Electricity storage information processing method, computer program, and electricity storage information processing device

Abstract

This electricity storage information processing method acquires the internal state amount of an electricity storage element, estimates, on the basis of the acquired internal state amount and charging or discharging duration time requested to the electricity storage element, a power amount or power that can be charged or discharged for the duration time by the electricity storage element and a temperature, and executes, using a computer, processing for outputting the estimated power amount or power and temperature.

Description

Electricity storage information processing method, computer program, and electricity storage information processing device

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

[0002] The use of energy storage devices is expanding to stabilize and effectively utilize the electricity generated by power generation facilities such as solar power generation facilities and wind power generation facilities. To ensure stable operation of energy storage devices, it is important to understand the performance of the energy storage devices.

[0003] Patent Document 1 discloses a battery control device that predicts the power required from a battery from the history of the power consumption trends of a load and calculates the available power output from the battery based on the estimated temperature of the battery.

[0004] Patent No. 6047929

[0005] The internal state of an energy storage element changes depending on use. In situations where such an energy storage element is used continuously for a certain period of time, there is a need to understand the charge or discharge capacity of the energy storage element taking into account the internal state of the energy storage element and the duration of current flow. There is also a need to suppress deterioration of the energy storage element during operation.

[0006] An object of one aspect of the present disclosure is to provide a technology that can grasp the charge capacity or discharge capacity that can suppress deterioration according to the internal state of an energy storage element.

[0007] A storage information processing method according to one aspect of the present disclosure includes a computer executing a process to acquire an internal state quantity of a storage element, estimate the amount of power or power and temperature that the storage element can charge or discharge over a duration of charging or discharging required of the storage element based on the acquired internal state quantity and the duration of charging or discharging required of the storage element, and output the estimated amount of power or power and temperature.

[0008] A computer program according to one aspect of the present disclosure causes a computer to execute a process of acquiring an internal state quantity of a storage element, estimating the amount of power or power and temperature that the storage element can charge or discharge over a duration of charging or discharging required of the storage element based on the acquired internal state quantity and the duration of charging or discharging required of the storage element, and outputting the estimated amount of power or power and temperature.

[0009] An energy storage information processing device according to one aspect of the present disclosure includes a control unit that acquires an internal state quantity of an energy storage element, estimates the amount of power or power and temperature that the energy storage element can charge or discharge over the duration based on the acquired internal state quantity and the duration of charging or discharging required of the energy storage element, and outputs the estimated amount of power or power and temperature.

[0010] According to one aspect of the present disclosure, it is possible to grasp the charge capacity or discharge capacity that can suppress deterioration according to the internal state of the energy storage element.

[0011] 1 is a schematic diagram of an electricity storage information processing system. FIG. 1 is a schematic diagram showing an example of the internal configuration of a battery panel and a control panel. FIG. 2 is an explanatory diagram explaining an example of the circuit configuration of an electricity storage facility. FIG. 3 is a block diagram showing an example of the configuration of an information processing device. FIG. 4 is a block diagram showing an example of the configuration of an information terminal device. FIG. 5 is a diagram showing an example of the contents of information stored in a measurement DB. FIG. 6 is a diagram showing an example of the contents of information stored in a charge / discharge condition DB. FIG. 7 is a diagram explaining a method of generating a charge / discharge condition table. FIG. 8 is a flowchart showing an example of processing procedures executed by an information processing device. FIG. 9 is a block diagram showing an example of the configuration of an information processing device of a second embodiment. FIG. 10 is a circuit diagram showing an example of the configuration of an equivalent circuit model. FIG. 11 is a diagram explaining a method of estimating charge / discharge capacity using an equivalent circuit model. FIG. 12 is a diagram explaining a method of estimating charge / discharge capacity using an equivalent circuit model. FIG. 13 is a flowchart showing an example of processing procedures executed by an information processing device of a second embodiment.

[0012] (1) In a method for processing energy storage information according to one aspect of the present disclosure, a computer executes a process of acquiring an internal state quantity of an energy storage element, estimating the amount of power or power and temperature that the energy storage element can charge or discharge over a duration of charging or discharging required of the energy storage element based on the acquired internal state quantity and the duration of charging or discharging required of the energy storage element, and outputting the estimated amount of power or power and temperature.

[0013] The power storage facility may be a facility that is installed alongside a power generation facility such as a solar power generation facility or a wind power generation facility, stores power supplied from the power generation facility, and supplies the stored power to a load. An example of the power storage facility is an energy storage system (ESS). Alternatively, the power storage facility may be a power conditioner with a storage battery or a backup power supply device.

[0014] In recent years, efforts have been made to maintain stable operation of the power grid, and ESS is being applied to these efforts. For example, there is a system (demand response) in which users reduce their electricity usage during times of sudden increase in power demand and receive compensation according to the amount of power that can be reduced or the amount of power actually reduced. Using ESS, the compensation can be increased by discharging as much power as possible during a predetermined target time period. Demand response requires that demand response can always be activated during the target time period. If reduction targets are not achieved, penalties may be imposed.

[0015] Another initiative is a system (supply and demand balancing market) in which users bid to procure adjustment power to stabilize the power grid. In the supply and demand balancing market, there are multiple products with different requirements, such as response time and duration, and all bids are made in kilowatt units. For example, when bidding for a product with a duration requirement of three hours, the bid is for electricity that can be charged and discharged for three consecutive hours. By using ESS to charge and discharge as much electricity as possible within a specified time period, rewards can be increased. In the supply and demand balancing market, users are required to charge and discharge continuously for a specified period of time. Penalties may be imposed if the requirements are not met.

