Power storage information processing device, power storage information processing system, power storage information processing method, and computer program

Abstract

This power storage information processing device comprises a processing unit that executes processing for: acquiring the amount of change in the SOC of each of a plurality of power storage elements in a power storage element group; calculating the distribution of a charge / discharge command value for the power storage element group to each of the power storage elements in accordance with the acquired amount of change in the SOC of each of the power storage elements; and outputting the calculated charge / discharge command value for each of the power storage elements.

Description

Power storage information processing device, power storage information processing system, power storage information processing method, and computer program

[0001] The present invention relates to a power storage information processing device, a power storage information processing system, a power storage information processing method, and a computer program.

[0002] For the purpose of stabilizing and effectively utilizing the electric power generated by power generation facilities such as solar power generation facilities and wind power generation facilities, the use of power storage facilities equipped with a plurality of power storage elements is expanding. In such a power storage facility equipped with a plurality of power storage elements, a technique for distributing command values such as charge / discharge power to the entire power storage facility to individual power storage elements has been proposed (see, for example, Patent Document 1).

[0003] Japanese Patent No. 6157880

[0004] The capacity of a power storage element decreases and deterioration progresses by repeating charge and discharge. For example, when priorities are set for a plurality of power storage elements and command values are distributed to each power storage element according to the priorities, current may concentrate on some of the power storage elements in the power storage facility, and there is a risk of accelerating the deterioration of some of the power storage elements. In the distribution of charge / discharge command values in a group of power storage elements equipped with a plurality of power storage elements, a technique capable of suppressing the deterioration of individual power storage elements is desired.

[0005] An object of the present disclosure is to provide a technique capable of suppressing the deterioration of each power storage element in a group of power storage elements.

[0006] A power storage information processing device according to one aspect of the present disclosure acquires the amount of change in the state of charge (SOC) of each of a plurality of power storage elements in a group of power storage elements, and according to the amount of change in the SOC of each acquired power storage element, calculates the distribution of a charge / discharge command value for the group of power storage elements to each of the power storage elements, and includes a processing unit that executes a process of outputting the calculated charge / discharge command value for each of the power storage elements.

[0007] According to the present disclosure, the deterioration of each power storage element in a group of power storage elements can be suppressed.

[0008] This is an overview diagram of the energy storage information processing system. It shows an example of the container configuration of the energy storage equipment. It shows an example of the electrical connection configuration of the energy storage equipment. This is a block diagram showing an example of the configuration of the information processing device. This diagram explains the method of distributing charge / discharge command values. This is a flowchart showing an example of the processing procedure executed by the information processing device.

[0009] (1) A device for storing energy information according to one aspect of the present disclosure includes a processing unit that acquires the change in state of charge (SOC) of each of a plurality of energy storage elements in a group of energy storage elements, calculates the distribution of charge / discharge command values ​​for the group of energy storage elements to each of the energy storage elements according to the acquired change in SOC of each energy storage element, and outputs the calculated charge / discharge command values ​​for each of the energy storage elements.

[0010] In this disclosure, SOC (State of Charge) means the charge level of an energy storage element. SOC (in %) is the ratio of the charge capacity at the time of measurement (in Ah (ampere-hours)) to the full charge capacity (in Ah (ampere-hours)) of the energy storage element. The energy storage element is preferably a rechargeable battery such as a lithium-ion battery or a lead-acid battery, or a capacitor. The energy storage element may be an energy storage cell such as a lithium-ion battery, a module with multiple energy storage cells connected together, a bank with multiple modules connected together, a domain with multiple banks connected together, or an energy storage facility including multiple domains.

[0011] In a group of energy storage elements comprising multiple energy storage elements, charge and discharge command values ​​for the entire group are distributed to each energy storage element. Failure to distribute charge and discharge command values ​​may accelerate the degradation of specific energy storage elements. For example, when determining the priority of energy storage elements for charging and discharging based on their State of Charge (SOC), during charging, a larger command value is preferentially allocated to the energy storage element with the lowest SOC, causing its SOC to rise. Subsequently, during discharge, the priority of the energy storage element with the higher SOC increases. As a result, the allocation of command values ​​becomes concentrated on some energy storage elements. Energy storage elements with concentrated command value allocation experience a temperature rise associated with charging and discharging, and if sufficient cooling is not performed, the degradation of these energy storage elements will accelerate.

