JP2019140716A - Power storage control device, power storage control method, and power storage control program - Google Patents

Abstract

To execute a uniform charging in accordance with a state of a lead-acid battery.SOLUTION: A power storage control device according to one embodiment controls a power storage device provided with a lead-acid battery. The power storage control device comprises a determination part for determining a point when SOC of the lead-acid battery for which a first uniform charging is completed is lowered to a predetermined threshold, as a starting point in a judgement period for judging a discharging state of the lead-acid battery; a judgement part for judging the discharging state of the lead-acid battery in the judgement period ;a selection part for selecting a uniform charging method corresponding to the judged discharging state out of a plurality of predetermined uniform charging methods; and an instruction part for transmitting, to the power storage device, a charging instruction for executing a second uniform charging next to the first uniform charging to the lead-acid battery by the selected uniform charging method.SELECTED DRAWING: Figure 2

Description

  One aspect of the present invention relates to a power storage control device, a power storage control method, and a power storage control program.

  A technique for managing charge / discharge of a power storage device is conventionally known. For example, Patent Document 1 below describes a technique for extending the life of a lead storage battery used in a natural energy utilization system. The lead storage battery includes a battery state measurement unit that measures the state of the lead storage battery, an SOC model that represents the relationship between the current, voltage, and temperature of the lead storage battery and the charge state of the lead storage battery, and an equal charge of the lead storage battery. It has an equal charge execution part to implement.

Japanese Patent No. 5447282

  For lead-acid batteries that are used while being repeatedly charged and discharged, uniform charging is performed at regular intervals to prevent a decrease in capacity due to insufficient charging. However, since this equal charge is uniformly performed regardless of the state of the lead-acid battery, there is an excess or shortage of charge, and as a result, the battery life may be shorter than expected. Therefore, it is desired to perform uniform charging according to the state of the lead storage battery.

  A power storage control device according to an aspect of the present invention is a power storage control device that controls a power storage device having a lead storage battery, and the time when the SOC of the lead storage battery for which the first equal charge has ended is lowered to a predetermined threshold value. Is determined from a determination unit that determines the starting point of the determination period for determining the discharge state of the lead storage battery, a determination unit that determines the discharge state of the lead storage battery in the determination period, and a plurality of predetermined equal charge methods A selection unit that selects an equal charge method corresponding to the discharged state, and a charge instruction for causing the lead storage battery to execute a second equal charge next to the first equal charge by the selected equal charge method. And an instruction unit for transmission toward

  A power storage control method according to one aspect of the present invention is a power storage control method executed by a power storage control device that controls a power storage device having a lead storage battery, wherein the SOC of the lead storage battery for which the first equal charge has ended is predetermined. A determination step for determining a time point when the threshold value is lowered to a predetermined threshold as a starting point of a determination period for determining a discharge state of the lead storage battery, a determination step for determining a discharge state of the lead storage battery in the determination period, and a plurality of predetermined numbers A step of selecting an equal charge method corresponding to the determined discharge state from the equal charge method, and causing the lead storage battery to execute a second equal charge next to the first equal charge by the selected equal charge method. And an instruction step of transmitting a charging instruction for the power storage device to the power storage device.

  A power storage control program according to one aspect of the present invention is a power storage control program that causes a computer to function as a power storage control device that controls a power storage device having a lead storage battery. A determination step for determining a time point when the lead-acid battery is discharged to a predetermined threshold as a starting point of a determination period for determining a discharge state of the lead-acid battery; a determination step for determining a discharge state of the lead-acid battery in the determination period; A selection step for selecting an equal charge method corresponding to the determined discharge state from a plurality of equal charge methods, and a second equal charge subsequent to the first equal charge for the lead storage battery by the selected equal charge method. And causing the computer to execute an instruction step of transmitting a charging instruction to the power storage device.

  In such an aspect, a plurality of methods are prepared in advance for equal charge. And the determination period for determining the discharge state of a lead acid battery is defined, and the next equal charge is performed by the equal charge method corresponding to the discharge state in this determination period. Therefore, equal charge can be executed according to the state of the lead storage battery.

  According to one aspect of the present invention, equal charge can be performed according to the state of the lead storage battery.

