-power storage battery unit 10 # 1, and the one with a lower charge / discharge rate is used. Used as the capacity type storage battery unit 10 # 2. The capacity ratio between the high-power storage battery unit 10 # 1 and the large-capacity storage battery unit 10 # 2 is set to, for example, about 1:10 to 1: 2. In addition, not only the storage battery illustrated in FIG. 2 but another kind of storage battery may be used. Moreover, it is not limited to using two types of storage batteries, and three or more types of storage batteries may be used, and control described below may be performed for any two types of storage batteries.

[Storage battery unit and PCS]
FIG. 3 is a diagram showing the configuration of each storage battery unit and the connection relationship with the PCS. In the figure, a solid line indicates a power line, and a broken line indicates a communication line. In the description related to FIG. 3, the high-power storage battery unit 10 # 1 and the large-capacity storage battery unit 10 # 2 and the high-power PCS 40 # 1 and the large-capacity PCS 40 # 2 are not distinguished from each other, and are described as the storage battery unit 10 and the PCS 40. .

  The storage battery unit 10 includes, for example, storage battery devices (power storage panels) 11-1 to 11-n. Each storage battery device has the same configuration, for example, n = 16. In FIG. 3, only the inside of one storage battery device 11-1 is displayed. Hereinafter, the configuration of one storage battery device 11-1 will be mainly described. The storage battery device 11-1 includes m (for example, 16) assembled battery units 12-1 to 12-m connected in parallel. Each assembled battery unit has the same configuration, for example, m = 22. Hereinafter, the configuration of one assembled battery unit 12-1 will be mainly described.

  The assembled battery unit 12-1 includes k (for example, 22) battery modules 13-1 to 13-k connected in series. A switch 15 may be provided between the battery modules. The switch 15 is used, for example, to turn off the series circuit when any battery module is removed for inspection. The switch 15 may be used also as a disconnector (service disconnect), and may function as a fuse. In this case, wiring for notifying the BMU (Battery Management Unit) 17 of the insertion / extraction state and the fuse state may be provided.

  Each of the battery modules 13-1 to 13-k includes at least a plurality of battery cells connected in series, and CMUs (Cell Monitoring Units) 14-1 to 14- that monitor temperatures and voltages of the plurality of battery cells. k. Each CMU 14-1 to 14-k monitors the voltage between terminals of each battery, the temperature of each battery cell, the temperature in the battery module, etc., and via multiple communication lines such as a CAN (Control Area Network) communication line, Output to BMU17.

  A current sensor 16 is provided at one terminal of a series circuit in which a plurality of battery modules 13-1 to 13-k are connected in series. The detection value of the current sensor 16 is output to the BMU 17. The one terminal is connected to the first charge / discharge terminal 22 of the battery 10 via the switch circuit 18. In the switch circuit 18, for example, a switch S1 having no resistance (a resistance value of, for example, 1/10 or less of that of the resistance R) and a switch S2 in which the resistance R is connected in series are connected in parallel. The first charge / discharge terminal 22 is connected to, for example, the positive terminal of each of the assembled battery units 12-1 to 12-m, and the other second charge / discharge terminal 23 is connected to each of the assembled battery units 12-1 to 12-1. For example, a 12-m negative terminal is connected.

  The BMU 17 includes a processor such as a CPU (Central Processing Unit). The BMU 17 outputs a control signal for controlling the switches S1 and S2 of the switch circuit 18. The BMU 17 is connected to a gateway control device (gateway device) 19 and a measurement computer 20, and can communicate with each other. The barrier control device 19 transmits information input from the BMU 17 to the control computer 32 of the battery terminal board 30 and outputs information received from the control computer 32 to the BMU 17 or the like. The measurement computer 20 receives data such as the voltage between terminals of the battery cells in each battery module, the temperature, the detected value of the current sensor 16 and the SOC (State Of Charge) measured by the BMU 17. Acquire and calculate the value of internal resistance. The DC power supply 21 supplies power to the BMU 17 and the CMUs 14-1 to 14-k using the power supplied from the PCS 40 to the control computer 32.

  A battery terminal board 30 is connected between the storage battery unit 10 and the PCS 40. The battery terminal board 30 includes circuit breakers 31-1 to 31-n corresponding to the storage battery devices 11-1 to 11-n, respectively. Each of the circuit breakers 31-1 to 31-n is manually opened and closed. The positive electrode side terminal and the negative electrode side terminal of each circuit breaker are commonly used and connected to the PCS 40. The output from the shared battery terminal board 30 is set to a voltage of about DC 490 [V] to 778 [V], for example. By duplicating the switch circuit and the circuit breaker, the storage battery devices 11-1 to 11-n can be safely disconnected from the system even when one switch circuit is welded. The control computer 32 includes a processor such as a CPU. The control computer 32 monitors the state of each of the circuit breakers 31-1 to 31-n, transmits information received from the PCS 40 to the storage battery unit 10, and transmits information received from the storage battery unit 10 to the PCS 40.

  The PCS 40 boosts the DC voltage input from the storage battery unit 10 by switching, and generates an alternating current (AC) output. The AC output is, for example, 6.6 [kV] at 50 Hz. The PCS 40 converts the AC voltage input from the power generation device G into a DC voltage, and charges each battery cell of the storage battery unit 10. The PCS 40 includes a processor such as a CPU and a communication interface for bidirectional communication with the control controller 50.

[Control controller]
Hereinafter, the configuration and function of the controller 50 will be described. The controller 50 bidirectionally communicates with a processor such as a CPU, a read only memory (ROM), a random access memory (RAM), a hard disk drive (HDD), a storage unit 82 such as a flash memory (see FIG. 4), and the PCS 40. A communication interface or the like.