[0012] According to the energy storage information processing device described in (1) above, the charge / discharge command value for each energy storage element can be determined according to the change in SOC of each energy storage element in the energy storage element group, thus enabling charge / discharge control according to the degradation state of each energy storage element. Even when charging or discharging with the same charge / discharge command value, the change in SOC will differ depending on the degree of degradation of the energy storage element. By considering the change in SOC, the degree of degradation of the energy storage element can be reflected in the calculation of the charge / discharge command value, enabling charge / discharge control according to the degree of degradation of each energy storage element. By adjusting the distribution to each energy storage element according to the change in SOC, the variation in the change in SOC and the variation in degradation among each energy storage element can be reduced, and the efficiency of energy operation of the entire energy storage element group can be improved. By acquiring the change in SOC of each energy storage element in real time, charge / discharge can be controlled with high precision according to the current state of each energy storage element. For example, it can be applied not only to degradation but also to SOC balancing among energy storage elements such as a bank. Even when old and new energy storage elements are mixed together in a group of energy storage elements, they can be degraded over a similar period, making it possible to predict the maintenance and replacement timing to some extent.

[0013] (2) The energy storage information processing device described in (1) above may set a weighting coefficient according to the amount of change in the SOC and calculate the charge / discharge command value by multiplying the set weighting coefficient by the reference value.

[0014] According to the above configuration, charge and discharge command values ​​can be efficiently calculated using weighting coefficients and reference values. By setting weighting coefficients according to the change in SOC, command values ​​weighted according to the degree of degradation of each energy storage element can be distributed to each energy storage element, thereby reducing variations in degradation among energy storage elements.

[0015] (3) The energy storage information processing device described in (2) above may be configured to set the weighting coefficient to be larger as the amount of change in the SOC decreases.

[0016] With the above configuration, the charge / discharge command value is calculated such that the smaller the change in SOC, the larger the value. This allows for preferential charging or discharging of energy storage elements that have not deteriorated. As a result, charge / discharge control eliminates variations in the change in SOC among the energy storage elements, and the deterioration of each energy storage element can be made uniform.

[0017] (4) Any one of the energy storage information processing devices described in (1) to (3) above may acquire the amount of change in SOC of a plurality of energy storage elements when they are charged or discharged according to the charge / discharge command value, and if the difference in the amount of change in SOC between the plurality of energy storage elements acquired is greater than or equal to a predetermined value, it may perform a repetitive process including the calculation of the charge / discharge command value and the output of the charge / discharge command value.

[0018] According to the above configuration, by repeatedly performing processing, the charge / discharge command value corresponding to the change in SOC can be appropriately calculated, and variations in the change in SOC between each energy storage element can be reliably eliminated.

[0019] (5) In the energy storage information processing device described in (4) above, in the iterative processing, the charge / discharge command value may be calculated using a weighting coefficient, and the weighting coefficient used to calculate the current charge / discharge command value may be set based on a comparison between the amount of change in SOC corresponding to the charge / discharge command value calculated in the previous processing and the amount of change in SOC obtained the first time.

[0020] With the above configuration, the amount of change in SOC corresponding to the previous charge / discharge command value can be set as the weighting coefficient used to calculate the current charge / discharge command value. This allows for the efficient and accurate calculation of charge / discharge command values ​​to eliminate variations in the amount of change in SOC of each energy storage element.

[0021] (6) Any one of the energy storage information processing devices described in (1) to (5) above may output the same charge / discharge command value for each of the energy storage elements and obtain the amount of change in the SOC of each of the energy storage elements when they are charged or discharged according to the same charge / discharge command value output.

[0022] With the above configuration, by charging or discharging each energy storage element under the same conditions, the change in SOC, which accurately reflects the degree of degradation of each energy storage element, can be obtained, and therefore, charge / discharge command values ​​that correspond to the degree of degradation of each energy storage element can be calculated with high accuracy.

[0023] (7) Any one of the energy storage information processing devices described in (1) to (6) above may output the amount of change in the SOC of each energy storage element.

[0024] With the above configuration, the degree of degradation of each energy storage element can be determined from the change in SOC, which allows for measures such as prioritizing replacement during maintenance work, thus improving convenience.

[0025] (8) A power storage information processing system according to one aspect of the present disclosure comprises a plurality of power storage elements constituting a group of power storage elements and a power storage information processing device, wherein the power storage information processing device includes a processing unit that acquires the change in SOC of each of the plurality of power storage elements, calculates the distribution of charge / discharge command values ​​for the group of power storage elements to each of the power storage elements according to the acquired change in SOC of each power storage element, and outputs the calculated charge / discharge command values ​​for each of the power storage elements.

[0026] (9) A method for processing energy storage information according to one aspect of the present disclosure acquires the change in state of charge (SOC) of each of the multiple energy storage elements in the group of energy storage elements, calculates the distribution of charge / discharge command values ​​for the group of energy storage elements to each of the energy storage elements according to the acquired change in SOC of each energy storage element, and outputs the calculated charge / discharge command values ​​for each of the energy storage elements.

[0027] (10) A computer program according to one aspect of the present disclosure obtains the change in state of charge (SOC) of each of the multiple energy storage elements in the group of energy storage elements, calculates the distribution of charge / discharge command values ​​for the group of energy storage elements to each of the energy storage elements according to the obtained change in SOC of each energy storage element, and causes the computer to execute a process to output the calculated charge / discharge command values ​​for each of the energy storage elements.