It is a figure which shows typically an example of a structure of an electrical storage system and its periphery. It is a figure which shows the function structure of the integrated controller (electric storage control apparatus) which concerns on embodiment. It is a flowchart which shows operation | movement of the integrated controller (electric storage control apparatus) which concerns on embodiment. It is a figure which shows the example of a selection rule.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description is omitted.

[Entire configuration of power storage system]
The power storage control device according to the embodiment is a device that functions as a part of the power storage system 1. The power storage system 1 is a system that manages electricity generated using renewable energy, and can be used in various places such as a home, an office, a factory, and a farm.

  Before describing the power storage control device, an overall image of the power system including the power storage system 1 will be described. FIG. 1 is a diagram schematically illustrating an example of the configuration of the power storage system 1 and its surroundings. The power storage system 1 is provided between the power generator 2, the power system 4, and the load 5. A DC system including the power storage system 1 and the power generation device 2 and an AC system including the power system 4 and the load 5 are electrically connected via a PCS (power conditioning system) 3. The power storage system 1, the power generation device 2, and the PCS 3 are electrically connected via a DC (Direct Current) bus 6 through which a direct current flows. The power system 4, the load 5, and the PCS 3 are electrically connected via an AC (Alternating Current) bus 7 in which an alternating current flows. The electricity generated by the power generation device 2 or the electricity stored in the power storage system 1 is supplied to the load 5 and may be supplied to the power system 4 side (for example, power sale). The power storage system 1 also plays a role of mitigating fluctuations in power supply from the power generation device 2 to the power system 4 or the load 5 by using the storage battery like a cushion.

  The power generation device 2 is a device that generates power using renewable energy. The type of power generation method and power generation device 2 is not limited at all. For example, the power generation device 2 may be a solar power generation device or a wind power generator.

  The electric power system 4 is a commercial power supply facility that integrates power generation, power transformation, power transmission, and power distribution, and is provided by, for example, an electric power company.

  The load 5 is a set of one or more devices or apparatuses that consume power, for example, a set of one or more various electric devices for home use or business use.

  The PCS 3 is a device that converts direct current electricity into alternating current, and is a kind of power converter. The PCS 3 has a DC terminal connected to the DC bus 6 and an AC terminal connected to the AC bus 7.

  The power storage system 1 includes a power storage device 10, a power converter 20, and a general controller 30. One power converter 20 corresponds to one power storage device 10, and these two devices are electrically connected via a DC bus. A pair of the power storage device 10 and the power converter 20 that correspond to each other can also be referred to as a power storage unit. In the example of FIG. 1, the power storage system 1 includes three sets of power storage devices 10 and power converters 20 (three power storage units), but the number of sets is not limited, and may be 1, 2 or 4 or more. When there are a plurality of power storage units, the performance of the power storage device 10 (for example, rated capacity, response speed, etc.) and the performance of the power converter 20 (for example, rated output, response speed, etc.) may be unified. It does not have to be unified. The overall controller 30 is communicably connected to each power storage device 10 and each power converter 20 via the communication line 40.

  The power storage device 10 is a device that stores the electricity generated by the power generation device 2 by converting it into chemical energy, and can be charged and discharged. The power storage device 10 can also be used to reduce (level) fluctuations in DC power generated by the power generation device 2. The power storage device 10 includes a lead storage battery 11 including a plurality of cells connected in series. The number of cells constituting the lead storage battery 11 is not limited, and may be 200 or 288, for example. The power storage device 10 further includes a control function such as a battery control unit (BCU), and the control function can transmit data related to the power storage device 10 to the overall controller 30.

  The power converter 20 is a device that controls charging and discharging of the power storage device 10. The power converter 20 receives an instruction signal (data signal) from the overall controller 30 and controls charging / discharging of the power storage device 10 based on the instruction signal. The power converter 20 stores the electricity flowing from the power generation device 2 in the power storage device 10 in the charge mode, discharges the power storage device 10 to supply power to the outside in the discharge mode, and performs charge / discharge in the stopped state. Absent. The power converter 20 may be a DC / DC converter, for example.

