JP2019129554A - Power storage control device, power storage control method, and power storage control program - Google Patents

Abstract

To execute uniform charging in accordance with a state of a lead storage battery.SOLUTION: A power storage control device is configured to control a power storage apparatus including a lead storage battery. The power storage control device comprises: a discrimination section which discriminates a deterioration state of the lead storage battery after end of uniform charging; a selection section which selects a uniform charging method corresponding to the discriminated deterioration state from among predetermined multiple uniform charging methods; and an instruction section which transmits to the power storage apparatus a charging instruction for performing the next uniform charging on the lead storage battery in accordance with 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 method of managing charge and 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-acid battery includes a battery state measurement unit that measures the state of the lead-acid battery, an SOC model that represents the relationship between the output factor including the current, voltage, and temperature of the lead-acid battery and the charge state of the lead-acid 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 uniform charging is uniformly performed regardless of the state of the lead storage battery, excess and deficiency of charging may occur, and as a result, the life of the battery may be shorter than expected. Therefore, it is desired to perform uniform charging according to the state of the lead storage battery.

  The storage control device according to one aspect of the present invention is a storage control device that controls a storage device having a lead storage battery, and is determined in advance with a determination unit that determines a deterioration state of the lead storage battery after completion of the equal charge. A selection unit for selecting the equal charge method corresponding to the determined deterioration state from the plurality of equal charge methods, and a charge instruction for causing the lead storage battery to execute the next equal charge using the selected equal charge method And an instruction unit that transmits the information to the power storage device.

  An electric storage control method according to an aspect of the present invention is an electric storage control method executed by an electric storage control device that controls an electric storage device having a lead storage battery, and determines a deterioration state of the lead storage battery after completion of uniform charging. A determination step; a selection step for selecting an equal charge method corresponding to the determined deterioration state from a plurality of predetermined equal charge methods; and a next equal charge for the lead storage battery with the selected equal charge method. And an instruction step of transmitting a charging instruction for execution to the power storage device.

  The storage control program according to one aspect of the present invention is a storage control program that causes a computer to function as a storage control device that controls a storage device having a lead storage battery, and determines the deterioration state of the lead storage battery after the equal charge ends. Determination step, a selection step of selecting an equal charge method corresponding to the determined deterioration state from a plurality of predetermined equal charge methods, and the next equal charge to the lead storage battery by the selected equal charge method And causing the computer to execute an instruction step of transmitting to the power storage device a charging instruction for causing the power storage device to execute.

  In such an aspect, after a plurality of methods for equal charge are prepared in advance, equal charge is executed by an equal charge method corresponding to the deterioration state of the lead storage battery. 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 a 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 will be denoted by the same reference symbols, without redundant description.

[Overall configuration of storage system]
The storage control device according to the embodiment is a device that functions as a part of the storage system 1. The storage system 1 is a system that manages electricity generated using renewable energy, and can be used in various places such as homes, offices, factories, farms, and the like.

  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. Storage system 1, power generation device 2, and PCS 3 are electrically connected via direct current (DC) bus 6 through which 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 storage system 1 also plays a role of alleviating fluctuation of the power supply from the power generation device 2 to the power system 4 or the load 5 by utilizing the storage battery as 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 storage system 1 includes three sets of storage devices 10 and power converters 20 (three storage units), but the number of sets is not limited, and may be one or two or four 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. Power storage device 10 includes a lead storage battery 11 configured to include a plurality of cells connected in series. The number of cells constituting the lead storage battery 11 is not limited, and may be, for example, 200 or 288. 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.

  Power converter 20 is a device that controls charging and discharging of 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. Power converter 20 stores the electricity flowing from power generation device 2 in power storage device 10 in the charge mode, discharges power storage device 10 in the discharge mode to supply power to the outside, and performs charge / discharge in the stopped state. Absent. The power converter 20 may be a DC / DC converter, for example.