[0028] This disclosure will be described in detail with reference to drawings illustrating embodiments thereof.

[0029] Figure 1 is a schematic diagram of the energy storage information processing system 100. The energy storage information processing system 100 of this embodiment comprises an energy storage device 1 equipped with a plurality of energy storage elements 10, and an information processing device 3. The energy storage device 1 and the information processing device 3 are communicated together via a network N. The information processing device 3 is an example of an energy storage information processing device.

[0030] The energy storage device 1 consists of a container 11 that houses multiple energy storage elements 10. The energy storage device 1 is, for example, an ESS (Energy Storage System) and is used in power generation systems PG such as solar power generation systems, wind power generation systems, hydroelectric power generation systems, biomass power generation systems, geothermal power generation systems, and thermal power generation systems. The energy storage device 1 stores the electricity supplied from the power generation system PG and supplies the stored electricity to the load. The load includes power-consuming facilities such as factories, office buildings, schools, hospitals, restaurants, and airports.

[0031] The energy storage device 1 may be connected to the power grid (grid-connected) and used to suppress voltage fluctuations and frequency fluctuations in the power grid. The energy storage device 1 may be installed on the premises of power consumers such as factories and used for BCP (Business Continuity Plan) measures, energy management such as peak shifting, and may also be used for electricity trading in the electricity market. The energy storage device 1 may be used as a backup power supply system (emergency power supply system). The energy storage device 1 is not limited to industrial use and may also be for household use.

[0032] The energy storage system 1 includes a power conditioner 2 (PCS: Power Conditioning System). The power conditioner 2 converts the power (AC power or DC power) supplied from the power generation system PG into DC power of a predetermined magnitude and supplies the converted DC power to the energy storage system 1. The energy storage system 1 stores the power supplied from the power generation system PG via the power conditioner 2. The energy storage system 1 supplies the stored power to the load in response to an external request. The power supplied from the energy storage system 1 to the load is converted from DC power to AC power by the power conditioner 2.

[0033] Network N is a wired or wireless network, including, for example, the Internet, a carrier network that implements wireless communication according to a predetermined mobile communication standard, or a general optical fiber line. Network N may also include a local network for the manufacturer or maintenance provider of the energy storage element 10.

[0034] The information processing device 3 is a device capable of various information processing and information transmission / reception, such as a server computer, personal computer, or quantum computer. The information processing device 3 acquires measurement data related to the energy storage equipment 1 via the network N and, based on the acquired measurement data, allocates command values ​​for charge / discharge power or charge / discharge current to each energy storage element 10. The information processing device 3 may be installed within the energy storage equipment 1.

[0035] Figure 2 shows an example of the configuration of the container 11 of the energy storage system 1. The container 11 houses multiple power storage panels 12. Although not shown, the energy storage system 1 may be configured by omitting the container 11 and installing multiple power storage panels 12 outdoors. The container 11 may also house ancillary equipment such as air conditioners and lighting devices.

[0036] Each power storage panel 12 has multiple banks 14. Each bank 14 is configured by electrically connecting multiple energy storage modules 15 in series. Each bank 14 is connected in parallel to one another. A configuration in which multiple banks 14 are connected in parallel is also called a domain. The number of banks 14 provided in the power storage panel 12, the number of energy storage modules 15 that make up each bank 14, and the number of domains can be arbitrarily selected.

[0037] The energy storage module 15 is constructed by connecting multiple energy storage cells in series. In one example, the energy storage cells are lithium-ion secondary battery cells. Alternatively, the energy storage cells may be solid-state batteries, lead-acid batteries, redox flow batteries, zinc-air batteries, alkaline manganese batteries, lithium-sulfur batteries, sodium-sulfur batteries, silver-zinc oxide batteries, nickel-metal hydride batteries, molten salt thermal batteries, etc., or they may be capacitors. The number of energy storage cells constituting the energy storage module 15 can be arbitrarily selected.

[0038] Figure 3 shows an example of the electrical connection configuration of the energy storage system 1. Figure 3 shows the electrical connection configuration of one battery panel 12 included in the energy storage system 1. The energy storage system 1 comprises a plurality of banks 14, a plurality of bank BMUs 17 (Battery Management Units) provided corresponding to each bank 14, a domain BMU 18, and communication equipment 19. The domain BMU 18 and communication equipment 19 are separate from the battery panel 12 and may be housed in a control panel built into the container 11.

[0039] Bank 14 is connected to the outside (for example, power conditioner 2, load, etc.) via power line 41. Bank 14 stores (charges) the power supplied through power conditioner 2 and power line 41, and supplies (discharges) the stored power to the external power supply destination via power line 41 and power conditioner 2.