[Configuration of general controller]
The overall controller 30 is a computer (for example, a microcomputer) that controls the power converter 20 and the power storage device 10. FIG. 2 is a diagram illustrating a functional configuration of the overall controller 30. As shown in this figure, the overall controller 30 includes a processor 101, a memory 102, and a communication interface 103 as hardware devices. The processor 101 is, for example, a CPU and the memory 102 is, for example, a flash memory. However, the types of hardware devices that constitute the overall controller 30 are not limited to these, and may be arbitrarily selected. Each function of the overall controller 30 is realized by the processor 101 executing a program stored in the memory 102. For example, the processor 101 performs a predetermined operation on the data read from the memory 102 or the data received via the communication interface 103, and outputs the operation result to the other device, so that the other device is Control. Alternatively, the processor 101 stores the received data or calculation result in the memory 102. The overall controller 30 may be configured by a single computer or a set of a plurality of computers (that is, a distributed system).

  One of the features of the power storage system 1 is the control of equal charge, and this feature is realized by the overall controller 30 in particular. In this embodiment, the power storage control device according to the present invention is applied to the overall controller 30. Below, the function and structure of the general controller 30 regarding equal charge are demonstrated. The equal charge is a charge for making the voltage constant between a plurality of cells constituting one lead storage battery 11. When voltage variation occurs between individual cells of the lead storage battery 11, a circulating current due to a potential difference may be generated and adversely affect the cells. The equal charge is a process of resetting the battery quality by eliminating such voltage variation between cells.

  The processor 101 functions as an acquisition unit 31, a determination unit 32, a determination unit 33, a selection unit 34, and an instruction unit 35. The acquisition unit 31 is a functional element that acquires data related to the lead storage battery 11. The determination unit 32 is a functional element that determines a determination period for determining the discharge state of the lead storage battery 11. The determination unit 33 is a functional element that determines the discharge state of the lead storage battery 11 in the determined determination period. The discharged state is a concept indicating how much electricity the lead storage battery 11 has released compared to the fully charged state, and can be expressed using various indicators. The selection unit 34 is a functional element that selects one equal charge method from a plurality of predetermined equal charge methods based on the determined discharge state. The instruction unit 35 is a functional element that transmits a charging instruction based on the selected equal charging method to the power storage device 10. The charge instruction is a data signal for causing the power storage device 10 to perform equal charge of the lead storage battery 11. In this way, the processor 101 performs equal charge on the lead storage battery 11 by a method that matches the discharge state of the lead storage battery 11 of the power storage device 10.

  The discharge state of the lead storage battery 11 is a clue to know the degree of decrease in the capacity of the lead storage battery 11. Typically, non-conductive crystals (sulfation) generated in the electrodes increase the internal resistance in the battery and decrease the capacity of the lead storage battery 11, which means deterioration of the lead storage battery 11. Therefore, it can be said that performing equal charge by a method suitable for the discharge state of the lead storage battery 11 is performing equal charge according to the degree of deterioration of the lead storage battery 11.

  The memory 102 stores information necessary for the operation of the processor 101. For example, the memory 102 stores the selection rule 36. The selection rule 36 is information that defines a plurality of equal charge methods, and each equal charge method is associated with an assumed discharge state of the lead storage battery 11. Therefore, the selection rule 36 is a rule for selecting one equal charge method corresponding to the determined discharge state from a plurality of equal charge methods prepared in advance. The description method of the selection rule 36 is not limited. For example, the selection rule 36 may be represented by any one of an equation, an algorithm, and a correspondence table, or may be represented by any combination of two or more of the equation, the algorithm, and the correspondence table. Alternatively, the selection rule 36 may be a part of a program executed by the processor 101.

  The selection rule 36 may be rewritable. For example, when the power storage device 10 is replaced with another type or a new type of power storage device 10 is added, the administrator rewrites the selection rule 36 in the memory 102 according to the change in the configuration. In this case, the administrator accesses the overall controller 30 with a management computer (not shown) via a predetermined communication network (not shown), and sets a new selection rule 36 reflecting the change in configuration to the overall controller 30. You may forward to. By this transfer, the selection rule 36 in the memory 102 is rewritten.

  The communication interface 103 executes data transmission / reception in cooperation with the processor 101. For example, the communication interface 103 cooperates with the acquisition unit 31 to receive input data necessary for charge / discharge control. In addition, the communication interface 103 transmits a charging instruction to the power converter 20 in cooperation with the instruction unit 35.

