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

Abstract

In this power storage information processing method, a computer executes processing for acquiring measurement data including at least one of the current, voltage, or temperature in a prescribed period of time in a power storage facility that includes a plurality of power storage elements, interpolating missing data by a first scheme when the period of time for which data was missing or the quantity of the missing data in the acquired measurement data is equal to or greater than a predetermined first threshold and less than a second threshold, and interpolating missing data by a second scheme when the period of time for which data was missing or the quantity of the missing data in the acquired measurement data is equal to or greater than the second threshold.

Description

Power storage information processing method, power storage information processing apparatus, and program

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

[0002] For the purpose of stabilizing and effectively utilizing the 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. The power storage element deteriorates as its capacity decreases due to repeated charging and discharging. It is important to monitor the state of the power storage element when operating the power storage facility.

[0003] A technique has been proposed in which an external server collects and analyzes data related to power storage elements and remotely monitors the power storage elements. The remote monitoring system disclosed in Patent Document 1 includes a plurality of battery systems and an external server. The external server uses the operation history data of the battery measured during the rest of the vehicle equipped with the battery system, received from the battery system, to predict the life of the battery.

[0004] Japanese Patent Application Laid-Open No. 2022-156037

[0005] When collecting measurement data such as current, voltage, and temperature of a power storage facility, the data may be missing due to various reasons. When there is a missing value in the measurement data, it becomes difficult to accurately perform analysis processing based on the measurement data, such as deterioration prediction calculation. A technique that can interpolate missing measurement data is required. In addition, the missing data may be only one point or may cover multiple points. A technique that can interpolate missing measurement data in consideration of the state of the missing data is required.

[0006] An object of the present disclosure is to provide a technique capable of interpolating data by a method according to the state of missing measurement data.

[0007] A method for processing energy storage information relating to one aspect of this disclosure involves a computer that acquires measurement data including at least one of current, voltage, and temperature for a predetermined period in an energy storage facility equipped with multiple energy storage elements, and if the period or number of missing data in the acquired measurement data is between a predetermined first threshold and a predetermined second threshold, the computer interpolates the missing data using a first method, and if the period or number of missing data in the acquired measurement data is equal to or greater than the second threshold, the computer interpolates the missing data using a second method.

[0008] A method for processing energy storage information relating to one aspect of this disclosure acquires measurement data including at least one of current, voltage, and temperature for a predetermined period in an energy storage facility equipped with multiple energy storage elements, and if there are gaps in the acquired measurement data, a computer performs a process to determine whether to use the first method or the second method to interpolate the missing data based on the length or number of periods of gaps.

[0009] According to this disclosure, it becomes possible to interpolate data using methods that correspond to the state of missing data in the measurement data.

[0010] This is a schematic diagram of a remote monitoring system. This shows an example of the configuration of a container for an energy storage system. This shows an example of the electrical connection configuration of an energy storage system. This is a block diagram showing an example of the configuration of an information processing device. This shows an example of an interpolation method using the first method. This shows an example of an interpolation method using the second method. This shows another example of an interpolation method using the second method. This is a flowchart showing an example of a processing procedure performed by an information processing device. This is a flowchart showing an example of a processing procedure performed by an information processing device of the second embodiment. This shows an example of an interpolation method using the second method of the second embodiment. This shows another example of an interpolation method using the second method of the second embodiment.

[0011] (1) A method for processing energy storage information according to one aspect of the present disclosure involves a computer that acquires measurement data including at least one of current, voltage, and temperature for a predetermined period in an energy storage facility equipped with a plurality of energy storage elements, and if the period or number of missing data in the acquired measurement data is greater than or equal to a predetermined first threshold and less than a predetermined second threshold, the computer interpolates the missing data using a first method, and if the period or number of missing data in the acquired measurement data is greater than or equal to the second threshold, the computer interpolates the missing data using a second method.

[0012] In this disclosure, 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 in which multiple energy storage cells are connected, a bank in which multiple modules are connected, or a domain in which multiple banks are connected. The first method may be a method relating to data estimation or correction. Estimation includes, for example, interpolation, theoretical estimates (theoretical values), and model calculations. The second method may be a method relating to data copying.

[0013] According to the energy storage information processing method described in (1) above, missing data in the measurement data can be interpolated using an interpolation method that corresponds to the missing period or number of missing data points in the measurement data. The amount of data to be interpolated varies depending on the length of the missing period and the number of missing data points. By using different interpolation methods depending on the state of the missing data, it is possible to improve the efficiency and accuracy of the interpolation process.