[0040] Bank BMU 17 is a management device for monitoring the status of the corresponding bank 14. Bank BMU 17 communicates with a control board (CMU: Cell Monitoring Unit) with communication functions, which is built into each energy storage module 15, in accordance with a predetermined communication protocol.

[0041] The control board acquires measurement data for each energy storage cell through various sensors (not shown) provided on the energy storage module 15 and bank BMU 17. The measurement data includes the current, voltage, and temperature of the energy storage element. The measurement data can be repeatedly acquired at appropriate intervals, such as 0.1 seconds, 0.5 seconds, or 1 second.

[0042] Bank BMU 17 acquires measurement data from the energy storage cells and monitors the state of operation (SOC) of the energy storage cells in Bank 14 at each given time based on the acquired measurement data. Bank BMU 17 also notifies Domain BMU 18, a higher-level management device, of the measurement data from the energy storage cells.

[0043] Domain BMU 18 is a management device for monitoring the state of the entire domain and bank 14. Domain BMU 18 is communicably connected to bank BMU 17 of each bank 14. Domain BMU 18 aggregates measurement data from bank BMU 17 of each bank 14 belonging to the domain. Existing communication standards such as CAN (Controller Area Network) are used for communication between domain BMU 18 and each bank BMU 17. Alternatively, communication standards such as LIN (Local Interconnect Network), ECHONET (registered trademark), and ECHONET Lite (registered trademark) may be used.

[0044] Communication device 19 includes a communication interface for realizing communication with domain BMU 18 to which communication device 19 is connected, and a communication interface for connecting to network N. Communication device 19 securely transmits and receives data to and from each device wirelessly or by wire. Communication device 19 may be, for example, a network interface card. Serial communication may be used for communication between communication device 19 and domain BMU 18, and the same communication standard as that used for communication between domain BMU 18 and each bank BMU 17 may be used. Communication device 19 may be integrally configured with domain BMU 18. Communication device 19 may be provided or connected to a control unit such as power conditioner 2 or container 11.

[0045] Domain BMU 18 transmits measurement data of power storage element 10 acquired from each bank BMU 17 to information processing device 3 through communication device 19. Domain BMU 18 or communication device 19 may hold measurement data for a predetermined time and transmit the measurement data to information processing device 3 every predetermined time.

[0046] Information processing device 3 collects and stores measurement data transmitted from communication device 19. The measurement data includes the current, voltage, and temperature of power storage element 10. The measurement data may be associated with power storage element identification information for identifying power storage element 10 to be measured, power storage facility identification information for identifying power storage facility 1 including power storage element 10, a connection configuration such as the number of connections of power storage element 10, and the like.

[0047] FIG. 4 is a block diagram showing a configuration example of the information processing apparatus 3. The information processing apparatus 3 is a dedicated or general-purpose computer and includes a processing unit 31, a storage unit 32, and a communication unit 33. The information processing apparatus 3 may be a single computer, or may be a computer system composed of a plurality of computers, peripheral devices, and the like. The information processing apparatus 3 may be a virtual machine in which the entity is virtualized, or may be a cloud.

[0048] The processing unit 31 includes one or more processors such as a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit). The processing unit 31 includes a memory which is a temporary storage medium such as SRAM (Static Random Access Memory) or DRAM (Dynamic Random Access Memory). The processing unit 31 may have functions such as a timer for measuring the elapsed time from when a measurement start instruction is given until a measurement end instruction is given, a counter for counting numbers, and a clock for outputting date and time information. The CPU or the like included in the processing unit 31 reads and executes various computer programs stored in the storage unit 32 to control each part of the hardware and make the entire apparatus function as the power storage information processing apparatus in the present disclosure. The processing unit 31 may be realized software-wise, or part or all of it may be realized by hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0049] The storage unit 32 includes a non-volatile storage device such as a hard disk or a flash memory. The storage unit 32 may be separate from the information processing apparatus 3 and may be one or more externally connected external storage devices. The storage unit 32 stores various computer programs and data that the processing unit 31 refers to. In the storage unit 32 of the present embodiment, a program 3P for causing a computer to execute processing related to the calculation of charge / discharge command values and a measurement DB (Data Base) 321 for storing measurement data of the power storage element 10 are stored.

[0050] The measurement database 321 stores measurement data received from each energy storage device 1. For example, the measurement database 321 stores records that associate energy storage element identification information, measurement date and time, and values ​​such as current, voltage, and temperature. The measurement database 321 is updated as needed.

[0051] A computer program (program product) including program 3P may be provided on a non-temporary recording medium 3A on which the computer program is recorded in a readable format. The recording medium 3A is a portable memory such as a CD-ROM, USB memory, or SD (Secure Digital) card. The processing unit 31 reads the desired computer program from the recording medium 3A using a reading device (not shown) and stores the read computer program in the storage unit 32. Alternatively, the computer program may be provided by communication. Program 3P may be a single computer program or may consist of multiple computer programs. Program 3P may also be executed on a single computer or executed collaboratively by multiple computers.