  FIG. 4 is a block diagram illustrating a functional configuration example of the controller 50. The controller 50 includes, for example, a high output side primary charge / discharge command generation unit 60, a high output side SOC calculation unit 62, a high output side expected SOC calculation unit 64, a large capacity side primary charge / discharge command generation unit 70, A correction unit 80 and a storage unit 82 are provided. These functional units are software functional units that function when a processor such as a CPU executes a program stored in the storage unit 82, for example. The program may be stored in the storage unit in advance at the time of shipment of the control controller 50, or the program stored in the portable storage device may be installed in the control controller 50. Further, the program may be downloaded to the controller 50 from another computer device via a network such as the Internet. Further, some or all of the functional units included in the controller 50 may be hardware functional units such as an LSI (Large Scale Integration) and an ASIC (Application Specific Integrated Circuit). In addition to the above program, the storage unit 82 stores a correction coefficient described later.

The high output side primary charge / discharge command generation unit 60 generates a primary charge / discharge command PP # 1 for the high output storage battery unit 10 # 1 based on a smoothing technique represented by a moving average, a primary delay, and the like. When using the moving average as a smoothing method, high-output-side primary discharge command generation unit 60 obtains the short-term moving average P _AVS for supplying electric power P _G from power generator G, the supply power P _G and short moving average P _AVS Is the primary charge / discharge command PP # 1 for the high-power storage battery unit 10 # 1. When the supply power P _G > short-term moving average P _AVS is satisfied, the high-power-side primary charge / discharge command generating unit 60 sets the charge command for the high-power storage battery unit 10 # 1 as the primary charge / discharge command PP # 1 and supplies it. When electric power P _G <short-term moving average _PAVS , the discharge command for the high-power storage battery unit 10 # 1 is the primary charge / discharge command PP # 1.

When using the first-order lag as the smoothing method, high-output-side primary discharge command generation unit 60, a power supply P (for example, about several minutes) short time constant with respect to _G primary delay P _DS from power generator G It obtains the difference between the supply electric power _{P G} and the first-order lag _{P DS,} as a high-output battery unit 10 primary discharge command to the # 1 PP # 1. Here, the first-order lag transfer function G (s) is expressed by Equation (1). In the formula, Ts is a time constant of first order delay.
G (s) = 1 / (1 + Ts) (1)

The high output side primary charge / discharge command generation unit 60 sets the charge command for the high power storage battery unit 10 # 1 as the primary charge / discharge command PP # 1 when the supply power P _G > the primary delay P _DS and the supply power When P _G <primary delay P _DS , the discharge command for the high-power storage battery unit 10 # 1 is the primary charge / discharge command PP # 1.

  The high output side SOC calculation unit 62 calculates the charging rate SOC # 1 of the high output side storage battery unit 10 # 1. In an actual operation situation, a value acquired from the BMU 17 or the like may be used as the charging rate SOC # 1 of the high output side storage battery unit 10 # 1.

  The high output side predicted SOC calculation unit 64 subtracts the primary charge / discharge command PP # 1 from the charge rate (previous SOC # 1) calculated most recently by the high output side SOC calculation unit 62, thereby obtaining a high output side storage battery. The expected charging rate SOC * # 1 of the unit 10 # 1 is calculated.

The large-capacity primary charge / discharge command generation unit 70 generates a primary charge / discharge command PP # 2 for the large-capacity storage battery unit 10 # 2 based on a smoothing technique typified by a moving average or a primary delay. When the moving average is used as the smoothing method, the large-capacity primary charge / discharge command generator 70 generates the supply power PG from the power generator _G and the primary charge / discharge command PP # 1 for the high-power storage battery unit 10 # 1. For the difference ΔP _G1 , the long-term moving average P _AVL for a longer period than the short-term moving average P _AVS is obtained, and the difference between the difference ΔP _G1 and the long-term moving average P _AVL is used as a primary charge / discharge command for the large capacity storage battery unit 10 # 2. PP # 2. When the difference ΔP _G1 > the long-term moving average P _AVL , the large-capacity primary charge / discharge command generation unit 70 sets the charge command for the large-capacity storage battery unit 10 # 2 as the primary charge / discharge command, and the difference ΔP _G1 <long-term In the case of the moving average _PAVL , the discharge command for the large capacity storage battery unit 10 # 2 is the primary charge / discharge command PP # 2.

When the primary delay is used as the smoothing method, the large-capacity primary charge / discharge command generator 70 generates the supply power PG from the power generator _G and the primary charge / discharge command PP # 1 for the high-power storage battery unit 10 # 1. seeking long first-order lag _{P DL} of the time constant on the difference [Delta] P _G1, a difference between the difference [Delta] P _G1 and the first-order lag _{P DL,} the primary charge and discharge command PP # 2 for high-capacity battery unit 10 # 2. The large-capacity primary charge / discharge command generator 70 generates a charge command for the large-capacity storage battery unit 10 # 2 as the primary charge / discharge command PP # 2 when the difference ΔP _G1 > primary delay P _DL. When ΔP _G1 <primary delay P _DL is satisfied, a discharge command for the large-capacity storage battery unit 10 # 2 is generated as a primary charge / discharge command PP # 2.

  The primary charge / discharge command PP # 1 obtained as described above is a short cycle variation command value that repeats charging and discharging in a short time compared to the primary charge / discharge command PP # 2, and thus continued in one direction. The battery capacity required for the high-power storage battery unit 10 # 1 is smaller than that of the large-capacity storage battery unit 10 # 2. On the other hand, since the primary charge / discharge command PP # 2 is a long-period fluctuation command value compared to the primary charge / discharge command PP # 1, it is a command that continues in one direction, and is more charged / discharged than the electric power output instantaneously. As a result, the required battery capacity tends to increase.