[0014] Measurement data collected from energy storage equipment is used in various calculations to analyze the state of energy storage elements. For example, the applicant possesses technology to determine the degradation of the capacity of energy storage elements through simulations based on assumed load patterns (e.g., Patent No. 6428957, Patent No. 7173180). The assumed load pattern is determined based on measurement data of the current, voltage, and temperature of the energy storage elements over a certain period.

[0015] The measurement data for a predetermined period is time-series data containing current, voltage, and temperature measurements taken at pre-set measurement intervals. If there are no missing values, the measurement data contains consecutive measurements at each measurement interval. However, the actual acquired measurement data may contain missing data. There are various reasons for missing measurement data, including, for example, abnormalities in the communication environment or malfunctions in equipment related to the acquisition and output of measurement data.

[0016] In particular, in the case of remote monitoring systems that monitor energy storage equipment from a distance, measurement data measured by sensors is output to external devices via multiple devices, such as various management devices and communication equipment installed in the energy storage equipment. In remote monitoring systems, the possibility of incorrect data acquisition due to communication errors is higher compared to systems with fewer devices involved in acquiring measurement data. Furthermore, in remote monitoring systems, measurement data must be acquired and temporarily stored at each of the multiple devices, which increases the possibility of data loss due to processing errors. An increase in the number of energy storage elements for which measurement data is to be stored, and an increase in the length of the measurement data storage period, can also be contributing factors to data loss.

[0017] If there are gaps in the measurement data and the measured values ​​are discontinuous, the load on the energy storage element during the discontinuous period is unknown, making it impossible to accurately determine the assumed load pattern. If an accurate assumed load pattern cannot be obtained, it becomes difficult to estimate degradation that is in line with the actual state of the energy storage element. In order to improve the accuracy of various calculations, including degradation estimation, it is important to acquire measurement data including continuous current, voltage, and temperature at regular intervals. This energy storage information processing method can improve the accuracy of various calculations using measurement data by accurately generating measurement data with interpolated gaps.

[0018] (2) In the energy storage information processing method described in (1) above, the first method may be a method in which the voltage and temperature during the data gap period in the measurement data are interpolated with the voltage and temperature at the measurement points before and after the gap period, and the current during the gap period is filled with a predetermined current correction value.

[0019] According to the energy storage information processing method described in (2) above, data can be accurately interpolated when the data loss period is relatively short or the number of data loss periods is small. In measurement data of current, voltage, and temperature measured at predetermined intervals, the voltage behavior and temperature behavior are usually expected to show continuity. On the other hand, the current behavior is expected to include instantaneous changes, such as a sudden rise or fall. For voltage and temperature, which are expected to change continuously, interpolation can be performed using measured values ​​before and after the data loss period to accurately generate interpolated values ​​that take into account the behavior experienced by the energy storage element before and after the data loss period. For current, which tends to change moment by moment, overestimation of the current value can be suppressed by filling in the gaps with a predetermined current correction value.

[0020] (3) In the energy storage information processing method described in (2) above, the current correction value may be zero.

[0021] According to the energy storage information processing method described in (3) above, the gap period can be defined as a period of no power supply during which charging or discharging is not occurring. By providing an interpolated current value that is larger than the actual value, the decrease in the estimation accuracy of the charge rate and discharge rate of the energy storage element during the gap period can be suppressed, and the accuracy of subsequent calculations using the measurement data can be improved.

[0022] (4) In any one of the energy storage information processing methods described in (1) to (3) above, the second method may be a method of filling in the current, voltage and temperature of the data loss period in the measurement data with the current, voltage and temperature of a period of the same length as the loss period before or after the loss period, or a method of connecting the current, voltage and temperature of the period before the loss period with the current, voltage and temperature of the period after the loss period.

[0023] According to the energy storage information processing method described in (4) above, data with relatively long gaps or a large number of gaps can be accurately interpolated. Instead of interpolating data point by point during the gap, the interpolation process is simplified by interpolating the measurement data for the entire period together. By using measurement data from the periods before and after the gap, the actual state of the energy storage element can be appropriately reflected in the interpolated data, improving the interpolation accuracy.

[0024] (5) In any one of the energy storage information processing methods described in (1) to (4) above, the measurement data is stored as a data file for each unit period containing data from multiple measurement times, and the second method may be a method of generating a copy of the data file for the unit period before or after the missing period as a data file for the missing period, or a method of sequentially arranging the data files for the unit periods before and after the missing period.

[0025] According to the energy storage information processing method described in (5) above, data loss can be interpolated on a data file basis, making it particularly suitable when measurement data is stored on a data file basis.

[0026] (6) Any one of the energy storage information processing methods described in (1) to (5) above may not perform interpolation by the first method and the second method if the missing period or number of missing data in the measurement data is less than the first threshold.