[0052] The communication unit 33 is equipped with a communication interface for communication over the network N. The processing unit 31 sends and receives data to and from the communication device 19 connected to the network N through the communication unit 33.

[0053] The configuration of the information processing device 3 is not limited to the example described above, and may include, for example, a display unit for displaying images, an operation unit for receiving user input, and so on.

[0054] Figure 5 illustrates the method for distributing charge and discharge command values. Using Figure 5, the method for distributing charge and discharge command values ​​executed by the information processing device 3 will be explained. The following process may be performed periodically after the start of operation, or it may be performed when the energy storage element 10 is shipped or installed.

[0055] The information processing device 3 distributes charge and discharge command values ​​to a group of energy storage elements 10, according to the state of each energy storage element 10. The energy storage element 10 that executes the distributed charge and discharge command values ​​may be an energy storage cell, an energy storage module 15, a bank 14, a domain (energy storage panel 12), or an energy storage system 1 including multiple domains. The group of energy storage elements may be any multiple energy storage elements 10 connected in parallel. Depending on the selection of the group of energy storage elements and the energy storage elements 10, it becomes possible to optimize the charging and discharging power at a desired scale, such as in a power conversion circuit group, a power supply equipment group, or a power generation system group.

[0056] Figure 5 shows an example where the energy storage element 10 constitutes an energy storage unit that makes up one container 11, and the charge / discharge command value for the energy storage equipment 1 is distributed to N energy storage units, from energy storage unit #1 to #n. Each energy storage unit #1 to #n is connected to the power grid via PCS2-1 to PCS2-n.

[0057] As conceptually shown in Figure 5, each energy storage unit #1 to #n in the energy storage facility 1 has a different full charge capacity and charge capacity at the time of measurement, resulting in different SOC values. The information processing device 3 distributes charge / discharge command values ​​to each energy storage unit based on a comparison of the amount of change in SOC due to charging and discharging over a certain period between each energy storage unit, such that the charge / discharge command value decreases as the amount of change in SOC increases. Hereinafter, the amount of change in SOC will also be referred to as ΔSOC. ΔSOC is the absolute value of the change in SOC of the energy storage element over a certain period.

[0058] The charge / discharge command value for the entire energy storage system 1, i.e., the total charge / discharge command value, may be provided by a higher-level device such as an aggregator server, set by an operator, or set by the information processing device 3. The charge / discharge command value is a command value for charging power or discharging power. The charge / discharge command value may be expressed as a negative value for discharging and a positive value for charging. Alternatively, the charge / discharge command value may be a command value for charging current or discharging current.

[0059] The information processing device 3 calculates charge / discharge command values ​​for each energy storage unit #1 to #n by assigning a weighting coefficient for each energy storage unit to a reference charge / discharge command value (hereinafter also referred to as the reference value). The reference value is a value common to all energy storage units to which command values ​​are allocated. The reference value can be a value obtained by dividing the total charge / discharge command value equally among the total number of energy storage units to which charge / discharge command values ​​are allocated. The reference value may be reset for maintenance, etc.

[0060] In other words, if the total charge / discharge command value for energy storage equipment 1 is y, and the charge / discharge command values ​​for energy storage units #1 to #n are y1 to yn, then y1 to yn are determined such that the total charge / discharge command value is expressed as the sum of the charge / discharge command values ​​for each energy storage unit in the following equation (1): y = y1 + y2 + ... + yn y1 = C1 × y / N y2 = C2 × y / N ... yn = Cn × y / N ... (1) Here, N is the total number of energy storage units to which the charge / discharge command value is allocated, and C1 to Cn are weighting coefficients corresponding to each energy storage unit #1 to #n.

[0061] The weighting coefficient for each energy storage unit is set based on the ΔSOC of each unit. The smaller the ΔSOC, the larger the weighting coefficient. If no weighting is applied, the weighting coefficient is 1.

[0062] The information processing device 3 calculates the weighting coefficient for each energy storage unit by dividing the sum of the ΔSOC for each energy storage unit by the ΔSOC of each energy storage unit, for example, according to the following equation (2): Cn = (ΔSOC1 + ΔSOC2 + ... + ΔSOCn) / ΔSOCn × M ... (2) Here, ΔSOC1 to ΔSOCn are the change in SOC corresponding to each energy storage unit #1 to #n, and M is a normalization coefficient to make the sum of the weighting coefficients for each energy storage unit equal to the number of energy storage units N.