5, the supply power P _G from power generator G, is a diagram showing a simulation result of performing change suppression based on the primary charge and discharge command PP # 1 and primary charging and discharging command PP # 2. Note that the simulation results of FIG. 5 and FIGS. 6 and 8 described later are results when a first-order lag is used as the smoothing method. In this simulation, the capacity ratio between the high-power storage battery unit 10 # 1 and the large-capacity storage battery unit 10 # 2 was 1: 6.

The supply power P _G from the uppermost diagram power generator G in FIG. 5, the second figure the primary charge and discharge command PP # 1 from the top, third figure from the top of the primary charge and discharge command PP # 2, respectively Show. Bottom panel of Figure 5, the supply power P _G from power generator G, which shows the power P _FLT after the smoothing obtained by adding the primary charge and discharge command PP # 1 and primary charging and discharging command PP # 2. As shown in the figure, as a result of suppressing the fluctuation based on the primary charge / discharge command PP # 1 and the primary charge / discharge command PP # 2, the supplied power PG from the power generator _G is smoothed, and the power consumption side or the commercial power is supplied. The burden on the supply source is reduced.

However, as described above, the high-power storage battery unit 10 # 1 has a smaller capacity than the large-capacity storage battery unit 10 # 2. Therefore, when the primary charge / discharge command PP # 1 to the high-power storage battery unit 10 # 1 is biased to one of the charge side or the discharge side, the high-power storage battery unit 10 # 1 can be easily fully charged or completely discharged. Will be reached. FIG. 6 shows the assumed charging rate SOC # 1 of the high-power storage battery unit 10 # 1 and the large-capacity storage battery unit that appear as simulation results of generating and supplying the primary charge / discharge commands PP # 1 and PP # 2 to the battery unit. It is a figure which shows 10 # 2 assumption charging rate SOC # 2. As shown in the figure, high-power storage battery unit 10 # 1 has an assumed charging rate of 100% at time t1, that is, a fully charged state, and high-power storage battery unit 10 # 1 is charged after time t1. In a period in which the rate exceeds 100%, charging according to the primary charge / discharge command PP # 1 cannot be performed. When such a state occurs, the smoothing function by the high-power storage battery unit 10 # 1 stops, and the power _PFLT after smoothing may show a large fluctuation temporarily.

  In view of this, the controller 50 of the present embodiment uses the correction unit 80 to issue the primary charge / discharge commands PP # 1 and PP # 2 so that at least the high-power storage battery unit 10 # 1 is not fully charged or completely discharged. By generating the corrected secondary charge / discharge commands PS # 1 and PS # 2, it is possible to suppress the occurrence of the inconvenience as described above. Hereinafter, this will be described with reference to a flowchart.

  FIG. 7 is a flowchart showing a flow of processing executed by the controller 50 according to the first embodiment. The processing of this flowchart is repeatedly executed at a predetermined cycle, for example. Here, when the charge / discharge command value is positive, it means discharge, and when the charge / discharge command value is negative, it means charge.

  First, the high output side primary charge / discharge command generation unit 60 of the controller 50 calculates the primary charge / discharge command PP # 1 (step S100), and the large capacity side primary charge / discharge command generation unit 70 performs the primary charge / discharge command PP # 2. Is calculated (step S102).

  Next, the high output side predicted SOC calculation unit 64 calculates the primary charge / discharge command PP from the charge rate (previous SOC # 1) of the high output storage battery unit 10 # 1 calculated when the previous routine of this flowchart is executed. By subtracting # 1, the expected charging rate SOC * # 1 of the high-power storage battery unit 10 # 1 is calculated (step S104).

Then, correction unit 80 determines whether or not expected charging rate SOC * # 1 exceeds upper limit value SOC _UPPER (step S106). The upper limit value SOC _UPPER may be a standard upper limit value, that is, 100%, or a value in the vicinity thereof, or may be a value obtained by subtracting some margin.

When the expected charging rate SOC * # 1 exceeds the upper limit value SOC _UPPER , the correction unit 80 determines whether or not the primary charge / discharge command PP # 2 for the large capacity storage battery unit 10 # 2 is negative, that is, on the charging side. (Step S108).

  When primary charge / discharge command PP # 2 for large-capacity storage battery unit 10 # 2 is negative, that is, on the charging side, correction unit 80 responds to primary charge / discharge command PP # 2 for large-capacity storage battery unit 10 # 2. By multiplying the correction coefficient Ga, a secondary charge / discharge command PS # 2 for the large capacity storage battery unit 10 # 2 is generated (step S110). The correction coefficient Ga is a positive value of 1 or more, for example. Secondary charge / discharge command PS # 1 for high-power storage battery unit 10 # 1 subtracts correction (PS # 2-PP # 2) for large-capacity storage battery unit 10 # 2 from primary charge / discharge command PP # 1 (See step S126 described later). Therefore, the large-capacity storage battery unit 10 # 2 is charged more than the amount indicated by the primary charge / discharge command PP # 2, so that the primary charge / discharge command PP # 1 is given to the high-power storage battery unit 10 # 1 as it is. The amount of charge of the high-power storage battery unit 10 # 1 will be reduced compared to the case where

  When primary charge / discharge command PP # 2 for large-capacity storage battery unit 10 # 2 is positive, that is, on the discharge side, correction unit 80 responds to primary charge / discharge command PP # 2 for large-capacity storage battery unit 10 # 2. By multiplying the correction coefficient Gb, a secondary charge / discharge command PS # 2 for the large capacity storage battery unit 10 # 2 is generated (step S112). The correction coefficient Gb is a value less than 1, for example. As a result, the amount of discharge of the large-capacity storage battery unit 10 # 2 is suppressed, or the large-capacity storage battery unit 10 # 2 is charged, not discharged, and the charge amount of the high-power storage battery unit 10 # 1 is reduced. Will be reduced.

On the other hand, when expected charging rate SOC * # 1 is equal to or lower than upper limit value SOC _UPPER , correction unit 80 determines whether or not expected charging rate SOC * # 1 is lower than lower limit value SOC _LOWER (step S114). The lower limit SOC _LOWER may be a standard lower limit, that is, 0%, or a value in the vicinity thereof, or may be a value obtained by adding a slight margin to them.