[Operation of general controller]
The operation of the overall controller 30 will be described with reference to FIGS. 3 and 4 and the power storage control method according to the present embodiment will be described. FIG. 3 is a flowchart showing an example of the operation of the overall controller 30, and specifically shows a process of performing equal charge on one power storage device 10. FIG. 4 is a diagram illustrating an example of the selection rule 36.

  In step S11, the determination part 32 determines a determination period (decision step). More specifically, the determination unit 32 determines the start point and the end point of the determination period based on the data acquired by the acquisition unit 31. Both the start point and the end point of the determination period are set within the time period from the end of the previous equal charge (first equal charge) to the start of the next equal charge (second equal charge). Is done.

  The acquisition unit 31 starts acquiring data after the first equal charge is completed. The acquisition unit 31 receives data from the power storage device 10 or the power converter 20 corresponding to the power storage device 10 via the communication line 40, thereby obtaining data indicating a charge rate (States Of Charge: SOC) of the lead storage battery 11. get. The SOC specified based on this data may be an average SOC, which is an average value of the SOC of individual cells constituting one lead storage battery 11. Alternatively, the obtained SOC may be the SOC of a specific part of cells constituting one lead storage battery 11. The acquisition unit 31 periodically acquires data for determination of the determination period.

  The determination unit 32 determines whether or not the SOC specified by the acquired data has decreased to a predetermined threshold value Ta. This threshold value Ta is stored in the memory 102 in advance, and the determination unit 32 can obtain the threshold value Ta by referring to the memory 102. The threshold value Ta may be set to 90% or a value close to 90%. For example, the threshold value Ta may be a value within a range of 85% or more and less than 95%, a value within a range of 88% or more and less than 92%, or a range of 89% or more and less than 91%. May be the value. Corresponding to the acquisition unit 31 periodically acquiring data, the determination unit 32 can repeatedly execute this determination process.

  When the specified SOC does not fall to the threshold value Ta, that is, when the SOC is larger than the threshold value Ta, the determination unit 32 does not set the start point of the determination period. In this case, the process does not proceed to step S12, and the process of step S11 is executed again.

  When the specified SOC falls to the threshold value Ta, that is, when the SOC is equal to or less than the threshold value Ta, the determination unit 32 determines the current time point as the start point of the determination period. This process is a process of determining the time point when the SOC of the lead storage battery 11 that has completed the first equal charge has dropped from a value (for example, 100%) immediately after the first equal charge to the threshold value Ta as the start point of the determination period.

  The technical significance of determining not the time immediately after the end of the first equal charge but the time when the SOC has decreased to the threshold value Ta as the starting point of the determination period will be described. One factor that shortens the life of the lead storage battery 11 is the elongation of the positive electrode plate of the lead storage battery 11. The elongation of the electrode plate proceeds due to the corrosion of the grid. There are two types of corrosion, intergranular corrosion and general corrosion. Intergranular corrosion proceeds so that the lattice cracks, and the lattice elongation increases as corrosion enters the lattice. In the case of the general corrosion, the lattice elongation is smaller than the intergranular corrosion, and the increase in the amount of corrosion is gradual. Intergranular corrosion is considered to be caused by a longer stay period at the potential at which intergranular corrosion occurs due to overcharging of the lead storage battery 11. Since intergranular corrosion significantly affects battery life, it is necessary to prevent intergranular corrosion from occurring.

  Since the operation of mitigating fluctuations in power supply depends on the natural environment, there is a possibility that high-rate charging may be performed immediately after the start of the operation. That is, if charging is performed in a state where the SOC is 100% or close to 100%, overcharging may occur. It has been confirmed that when charging is performed at a maximum allowable rate for a certain period in a state where the SOC is 100%, the terminal voltage significantly increases (that is, overcharge). This overcharge increases the risk of intergranular corrosion. On the other hand, when charging is performed in a state where the SOC is 90% or less, the potential rise is small, and the potential does not reach a level at which intergranular corrosion may occur.