[0016] When using the ESS as the above-mentioned adjustment capability, it is required to guarantee charging and discharging capability over a relatively long period of time, such as several tens of minutes or several hours, rather than a relatively short period of time, such as a few seconds or a few minutes. It is important to accurately determine the power that can be continuously charged and discharged for a predetermined period of time, i.e., the amount of power that can be continuously charged and discharged for a predetermined period of time. Since the internal state of the ESS changes from moment to moment, it is important to consider the internal state of the ESS in order to accurately estimate the amount of power.

[0017] It is also desirable to suppress the deterioration of the storage elements when operating an ESS. The internal resistance of a storage element changes depending on the temperature environment, and the amount of power that can be charged and discharged also fluctuates as the internal resistance changes. As the temperature of the storage element decreases, the internal resistance increases, and the amount of power that can be charged and discharged decreases. In order to reduce the internal resistance, it is desirable to raise the temperature of the storage element. On the other hand, if the temperature of the storage element is raised excessively, the effect of reducing the internal resistance is reduced, and the increase in temperature makes the storage element more susceptible to deterioration. Ideal ESS operation involves minimizing the amount of temperature rise and suppressing deterioration of the storage element while ensuring as much power that can be charged and discharged as possible.

[0018] According to the electricity storage information processing method described in (1) above, it is possible to output a combination of the amount of electricity (unit: kilowatt-hour (kWh)) or power (unit: kilowatt (kW)) that can be charged or discharged over a continuous period of time, taking into account the internal state of the electricity storage element, and the temperature (unit: °C) that is suitable for charging or discharging. It is possible to estimate charging and discharging conditions that ensure both securing a larger amount of electricity and suppressing deterioration, according to the state of the electricity storage element that changes from moment to moment.

[0019] (2) In the energy storage information processing method described in (1) above, when a storage element showing a predetermined internal state quantity is charged or discharged under a plurality of power and temperature conditions, whether charging or discharging is possible over the duration and the amount of energy that can be charged or discharged are obtained, and based on a comparison of whether charging or discharging is possible and the amount of energy under each condition, the amount of energy or power and temperature under which charging or discharging is possible and which maximizes the amount of energy and minimizes the temperature may be estimated.

[0020] According to the above-mentioned (2) power storage information processing method, the optimal charge / discharge capacity and temperature can be easily and accurately estimated by comparing the possibility of charging / discharging under a plurality of different power and temperature conditions with the amount of power that can be charged / discharged.

[0021] (3) In the energy storage information processing method described in (1) or (2) above, correspondence information indicating the correspondence relationship between the amount of power or electricity that the energy storage element can charge or discharge over the duration and the temperature for each internal state quantity may be stored, and the amount of power or electricity and temperature corresponding to the internal state quantity and the duration may be estimated based on the stored correspondence information.

[0022] According to the above-mentioned (3) method for processing stored power information, the estimation process is performed based on correspondence information stored in advance, thereby reducing the processing load and enabling a high-speed response.

[0023] (4) In the energy storage information processing method described in any one of (1) to (3) above, a charge / discharge test may be performed using an energy storage element that exhibits a predetermined internal state quantity, thereby determining whether charging or discharging is possible over the duration and the amount of power that can be charged or discharged.

[0024] According to the electricity storage information processing method (4) above, correspondence information can be generated with high accuracy based on actual measurement data.

[0025] (5) In the energy storage information processing method described in any one of (1) to (3) above, the internal state quantity and power and temperature conditions may be applied to an energy storage element model that simulates the behavior of the energy storage element, thereby obtaining whether charging or discharging is possible over the duration and the amount of power that can be charged or discharged.

[0026] According to the electricity storage information processing method (5) above, it is possible to accurately estimate the charge / discharge capacity corresponding to various durations and deterioration states of the electricity storage elements.

[0027] (6) In the electricity storage information processing method according to any one of (1) to (3) above, the duration may be a duration of a product in a supply and demand adjustment market or a target time for demand response.

[0028] According to the electricity storage information processing method of (6) above, the electricity storage elements can be suitably applied to the supply and demand adjustment market and demand response, and the deterioration of the electricity storage elements when they are utilized can be suppressed while maximizing profits.

[0029] (7) A computer program according to one aspect of the present disclosure causes a computer to execute a process of acquiring an internal state quantity of a storage element, estimating the amount of power or power and temperature that the storage element can charge or discharge over a duration of charging or discharging required of the storage element based on the acquired internal state quantity and the duration of charging or discharging required of the storage element, and outputting the estimated amount of power or power and temperature.

[0030] (8) An energy storage information processing device according to one aspect of the present disclosure includes a control unit that acquires an internal state quantity of an energy storage element, estimates the amount of power or power and temperature that the energy storage element can charge or discharge over the duration based on the acquired internal state quantity and the duration of charging or discharging required of the energy storage element, and outputs the estimated amount of power or power and temperature.

[0031] The present disclosure will be specifically described with reference to the drawings showing embodiments thereof.

[0032] (First embodiment) Fig. 1 is a schematic diagram of an energy storage information processing system 100. The energy storage information processing system 100 of this embodiment includes an energy storage facility 1 having energy storage elements, an information processing device 3, and an information terminal device 5. The information processing device 3 is communicably connected to the energy storage facility 1 and the information terminal device 5 via a communication network NW. The communication network NW may be a general line such as the Internet network, or may be a dedicated line. The information processing device 3 may be communicatively connected to the energy storage facility 1 via a local network, and may also be communicatively connected to the information terminal device 5 via the Internet. A plurality of energy storage facilities 1 and a plurality of information terminal devices 5 may be provided.