[0027] According to the energy storage information processing method described in (6) above, the execution of interpolation processing under predetermined conditions is restricted, thereby improving processing efficiency and convenience.

[0028] (7) Any one of the energy storage information processing methods described in (1) to (6) above may involve the computer located remotely from the energy storage equipment acquiring the measurement data via communication.

[0029] According to the energy storage information processing method described in (7) above, measurement data can be interpolated by a remote computer.

[0030] (8) A method for processing energy storage information according to one aspect of the present disclosure acquires measurement data including at least one of current, voltage, and temperature for a predetermined period in an energy storage facility equipped with a plurality of energy storage elements, and if there are gaps in the acquired measurement data, a computer performs a process to determine whether to use the first method or the second method to interpolate the missing data based on the length or number of periods of gaps.

[0031] According to the energy storage information processing method described in (8) above, an interpolation method suitable for the state of data loss can be determined in order to perform interpolation according to the state of data loss in the measurement data. Since an interpolation method suitable for data interpolation can be determined according to the period or number of data loss in the measurement data, interpolation processing according to the period or number of data loss can be performed using the determined interpolation method.

[0032] (9) A device for processing energy storage information according to one aspect of the present disclosure includes a processing unit which acquires measurement data including at least one of current, voltage, and temperature for a predetermined period of time in an energy storage facility having a plurality of energy storage elements, and which interpolates the missing data by a first method if the missing period or number of missing data in the acquired measurement data is greater than or equal to a predetermined first threshold and less than a predetermined second threshold, and which interpolates the missing data by a second method if the missing period or number of missing data in the acquired measurement data is greater than or equal to the second threshold.

[0033] (10) A program according to one aspect of the present disclosure acquires measurement data including at least one of current, voltage, and temperature for a predetermined period in an energy storage facility equipped with a plurality of energy storage elements, and causes a computer to perform the following processes: if the period or number of missing data in the acquired measurement data is greater than or equal to a predetermined first threshold and less than a predetermined second threshold, interpolate the missing data using a first method; and if the period or number of missing data in the acquired measurement data is greater than or equal to the second threshold, interpolate the missing data using a second method.

[0034] This disclosure will be described in detail with reference to drawings illustrating embodiments thereof.

[0035] (First Embodiment) Figure 1 is a schematic diagram of the remote monitoring system 100. The remote monitoring 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 remote monitoring system 100 enables remote access to information regarding the energy storage elements 10 included in the energy storage device 1. The energy storage device 1 and the information processing device 3 are connected to each other via a network N so as to be able to communicate.

[0036] 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.

[0037] 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.

[0038] The energy storage system 1 may include 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.

[0039] In the example shown in Figure 1, the power conditioner 2 is installed outside the energy storage system 1. Alternatively, the power conditioner 2 may be installed inside the energy storage system 1.

[0040] The information processing device 3 is a device capable of various information processing and information transmission and reception, such as a server computer, a personal computer, a quantum computer, etc. The information processing device 3 acquires measurement data regarding the power storage facility 1 through communication via the network N and remotely monitors the state of the power storage facility 1. The information processing device 3 is an example of a power storage information processing device.

[0041] The network N is a wired or wireless network including, for example, the Internet, a carrier network that realizes wireless communication according to a predetermined mobile communication standard, a general optical line, etc. The network N may include a local network for the manufacturer or maintenance provider of the power storage element 10.

[0042] FIG. 2 shows an example of the configuration of the container 11 of the power storage facility 1. A plurality of power storage boards 12 are accommodated in the container 11. Although not shown, the power storage facility 1 may be configured by omitting the container 11 and installing a plurality of power storage boards 12 outdoors. The container 11 may accommodate auxiliary equipment such as an air conditioner and a lighting device.

[0043] Each power storage board 12 includes a plurality of banks 14. Each bank 14 is configured by electrically connecting a plurality of power storage modules 15 in series. Each bank 14 is connected in parallel with each other. The configuration in which a plurality of banks 14 are connected in parallel is also called a domain. The number of banks 14 included in the power storage board 12, the number of power storage modules 15 constituting each bank 14, and the number of domains are arbitrarily selected.

[0044] The power storage module 15 is configured by connecting a plurality of power storage cells in series. In one example, the power storage cell is a battery cell using a lithium-ion secondary battery. Alternatively, the power storage cell may be a battery cell using an all-solid-state battery, a lead battery, a redox flow battery, a zinc-air battery, an alkaline manganese battery, a lithium-sulfur battery, a sodium-sulfur battery, a silver-zinc oxide battery, a nickel-metal hydride battery, a molten salt thermal battery, etc., or may be a capacitor. The number of power storage cells constituting the power storage module 15 is arbitrarily selected.