[0063] The method for setting the weighting coefficients is not limited to the above example, as long as it assigns weights so that the charge / discharge command values ​​for energy storage units with small ΔSOCs are calculated to be larger, and the charge / discharge command values ​​for energy storage units with large ΔSOCs are calculated to be smaller. The information processing device 3 may, for example, store in advance the correspondence between ΔSOC and the weighting coefficients and identify the weighting coefficients corresponding to ΔSOC according to this correspondence. The weighting coefficients may be stored in association with ΔSOC bands divided into arbitrary ranges. The information processing device 3 may also store in advance a plurality of weighting coefficients set to increase gradually, and set the weighting coefficients for each energy storage unit by assigning the set weighting coefficients in order from the energy storage unit with the largest ΔSOC to the energy storage unit. The same value may be set for multiple energy storage units with similar ΔSOCs as the weighting coefficients.

[0064] The information processing device 3 calculates the charge / discharge command value for each energy storage unit by setting the initial weighting coefficient for all energy storage units to 1, and outputs a charge / discharge command to the energy storage equipment 1 to perform charging or discharging for a predetermined period of time with the same calculated charge / discharge command value. The energy storage equipment 1 receives the charge / discharge command via the communication device 19 and performs charging or discharging of each energy storage unit according to the received charge / discharge command. In the energy storage equipment 1, the higher-level communication device 19 may receive the charge / discharge command from the information processing device 3, and the higher-level communication device 19 may output a charge / discharge command corresponding to the received charge / discharge command to each energy storage unit via the lower-level communication device 19.

[0065] The information processing device 3 obtains the ΔSOC of each energy storage unit when it is charged or discharged according to a charge / discharge command relating to the same charge / discharge command value, via the energy storage equipment 1. ΔSOC is represented by the difference between the SOC at the start of charging or discharging and the SOC at the end of charging or discharging. The SOC at each point in time is determined by methods such as current integration, based on measurement data such as the current, voltage, and temperature of the energy storage unit.

[0066] The information processing device 3 sets the weighting coefficient for each energy storage unit based on a comparison of the acquired ΔSOC of each energy storage unit, such that the smaller the ΔSOC, the larger the weighting coefficient. The information processing device 3 calculates a new charge / discharge command value for each energy storage unit by multiplying the set weighting coefficient by a reference value. The information processing device 3 outputs a charge / discharge command to the energy storage equipment 1 to perform charging or discharging according to the calculated new charge / discharge command value. The charge / discharge command includes the charge / discharge command value for each energy storage unit. The energy storage equipment 1 performs charging or discharging of each energy storage unit according to the charge / discharge command related to the new charge / discharge command value.

[0067] Subsequently, the total charge / discharge command value for energy storage equipment 1 is allocated to each energy storage unit by applying the latest weighting coefficients. The latest weighting coefficients may continue to be used until the next weighting coefficient update.

[0068] The setting of weighting coefficients may be repeated. For example, the process of setting weighting coefficients may be repeated until the ΔSOC difference between multiple energy storage units falls below a predetermined threshold.

[0069] After calculating the new charge / discharge command value described above, the information processing device 3 obtains the ΔSOC of each energy storage unit when it is charged or discharged according to the charge / discharge command related to the new charge / discharge command value. The information processing device 3 calculates the ΔSOC difference between multiple energy storage units by comparing the ΔSOC of each energy storage unit. The ΔSOC difference between multiple energy storage units is the absolute value of the difference in ΔSOC between different energy storage units. Hereinafter, the ΔSOC difference between multiple energy storage units will also be referred to as δΔSOC. δΔSOC may be the absolute value of the difference in ΔSOC between two energy storage units arbitrarily selected from N energy storage units or according to a predetermined rule. δΔSOC may also be the absolute value of the difference in ΔSOC between the energy storage unit with the largest ΔSOC and the energy storage unit with the smallest ΔSOC among the N energy storage units. Multiple δΔSOCs corresponding to different combinations of energy storage units may be calculated.

[0070] If the calculated δΔSOC is greater than or equal to a pre-set threshold, the information processing device 3 repeatedly performs a series of processes including setting weighting coefficients, calculating charge / discharge command values, and outputting charge / discharge commands.

[0071] In the weighting coefficient setting process in the iterative processing, for example, the weighting coefficient is updated for each energy storage unit so that the difference between the initial ΔSOC and the previous ΔSOC is small. The previous ΔSOC is the ΔSOC corresponding to the charge / discharge command value calculated using the weighting coefficient set in the iterative processing of the previous processing. The initial ΔSOC is the ΔSOC corresponding to the same charge / discharge command value calculated with a weighting coefficient of 1. The information processing device 3 sets the weighting coefficient for the current iterative processing by subtracting a predetermined value from the previous weighting coefficient if the previous ΔSOC is larger than the initial ΔSOC, and by adding a predetermined value to the previous weighting coefficient if the previous ΔSOC is smaller than the initial ΔSOC.

[0072] In setting the weighting coefficients in the iterative process, calculations using the above formula (2) may be performed.