[Configuration of integrated controller]
The integrated controller 30 is a computer (for example, a microcomputer) that controls the power converter 20 and the storage device 10. FIG. 2 is a diagram showing a functional configuration of the general controller 30. As shown in FIG. As shown in this figure, the general 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. The types of hardware devices constituting the general controller 30 are not limited to these, and may be selected arbitrarily. Each function of the general controller 30 is realized by the processor 101 executing a program stored in the memory 102. For example, the processor 101 executes a predetermined operation on data read from the memory 102 or data received via the communication interface 103, and outputs the operation result to another device to execute the other device. 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 eliminating such a variation in voltage among cells to reset the quality of the battery.

  The processor 101 functions as an acquisition unit 31, a determination unit 32, a selection unit 33, and an instruction unit 34. 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 the deterioration state (States Of Health: SOH) of the lead storage battery 11 in the power storage device 10 based on the data. The deteriorated state is a concept indicating how much the performance of the lead storage battery 11 has deteriorated from the initial state (the state at the time of manufacture). A typical example of the deterioration of the lead storage battery 11 is that the non-conductive crystal (sulfation) generated at the electrode increases the internal resistance in the battery and the capacity of the lead storage battery 11 decreases. The selection unit 33 is a functional element that selects one equal charging method from a plurality of predetermined equal charging methods based on the determined deterioration state. Instruction unit 34 is a functional element that transmits to storage device 10 a charging instruction based on the selected even charging method. The charge instruction is a data signal for causing the power storage device 10 to execute equal charge of the lead storage battery 11. As described above, the processor 101 executes equal charge to the lead storage battery 11 by a method suitable for the deterioration state of the lead storage battery 11 of the power storage device 10.

  The memory 102 stores information necessary for the operation of the processor 101. For example, the memory 102 stores the selection rule 35. The selection rule 35 is information that defines a plurality of equal charge methods, and each equal charge method is associated with an assumed deterioration state of the lead storage battery 11. Therefore, the selection rule 35 is a rule for selecting one equal charge method corresponding to the determined deterioration state from a plurality of equal charge methods prepared in advance. The description method of the selection rule 35 is not limited. For example, the selection rule 35 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 35 may be a part of a program executed by the processor 101.

  The selection rule 35 may be rewritable. For example, when the power storage device 10 or the lead storage battery 11 is replaced with another type or a new type of the power storage device 10 or the lead storage battery 11 is added, the administrator changes the memory 102 according to the change in the configuration. The selection rule 35 is rewritten. 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 the new selection rule 35 reflecting the change in configuration to the overall controller 30. You may forward to. By this transfer, the selection rule 35 in the memory 102 is rewritten.

  The communication interface 103 cooperates with the processor 101 to execute transmission and reception of data. 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 charge instruction to the power converter 20 in cooperation with the instruction unit 34.

[Operation of integrated 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 shows an example of the selection rule 35. As shown in FIG.

  After the previous equal charge for power storage device 10 is completed in step S11, the next process for equal charge (process after step S12) is executed. The timing at which the process for the next equal charge is performed is not limited, and may be performed, for example, at a predetermined date and time, or may be started when the power storage device 10 starts discharging.

  In step S12, the acquisition unit 31 acquires the voltage Va of the lead storage battery 11 at the start of discharge. In step S13, the acquisition unit 31 acquires the voltage Vb of the lead storage battery 11 when a predetermined time T (seconds) has elapsed from the start of discharge. The voltage Vb is a voltage at the time when the power storage device 10 continues to execute discharging for T seconds. The acquiring unit 31 acquires a voltage 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 two voltages Va and Vb are used to determine the deterioration state of the lead storage battery 11. The discharge in steps S12 and S13 may be intentionally performed in order to determine the deterioration state. In this case, instruction unit 34 generates a discharge instruction for discharging power storage device 10 for T seconds, and transmits the discharge instruction to power storage device 10. Then, voltages Va and Vb are acquired from power storage device 10 (or power converter 20 corresponding to power storage device 10) in which acquisition unit 31 has started discharging in response to the transmission. Alternatively, the discharge in steps S12 and S13 may be a discharge for supplying power to the power system 4 or the load 5. In this case, the acquisition unit 31 acquires the voltage Va at the time when the discharge is started and the voltage Vb after the elapse of T seconds from the power storage device 10 by using this discharge opportunity.

  In step S14, the determination unit 32 determines the deterioration state of the lead storage battery 11 after the equal charge is finished (that is, after step S11) (determination step). In the present embodiment, the determination unit 32 calculates a voltage drop that is a difference between the voltages Va and Vb, and obtains the calculation result as a deterioration state of the lead storage battery 11.