[0045] Figure 3 shows an example of the electrical connection configuration of the power storage equipment 1. Figure 3 shows the electrical connection configuration in one power storage panel 12 included in the power storage equipment 1. The power storage equipment 1 includes a plurality of banks 14, a plurality of bank BMUs 17 (Battery Management Unit) provided corresponding to each bank 14, a domain BMU 18, and a communication device 19. The domain BMU 18 and the communication device 19 are separate from the power storage panel 12 and may be housed in a control panel built into the container 11. In Figure 3, three banks 14 are shown for simplicity of explanation, but the power storage panel 12 may incorporate a large number of banks 14, such as several tens.

[0046] The bank 14 is connected to the outside (for example, the power conditioner 2, the power supply source, the power supply destination, etc.) via the power line 41. The bank 14 stores (charges) the power supplied through the power conditioner 2 and the power line 41, and supplies (discharges) the stored power to an external power supply destination through the power line 41 and the power conditioner 2.

[0047] In addition to the bank BMU 17, each bank 14 includes a current sensor 42, a voltage sensor 43, and a temperature sensor 44. The current sensor 42 measures the current flowing through the bank 14 in a time series. The current sensor 42 is, for example, a Hall sensor. The voltage sensor 43 measures the voltage of the storage cell or the bank 14 in a time series. The temperature sensor 44 is installed inside or near the bank 14 to measure the temperature of the storage cell or the bank 14 in a time series. The temperature sensor 44 is, for example, a thermistor. Each sensor can repeatedly acquire measurement values at a preset fixed period.

[0048] A plurality of each sensor may be provided. For example, the voltage sensor 43 may be provided for each storage module 15. The temperature sensor 44 may be provided at a plurality of locations to measure the temperature at a plurality of locations of the bank 14.

[0049] The measurement times of the current by the current sensor 42, the voltage by the voltage sensor 43, and the temperature by the temperature sensor 44 may be synchronized or asynchronous, and synchronization is preferred.

[0050] Measurement data, including voltage, current, and temperature of the energy storage elements measured by each sensor, is output to bank BMU 17. The measurement data may also be transmitted to bank BMU 17 via a control board provided for each energy storage module 15, which has a communication function compliant with a predetermined communication protocol.

[0051] Bank BMU 17 is a device for monitoring the status of Bank 14. Bank BMU 17 acquires measurement data such as voltage, current, and temperature of the energy storage cells, and monitors the status of Bank 14 at each time point by calculating the State of Control (SOC) of the energy storage cells in Bank 14 based on the acquired measurement data. Bank BMU 17 may also control the start and stop of charging and discharging according to the status of the monitored Bank 111.

[0052] The Domain BMU 18 is a device for monitoring the status of the entire domain and bank 14. The Domain BMU 18 is communicated with the bank BMU 17 of each bank 14. The Domain BMU 18 aggregates measurement data from the 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 the Domain BMU 18 and each bank BMU 17. Alternatively, communication standards such as LIN (Local Interconnect Network), ECHONET®, and ECHONETLight® may be used.

[0053] The communication device 19 has an interface for connecting to the network N and securely transmits data to the information processing device 3 wirelessly or via a wired connection. The communication device 19 may be, for example, a network interface card. The domain BMU 18 transmits measurement data of energy storage elements acquired from each bank BMU 17 to the information processing device 3 via the communication device 19. The domain BMU 18 or the communication device 19 may retain measurement data for a predetermined time and transmit the measurement data to the information processing device 3 at predetermined intervals. The measurement data may be transmitted as a data file containing measurement values ​​for multiple measurement times within a predetermined time.

[0054] The information processing device 3 collects and stores measurement data transmitted from the communication device 19. The measurement data includes the current, voltage, and temperature of the energy storage elements. The measurement data may also be associated with energy storage element identification information for identifying the energy storage element to be measured, and energy storage equipment identification information for identifying the energy storage equipment 1 equipped with the energy storage elements. Measurement data for current, voltage, and temperature may be acquired for each energy storage cell, each bank 14, each domain, or a combination thereof, and stored in the information processing device 3. If the energy storage equipment 1 is equipped with a power conditioner 2, measurement data for current, voltage, and temperature may be acquired for the power conditioner 2.

[0055] Figure 4 is a block diagram showing an example configuration of the information processing device 3. The information processing device 3 is a dedicated or general-purpose computer and comprises a processing unit 31, a storage unit 32, and a communication unit 33. The information processing device 3 may be a single computer or a computer system composed of multiple computers and peripheral devices. The information processing device 3 may be a virtualized virtual machine or a cloud.