  On the other hand, it is known that when the operation is performed in a state where the SOC is low, the overall corrosion amount is increased as compared with the operation in a state where the SOC is high. The inventor of the present invention tested the life of the lead-acid battery 11 in simulated fluctuation mitigation in each of the three cases where the SOC was maintained at about 30%, about 60%, and about 90%. As a result, in two cases where the SOC was 30% and 60%, an increase in the overall corrosion amount was confirmed. On the other hand, when the SOC was 90%, an increase in the corrosion amount was suppressed. Based on these results, the inventor of the present invention predicted a change in the amount of corrosion when the SOC was between 60% and 90%. As a result, the inventors have found that adjusting the SOC to about 90% is most effective in maintaining the life of the lead storage battery 11 for a long time. Therefore, the threshold Ta may be set to 90% or a value close to 90%, and the time point when the SOC decreases to the threshold Ta may be set as the start point of the determination period.

  After determining the start point of the determination period, the determination unit 32 determines the end point of the determination period. For example, the determination unit 32 determines a time point at which a predetermined fixed period Tx elapses from the start point as the end point of the determination period. The fixed period Tx is stored in the memory 102 in advance, and the determination unit 32 can obtain the fixed period Tx by referring to the memory 102. The fixed period Tx may be set corresponding to the power storage device 10 or the lead storage battery 11. For example, the fixed period Tx may be set according to the type or performance of the power storage device 10, or may be set according to the type or performance of the lead storage battery 11. The specific length of the fixed period Tx is not limited, and may be, for example, two weeks or one month corresponding to the power storage device 10 or the lead storage battery 11. Alternatively, the fixed period Tx may be a constant value regardless of the power storage device 10 and the lead storage battery 11. The end point of the determination period may be a time point immediately before the next equal charge (second equal charge). When the determination period is determined, the process proceeds to step S12.

  In step S12, the acquisition unit 31 acquires the state of the lead storage battery 11 in the determined determination period. More specifically, the acquisition unit 31 acquires the state of the lead storage battery 11 in the time zone from the start point to the end point of the determination period. The acquisition unit 31 acquires data indicating the state of the lead storage battery 11 by receiving data from the power storage device 10 or the power converter 20 corresponding to the power storage device 10 via the communication line 40. The type of data indicating the state of the lead storage battery 11 is not limited. For example, the data indicating the charge amount or the charge rate of the lead storage battery 11 or the data indicating the discharge amount of the lead storage battery 11 may be used. . The timing at which the acquisition unit 31 acquires the data is not limited. For example, the acquisition unit 31 may repeat data acquisition periodically during the determination period. Or the acquisition part 31 may acquire the data which show the state of the lead storage battery 11 in the determination period at once.

  In step S13, the determination part 33 determines the discharge state of the lead storage battery 11 in the determination period based on the acquired data (determination step). The determination unit 33 executes this determination process in response to determination of the determination period. The determination unit 33 may determine the discharge state by calculation based on the acquired data, or may determine the acquired data as the discharge state as it is. The index used for determining the discharge state is not limited, and may be, for example, an average SOC or an integrated discharge amount. The integrated discharge amount is the total amount of electricity released from the lead storage battery 11 during the determination period.

  In step S14, the selection unit 34 refers to the selection rule 36, and selects one equal charging method corresponding to the determined discharge state from among a plurality of equal charging methods (selection step). The selection rule 36 is defined according to the type of discharge state to be determined, and the method for selecting the equal charge method also varies depending on the type of discharge state. Below, the selection method at the time of using any one of average SOC and integrated discharge amount as a discharge state is illustrated.

  Assume that the memory 102 stores the selection rule 36 shown in the example (a) of FIG. In example (a), the selection rule 36 defines three equal charge methods, a first method, a second method, and a third method, and each equal charge method includes an average SOC, a charge time The correspondence with the set voltage is shown. The first method means that equal charge is performed at a set voltage of 2.50 V / cell if the average SOC is less than 50%. The second method means that equal charge is performed at a set voltage of 2.45 V / cell if the average SOC is 50% or more and less than 70%. The third method means that equal charge is performed at a set voltage of 2.42 V / cell if the average SOC is 70% or more and less than 90%. When using the average SOC, the selection unit 34 refers to the selection rule 36 and selects one equal charging method corresponding to the average SOC determined by the determination unit 33.