When the expected charging rate SOC * # 1 is less than the lower limit SOC _LOWER , the correction unit 80 determines whether or not the primary charge / discharge command PP # 2 for the large-capacity storage battery unit 10 # 2 is positive, that is, on the discharge side. Determination is made (step S116).

  When primary charge / discharge command PP # 2 for large-capacity storage battery unit 10 # 2 is positive, that is, on the discharge side, correction unit 80 responds to primary charge / discharge command PP # 2 for large-capacity storage battery unit 10 # 2. By multiplying the correction coefficient Ga, a secondary charge / discharge command PS # 2 for the large capacity storage battery unit 10 # 2 is generated (step S118). As a result, the large-capacity storage battery unit 10 # 2 discharges more than the amount indicated by the primary charge / discharge command PP # 2, and the discharge amount of the high-power storage battery unit 10 # 1 is reduced.

  When primary charge / discharge command PP # 2 for large-capacity storage battery unit 10 # 2 is negative, that is, on the charging side, correction unit 80 responds to primary charge / discharge command PP # 2 for large-capacity storage battery unit 10 # 2. By multiplying the correction coefficient Gb, a secondary charge / discharge command PS # 2 for the large capacity storage battery unit 10 # 2 is generated (step S120). As a result, the large-capacity storage battery unit 10 # 2 is discharged instead of being charged, and the discharge amount of the high-power storage battery unit 10 # 1 is reduced.

  When the processes of steps S110, S112, S118, and S120 are performed, the correction unit 80 corrects the correction amount (PS) for the large-capacity storage battery unit 10 # 2 from the primary charge / discharge command PP # 1 for the high-power storage battery unit 10 # 1. By subtracting # 2-PP # 2), a secondary charge / discharge command PS # 1 for the high-power storage battery unit 10 # 1 is generated (step S122).

Further, when a negative determination is obtained in both step S106 and step S114, that is, the predicted SOC * # 1 of the high-power storage battery unit 10 # 1 falls between the upper limit value SOC _UPPER and the lower limit value SOC _LOWER. If determined, the correction unit 80 directly uses the primary charge / discharge commands PP # 1 and PP # 2 as the secondary charge / discharge commands PS # 1 and PS # 2 (step S124).

  Then, the high output side SOC calculation unit 62 calculates the secondary charge / discharge command PS from the charge rate (previous SOC # 1) of the high output storage battery unit 10 # 1 calculated when the previous routine of this flowchart is executed. By subtracting # 1, the charging rate SOC # 1 of the high-power storage battery unit 10 # 1 that appears as a result of the current control is calculated (step S126). This charging rate SOC # 1 is used as the previous SOC # 1 in the next routine of this flowchart.

FIG. 8 shows an assumed charging rate of the high-power storage battery unit 10 # 1 that appears as a simulation result that is generated and given to the battery unit by generating the secondary charge / discharge commands PS # 1 and PS # 2 by the method of the first embodiment. It is a figure which shows SOC # 1 and assumption charge rate SOC # 2 of large capacity type storage battery unit 10 # 2. As shown in the figure, when the secondary charge / discharge commands PS # 1 and PS # 2 are given to the high-power storage battery unit 10 # 1 and the large-capacity storage battery unit 10 # 2, respectively, the high-power storage battery unit 10 # 1 is assumed. As a result, the charging rate SOC # 1 was within the range of 0% to 100% in all time periods, and the period during which the control was difficult did not appear. Further, the smoothed power _PFLT was the same as that shown in the bottom diagram of FIG.

  According to the power storage system 1 according to the first embodiment described above, the primary charge for each of the high-power storage battery unit 10 # 1 and the large-capacity storage battery unit 10 # 2 based on the power supplied from the power generator G. Expected charging rate SOC * # 1 of high-power storage battery unit 10 # 1 when discharge commands PP # 1 and PP # 2 are generated and primary charge / discharge command PP # 1 is applied to high-power storage battery unit 10 # 1 Is determined to be out of the setting range, and when it is determined to be out of the setting range, the secondary charge is corrected so that the charging rate SOC # 1 of the high-power storage battery unit 10 # 1 does not go out of the setting range. Since the discharge commands PS # 1 and PS # 2 are generated, it is possible to suppress the high-power storage battery unit 10 # 1 from reaching a fully charged or fully discharged state.

(Second Embodiment)
Hereinafter, the second embodiment will be described. In the first embodiment, the correction unit 80 determines whether or not the charging rate of the high-power storage battery unit 10 # 1 is outside the set range. The correction unit according to the second embodiment 80 determines whether or not the charging rate of the large-capacity storage battery unit 10 # 2 is out of the setting range, and when the charging rate of the large-capacity storage battery unit 10 # 2 is out of the setting range, A secondary charge / discharge command corrected in a direction in which the charging rate of the capacity type storage battery unit 10 # 2 does not fall outside the set range is generated.

  FIG. 9 is a block diagram illustrating a functional configuration example of the control controller 50A according to the second embodiment. The control controller 50A includes a large-capacity side SOC calculation unit 72 and a large-capacity side predicted SOC calculation unit 74 in addition to the configuration according to the first embodiment.

  The large-capacity side SOC calculation unit 72 calculates the charging rate SOC # 2 of the large-capacity storage battery unit 10 # 2. In an actual operation situation, a value acquired from the BMU 17 or the like may be used as the charging rate SOC # 2 of the large-capacity storage battery unit 10 # 2.

  The large-capacity-side predicted SOC calculation unit 74 subtracts the primary charge / discharge command PP # 1 from the charge rate (previous SOC # 2) most recently calculated by the large-capacity-side SOC calculation unit 72 to thereby store the large-capacity storage battery. The expected charging rate SOC * # 2 of unit 10 # 2 is calculated.