[0056] The processing unit 31 comprises one or more processors such as CPUs (Central Processing Units) or MPUs (Micro-Processing Units). The processing unit 31 includes 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 also include functions such as a timer for measuring the elapsed time from the time a measurement start instruction is given to the time a measurement end instruction is given, a counter for counting numbers, and a clock for outputting date and time information. The CPU and other components of the processing unit 31 control each part of the hardware by reading and executing various computer programs stored in the storage unit 32, thereby making the entire device function as an energy storage information processing device in this disclosure. The processing unit 31 may be implemented in software, or part or all of it may be implemented in hardware such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array).

[0057] The storage unit 32 includes, for example, a non-volatile storage device such as a hard disk or flash memory. The storage unit 32 is separate from the information processing device 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 this embodiment, the storage unit 32 stores a program 3P that causes the computer to perform processing related to interpolating missing measurement data, and a measurement DB (Data Base) 321 that stores measurement data of the energy storage element 10.

[0058] 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.

[0059] The measurement data stored in the measurement DB 321 may be stored as a single data group containing records of multiple measurement dates and times that are consecutive in time series. Records of multiple measurement dates and times may be stored together in a single data file. The data file is generated in units of a predetermined period. The unit period for generating the data file may be, for example, one hour, one day, or one month. When the processing unit 31 receives measurement data measured at predetermined measurement intervals from the energy storage equipment 1, it temporarily stores the received measurement data and generates a single data file containing the measurement data for each predetermined unit period. The file format of the data file is not particularly limited, but may be, for example, a CSV file. The generation of the CSV file is performed in the energy storage equipment 1, and the measurement data in the generated data file format may be transmitted from the energy storage equipment 1 to the information processing device 3.

[0060] 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.

[0061] The communication unit 33 is equipped with a communication device for performing 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.

[0062] 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.

[0063] If there are missing values ​​in the collected measurement data, the information processing device 3 generates measurement data without missing values ​​by interpolating the data using multiple interpolation methods corresponding to the state of the missing values ​​in the measurement data.

[0064] The following describes the interpolation method for measurement data. The information processing device 3 refers to the measurement DB 321 and extracts measurement data for a predetermined period to be processed. The predetermined period to be processed may be, for example, the period from the time of the previous processing to the present time. For the measurement data for the predetermined period, the information processing device 3 calculates the time interval Δt for each of the consecutive measurement data in the time series. Typically, the time interval Δt is the same as or greater than the measurement interval of the sensor, which is set in advance.

[0065] The information processing device 3 determines whether interpolation processing is necessary by determining whether the calculated time interval Δt is greater than or equal to a preset threshold T1. If the time interval Δt is less than the preset threshold T1, it is determined that there are no missing data in the measurement data to be processed and interpolation processing is unnecessary. If the time interval Δt is greater than or equal to the preset threshold T1, it is determined that there are missing data in the measurement data to be processed and interpolation processing is necessary. The above determination process is performed on the time interval Δt between all data included in the measurement data. If at least one of the time intervals Δt is greater than or equal to the threshold T1, it is determined that interpolation processing is necessary. The period corresponding to the time interval Δt that is greater than or equal to the threshold T1 corresponds to the period in which data is missing.

[0066] If interpolation processing is deemed necessary, the information processing device 3 determines the interpolation method to use based on the missing data state of the measurement data. The missing data state of the measurement data is identified based on the length of the missing period, i.e., the length of the time interval Δt. The information processing device 3 determines the interpolation method by determining whether the time interval Δt is less than a preset threshold T2. If the time interval Δt is less than the preset threshold T2, it is identified as a short-term missing data with a relatively short data missing period and a small number of missing data points. If the time interval Δt is greater than or equal to the preset threshold T2, it is identified as a long-term missing data with a relatively long data missing period and a large number of missing data points.

[0067] Thresholds T1 and T2 can be set appropriately so as to satisfy the relationship: sensor measurement interval < threshold T1 < threshold T2. Threshold T2 may be set considering the unit period of the data file, for example, to the same value as the unit period of the data file (e.g., 1 hour, 24 hours, etc.).

[0068] The above-described determination process may be performed based on the number of missing data points. The number of missing data points is obtained by dividing the time interval Δt between data points by the measurement interval of the sensor. If the number of missing data points is less than the threshold N1, interpolation is deemed unnecessary. If the number of missing data points is greater than or equal to threshold N1 and less than threshold N2, it is identified as a short-term data point. If the number of missing data points is greater than or equal to threshold N2, it is identified as a long-term data point. Here, threshold N1 < threshold N2.