[0033] The power storage facility 1 is, for example, an ESS, which stores power supplied from a power generation facility PG and supplies the stored power to a load PC. The power generation facility PG includes a solar power generation facility, a wind power generation facility, etc. The load PC includes power consumption facilities such as factories, office buildings, schools, hospitals, restaurants, and airports.

[0034] The power storage facility 1 may store power supplied from the power generation facility PG and supply the stored power to the power grid PS. The power storage facility 1 may store power supplied from the power grid PS and supply the stored power to the load PC. The power storage facility 1 may be used as an adjustment capacity for, for example, demand response, a supply and demand adjustment market, etc.

[0035] The power storage facility 1 includes a container 10. The container 10 is a housing with an openable and closable door, and has a substantially rectangular parallelepiped shape. The container 10 houses a battery panel 11, a control panel 12, and a temperature adjustment device 13 for adjusting the temperature inside the container 10. The temperature adjustment device 13 is, for example, an air conditioner. The power storage facility 1 may include two or more battery panels 11.

[0036] A power converter 2 is installed between the power storage facility 1 and the power generation facility PG and load PC. The power converter 2 is also called a PCS (Power Conditioning System). The power converter 2 converts power (AC power or DC power) supplied from the power generation facility PG into DC power of a predetermined magnitude and supplies the converted DC power to the power storage facility 1. The power storage facility 1 stores the power supplied from the power generation facility PG via the power converter 2. The power storage facility 1 supplies the stored power to the load PC in response to an external request. The power supplied from the power storage facility 1 to the load PC is converted from DC power to AC power by the power converter 2.

[0037] 1, the power converter 2 is installed outside the power storage facility 1. Alternatively, the power converter 2 may be installed inside the power storage facility 1.

[0038] The information processing device 3 is a device capable of various information processing and transmitting and receiving information, and is, for example, a server computer, a personal computer, a quantum computer, etc. The information processing device 3 acquires measurement data related to the energy storage elements from the energy storage facility 1 and estimates the charge / discharge capabilities of the energy storage elements based on the measurement data. The information processing device 3 is, for example, a remote monitoring server that remotely monitors the energy storage facility 1. Alternatively, the information processing device 3 may be a local computer used near the energy storage facility 1, or may be a management device such as a domain management device 122 (see FIG. 3 ) provided in the container 10 of the energy storage facility 1.

[0039] The information terminal device 5 is an information terminal device having a communication function, and is, for example, a smartphone, a tablet terminal, a personal computer, etc. The information terminal device 5 is used by a user of the power storage facility 1.

[0040] FIG. 2 is a schematic diagram showing an example of the internal configuration of the battery panel 11 and the control panel 12. The battery panel 11 includes multiple banks 111 and a battery management unit 112. Each bank 111 is configured by electrically connecting multiple power storage modules BT in series. In the example of FIG. 2, the battery panel 11 includes three banks 111, and each bank 111 is configured by electrically connecting a total of 18 power storage modules BT in series in two vertical columns. These three banks 111 are connected in parallel with each other. A configuration in which multiple banks 111 are connected in parallel is also called a domain 121. The number of banks 111 included in the battery panel 11 and the number of power storage modules BT constituting each bank 111 are selected arbitrarily. Although the power storage facility 1 in FIG. 2 includes one domain 121, it may include multiple domains.

[0041] The power storage module BT is configured by connecting multiple power storage cells in series. In one example, the power storage cells are battery cells based on lithium-ion secondary batteries. Alternatively, the power storage cells may be battery cells based on all-solid-state batteries, lead 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, or the like, or may be capacitors. The number of power storage cells constituting the power storage module BT is selected arbitrarily. In this specification, the term "power storage element" may refer to a power storage cell, a power storage module BT, a bank 111, or a domain 121.

[0042] The battery management device 112 is a device for monitoring the state of the bank 111. A battery management device 112 is provided for each bank 111. In the example of Fig. 2, a battery management device 112 is provided above each bank 111. The battery management device 112 monitors the state of the corresponding bank 111 and notifies the obtained information about the bank 111 to a higher-level management device (the domain management device 122 shown in Fig. 3).

[0043] Fig. 3 is an explanatory diagram illustrating an example of the circuit configuration of the power storage facility 1. The battery panel 11 of the power storage facility 1 includes a plurality of banks 111 and a battery management device 112 provided corresponding to each bank 111. In the example of Fig. 3, the battery panel 11 includes three banks 111 and three battery management devices 112 provided corresponding to each bank 111. The number of banks 111 and battery management devices 112 to be installed can be designed as appropriate.

[0044] The banks 111 are connected to the outside (such as the power converter 2, a power supply source, and a power supply destination) via a main circuit MC. The main circuit MC has a main path P1 connected to the outside, and branch paths P2 branching from the main path P1 and connected to each bank 111. A switch may be provided in the branch path P2 to switch the target of charging or discharging.

[0045] The power supply source for the bank 111 is the power generation facility PG (or the power system PS), and the power supply destination of the bank 111 is the load PC (or the power system PS). The above-mentioned power converter 2 is provided between the bank 111 and the power supply source or the power supply destination. The bank 111 stores (charges) power supplied via the power converter 2 and the main circuit MC, and supplies (discharges) the stored power to an external power supply destination via the main circuit MC and the power converter 2.

[0046] Each bank 111 includes a current sensor SA, a voltage sensor SV, and a temperature sensor ST. The current sensor SA is an existing current sensor such as a Hall sensor, and measures the current flowing through each bank 111 over time. The voltage sensor SV is an existing voltmeter, and measures the voltage of each bank 111 over time. The temperature sensor ST is an existing temperature sensor such as a thermistor, and is installed inside or near each bank 111 to measure the temperature of each bank 111 over time. A plurality of various sensors may be provided. For example, the voltage sensor SV may be provided for each power storage module BT. The temperature sensor ST may be provided at multiple locations in the bank 111 to measure the temperature at multiple locations. Each bank 111 may also include an internal resistance sensor that measures internal resistance.