  When the average SOC is relatively small, the capacity of the lead storage battery 11 is reduced (in other words, since the deterioration of the lead storage battery 11 is advanced), it is difficult for electricity to enter the lead storage battery 11. Therefore, in the first method, electricity is easily entered into the lead storage battery 11 by increasing the set voltage for charging. On the other hand, when the average SOC is relatively large, since the capacity of the lead storage battery 11 is not reduced (in other words, the deterioration of the lead storage battery 11 is not progressing), electricity enters the lead storage battery 11. easy. Therefore, in the third method, the set voltage is lowered so that overcharging does not occur. It can be said that the second method is intermediate between the first method and the third method.

  As another aspect, it is assumed that the memory 102 stores the selection rule 36 shown in the example (b) of FIG. In the example (b), the selection rule 36 defines three equal charge methods, the first method, the second method, and the third method. The correspondence with the set voltage is shown. The first method means that equal charge is performed at a set voltage of 2.50 V / cell if the accumulated discharge amount is 8000 Ah or more and less than 11000 Ah. The second method means that equal charge is performed at a set voltage of 2.45 V / cell when the accumulated discharge amount is 5000 Ah or more and less than 8000 Ah. The third method means that equal charge is performed at a set voltage of 2.42 V / cell when the accumulated discharge amount is 1000 Ah or more and less than 5000 Ah. When the integrated discharge amount is used, the selection unit 34 refers to the selection rule 36 and selects one equal charging method corresponding to the integrated discharge amount determined by the determination unit 33.

  When the accumulated discharge amount is relatively large, the capacity of the lead storage battery 11 is reduced, and it is difficult for electricity to enter the lead storage battery 11. Therefore, in the first method, electricity is easily entered into the lead storage battery 11 by increasing the set voltage for charging. On the other hand, when the integrated discharge amount is relatively small, the capacity of the lead storage battery 11 does not decrease, and thus the lead storage battery 11 is easily charged with electricity. Therefore, in the third method, the set voltage is lowered so that overcharging does not occur. It can be said that the second method is intermediate between the first method and the third method.

  The reference value and the boundary value in each example in FIG. 4 are merely examples. Regardless of whether the average SOC or the integrated discharge amount is adopted, the conditions of the individual equal charging method are set according to any standard according to the performance of the lead storage battery 11 or the like.

  The equal charge method may be defined using parameters other than the set voltage. For example, the equal charging method may be defined using a charging time or may be defined using a charging frequency. The charging time is an execution time of charging the lead storage battery 11 in one uniform charge. For example, the uniform charging method is defined so that the charging time becomes longer as the average SOC is smaller (or as the integrated discharge amount is larger). The charging frequency is the number of executions of uniform charging per unit time (for example, one week). For example, the equal charging method is defined so that the charging frequency increases as the average SOC decreases (or as the integrated discharge amount increases). Alternatively, the equal charge method may be defined by a combination of any two or more parameters among the set voltage, the charge time, and the charge frequency. The number of equal charge methods set in advance may be two or four or more.

  In step S15, instructing unit 35 generates a charging instruction based on the selected equal charging method, and transmits the charging instruction to power storage device 10 (instruction step). “Sending a charging instruction toward the power storage device” means transmitting a charging instruction to the power storage device 10 or another device corresponding to the power storage device 10 in order to perform equal charge. . In the present embodiment, the instruction unit 35 transmits a charging instruction to the power converter 20 corresponding to the power storage device 10 via the communication line 40. The charging instruction includes the IP address of power converter 20 and data based on the selected equal charging method. For example, if the selected equal charging method is the first method shown in the example (a) of FIG. 4, the charging instruction includes data indicating the set voltage 2.50 V / cell.

  In step S <b> 16, power converter 20 that has received the charging instruction transitions to the charging mode, and executes second equal charging for power storage device 10 in accordance with the charging instruction. The second equal charge is equal charge that is executed next to the first equal charge.

  In this way, the overall controller 30 determines the start point and end point of the determination period after the previous equal charge (first equal charge) ends, and determines the discharge state of the lead storage battery 11 in the determination period. Then, the overall controller 30 selects the equal charge method corresponding to the determined discharge state, and starts the next equal charge (second equal charge) with the selected equal charge method.