[0069] If the data loss is short-term, the data for the missing period is interpolated using the first method. Figure 5 shows an example of the interpolation method using the first method. In the upper graph of Figure 5, the vertical axis is voltage (V) or temperature (°C), and the horizontal axis is time (sec). In the lower graph of Figure 5, the vertical axis is current (A), and the horizontal axis is time (sec).

[0070] The first method is a combination of linear interpolation and filling with predetermined values, and the processing differs for voltage and temperature and current. In the first method, the information processing device 3 interpolates the missing voltage and temperature by performing a process to calculate the value of the discontinuity point during the missing period by linear interpolation from the measured values ​​immediately before and after the missing period, for both voltage and temperature. As shown in Figure 5, the interpolated value shown by the triangle is generated by linear interpolation between the two points shown by the circle (〇).

[0071] Furthermore, the information processing device 3 interpolates the current by performing a process that fills in the discontinuities in the current during the loss period with a preset current correction value. The current correction value is preferably a relatively small value, and may be zero, for example. In the lower part of Figure 5, the current during the loss period is interpolated with a zero value indicated by a triangle (△).

[0072] In the first method, the interpolation method for voltage and temperature only needs to consider the measured values ​​of voltage and temperature before and after the missing period, and may also be other interpolation methods such as spline interpolation.

[0073] Figure 5 shows an example of interpolating data from one measurement point within a missing period, but the number of data points to be interpolated may be multiple. The information processing device 3 can identify the number of missing data points based on the measurement interval and interpolate the measured values ​​of each measurement point within the missing period.

[0074] If the data loss is long-term, the second method interpolates the data for the missing period. Figure 6 shows an example of the interpolation method using the second method. In Figure 6, the vertical axis represents current (A), voltage (V), or temperature (°C), and the horizontal axis represents time (sec). The second method is a method that fills in the missing period with data from a certain period before or after the missing period. In the second method, the information processing device 3 extracts a series of data from another period having the same duration (duration width) as the missing period, and interpolates the missing series of data all at once by performing a process to fill in the discontinuities of the missing period with the extracted series of data. The information processing device 3 performs the above process for all of the current, voltage, and temperature.

[0075] The alternative period from which data is extracted is preferably a period close to the missing period. The alternative period from which data is extracted may be a period of the same length immediately preceding the missing period, or a period of the same length immediately following the missing period. Whether to select the alternative period before or after the missing period may be predetermined, or it may be determined probabilistically each time the interpolation process is performed.

[0076] Figure 7 shows another example of the interpolation method using the second method. In Figure 7, the vertical axis represents current (A), voltage (V), or temperature (°C), and the horizontal axis represents time (sec). The second method may also be a method that performs a process to concatenate data from the periods before and after the missing period. In another example of the second method, the information processing device 3 concatenates the data from the period before the missing period and the data from the period after the missing period to generate a series of data in which the measured values ​​are consecutive at predetermined intervals, thereby interpolating the series of missing data together. The information processing device 3 may also rewrite the measurement date and time of the data from the period after the missing period to a date and time in the past by the length of the missing period.

[0077] The information processing device 3 may adjust the total duration of the interpolated data to match the original measurement period by concatenating a series of data from a specific period having the same duration as the missing period to the beginning or end of the newly generated series of data by interpolation.

[0078] The choice of which of the multiple second methods to use may be predetermined depending on the type and application of the energy storage equipment 1 to be monitored. For example, in the case of energy storage equipment 1 used in solar power generation systems, backup power systems, etc., where the measurement data shows periodicity between preceding and succeeding periods, the method of filling in missing periods with data from preceding and succeeding periods, as shown in Figure 6, is applied. In the case of energy storage equipment 1 used in wind power generation systems, etc., where the measurement data does not show much periodicity between preceding and succeeding periods, the method of concatenating data from preceding and succeeding periods, as shown in Figure 7, is applied. The information processing device 3 may also determine which second method to use by analyzing the shape of the most recent measurement data and determining whether or not there is periodicity.

[0079] Figure 8 is a flowchart showing an example of a processing procedure performed by the information processing device 3. The processing unit 31 of the information processing device 3 performs the following processing according to the program 3P stored in the storage unit 32. The processing unit 31 repeatedly performs the following processing, for example, at predetermined or appropriate time intervals. The processing unit 31 may start the following processing at the timing when it receives an instruction to execute processing.

[0080] The processing unit 31 of the information processing device 3 acquires measurement data, including the measured values ​​of current, voltage, and temperature of the energy storage element for a predetermined period, by, for example, reading measurement data for a predetermined period from the measurement DB 321 (step S11).