[0047] The current sensor SA, voltage sensor SV, and temperature sensor ST output the measurement data obtained by the measurements to the battery management device 112. The measurement data can be repeatedly acquired at an appropriate period, such as every 1 second, 10 seconds, or 30 seconds.

[0048] The battery management unit 112 acquires measurement data output from the current sensor SA, voltage sensor SV, and temperature sensor ST. The various sensors may be mounted on a measurement board with a communication function, and the battery management unit 112 may acquire the measurement data by communicating with the measurement board. The measurement data includes measurement values ​​such as the current, voltage, and temperature of each storage element in the battery management unit 112. The battery management unit 112 monitors the state of the bank 111 at each time by, for example, calculating the capacity maintenance rate (SOC: State Of Charge) of the bank 111 based on time-series data of the acquired measurement data.

[0049] The control panel 12 of the energy storage facility 1 includes a domain management device 122 and a communication device 123. The domain management device 122 is a device for monitoring the status of the domain 121 (the entire bank). The domain management device 122 is communicatively connected to the battery management devices 112 of each bank 111. The domain management device 122 aggregates measurement data from the battery management devices 112 of each bank belonging to the domain. The measurement data transmitted from the battery management devices 112 to the domain management device 122 includes, for example, measurement values ​​of current, voltage, and temperature acquired from various sensors, and an SOC based on these measurement values. An existing communication standard such as CAN (Controller Area Network) is used for communication between the domain management device 122 and each battery management device 112. Alternatively, communication standards such as LIN (Local Interconnect Network), ECHONET (registered trademark), and ECHONET Light (registered trademark) may be used.

[0050] The communication device 123 has a communication interface for connecting to the communication network NW. The domain management device 122 transmits measurement data of the energy storage elements acquired from each battery management device 112 to the information processing device 3 via the communication device 123. The domain management device 122 or the communication device 123 may hold measurement data for a predetermined time period and transmit the measurement data to the information processing device 3 at predetermined time intervals. The domain management device 122 and the communication device 123 may be housed in the battery panel 11.

[0051] 4 is a block diagram showing an example of the configuration of the information processing device 3. The information processing device 3 includes a control unit 31, a storage unit 32, and a communication unit 33. The information processing device 3 may be a single computer, or may be a computer system configured with multiple computers and peripheral devices. The information processing device 3 may be a virtual machine whose entity is virtualized, or may be a cloud.

[0052] The control unit 31 is an arithmetic circuit including a central processing unit (CPU), a graphics processing unit (GPU), a read-only memory (ROM), a random access memory (RAM), etc. The CPU or GPU included in the control unit 31 reads and executes various computer programs stored in the ROM or the storage unit 32 to control each hardware unit and cause the entire device to function as the power storage information processing device of the present disclosure. The control unit 31 may include functions such as a timer that measures the elapsed time from when a measurement start instruction is given to when a measurement end instruction is given, a counter that counts numbers, and a clock that outputs date and time information. Each functional unit of the control unit 31 may be realized by software, or some or all of it may be realized by hardware such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

[0053] 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 device 3 and may be one or more external storage devices connected externally. The storage unit 32 stores various computer programs and data referenced by the control unit 31. The storage unit 32 of this embodiment stores a program 321 for causing a computer to execute processing related to estimation of the charge / discharge capacity of the energy storage element, a measurement database (DB) 322, and a charge / discharge condition DB 323.

[0054] A computer program (program product) including the program 321 may be provided by a non-transitory recording medium 3A on which the computer program is readably recorded. The recording medium 3A is a portable memory such as a CD-ROM, a USB memory, or an SD (Secure Digital) card. The control 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 memory unit 32. Alternatively, the computer program may be provided via communication. The program 321 may be a single computer program or may be composed of multiple computer programs. The program 321 may also be executed on a single computer or may be executed cooperatively by multiple computers.

[0055] The communication unit 33 includes a communication interface that realizes communication via the network N. The control unit 31 receives the measurement data transmitted from the power storage equipment 1 via the communication unit 33.

[0056] The configuration of the information processing device 3 is not limited to the above example, and may include, for example, a display unit that displays images, an operation unit that accepts user operations, and the like.

[0057] 5 is a block diagram showing an example of the configuration of the information terminal device 5. The information terminal device 5 includes a control unit 51, a storage unit 52, a communication unit 53, a display unit 54, and an operation unit 55.

[0058] The control unit 51 is an arithmetic circuit including one or more CPUs, GPUs, ROMs, RAMs, etc. The CPUs or GPUs included in the control unit 51 execute various computer programs stored in the ROM or storage unit 52, and control the operation of each of the above-mentioned hardware components.

[0059] The storage unit 52 includes a nonvolatile memory such as a hard disk, a flash memory, etc. The storage unit 52 stores various computer programs and data referenced by the control unit 51.

[0060] The communication unit 53 includes a communication module that communicates with external devices via the network N. The control unit 51 transmits and receives various types of information to and from the information processing device 3 via the communication unit 53.

[0061] The display unit 54 includes a display device such as a liquid crystal display, an organic EL (Electro Luminescence) display, etc. In accordance with instructions from the control unit 51, the display unit 54 displays various information including the estimation results of the charge / discharge capacities of the energy storage elements received from the information processing device 3.