  In step S15, the selection unit 33 refers to the selection rule 35 and selects one equal charging method corresponding to the determined deterioration state from among a plurality of equal charging methods (selection step). In the present embodiment, the selection unit 33 selects one equal charging method corresponding to the calculated voltage drop.

  For example, it is assumed that the memory 102 stores the selection rule 35 shown in FIG. In the example of FIG. 4, the selection rule 35 defines two equal charge methods, the first method and the second method. The equal charge methods are voltage drop and set voltage (lead-acid battery) at the time of charge. 11 shows the correspondence with the set voltage per cell). The first method means that equal charge is performed at a set voltage of 2.50 V / cell if the voltage drop is equal to or greater than the threshold value Td. The second method means that equal charge is performed at a set voltage of 2.42 V / cell if the voltage drop is less than the threshold value Td. The threshold value Td is set based on an arbitrary standard according to the performance of the lead storage battery 11 and the like. When the voltage drop is relatively large, the lead storage battery 11 is hard to enter electricity since the deterioration of the lead storage battery 11 is progressing. Therefore, in the first method, the lead storage battery 11 is made easy to enter electricity by raising the set voltage for charging. On the other hand, when the voltage drop is relatively small, the lead storage battery 11 is likely to receive electricity since the deterioration of the lead storage battery 11 is not progressing. Therefore, in the second method, the set voltage is lowered so that overcharging does not occur. When the selection rule 35 is the example shown in FIG. 4, the selection unit 33 compares the calculated voltage drop with the threshold value Td, and selects one of the two equal charging methods according to the comparison result.

  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. The charging frequency is the number of executions of uniform charging per unit time (for example, one week). For example, the selection rule 35 may be defined as charging time Ta if the voltage drop is greater than or equal to the threshold Td, and charging time Tb if the voltage drop is less than the threshold Td (where Tb <Ta). Good. Alternatively, the selection rule 35 may be defined such that the charging frequency is twice per week if the voltage drop is equal to or higher than the threshold Td and that the charging frequency is once per week if the voltage drop is less than the threshold Td. . 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 preset equalizing methods may be three or more.

  In step S <b> 16, instructing unit 34 generates a charging instruction based on the selected equal charging method, and transmits the charging instruction to power storage device 10 (instruction step). “Transmit a charge instruction to the storage device” means to transmit the charge instruction to the storage device 10 or to another device corresponding to the storage device 10 in order to execute equal charge. . In the present embodiment, the instruction unit 34 transmits a charging instruction to the power converter 20 corresponding to the power storage device 10 via the communication line 40. The charge instruction includes the IP address of power converter 20 and data based on the selected equal charge method. For example, if the selected equal charge method is the first method shown in FIG. 4, the charge instruction includes data indicating the set voltage 2.50 V / cell.

  In step S <b> 17, power converter 20 that has received the charging instruction transitions to the charging mode, and performs equal charging on power storage device 10 according to the charging instruction. As a result, the variation in voltage among the individual cells of the lead storage battery 11 is eliminated.

  When the storage system 1 includes a plurality of storage devices 10, the general controller 30 executes the processing of steps S11 to S17 for all the storage devices 10. The processing of steps S11 to S17 is repeatedly (for example, periodically) executed for one power storage device 10.

[program]
The storage control program for causing the computer to function as the general controller 30 includes program codes for causing the computer to function as the acquisition unit 31, the determination unit 32, the selection unit 33, and the instruction unit 34. 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 storage control program may be provided via a communication network as a data signal superimposed on a carrier wave. The provided storage control program is stored, for example, in the memory 102. The processor 101 executes the storage control program in cooperation with the memory 102 to realize the above-described functional elements.

[effect]
As described above, the storage control device according to one aspect of the present invention is a storage control device that controls a storage device having a lead storage battery, and is a determination that determines the deterioration state of the lead storage battery after completion of the equal charge. The following equal charge is performed on the lead storage battery by the selected equal charge method and the selection portion which selects the equal charge method corresponding to the determined deterioration state from the part and a plurality of predetermined equal charge methods. And an instruction unit that transmits a charge instruction for causing the storage device to perform charging.