  When the power storage system 1 includes a plurality of power storage devices 10, the overall controller 30 executes the processes of steps S <b> 11 to S <b> 16 for all the power storage devices 10. For one power storage device 10, the processes of steps S11 to S16 are repeatedly performed (for example, in order to perform the next equal charge).

[program]
The power storage control program for causing the computer to function as the overall controller 30 includes program code for causing the computer to function as the acquisition unit 31, the determination unit 32, the determination unit 33, the selection unit 34, and the instruction unit 35. This power storage control program may be provided after being fixedly recorded on a tangible recording medium such as a CD-ROM, DVD-ROM, or semiconductor memory. Alternatively, the power storage control program may be provided via a communication network as a data signal superimposed on a carrier wave. The provided power storage control program is stored in the memory 102, for example. The processor 101 cooperates with the memory 102 to execute the power storage control program, thereby realizing each functional element described above.

[effect]
As described above, the power storage control device according to one aspect of the present invention is a power storage control device that controls a power storage device having a lead storage battery, and the SOC of the lead storage battery for which the first equal charge has been completed is determined in advance. A determination unit that determines a time point when the threshold value is lowered to a threshold value as a starting point of a determination period for determining a discharge state of the lead storage battery, a determination unit that determines a discharge state of the lead storage battery in the determination period, and a plurality of predetermined A selection unit that selects an equal charge method corresponding to the determined discharge state from the equal charge method, and a second equal charge next to the first equal charge for the lead storage battery using the selected equal charge method. An instruction unit that transmits the charging instruction to the power storage device.

  A power storage control method according to one aspect of the present invention is a power storage control method executed by a power storage control device that controls a power storage device having a lead storage battery, wherein the SOC of the lead storage battery for which the first equal charge has ended is predetermined. A determination step for determining a time point when the threshold value is lowered to a predetermined threshold as a starting point of a determination period for determining a discharge state of the lead storage battery, a determination step for determining a discharge state of the lead storage battery in the determination period, and a plurality of predetermined numbers A step of selecting an equal charge method corresponding to the determined discharge state from the equal charge method, and causing the lead storage battery to execute a second equal charge next to the first equal charge by the selected equal charge method. And an instruction step of transmitting a charging instruction for the power storage device to the power storage device.

  A power storage control program according to one aspect of the present invention is a power storage control program that causes a computer to function as a power storage control device that controls a power storage device having a lead storage battery. A determination step for determining a time point when the lead-acid battery is discharged to a predetermined threshold as a starting point of a determination period for determining a discharge state of the lead-acid battery; a determination step for determining a discharge state of the lead-acid battery in the determination period; A selection step for selecting an equal charge method corresponding to the determined discharge state from a plurality of equal charge methods, and a second equal charge subsequent to the first equal charge for the lead storage battery by the selected equal charge method. And causing the computer to execute an instruction step of transmitting a charging instruction to the power storage device.

  In such an aspect, a plurality of methods are prepared in advance for equal charge. And the determination period for determining the discharge state of a lead acid battery is defined, and the next equal charge is performed by the equal charge method corresponding to the discharge state in this determination period. Therefore, equal charge can be executed according to the state of the lead storage battery.

  In the power storage control device according to another aspect, the predetermined threshold may be a value within a range of 85% or more and less than 95%. By setting the threshold value in this way, it is possible to perform equal charge according to the state of the lead storage battery while maintaining the long life of the lead storage battery.

  In the power storage control device according to another aspect, the determination unit may determine, as an end point of the determination period, a time point at which a predetermined fixed period elapses from the start point corresponding to the lead storage battery or the power storage device. By setting the determination period in this way, the discharge state of the lead storage battery can be accurately determined.

  In the power storage control device according to another aspect, the determination unit may determine the average SOC of the lead storage battery in the determination period as a discharge state, and the selection unit may select an equal charging method corresponding to the determined average SOC. . By looking at the average SOC, the discharge state of the lead storage battery can be accurately determined.

  In the power storage control device according to another aspect, the determination unit determines the integrated discharge amount of the lead storage battery in the determination period as a discharge state, and the selection unit selects an equal charge method corresponding to the determined integrated discharge amount. Also good. By looking at the accumulated discharge amount, the discharge state of the lead storage battery can be accurately determined.