[0062] The operation unit 55 is an interface that accepts user operations. The operation unit 55 includes, for example, a keyboard, a mouse, a touch panel device with a built-in display, a speaker, a microphone, etc. The operation unit 55 accepts operation input from the user and sends a control signal corresponding to the operation content to the control unit 51.

[0063] FIG. 6 is a diagram showing an example of the content of information stored in the measurement DB 322. The measurement DB 322 is a database that stores measurement data received from the energy storage facility 1. The measurement DB 322 stores records in chronological order, in which information such as identification information of the energy storage element, measurement date and time, and measurement data is linked using, for example, a data ID for identifying the measurement data as a key. The measurement data includes, for example, the current, voltage, temperature, and SOC of the energy storage element. The measurement data includes data when the energy storage element is charged or discharged. Every time the control unit 51 receives measurement data transmitted from the energy storage facility 1, the control unit 51 stores the received measurement data in chronological order in the measurement DB 322.

[0064] FIG. 7 is a diagram showing an example of information stored in the charge / discharge condition DB 323. The charge / discharge condition DB 323 is a database that stores charge / discharge condition information indicating optimal charge / discharge conditions for charging or discharging an energy storage element under predetermined conditions. The charge / discharge conditions include power and temperature related to charge / discharge. In the example shown in FIG. 7 , a charge / discharge condition table is stored as the charge / discharge condition information, storing values ​​of power and temperature related to charge / discharge for each SOC at predetermined intervals. The charge / discharge condition table may be associated with information indicating a duration for which the charge / discharge condition is applicable. The charge / discharge condition DB 323 may store multiple charge / discharge condition tables prepared for different durations. The charge / discharge condition table is an example of correspondence information indicating, for each internal state quantity, a correspondence relationship between the amount of power or power that can be charged or discharged over a duration and temperature.

[0065] 8 is a diagram illustrating a method for generating a charge / discharge condition table. The charge / discharge condition table is generated based on the results of a charge / discharge test using a storage element. The following describes an example of generating a table showing optimal conditions for discharging.

[0066] As the energy storage elements to be used in the discharge test, energy storage elements corresponding to a plurality of SOCs separated at predetermined intervals (10% in the example of FIG. 8 ) between the lower limit and the upper limit of the SOC are prepared. In addition, a plurality of discharge conditions are set, each of which is represented by a combination of discharge power (unit: kilowatts (kW)) and temperature (unit: ° C.). The discharge conditions are defined by different combinations of discharge power at predetermined intervals (1 kW in the example of FIG. 8 ) and temperature at predetermined intervals (5° C. in the example of FIG. 8 ).

[0067] A discharge test is performed in which the storage element is discharged for a predetermined duration at a discharge power and temperature corresponding to the discharge conditions, and whether discharge is possible for the duration and the amount of electricity discharged by the storage element are confirmed. By performing the discharge test under each of the predetermined discharge conditions, it is possible to determine whether discharge is possible for each discharge condition and the amount of electricity discharged (in kilowatt-hours (kWh)). "Ability to discharge for a continuous duration" means that electricity can be continuously supplied at a predetermined discharge power value for the continuous duration without the discharge stop condition being satisfied. The discharge stop condition is, for example, that the voltage of the storage element reaches or falls below a predetermined lower limit voltage value, or that the SOC reaches or falls below a predetermined lower limit SOC value.

[0068] The duration can be set depending on the purpose of estimating the charge / discharge performance. The duration may be the duration of a product in a supply and demand balancing market or the target time for demand response. In FIG. 8, the duration is set to 3 hours.

[0069] The optimal discharge conditions are identified by comparing the test results corresponding to all discharge conditions obtained for the same SOC. The optimal discharge conditions are those under which discharge is possible, the amount of power (absolute value of the amount of power), and the temperature are minimized. For an SOC of 100% shown in the upper part of Figure 8, the combination of discharge power and temperature under which discharge is possible, the amount of power is maximized, and the temperature is minimized is a discharge power of 10 kW and a temperature of 25°C. The above discharge power and temperature are identified as the optimal discharge conditions for an SOC of 100%. Similarly, for an SOC of 90%, the combination of a discharge power of 9 kW and a temperature of 20°C is identified as the optimal discharge condition.

[0070] A charge / discharge condition table is generated by identifying optimal discharge conditions for each SOC and recording the identified discharge power and temperature. FIGS. 7 and 8 show an example in which discharge power and temperature are stored in association with each other in the charge / discharge condition table. Alternatively, the charge / discharge condition table may store the amount of discharge power that can be discharged over a predetermined time in association with the temperature. A charge / discharge table may be generated for each of a plurality of expected durations. The charge / discharge table may be periodically updated, taking into account deterioration of the storage elements.

[0071] Using a similar procedure, a charging test is performed in which the storage element is charged for a predetermined duration, and a table showing optimal conditions for charging is generated by extracting the charging power and temperature at which charging is possible for the duration, the amount of power is maximum, and the temperature is minimum. In the case of charging, "being able to charge for a continuous duration" means that current can be continuously supplied at a predetermined charging power value for the duration without a charging stop condition being satisfied. Examples of charging stop conditions include the voltage of the storage element reaching or exceeding a predetermined upper voltage limit, or the SOC reaching or exceeding a predetermined upper SOC limit.

[0072] The information processing device 3 stores the charge / discharge condition table generated as described above in advance in the storage unit 32, and estimates the charge / discharge capacity according to the internal state of the storage element using the charge / discharge condition table. For example, if the current SOC of the storage element whose charge / discharge capacity is to be estimated is 100%, a discharge power of 10 kW and a temperature of 25° C. are derived as optimal discharge conditions from the charge / discharge condition table shown in FIG.