  FIG. 10 is a flowchart showing the flow of processing executed by the control controller 50A according to the second embodiment. The processing of this flowchart is repeatedly executed at a predetermined cycle, for example. Here, when the charge / discharge command value is positive, it means discharge, and when the charge / discharge command value is negative, it means charge.

  First, the high output side primary charge / discharge command generation unit 60 of the controller 50A calculates the primary charge / discharge command PP # 1 (step S200), and the large capacity side primary charge / discharge command generation unit 70 performs the primary charge / discharge command PP # 2. Is calculated (step S202).

  Next, the high output side predicted SOC calculation unit 64 calculates the primary charge / discharge command PP from the charge rate (previous SOC # 1) of the high output storage battery unit 10 # 1 calculated when the previous routine of this flowchart is executed. By subtracting # 1, the expected charging rate SOC * # 1 of the high-power storage battery unit 10 # 1 is calculated (step S204).

Then, correction unit 80 determines whether or not expected charging rate SOC * # 1 exceeds upper limit value SOC _UPPER (step S206). The significance of the upper limit SOC _UPPER is the same as in the first embodiment. When the expected charging rate SOC * # 1 exceeds the upper limit value SOC _UPPER , the correction unit 80 performs correction in a direction to reduce the charge amount of the high-power storage battery unit 10 # 1 (step S208). Note that the actual processing content of S208 may be the same as the processing of steps S108 to S112 in the first embodiment. As a result, the charge amount of the high-power storage battery unit 10 # 1 is reduced.

On the other hand, when expected charging rate SOC * # 1 is equal to or lower than upper limit value SOC _UPPER , correction unit 80 determines whether or not expected charging rate SOC * # 1 is less than lower limit value SOC _LOWER (step S210). The significance of the lower limit SOC _LOWER is the same as in the first embodiment. When the expected charging rate SOC * # 1 is less than the lower limit SOC _LOWER , the correction unit 80 performs correction in a direction to reduce the discharge amount of the high-power storage battery unit 10 # 1 (step S212). Note that the actual processing content of S212 may be the same as the processing of steps S116 to S120 in the first embodiment. As a result, the discharge amount of the high-power storage battery unit 10 # 1 is reduced.

When a negative determination is obtained in both step S206 and step S210, that is, when the predicted SOC * # 1 of the high-power storage battery unit 10 # 1 falls between the upper limit value SOC _UPPER and the lower limit value SOC _LOWER , The large-capacity side predicted SOC calculation unit 74 obtains the primary charge / discharge command PP # 2 from the charging rate (previous SOC # 2) of the large-capacity storage battery unit 10 # 2 calculated when the previous routine of this flowchart is executed. By subtracting, the expected charging rate SOC * # 2 of the large capacity storage battery unit 10 # 2 is calculated (step S214). In the actual operation scene, a value acquired from the BMU 17 or the like may be used as the last SOC # 2. Further, the process of step S214 may be performed before the determination process of step S206.

Then, correction unit 80 determines whether or not expected charging rate SOC * # 2 exceeds upper limit value SOC _UPPER (step S216). The upper limit _{SOC UPPER} against expected charging rate SOC * upper limit _{SOC UPPER} the expected charging rate SOC for # 1 * # 2 may be the same value or may be different values. When the expected charging rate SOC * # 2 exceeds the upper limit SOC _UPPER , the correction unit 80 performs correction in a direction to reduce the charge amount of the large capacity storage battery unit 10 # 2 (step S218). Specifically, the charge amount of the high output side storage battery unit 10 # 1 is increased, or correction is performed so that charging is performed instead of discharging. Thereby, the charge amount of large capacity type storage battery unit 10 # 2 is reduced.

On the other hand, when expected charging rate SOC * # 2 is equal to or lower than upper limit value SOC _UPPER , correction unit 80 determines whether or not expected charging rate SOC * # 2 is lower than lower limit value SOC _LOWER (step S220). The lower limit _{SOC LOWER} against expected charging rate SOC * lower limit _{SOC LOWER} the expected charging rate SOC for # 2 * # 2 may be the same value or may be different values. When the expected charging rate SOC * # 2 is less than the lower limit SOC _LOWER , the correction unit 80 performs correction in a direction to reduce the discharge amount of the high-power storage battery unit 10 # 1 (step S222). Specifically, the discharge amount of the high-output side storage battery unit 10 # 1 is increased, or correction is performed so that discharging is performed instead of charging. As a result, the discharge amount of the large-capacity storage battery unit 10 # 2 is reduced.

When a negative determination is obtained in any of step S206, step S210, step S216, and step S220, that is, the predicted SOC * # 1 of the high-power storage battery unit 10 # 1 is the upper limit value SOC _UPPER and the lower limit value SOC _LOWER. If it is determined that the predicted SOC * # 2 of the large-capacity storage battery unit 10 # 2 falls between the upper limit value SOC _UPPER and the lower limit value SOC _LOWER , the correction unit 80 performs the primary charge / discharge command PP #. 1, PP # 2 is directly used as secondary charge / discharge commands PS # 1 and PS # 2 (step S224).

  Then, the high output side SOC calculation unit 62 calculates the secondary charge / discharge command PS from the charge rate (previous SOC # 1) of the high output storage battery unit 10 # 1 calculated when the previous routine of this flowchart is executed. By subtracting # 1, the charging rate SOC # 1 of the high-power storage battery unit 10 # 1 that appears as a result of the current control is calculated (step S226). Further, the large-capacity-side SOC calculating unit 72 calculates the secondary charge / discharge command PS from the charging rate (previous SOC # 2) of the large-capacity storage battery unit 10 # 2 calculated when the previous routine of this flowchart is executed. By subtracting # 2, the charging rate SOC # 2 of the large capacity storage battery unit 10 # 2 that appears as a result of the current control is calculated (step S228).