[0073] The information processing device 3 calculates new charge / discharge command values ​​for each energy storage unit by multiplying the set weighting coefficient by the reference value, and outputs a charge / discharge command to the energy storage equipment 1 again to perform charging or discharging according to the calculated new charge / discharge command value.

[0074] The above process is repeated until the δΔSOC resulting from charging or discharging in response to the current charge / discharge command falls below a predetermined threshold, and the weighting coefficients are updated. When δΔSOC falls below the threshold, the information processing device 3 terminates updating the weighting coefficients.

[0075] Figure 6 is a flowchart showing an example of a processing procedure executed by the information processing device 3. The processing unit 31 of the information processing device 3 executes the following processing according to the program 3P stored in the storage unit 32.

[0076] The processing unit 31 of the information processing device 3 acquires the total charge / discharge command value for the energy storage equipment 1 that distributes charge / discharge command values ​​(step S1). The processing unit 31 determines whether or not it is time to set the weighting coefficients (step S2). The timing for setting the weighting coefficients may be, for example, a regular timing, or a timing when a predetermined period has elapsed since the previous setting of the weighting coefficients (i.e., the previous update of the weighting coefficients).

[0077] If it is determined that it is not time to set the weighting coefficient (S2: NO), the processing unit 31 reads the most recent weighting coefficient from the storage unit 32 and sets the read most recent weighting coefficient as the current weighting coefficient (step S3). The weighting coefficient is set for each of the multiple energy storage units that are subject to the allocation of charge / discharge command values ​​in the energy storage equipment 1. The connection configuration of the energy storage units in the energy storage equipment 1 may be stored in the information processing device 3 in advance, for example, or may be acquired in association with the measurement data of the energy storage equipment 1. If the weighting coefficient is not set, the processing unit 31 may set a common initial value 1 for each energy storage unit.

[0078] If the processing unit 31 determines that it is time to set the weighting coefficient (S2: YES), it outputs a charge / discharge command to the energy storage equipment 1, which is calculated by setting the same weighting coefficient of 1 for all energy storage units, and represents a uniform charge / discharge command value for each energy storage unit (step S4).

[0079] The processing unit 31 acquires time-series data of the State of Charge (SOC) of each energy storage unit over a predetermined period when it is charged or discharged according to a uniform charge / discharge command value in the output charge / discharge command (step S5). Based on the acquired time-series data, the processing unit 31 acquires the ΔSOC of each energy storage unit (step S6).

[0080] The processing unit 31 sets the weighting coefficient for each energy storage unit based on a comparison of the acquired ΔSOC of each energy storage unit, such that the smaller the ΔSOC, the larger the weighting coefficient (step S7).

[0081] The processing unit 31 calculates a charge / discharge command value for each energy storage unit by multiplying a reference value obtained by dividing the total charge / discharge command value of the energy storage equipment 1 equally by the number of energy storage units by a set weighting coefficient (step S8). The processing unit 31 outputs a charge / discharge command related to the calculated charge / discharge command value to the energy storage equipment 1 (step S9).

[0082] The processing unit 31 acquires time-series data of the State of Charge (SOC) of each energy storage unit during a predetermined period when it is charged or discharged according to the charge / discharge command value of the output charge / discharge command (step S10). Based on the acquired time-series data, the processing unit 31 acquires the ΔSOC of each energy storage unit (step S11).

[0083] The processing unit 31 calculates the difference in ΔSOC between multiple energy storage units (i.e., δΔSOC) by comparing the ΔSOC of each energy storage unit obtained, and determines whether the calculated δΔSOC is less than a preset threshold (step S12).

[0084] If the calculated δΔSOC is determined to be greater than or equal to a preset threshold (S12: NO), the processing unit 31 returns to step S7. The processing unit 31 then repeats the series of processes from step S7 to step S11.

[0085] In step S7 of the iterative process, the processing unit 31 may adjust the magnitude of the weighting coefficient for each of the multiple energy storage units in accordance with the decrease or increase of the previous SOC change amount obtained in step S11 relative to the initial SOC change amount obtained in step S6.

[0086] If the calculated δΔSOC is determined to be less than a preset threshold (S12: YES), the processing unit 31 estimates the degree of degradation of each energy storage unit based on the ΔSOC of each energy storage unit obtained in step S6 (step S13). The degree of degradation may be a relative evaluation value based on a comparison of the ΔSOCs between each energy storage unit. The processing unit 31 calculates the degree of degradation of each energy storage unit such that a larger ΔSOC indicates a higher degree of degradation, and a smaller ΔSOC indicates a lower degree of degradation. The degree of degradation may be indicated by a numerical value that increases as the degree of degradation increases, or it may be indicated by degradation levels classified into multiple stages.