[0073] 9 is a flowchart showing an example of a processing procedure executed by the information processing device 3. The control unit 31 of the information processing device 3 executes the following processing in accordance with the program 321 stored in the storage unit 32. The control unit 31 executes the following processing when it receives an output request for charging capacity or discharging capacity from, for example, an information terminal device 5 logged in with a user account.

[0074] The control unit 31 of the information processing device 3 acquires the current (estimation time) SOC of the energy storage element whose charging capacity or discharging capacity is to be estimated based on the information stored in the measurement DB 322 (step S11). A known method can be appropriately adopted as a calculation method for the SOC, and for example, the SOC may be obtained from a current integration method, an SOC-OCV characteristic, or the like. The SOC may be calculated by the information processing device 3, or may be calculated by the battery management device 112 or the domain management device 122 of the energy storage facility 1, or the like.

[0075] The control unit 31 refers to the charge / discharge condition table in the charge / discharge condition DB 323, reads out the optimal conditions corresponding to the current SOC of the acquired storage element, and estimates the power and temperature at which the storage element can be charged or discharged for a specified duration (step S12).

[0076] The control unit 31 outputs information based on the estimated power and temperature to the information terminal device 5 corresponding to the logged-in account (step S13). The control unit 31 ends the process. When an estimation result is obtained, the control unit 31 may output control information according to the estimation result to the power storage facility 1.

[0077] The estimation results are presented to the user via the display unit 54 of the information terminal device 5. The user can grasp the optimal power and temperature corresponding to the current internal state of the energy storage element via the display unit 54. By setting the control values ​​for power and temperature based on the optimal power and temperature, the user can respond appropriately to demand response and supply-demand balancing markets.

[0078] In the above process, the control unit 31 may estimate and output the amount of power that can be charged or discharged over a predetermined duration.

[0079] In the above process, the control unit 31 may accept a selection of a duration for which the charging capacity or discharging capacity should be estimated from a plurality of durations set in advance through the information terminal device 5. When the selection of the duration is accepted, the control unit 31 estimates the power and temperature that can be charged or discharged for the selected duration using a charge / discharge condition table corresponding to the selected duration.

[0080] In the above example, the SOC is used as the internal state quantity of the power storage element. Alternatively, the internal resistance, capacity maintenance rate (SOH), or the like of the power storage element may be used as the internal state quantity.

[0081] According to this embodiment, it is possible to estimate optimal charging and discharging conditions that are in accordance with the internal state of the storage element and that can ensure as much chargeable and dischargeable electric power as possible while suppressing deterioration of the storage element.

[0082] Second Embodiment In a second embodiment, the chargeable or dischargeable power and temperature are estimated using a storage element model. The following mainly describes the differences from the first embodiment, and the same reference numerals are used to designate the same components as those in the first embodiment, and detailed descriptions thereof will be omitted.

[0083] 10 is a block diagram showing an example of the configuration of the information processing device 3 of the second embodiment. Equivalent circuit model information 324 is stored in the storage unit 32 of the information processing device 3 of the second embodiment instead of the charge / discharge condition DB 323. The equivalent circuit model information 324 includes information related to an equivalent circuit model of an energy storage element. The equivalent circuit model is a model for simulating an energy storage element (energy storage cell) using an electric circuit. The equivalent circuit model is an example of an energy storage element model. The equivalent circuit model information 324 includes configuration information indicating the circuit configuration and parameters (circuit parameters) related to the circuit elements of the equivalent circuit model.

[0084] Fig. 11 is a circuit diagram showing an example of the configuration of an equivalent circuit model ECM. The equivalent circuit model ECM combines a voltage source for the energy storage cell with circuit elements such as resistors and capacitors to simulate the charge / discharge behavior of the energy storage cell. The equivalent circuit model ECM shown as an example in Fig. 11 includes a constant voltage source, a DC resistor, and an RC parallel circuit. The RC parallel circuit includes a first RC parallel circuit and a second RC parallel circuit connected in series.

[0085] The constant voltage source is configured as an ideal power supply and simulates the open circuit voltage (OCV), which is the voltage of a storage cell in an unloaded state. The OCV is given as a function of the SOC, temperature, etc. of the storage cell. The OCV is defined in advance for each SOC based on, for example, actual measurement data from a battery test.

[0086] The DC resistor includes a resistive element R0 and simulates the internal resistance of the energy storage cell. Two RC parallel circuits simulate the transient polarization characteristics of the energy storage cell. The first RC parallel circuit includes a resistive element R1 and a capacitive element C1 connected in parallel. The second RC parallel circuit includes a resistive element R2 and a capacitive element C2 connected in parallel. The values ​​of the resistive elements R0, R1, and R2 and the capacitive elements C1 and C2 (hereinafter also referred to as circuit parameters) are defined in advance based on, for example, actual measurement data from a storage cell test. The circuit parameters may be set as values ​​that vary depending on the SOC, temperature, current, etc. of the energy storage cell. The information processing device 3 stores the set circuit parameters in the equivalent circuit model information 324 in association with the SOC, temperature, current, etc.

[0087] In the above-described equivalent circuit model ECM, the terminal voltage V of the storage cell after the time t has elapsed can be expressed by the following equation (1).

[0088]

[0089] In equation (1), I is the current, the third term on the right hand side is the polarization voltage generated in the first RC parallel circuit, and the fourth term on the right hand side is the polarization voltage generated in the second RC parallel circuit. The current I is positive in the case of charging and negative in the case of discharging.