  According to the power storage system 1 according to the second embodiment described above, the primary charge for each of the high-power storage battery unit 10 # 1 and the large-capacity storage battery unit 10 # 2 based on the power supplied from the power generator G. Expected charging rate SOC * # 1 of high-power storage battery unit 10 # 1 when discharge commands PP # 1 and PP # 2 are generated and primary charge / discharge command PP # 1 is applied to high-power storage battery unit 10 # 1 Is determined to be out of the set range, and when it is determined to be out of the set range, the secondary charge / discharge command PS corrected so that the charging rate of the high-power storage battery unit 10 # 1 does not fall outside the set range # 1, PS # 2 is generated, and if the expected charging rate SOC * # 1 of the high-power storage battery unit 10 # 1 is not out of the set range, the expected charging rate of the large capacity storage battery unit 10 # 2 SOC When # 2 is outside the set range, secondary charge / discharge commands PS # 1 and PS # 2 are generated so that the charging rate SOC # 2 of the large capacity storage battery unit 10 # 2 is corrected so as not to be outside the set range. Therefore, not only the high-power storage battery unit 10 # 1 but also the large-capacity storage battery unit 10 # 2 can be prevented from reaching a fully charged or fully discharged state.

(Third embodiment)
Hereinafter, a third embodiment will be described. The functional configuration will be described with reference to FIG. 4 using the same names and symbols. In 3rd Embodiment, the correction | amendment part 80 produces | generates secondary charging / discharging instruction | command PS # 1 correct | amended so that the charging rate of high-power type storage battery unit 10 # 1 may approach the target value (for example, 50%). The correction amount is increased as the expected charging rate SOC * # 1 of the high-power storage battery unit 10 # 1 is farther from the target value. Correspondence information indicating a correspondence relationship between the expected charging rate SOC * # 1 of the high-power storage battery unit 10 # 1 and the correction amount is stored in the storage unit 82, and the correction unit 80 includes the high-power storage battery unit 10 #. The correction amount is determined by referring to the correspondence information using the expected charge rate SOC * # 1 of 1.

  FIG. 11 is a flowchart showing a flow of processing executed by the controller 50 according to the third embodiment. The processing of this flowchart is repeatedly executed at a predetermined cycle, for example. Here, when the charge / discharge command value is positive, it means discharge, and when the charge / discharge command value is negative, it means charge.

  First, the high output side primary charge / discharge command generation unit 60 of the controller 50 calculates the primary charge / discharge command PP # 1 (step S300), and the large capacity side primary charge / discharge command generation unit 70 performs the primary charge / discharge command PP # 2. Is calculated (step S302).

  Next, the high output side predicted SOC calculation unit 64 calculates the primary charge / discharge command PP from the charge rate (previous SOC # 1) of the high output storage battery unit 10 # 1 calculated when the previous routine of this flowchart is executed. By subtracting # 1, the expected charging rate SOC * # 1 of the high-power storage battery unit 10 # 1 is calculated (step S304).

  And the correction | amendment part 80 determines whether primary charging / discharging instruction | command PP # 2 is negative, ie, it is a charge side (step S306). When primary charge / discharge command PP # 2 is negative, correction unit 80 searches for correspondence information in storage unit 82 using expected charge rate SOC * # 1 of high-power storage battery unit 10 # 1, The correction coefficient Gc when the storage battery unit 10 # 2 is charged is determined (step S308), and the primary charge / discharge command PP # 2 is multiplied by the correction coefficient Gc, whereby the secondary of the large capacity storage battery unit 10 # 2 is obtained. Charge / discharge command PS # 2 is generated (step S310).

  FIG. 12 is a diagram illustrating a correction coefficient Gc when the large-capacity storage battery unit 10 # 2 is charged. As shown in the left diagram of FIG. 12, the correction coefficient Gc is, for example, a value that decreases as the predicted charge rate SOC * # 1 of the high-power storage battery unit 10 # 1 moves away from the target value of 50%. Thus, the larger the value is, the larger the value is determined. As a result, as the expected charging rate SOC * # 1 of the high-power storage battery unit 10 # 1 approaches the complete discharge, the charge amount of the large-capacity storage battery unit 10 # 2 is corrected to become smaller, and the high-power storage battery unit As the estimated charge rate SOC * # 1 of 10 # 1 approaches full charge, the charge amount of the large-capacity storage battery unit 10 # 2 is corrected so as to increase. As a result, the charging rate SOC # 1 of the high-power storage battery unit 10 # 1 is corrected in a direction closer to the target value than when the primary charge / discharge command PP # 1 is given to the high-power storage battery unit 10 # 1 as it is. Is done.

Further, as shown in the right diagram of FIG. 12, the correction coefficient Gc is determined when the expected charging rate SOC * # 1 of the high-power storage battery unit 10 # 1 falls between the upper limit value SOC _UPPER and the lower limit value SOC _LOWER. The correction coefficient Ga may be determined when the value is 1 and exceeds the upper limit value SOC _UPPER, and may be determined to be the correction coefficient Gb when the value is less than the lower limit value SOC _LOWER . As in the first embodiment, the correction coefficient Ga is a positive value of 1 or more, for example, and the correction coefficient Gb is a value of less than 1, for example. Even when the correction coefficient is determined in this way, the charge amount of the large-capacity storage battery unit 10 # 2 becomes smaller as the expected charge rate SOC * # 1 of the high-power storage battery unit 10 # 1 approaches complete discharge. The correction is made so that the charge amount of the large-capacity storage battery unit 10 # 2 increases as the expected charging rate SOC * # 1 of the high-power storage battery unit 10 # 1 approaches full charge. As a result, the charging rate SOC # 1 of the high-power storage battery unit 10 # 1 is corrected in a direction closer to the target value than when the primary charge / discharge command PP # 1 is given to the high-power storage battery unit 10 # 1 as it is. Is done.