[0087] The processing unit 31 outputs the estimated degree of degradation to an external device such as an operator's terminal device or to the display unit of the device itself (step S14), and ends the series of processes. The estimated degree of degradation may be shown, for example, by associating identification information that identifies the energy storage unit with the degree of degradation of each energy storage unit.

[0088] In the above-described process, in addition to the determination process in step S2, the processing unit 31 may also determine whether the ΔSOC difference between the multiple energy storage units is greater than or equal to a predetermined value. If it is the set timing and the ΔSOC difference between the multiple energy storage units is greater than or equal to the predetermined value, the processing unit 31 executes the processes in steps S4 to S7. If the ΔSOC difference between the multiple energy storage units is less than the predetermined value, the processing unit 31 executes the process in step S3.

[0089] If iterative processing for setting weighting coefficients is not performed, steps S10 to S12 may be omitted. The processing unit 31 may output the calculated charge / discharge command values ​​for each energy storage unit to a device other than the energy storage equipment 1.

[0090] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The technical features described in each embodiment can be combined with each other, and the scope of the present invention is intended to include all modifications within the claims and equivalents thereof. The sequences shown in each embodiment are not limiting, and within a consistent scope, each processing step may be performed in a different order, and multiple processes may be performed in parallel. The processing entities for each process are not limiting, and within a consistent scope, the processing of each device may be performed by other devices.

[0091] The matters described in each embodiment can be combined with each other. Furthermore, the independent and dependent claims described in the claims can be combined with each other in any combination, regardless of the form of reference. In addition, the claims use a form in which claims referencing two or more other claims (multi-claim form), but are not limited to this. A form in which multi-claims referencing at least one multi-claim (multi-multi-claim) may also be used.

[0092] 100 Energy Storage Information Processing System 1 Energy Storage Equipment 10 Energy Storage Element 3 Information Processing Device (Energy Storage Information Processing Device) 31 Processing Unit 32 Memory Unit 33 Communication Unit 3P Program 321 Measurement DB 3A Recording Medium

Claims

1. An energy storage information processing device comprising a processing unit that acquires the change in state of charge (SOC) of each of multiple energy storage elements in a group of energy storage elements, calculates the distribution of charge / discharge command values ​​for the group of energy storage elements to each of the energy storage elements according to the acquired change in SOC of each energy storage element, and outputs the calculated charge / discharge command values ​​for each of the energy storage elements.

2. The energy storage information processing device according to claim 1, wherein a weighting coefficient is set according to the amount of change in the SOC, and the charge / discharge command value is calculated by multiplying the set weighting coefficient by a reference value.

3. The energy storage information processing device according to claim 2, wherein the weighting coefficient is set to be larger the smaller the amount of change in the SOC.

4. The energy storage information processing device according to claim 1 or 2, which acquires the amount of change in SOC of a plurality of energy storage elements when they are charged or discharged according to the charge / discharge command value, and if the difference in the amount of change in SOC between the plurality of energy storage elements acquired is greater than or equal to a predetermined value, it performs a repetitive process including calculating the charge / discharge command value and outputting the charge / discharge command value.

5. In the iterative process, the charge / discharge command value is calculated using a weighting coefficient, and the weighting coefficient used to calculate the current charge / discharge command value is set based on a comparison between the amount of change in SOC corresponding to the charge / discharge command value calculated in the previous process and the amount of change in SOC obtained the first time. The energy storage information processing device according to claim 4.

6. The energy storage information processing device according to claim 1 or claim 2, which outputs the same charge / discharge command value for each of the energy storage elements and obtains the amount of change in the SOC of each of the energy storage elements when they are charged or discharged according to the same charge / discharge command value output.

7. The energy storage information processing device according to claim 1 or claim 2, which outputs the amount of change in the SOC of each of the energy storage elements.

8. An energy storage information processing system comprising a plurality of energy storage elements constituting a group of energy storage elements and an energy storage information processing device, wherein the energy storage information processing device includes a processing unit that acquires the change in SOC of each of the plurality of energy storage elements, calculates the distribution of charge / discharge command values ​​for the group of energy storage elements to each of the energy storage elements according to the acquired change in SOC of each energy storage element, and outputs the calculated charge / discharge command values ​​for each of the energy storage elements.

9. A method for processing energy storage information that acquires the change in state of charge (SOC) of each of multiple energy storage elements in a group of energy storage elements, calculates the distribution of charge / discharge command values ​​for the group of energy storage elements to each of the energy storage elements according to the acquired change in SOC of each energy storage element, and outputs the calculated charge / discharge command values ​​for each of the energy storage elements.

10. A computer program that causes a computer to perform the following processes: acquire the change in state of charge (SOC) of each of the multiple energy storage elements in a group of energy storage elements; calculate the distribution of charge / discharge command values ​​for the group of energy storage elements to each of the energy storage elements according to the acquired change in SOC of each energy storage element; and output the calculated charge / discharge command values ​​for each of the energy storage elements.

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