[0090] 11 shows an equivalent circuit model ECM including two RC parallel circuits. Alternatively, the number of RC parallel circuits in the equivalent circuit model ECM may be one or more than two. The equivalent circuit model ECM may be configured to include only a resistive element R instead of the RC parallel circuits.

[0091] The information processing device 3 of the second embodiment uses the above-described equivalent circuit model ECM to calculate the current-voltage behavior when the storage element is discharged under a plurality of charge-discharge conditions, thereby estimating the charge-discharge capacity of the storage element.

[0092] 12 and 13 are diagrams illustrating a method for estimating the charge / discharge capacity using the equivalent circuit model ECM. In Fig. 12 and Fig. 13, an example is described in which the current (estimation time) SOC of the storage element is 100% and the discharge capacity of the storage element is estimated.

[0093] As in the first embodiment, multiple discharge conditions indicated by combinations of discharge power and temperature are set in advance. The information processing device 3 also acquires the duration of discharge (e.g., 3 hours). The information processing device 3 may store the preset duration or may acquire the duration by receiving input from the user. The duration may be configured to be changeable each time the estimation process is performed. The information processing device 3 estimates the current-voltage behavior when discharging at the discharge power and temperature indicated in the discharge conditions using an equivalent circuit model ECM.

[0094] As an initial state, the current I (unit: ampere (A)), SOC (unit: %), and terminal voltage V (unit: volt (V)) at the estimation time (t=0) are defined as follows: I(t=0) = 0 [A] SOC(t=0) = 100 [%] V(t=0) = V OCV (SOC(t=0))=V OCV (SOC=100%)

[0095] As shown in Figure 12, when discharging at a constant discharge power P (kW), the current I and SOC at time t can be expressed by the following equations (2) and (3) using the discharge power P, the terminal voltage V at time t-Δt, and the actual capacity C of the storage cell. I(t) = P / V(t-Δt) (2) SOC(t) = SOC(t-Δt) + I(t) × Δt / C (3)

[0096] In the above formula (3), the actual capacity C may be calculated taking into account the SOH of the energy storage cell at the time of estimation. The SOH of the energy storage cell at the time of estimation may be calculated using a simulation method (e.g., Japanese Patent No. 6428957, Japanese Patent No. 7173180, etc.) based on an assumed load pattern that takes into account the history of the current, voltage, and temperature of the energy storage element.

[0097] The current I and SOC calculated by the above formulas (2) and (3) are substituted into the above formula (1), and the calculation process of formula (1) is executed to calculate the terminal voltage V when discharging at the discharge power P over a continuous period of time in a calculation cycle Δt. When circuit parameters dependent on the SOC, temperature, current, etc. are stored as the circuit parameters, the information processing device 3 may read out the circuit parameters corresponding to the current SOC and temperature of the storage element or the current under the discharge conditions, and use them in the calculation of formula (1).

[0098] The information processing device 3 determines the discharge end time as the time when the discharge stop condition is satisfied or the time when the duration has elapsed without the discharge stop condition being satisfied, and terminates the calculation process at the time when the discharge end time is satisfied. The discharge end time is, for example, when the terminal voltage V of the storage element reaches or falls below a predetermined lower limit voltage value, or when the SOC reaches or falls below a predetermined lower limit SOC value.

[0099] By performing calculation processing for each discharge condition, an estimated result of the current-voltage behavior for each discharge condition is obtained, as shown in FIG. 13 . For simplicity of explanation, FIG. 13 shows the estimated results for four discharge conditions, but the number of discharge conditions to be estimated may be five or more. Based on the estimated results, the information processing device 3 determines whether discharge is possible and the discharge quantity of electricity corresponding to each discharge condition. The information processing device 3 determines whether discharge is possible by taking t_max as the time until the end of discharge and determining whether the value of t_max is equal to or greater than the duration. If the value of t_max is equal to or greater than the duration, it is determined that discharge is possible. If the value of t_max is less than the duration, it is determined that discharge is impossible. The information processing device 3 also obtains the discharge quantity of electricity (kWh) by multiplying the value of t_max by the value of the discharge power.

[0100] By performing the above-described estimation process for each of the plurality of set discharge conditions, it is possible to obtain the possibility of discharge and the discharged quantity of electricity P_max corresponding to each discharge condition, as shown in the upper part of Fig. 8. In the second embodiment, it is possible to obtain an estimation result only for the current SOC of the storage element (SOC 100% in the examples of Figs. 12 and 13) that has been acquired in advance.

[0101] The information processing device 3 compares the estimation results corresponding to all the obtained discharge conditions, and derives the discharge conditions under which discharge is possible, the amount of electric power (absolute value of the amount of electric power), and the temperature are maximized as the optimal discharge conditions. In the example shown in Figure 13, the amount of discharge electric power is maximized under the discharge conditions of a discharge power of 10 kW and a temperature of 25°C, as indicated by the solid line.

[0102] The above describes the case where discharge capacity is estimated. Similarly, charge capacity can be estimated using the above-mentioned method. When estimating charge capacity, the charge stop condition is, for example, that the terminal voltage V of the storage element reaches or exceeds a predetermined upper limit voltage value, or that the SOC reaches or exceeds a predetermined upper limit SOC value.

[0103] FIG. 14 is a flowchart showing an example of a processing procedure executed by the information processing device 3 according to the second embodiment.

[0104] As in step S11, the control unit 31 of the information processing device 3 acquires the current SOC of the storage element whose charging or discharging capacity is to be estimated (step S21). The SOC may be calculated, for example, using a simulation method based on an assumed load pattern that takes into account the history of the current, voltage, and temperature of the storage element. The control unit 31 may also acquire the current temperature, internal resistance, etc. of the storage element. The control unit 31 acquires the duration of charging and discharging (step S22).