  On the other hand, when primary charge / discharge command PP # 2 is positive, correction unit 80 searches for correspondence information in storage unit 82 using predicted charge rate SOC * # 1 of high-power storage battery unit 10 # 1, A correction coefficient Gd for discharging the capacity-side storage battery unit 10 # 2 is determined (step S312), and the primary charge / discharge command PP # 2 is multiplied by the correction coefficient Gd, so that Next charge / discharge command PS # 2 is generated (step S314).

  FIG. 13 is a diagram illustrating a correction coefficient Gd when the large-capacity storage battery unit 10 # 2 is discharged. As shown in the left diagram of FIG. 13, the correction coefficient Gd increases as the estimated charge rate SOC * # 1 of the high-power storage battery unit 10 # 1 moves away from the target value of 50%, for example. Thus, the value is determined to be smaller as the distance from the target value is larger than 50%. As a result, as the expected charging rate SOC * # 1 of the high-power storage battery unit 10 # 1 approaches complete discharge, the discharge amount of the large-capacity storage battery unit 10 # 2 is corrected so as to increase. Correction is made so that the discharge amount of the large-capacity storage battery unit 10 # 2 becomes smaller as the expected charge rate SOC * # 1 of 10 # 1 approaches full charge. As a result, the charging rate SOC # 1 of the high-power storage battery unit 10 # 1 is corrected in a direction closer to the target value than when the primary charge / discharge command PP # 1 is given to the high-power storage battery unit 10 # 1 as it is. Is done.

Further, as shown in the right diagram of FIG. 13, the correction coefficient Gd is determined when the expected charging rate SOC * # 1 of the high-power storage battery unit 10 # 1 falls between the upper limit value SOC _UPPER and the lower limit value SOC _LOWER. The correction coefficient Gb may be determined when the value is 1 and exceeds the upper limit value SOC _UPPER, and may be determined to be the correction coefficient Ga when the value is less than the lower limit value SOC _LOWER . As in the first embodiment, the correction coefficient Ga is a positive value of 1 or more, for example, and the correction coefficient Gb is a value of less than 1, for example. Even when the correction coefficient is determined in this manner, the discharge amount of the large-capacity storage battery unit 10 # 2 increases as the expected charging rate SOC * # 1 of the high-power storage battery unit 10 # 1 approaches the complete discharge. The correction is made so that the discharge amount of the large-capacity storage battery unit 10 # 2 becomes smaller as the expected charge rate SOC * # 1 of the high-power storage battery unit 10 # 1 approaches full charge. As a result, the charging rate SOC # 1 of the high-power storage battery unit 10 # 1 is corrected in a direction closer to the target value than when the primary charge / discharge command PP # 1 is given to the high-power storage battery unit 10 # 1 as it is. Is done.

  When the process of step S310 or step S314 is completed, the correction unit 80 corrects the correction amount (PS # 2-) for the large-capacity storage battery unit 10 # 2 from the primary charge / discharge command PP # 1 for the high-power storage battery unit 10 # 1. By subtracting PP # 2), secondary charge / discharge command PS # 1 for high-power storage battery unit 10 # 1 is generated (step S316).

  Then, the high output side SOC calculation unit 62 calculates the secondary charge / discharge command PS from the charge rate (previous SOC # 1) of the high output storage battery unit 10 # 1 calculated when the previous routine of this flowchart is executed. By subtracting # 1, the charging rate SOC # 1 of the high-power storage battery unit 10 # 1 that appears as a result of the current control is calculated (step S318). This charging rate SOC # 1 is used as the previous SOC # 1 in the next routine of this flowchart.

  According to the power storage system 1 according to the third embodiment described above, primary charging for each of the high-power storage battery unit 10 # 1 and the large-capacity storage battery unit 10 # 2 based on the power supplied from the power generator G. Expected charging rate SOC * # 1 of high-power storage battery unit 10 # 1 when discharge commands PP # 1 and PP # 2 are generated and primary charge / discharge command PP # 1 is applied to high-power storage battery unit 10 # 1 Based on the above, the secondary charge / discharge command PP # 1 corrected so that the charging rate SOC # 1 of the high-power storage battery unit 10 # 1 approaches the target value is generated, and the expected charging of the high-power storage battery unit 10 # 1 Since the correction amount is increased as the rate SOC * # 1 is further from the target value, the high-power storage battery unit 10 # 1 can be prevented from reaching a fully charged state or a fully discharged state. Further, by determining the correction amount with reference to the correspondence information stored in the storage unit 82, high-speed processing can be realized.

FIG. 14 shows an assumed charging rate of the high-power storage battery unit 10 # 1 that appears as a simulation result that is generated and given to the battery unit by generating the secondary charge / discharge commands PS # 1 and PS # 2 by the method of the third embodiment. It is a figure which shows SOC # 1 and assumption charge rate SOC # 2 of large capacity type storage battery unit 10 # 2. Here, the correction coefficient determination method shown in the right diagrams of FIGS. 12 and 13 is adopted, the correction coefficient Ga is a larger value than in the first embodiment, and the correction coefficient Gb is a smaller value than in the first embodiment. To be determined. As shown in the figure, when the secondary charge / discharge commands PS # 1 and PS # 2 are given to the high-power storage battery unit 10 # 1 and the large-capacity storage battery unit 10 # 2, respectively, the high-power storage battery unit 10 # 1 is assumed. The charging rate SOC # 1 falls within the range of 0% to 100% in all time periods, and there is no period during which control becomes difficult. Further, the assumed charging rate of the high-power storage battery unit 10 # 1 at the peak time (time t2) The SOC # 1 has a value smaller than the peak time (time t2) in the first embodiment. Further, the smoothed power _PFLT was the same as that shown in the bottom diagram of FIG.