[0081] The processing unit 31 calculates the time interval Δt between preceding and succeeding measurement points in the acquired measurement data (step S12). For each calculated time interval Δt, the processing unit 31 determines whether the time interval Δt is greater than or equal to a predetermined threshold T1 (step S13). The determination process in step S13 corresponds to the determination process of whether or not interpolation processing is required. If it is determined that the time interval Δt is less than the threshold T1 (S13: NO), the processing unit 31 determines that interpolation processing is unnecessary and terminates the process.

[0082] If the processing unit 31 determines that the time interval Δt is greater than or equal to the threshold T1 (S13: YES), it determines whether interpolation processing is necessary and whether the time interval Δt is less than a preset threshold T2 (step S14). The determination process in step S14 corresponds to the determination process for the interpolation method. The processing unit 31 may execute the determination processes in steps S13 and S14 together.

[0083] If the processing unit 31 determines that the time interval Δt is greater than or equal to a preset threshold T2 (S14: NO), it decides to perform interpolation using the second method and executes the interpolation process using the second method (step S15). In step S15, the processing unit 31 interpolates the current, voltage, and temperature during the missing period by filling in the missing period with data from a period of the same length as the missing period, either before or after the missing period. The processing unit 31 may also interpolate the current, voltage, and temperature during the missing period by concatenating data from the periods before and after the missing period. The processing unit 31 proceeds to step S17.

[0084] If the processing unit 31 determines that the time interval Δt is less than a preset threshold T2 (S14: YES), it decides to perform interpolation using the first method and executes the interpolation process using the first method (step S16). In step S16, the processing unit 31 interpolates the voltage and temperature during the missing period by linearly interpolating from the measured values ​​immediately before and after the missing period. The processing unit 31 also interpolates the current during the missing period by filling in the current during the missing period with a preset current correction value.

[0085] The processing unit 31 stores the interpolated measurement data in the measurement DB 321 (step S17). The processing unit 31 may also add information to the measurement data to distinguish it from the actual measurement data and the measurement data calculated by the interpolation process, and then store it in the measurement DB 321. The processing unit 31 then completes the series of processes.

[0086] (Second Embodiment) In the second embodiment, the details of the interpolation method differ from those of the first embodiment. The following mainly describes the differences from the first embodiment, and components common to both embodiments are denoted by the same reference numerals and their detailed descriptions are omitted.

[0087] If measurement data is stored in the measurement DB 321 as data files for each unit period, it is conceivable that measurement data may be lost on a data file basis as an example of long-term data loss. The information processing device 3 of the second embodiment interpolates such data loss on a data file basis.

[0088] Figure 9 is a flowchart showing an example of a processing procedure performed by the information processing device 3 of the second embodiment.

[0089] The processing unit 31 of the information processing device 3 refers to the measurement DB 321 and acquires measurement data including the measured values ​​of current, voltage, and temperature of the energy storage element for a predetermined period to be processed (step S21). The measurement DB 321 stores the measurement data as data files for each unit period. The data files include time-series data of current, voltage, and temperature within the predetermined period.

[0090] The processing unit 31 determines whether all data files corresponding to each unit period exist within a predetermined period to be processed (step S22). If it determines that not all data files exist, that is, that some data files for some unit periods are missing (S22: NO), the processing unit 31 decides to perform interpolation using the second method and performs interpolation processing using the second method (step S23). The processing unit 31 proceeds to step S27.

[0091] Figure 10 shows an example of the interpolation method according to the second method of the second embodiment. In Figure 10, the horizontal axis represents time (sec). As conceptually shown in Figure 10, the second unit period from the left corresponds to a missing period in which no data file exists and the data file is missing. In the second method, the processing unit 31 interpolates the data file in the missing period by filling the missing period with a data file from a unit period before or after the missing period, as shown in the bottom of Figure 10. The processing unit 31 duplicates the data file from a unit period before or after the missing period and applies it as the data file for the missing period. Interpolation of the data file is preferably performed using a data file from a unit period close to the missing period, but it may also be performed using a data file from a unit period immediately before or after the missing period. In the example shown in the bottom of Figure 10, interpolation is performed using the data file immediately before the missing period.

[0092] The number of data files interpolated by the second method is not limited to one, but may be multiple. If there are multiple data files, the processing unit 31 may apply a data file for one unit period before or after the missing period to multiple missing periods in common. Alternatively, the processing unit 31 may duplicate the data files for multiple unit periods before or after the missing period and apply them to multiple missing periods.

[0093] Figure 11 shows another example of the interpolation method according to the second method of the second embodiment. In another example of the second method, the processing unit 31 may perform a process to connect data from a unit period prior to the missing period with data from a unit period after the missing period. As shown in the lower part of Figure 11, the processing unit 31 interpolates the data file in the missing period by sequentially connecting the data file immediately before the missing period with the data file immediately after the missing period.