[0105] The control unit 31 estimates current / voltage behavior using an equivalent circuit model based on the acquired current SOC and duration, and the power and temperature related to the charge / discharge conditions, thereby determining whether charge / discharge is possible over the duration corresponding to each of the multiple charge / discharge conditions and the amount of charge / discharge electricity (step S23).The control unit 31 compares whether charge / discharge is possible and the amount of charge / discharge electricity corresponding to each discharge condition, thereby estimating the charge / discharge power and temperature that maximize the amount of power and minimize the temperature (step S24).

[0106] The control unit 31 outputs information based on the estimated power and temperature to the information terminal device 5 (step S25), and ends the series of processes.

[0107] According to this embodiment, the internal state and duration of the energy storage element in the estimation process can be varied, making it possible to estimate the charge / discharge capacity of a variety of energy storage elements. By using an equivalent circuit model, it is possible to estimate voltage behavior with high accuracy. By providing the internal state of the energy storage element estimated using a simulation method based on an expected load pattern to the equivalent circuit model, it is possible to further improve the estimation accuracy of voltage behavior and estimate charge / discharge capacity with even greater accuracy.

[0108] The embodiments disclosed herein are illustrative in all respects and should not be considered limiting. 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 scope of the claims and equivalents thereto. The sequences shown in each embodiment are not limited, and within the scope of no contradiction, each processing step may be executed in a different order, or multiple processes may be executed in parallel. The entity that performs each process is not limited, and within the scope of no contradiction, the process of each device may be executed by another device.

[0109] The matters described in each embodiment can be combined with each other. Furthermore, the independent claims and dependent claims described in the claims can be combined with each other in any and all combinations, regardless of the reference format. Furthermore, the claims use a format in which a claim references two or more other claims (multiple claim format), but this is not limited to this. A multiple claim (multi-multi claim) that references at least one other multiple claim may also be used.

[0110] REFERENCE SIGNS LIST 100 Energy storage information processing system 1 Energy storage facility 2 Power converter 3 Information processing device 31 Control unit 32 Storage unit 33 Communication unit 34 Operation unit 35 Display unit 321 Program 322 Measurement DB 323 Charging / discharging condition DB 324 Equivalent circuit model information 3A Recording medium 5 Information terminal device

Claims

1. A method for processing information on electric storage devices, in which a computer executes the following process: acquire an internal state quantity of an electric storage device; estimate the amount of electric power or power and temperature that the electric storage device can charge or discharge over a duration of charging or discharging required of the electric storage device based on the acquired internal state quantity and the duration of charging or discharging required of the electric storage device; and output the estimated amount of electric power or power and temperature.

2. The method for processing energy storage information according to claim 1, wherein when a storage element showing a predetermined internal state quantity is charged or discharged under a plurality of power and temperature conditions, whether charging or discharging is possible for the duration and the amount of energy that can be charged or discharged are obtained, and based on a comparison of whether charging or discharging is possible and the amount of energy under each condition, the amount of energy or power and temperature under which charging or discharging is possible and which maximizes the amount of energy and minimizes the temperature are estimated.

3. The method for processing electricity storage information according to claim 2, wherein correspondence information indicating the correspondence relationship between the amount of electricity or power that the energy storage element can charge or discharge over the duration and temperature for each internal state quantity is stored, and the amount of electricity or power and temperature corresponding to the internal state quantity and the duration are estimated based on the stored correspondence information.

4. The method for processing electricity storage information according to claim 3, wherein the energy storage element stores the corresponding information corresponding to each of a plurality of the durations, and the amount of electricity or the power and temperature are estimated based on the corresponding information corresponding to a selected duration.

5. The method for processing information on stored electricity according to claim 2, wherein a charge / discharge test is performed using an electricity storage element that exhibits a predetermined internal state quantity, thereby determining whether charging or discharging is possible over the duration and the amount of electricity that can be charged or discharged.

6. The method for processing energy storage information according to claim 2, wherein the internal state quantity and power and temperature conditions are applied to an energy storage element model that simulates the behavior of the energy storage element, thereby obtaining whether charging or discharging is possible over the duration and the amount of energy that can be charged or discharged.

7. The electricity storage information processing method according to claim 1, wherein the duration is the duration of a product in a supply and demand adjustment market or the target time for demand response.

8. The method for processing electricity storage information according to claim 2, wherein the method determines whether or not the time taken for the terminal voltage of the electricity storage element to reach a predetermined lower limit voltage value or below, or for the SOC to reach a predetermined lower limit SOC value or below, is equal to or longer than the duration, thereby determining whether or not discharge is possible for the duration.

9. The method for processing electricity storage information according to claim 2, wherein the method determines whether charging for the duration is possible by determining whether the time required for the terminal voltage of the electricity storage element to reach or exceed a predetermined upper limit voltage value or for the SOC to reach or exceed a predetermined upper limit SOC value is equal to or greater than the duration.

10. A computer program that causes a computer to execute the following process: acquire an internal state quantity of a storage element; estimate the amount of power or power and temperature that the storage element can charge or discharge over a duration of charging or discharging required of the storage element based on the acquired internal state quantity and the duration of charging or discharging required of the storage element; and output the estimated amount of power or power and temperature.

11. A power storage information processing device comprising a control unit that executes the following processes: acquire an internal state quantity of a power storage element; estimate the amount of power or electric power and temperature that the power storage element can charge or discharge over the duration of charging or discharging required of the power storage element based on the acquired internal state quantity and the duration of charging or discharging required of the power storage element; and output the estimated amount of power or electric power and temperature.

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