  In the power storage control device according to another aspect, the equal charge method may be defined using at least one of a set voltage, charge time, and charge frequency per cell of the lead storage battery. By using parameters such as these, optimal equal charge can be executed.

[Modification]
The present invention has been described in detail based on the embodiments. However, the present invention is not limited to the above embodiment. The present invention can be variously modified without departing from the gist thereof.

  The processing procedure of the power storage control method executed by at least one processor is not limited to the example in the above embodiment. For example, some of the steps (processes) described above may be omitted, or the steps may be executed in a different order. Also, any two or more of the steps described above may be combined, or a part of the steps may be corrected or deleted. Alternatively, other steps may be executed in addition to the above steps.

  When comparing the magnitude relationship between the two values in the power storage system 1, either of the two criteria “greater than” or “greater than” may be used, and the two criteria “less than” and “less than” may be used. Either of these may be used. The selection of such a standard does not change the technical significance of the process of comparing the magnitude relationship between two numerical values.

  DESCRIPTION OF SYMBOLS 1 ... Power storage system, 2 ... Power generation device, 3 ... PCS, 4 ... Electric power system, 5 ... Load, 6 ... DC bus, 7 ... AC bus, 10 ... Power storage device, 11 ... Lead storage battery, 20 ... Power converter, 30 ... general controller (power storage control device), 31 ... acquisition unit, 32 ... determination unit, 33 ... determination unit, 34 ... selection unit, 35 ... instruction unit, 36 ... selection rule, 40 ... communication line.

Claims (8)

A power storage control device for controlling a power storage device having a lead storage battery,
A determination unit that determines a time point when the SOC of the lead storage battery that has finished the first equal charge has dropped to a predetermined threshold as a starting point of a determination period for determining a discharge state of the lead storage battery;
A determination unit for determining a discharge state of the lead storage battery in the determination period;
A selection unit that selects an equal charge method corresponding to the determined discharge state from a plurality of predetermined equal charge methods;
A power storage control device comprising: an instruction unit that transmits, to the power storage device, a charge instruction for causing the lead storage battery to execute a second equal charge subsequent to the first equal charge by the selected equal charge method. . The predetermined threshold is a value within a range of 85% or more and less than 95%.
The power storage control device according to claim 1. The determination unit determines, as an end point of the determination period, a time point at which a predetermined fixed period elapses corresponding to the lead storage battery or the power storage device from the start point.
The power storage control device according to claim 1 or 2. The determination unit determines an average SOC of the lead storage battery in the determination period as the discharge state,
The selection unit selects the equal charge method corresponding to the determined average SOC;
The power storage control device according to any one of claims 1 to 3. The determination unit determines an accumulated discharge amount of the lead storage battery in the determination period as the discharge state,
The selection unit selects the equal charge method corresponding to the determined integrated discharge amount;
The power storage control device according to any one of claims 1 to 3. The equal charge method is defined using at least one of a set voltage per cell of the lead storage battery, a charge time, and a charge frequency.
The power storage control device according to any one of claims 1 to 5. A power storage control method executed by a power storage control device that controls a power storage device having a lead storage battery,
A determination step of determining a time point when the SOC of the lead storage battery in which the first equal charge has been completed has decreased to a predetermined threshold as a start point of a determination period for determining a discharge state of the lead storage battery;
A determination step of determining a discharge state of the lead-acid battery in the determination period;
A selection step of selecting an equal charge method corresponding to the determined discharge state from a plurality of predetermined equal charge methods;
An instruction step of transmitting, to the power storage device, a charge instruction for causing the lead storage battery to execute a second equal charge next to the first equal charge by the selected equal charge method. . A power storage control program that causes a computer to function as a power storage control device that controls a power storage device having a lead storage battery,
A determination step of determining a time point when the SOC of the lead storage battery in which the first equal charge has been completed has decreased to a predetermined threshold as a start point of a determination period for determining a discharge state of the lead storage battery;
A determination step of determining a discharge state of the lead-acid battery in the determination period;
A selection step of selecting an equal charge method corresponding to the determined discharge state from a plurality of predetermined equal charge methods;
An instruction step of transmitting to the power storage device a charge instruction for causing the lead storage battery to execute a second equal charge next to the first equal charge by the selected equal charge method; A storage control program to be executed.

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