(Other)
In the first or second embodiment, as in the third embodiment, the correction amount is increased as the expected charging rate SOC * # 1 of the high-power storage battery unit 10 # 1 approaches the set range. Also good. Further, in the third embodiment, as in the second embodiment, when the expected charging rate SOC * # 2 of the large capacity storage battery unit 10 # 2 is outside the set range, the large capacity storage battery unit 10 # 2 is used. The secondary charge / discharge commands PS # 1 and PS # 2 may be generated so that the charging rate SOC # 2 is corrected so as not to fall outside the set range.

  In each of the above embodiments, the process of generating the primary charge / discharge commands PP # 1, PP # 2 and the secondary charge / discharge command is performed by the controller 50. However, the PCS 40, the BMU 17, or other main body May be executed by

  According to at least one embodiment described above, the high-power storage battery unit 10 # 1 is connected to an external power supply whose supply power fluctuates, and charge / discharge per capacity compared to the high-power storage battery unit 10 # 1. Primary charge / discharge commands PP # 1, PP # 2 for the high-capacity storage battery unit 10 # 2 having a low rate and the high-power storage battery unit 10 # 1 and the large-capacity storage battery unit 10 # 2 based on the supplied power High output side primary charge / discharge command generation unit 60, large capacity side primary charge / discharge command generation unit 70, and high output type when the primary charge / discharge command PP # 1 is given to the high output storage battery unit 10 # 1 The expected charging rate SOC * # 1 of the storage battery unit 10 # 1 is calculated, and the charging rate SOC # 1 of the high-power storage battery unit 10 # 1 is calculated based on the calculated expected charging rate SOC * # 1. By having a correction unit that generates the secondary charge / discharge command PS # 1 corrected in a direction that does not fall outside the set range, at least the high-power storage battery unit 10 # 1 reaches a fully charged or fully discharged state. Can be suppressed.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Power storage system, 5 ... Wattmeter, 10 # 1 ... High output type storage battery unit, 10 # 2 ... Large capacity type storage battery unit, 40 # 1 ... High output side PCS, 40 # 2 ... Large capacity side PCS, 50 ... Control controller 60 ... High output side primary charge / discharge command generation unit 62 ... High output side SOC calculation unit 64 ... High output side expected SOC calculation unit 70 ... High capacity side primary charge / discharge command generation unit 72 ... High capacity Side SOC calculation unit, 74 ... large capacity side expected SOC calculation unit, 80 ... correction unit, 82 ... storage unit

Claims (7)

A power storage system connected to an external power supply whose supply power fluctuates,
A first storage battery;
A second storage battery having a lower charge / discharge rate per capacity than the first storage battery;
Based on the supplied power, a generation unit that generates a primary charge / discharge command for each of the first storage battery and the second storage battery;
When the first charge / discharge command is given to the first storage battery, an expected charge rate of the first storage battery is calculated, and based on the calculated expected charge rate of the first storage battery, the first storage battery A correction unit that generates a secondary charge / discharge command corrected in a direction in which the charging rate does not fall outside the set range;
A power storage system comprising: The correction unit determines whether or not the calculated expected charging rate of the first storage battery is outside a setting range, and determines that the calculated expected charging rate of the first storage battery is outside the setting range. When a secondary charge / discharge command corrected in a direction in which the charging rate of the first storage battery does not fall outside the setting range is generated and it is determined that the calculated expected charging rate of the first storage battery is within the setting range The primary charge / discharge command generated by the generator is the secondary charge / discharge command.
The power storage system according to claim 1. The correction unit determines whether or not the calculated expected charging rate of the first storage battery is outside a setting range, and determines that the calculated expected charging rate of the first storage battery is outside the setting range. When a secondary charge / discharge command corrected in a direction in which the charging rate of the first storage battery does not fall outside the setting range is generated and it is determined that the calculated expected charging rate of the first storage battery is within the setting range Based on the expected charging rate of the second storage battery, a secondary charge / discharge command corrected in a direction in which the charging rate of the second storage battery does not fall outside the set range is generated.
The power storage system according to claim 1. The correction unit generates a secondary charge / discharge command corrected so that the charging rate of the first storage battery approaches a target value based on the calculated expected charging rate of the first storage battery, and the calculated first The correction amount is increased as the expected charging rate of the storage battery 1 becomes farther from the target value.
The power storage system according to claim 1. A storage unit storing correspondence information indicating a correspondence relationship between the expected charging rate of the first storage battery calculated by the correction unit and the correction amount;
The correction unit refers to correspondence information stored by the storage unit using the calculated expected charging rate of the first storage battery, and determines the correction amount.
The power storage system according to claim 4. A control computer for an electricity storage system, connected to an external power source whose supply power fluctuates, and comprising a first storage battery and a second storage battery having a lower charge / discharge rate per capacity than the first storage battery,
Based on the supplied power, a primary charge / discharge command is generated for each of the first storage battery and the second storage battery,
Calculating an expected charging rate of the first storage battery when the primary charge / discharge command is given to the first storage battery and the second storage battery;
Based on the calculated expected charging rate of the first storage battery, a secondary charge / discharge command corrected in a direction in which the charging rate of the first storage battery does not fall outside the set range,
Power storage control method. Connected to an external power source whose supply power fluctuates, a control computer for an electricity storage system comprising a first storage battery and a second storage battery having a lower charge / discharge rate per capacity than the first storage battery,
Based on the supplied power, a primary charge / discharge command is generated for each of the first storage battery and the second storage battery,
Calculating an expected charging rate of the first storage battery when the primary charge / discharge command is given to the first storage battery and the second storage battery;
Based on the calculated expected charge rate of the first storage battery, a secondary charge / discharge command corrected in a direction in which the charge rate of the first storage battery does not fall outside the set range is generated.
Power storage control program.

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