  An electric storage control method according to an aspect of the present invention is an electric storage control method executed by an electric storage control device that controls an electric storage device having a lead storage battery, and determines a deterioration state of the lead storage battery after completion of uniform charging. A determination step; a selection step for selecting an equal charge method corresponding to the determined deterioration state from a plurality of predetermined equal charge methods; and a next equal charge for the lead storage battery with the selected equal charge method. And an instruction step of transmitting a charging instruction for execution to the power storage device.

  The storage control program according to one aspect of the present invention is a storage control program that causes a computer to function as a storage control device that controls a storage device having a lead storage battery, and determines the deterioration state of the lead storage battery after the equal charge ends. Determination step, a selection step of selecting an equal charge method corresponding to the determined deterioration state from a plurality of predetermined equal charge methods, and the next equal charge to the lead storage battery by the selected equal charge method And causing the computer to execute an instruction step of transmitting to the power storage device a charging instruction for causing the power storage device to execute.

  In such an aspect, after a plurality of methods for equal charge are prepared in advance, equal charge is executed by an optimum equal charge method corresponding to the deterioration state of the lead storage battery. Therefore, equal charge can be executed according to the state of the lead storage battery.

  In the storage control device according to the other aspect, the determination unit determines the deterioration state by calculating the voltage drop of the lead storage battery, and the selection unit selects the equal charge method corresponding to the calculated voltage drop. Good. The voltage drop reflects the occurrence of sulfation, which is a performance degradation factor unique to lead-acid batteries. Therefore, by selecting the equal charge method based on this voltage drop, optimal equal charge can be executed according to the state of the lead storage battery.

  In the storage control device according to the other aspect, the voltage drop may be the difference between the voltage at the discharge start time after the equal charge end and the voltage at the time when a predetermined time has elapsed from the discharge start time . By selecting the equal charge method based on the voltage drop due to the discharge after the previous equal charge, the optimum equal charge can be executed according to the latest state of the lead storage battery.

  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 above 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 scope of the invention.

  The processing procedure of the 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 performed in another 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 performed 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 ... Storage system, 2 ... Power generation device, 3 ... PCS, 4 ... Electric power system, 5 ... Load, 6 ... DC bus, 7 ... AC bus, 10 ... Storage device, 11 ... Lead storage battery, 20 ... Power converter, 30 ... general controller (power storage control device), 31 ... acquisition unit, 32 ... determination unit, 33 ... selection unit, 34 ... instruction unit, 35 ... selection rule, 40 ... communication line.

Claims (6)

A storage control device for controlling a storage device having a lead storage battery, comprising:
A determination unit that determines a deterioration state of the lead storage battery after the equal charge is finished;
A selection unit that selects a uniform charging method corresponding to the determined degradation state from a plurality of predetermined uniform charging methods;
A 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 the next equal charge in the selected equal charge method. The determination unit determines the deterioration state by calculating a voltage drop of the lead storage battery,
The selection unit selects the equalizing method corresponding to the calculated voltage drop,
The power storage control device according to claim 1. The voltage drop is a difference between a voltage at a discharge start time after the equal charge is finished and a voltage at a predetermined time after the discharge start time.
The storage control device according to claim 2. 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 storage control device according to any one of claims 1 to 3. A storage control method that is executed by a storage control device that controls a storage device having a lead storage battery, comprising:
A determination step of determining a deterioration state of the lead storage battery after completion of the equal charge;
A selection step of selecting an equal charge method corresponding to the determined deterioration state from a plurality of predetermined equal charge methods;
A storage control method including an instruction step of transmitting to the storage device a charge instruction for causing the lead storage battery to execute the next equal charge according to the selected equal charge method. A storage control program that causes a computer to function as a storage control device that controls a storage device having a lead storage battery,
A determination step of determining a deterioration state of the lead storage battery after completion of the equal charge;
A selection step of selecting an equal charge method corresponding to the determined deterioration state from a plurality of predetermined equal charge methods;
A storage control program that causes the computer to execute an instruction step of transmitting to the storage device a charge instruction for causing the lead storage battery to execute the next equal charge according to the selected equal charge method.

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