[0094] As a result of the interpolation described above, the data files for each unit period after the missing period are shifted one unit period back in time. Therefore, there is no data file corresponding to the last unit period in the given period, and the overall length of the data is shortened. In another example of the second method, the processing unit 31 may duplicate any data file within the given period, for example, the first or last data file of a series of measurement data, and apply it as the data file for the last unit period. Through this process, the overall length of the interpolated data can be made to match the length of the original measurement period.

[0095] Returning to Figure 9, if it is determined that all data files exist (S22: YES), the processing unit 31 calculates the time interval Δt between the preceding and succeeding measurement points in the measurement data for each data file (step S24). The processing unit 31 then determines whether the calculated time interval Δt is greater than or equal to a preset threshold T1 (step S25). If it is determined that the time interval Δt is less than the threshold T1 (S25: NO), the processing unit 31 determines that interpolation processing is unnecessary and terminates the process.

[0096] If the processing unit 31 determines that the time interval Δt is greater than or equal to the threshold T1 (S25: YES), it decides to perform interpolation using the first method and executes the interpolation process using the first method (step S26). The interpolation process using the first method is the same as in the first embodiment.

[0097] The processing unit 31 stores the interpolated measurement data in the measurement DB 321 (step S27), and then terminates the series of processes.

[0098] The interpolation process in each of the above embodiments may be performed on at least one of the current, voltage, and temperature in the measurement data. The measurement data to be interpolated may be missing at least one of the current, voltage, and temperature.

[0099] 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.

[0100] 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.

[0101] 100 Remote monitoring 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

In an energy storage system equipped with multiple energy storage elements, measurement data including at least one of current, voltage, and temperature is acquired over a predetermined period. If the period or number of missing data points in the acquired measurement data is between a predetermined first threshold and a predetermined second threshold, the missing data is interpolated using the first method. If the missing period or number of missing data in the acquired measurement data is equal to or greater than the second threshold, the missing data is interpolated using the second method. A method for processing energy storage information, in which a computer performs the processing. 　 The first method is a method in which the voltage and temperature during the data gap period in the measurement data are interpolated with the voltage and temperature at the measurement points before and after the gap period, and the current during the gap period is filled with a predetermined current correction value. The energy storage information processing method according to claim 1. 　 The current correction value is zero. The energy storage information processing method according to claim 2. 　 The second method is to fill in the missing data periods in the measurement data with current, voltage, and temperature data from periods of the same length as the missing period, either before or after the missing period, or to connect the current, voltage, and temperature data from the period before the missing period with the current, voltage, and temperature data from the period after the missing period. The energy storage information processing method according to claim 1 or claim 2. 　 The aforementioned measurement data is stored as data files for each unit period, containing data from multiple measurement times. The second method is a method of generating a copy of the data file for a unit period before or after the missing period as a data file for the missing period, or a method of sequentially arranging the data files for the unit periods before and after the missing period. The energy storage information processing method according to claim 1 or claim 2. 　 If the missing period or number of missing data in the measurement data is less than the first threshold, interpolation by the first and second methods will not be performed. The energy storage information processing method according to claim 1 or claim 2. 　 The computer, located remotely from the aforementioned energy storage equipment, acquires the measurement data via communication. The energy storage information processing method according to claim 1 or claim 2. 　 In an energy storage system equipped with multiple energy storage elements, measurement data including at least one of current, voltage, and temperature is acquired over a predetermined period. If there are missing data in the acquired measurement data, the method to interpolate the missing data is determined based on the length or number of missing periods, using either the first method or the second method. A method for processing energy storage information, in which a computer performs the processing. 　 In an energy storage system equipped with multiple energy storage elements, measurement data including at least one of current, voltage, and temperature is acquired over a predetermined period. If the period or number of missing data points in the acquired measurement data is between a predetermined first threshold and a predetermined second threshold, the missing data is interpolated using the first method. If the missing period or number of missing data in the acquired measurement data is equal to or greater than the second threshold, the missing data is interpolated using the second method. It includes a processing unit that performs processing. Energy storage information processing device. 　 In an energy storage system equipped with multiple energy storage elements, measurement data including at least one of current, voltage, and temperature is acquired over a predetermined period. If the period or number of missing data points in the acquired measurement data is between a predetermined first threshold and a predetermined second threshold, the missing data is interpolated using the first method. If the missing period or number of missing data in the acquired measurement data is equal to or greater than the second threshold, the missing data is interpolated using the second method. A program that instructs a computer to perform a process.

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