Data interpolation system, data interpolation method, and data interpolation program product

Abstract

In a data interpolation system (10), a data acquisition unit (111) acquires battery data including at least time series data of current and state of charge (SOC). A defect determination unit (113) determines whether or not a defect section is included in the battery data. The interpolation unit (115) interpolates the battery data of the defective section on the basis of at least the battery data other than the defective section. An interpolation unit (115) interpolates the current data of the defective section when at least one of the front and rear of the defective section is in a charged state. The amount of charge is made to correspond to the amount of discharge during a charge / discharge period from the SOC in the charge state immediately after the defect section to the SOC corresponding in the past direction, or to the amount of charge during a charge / discharge period from the SOC in the charge state immediately before the defect section to the SOC corresponding in the future direction.

Description

Technical Field

[0001] The present invention relates to a data interpolation system, a data interpolation method, and a data interpolation program product for interpolating a missing section of battery data. Background Art

[0002] Services that save data related to batteries mounted on devices such as EVs and PCs in a cloud server and analyze the data are becoming widespread. The device that collects data collects data based on a certain sampling period. However, due to noise inside and outside the device, etc., data cannot be collected properly, and sometimes data is collected at intervals longer than the specified sampling interval. In this specification, a data section that does not satisfy the specified sampling interval is called a missing section.

[0003] In the analysis of the remaining capacity, degree of deterioration, etc. of a battery, the charge amount (Ah) obtained by integrating the current value is used. However, in the case where current data is missing, since the current value cannot be integrated, it becomes difficult to analyze the battery.

[0004] In Patent Document 1, for missing data, three interpolation methods are disclosed: "interpolation using data before and after", "interpolation using data with a high similarity over time", and "interpolation using data having a correlation".

[0005] [Prior Art Documents]

[0006] [Patent Documents]

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-176544 Summary of the Invention

[0008] [Problems to be Solved by the Invention]

[0009] In the above interpolation methods, it is necessary to satisfy preconditions such as data with a certain change over time, sufficient data obtained in the past, high similarity to the data obtained in the past, and a certain correlation. In particular, when the operation is different every day and the operation state of the system changes during the data missing period, it is difficult to maintain the interpolation accuracy. In addition, when the correlation changes due to the deterioration of the battery, it is also difficult to maintain the interpolation accuracy. For example, if the shape of the SOC (State Of Charge) - OCV (Open Circuit Voltage) curve changes due to deterioration, it is difficult to maintain the interpolation accuracy. If a missing section remains, it is difficult to analyze the battery.

[0010] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a technique for accurately interpolating a missing section of battery data.

[0011] [Technical Solution for Solving Technical Problems]

[0012] To solve the above problems, a data interpolation system according to an aspect of the present disclosure includes: a data acquisition unit that acquires battery data including at least time-series data of current and SOC; a defect determination unit that determines whether a defect interval is included in the battery data; and an interpolation unit that interpolates the battery data in the defect interval based on at least the battery data outside the defect interval. When at least one of the front and rear of the defect interval is in a charging state, the interpolation unit interpolates the current data in the defect interval so that the charge and discharge periods from the SOC in the charging state immediately after the defect interval to the corresponding SOC in the past direction, or from the SOC in the charging state immediately before the defect interval to the corresponding SOC in the future direction, have corresponding discharge and charge amounts.

[0013] In addition, any combination of the above components, and a solution obtained by converting the expressions of the present disclosure among devices, systems, methods, computer programs, etc. is also effective as a solution of the present disclosure.

[0014] [Advantages of the Invention]

[0015] According to the present disclosure, it is possible to interpolate the defect interval of battery data with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a diagram for explaining a data interpolation system for battery data.

[0017] Figure 2 It is an exemplary diagram showing a condition table for determining the operating state of an electric vehicle.

[0018] Figure 3 It is a diagram showing a first specific example of a first interpolation method.

[0019] Figure 4 It is a diagram showing a second specific example of a first interpolation method.

[0020] Figure 5 It is a diagram showing a third specific example of a first interpolation method.

[0021] Figure 6 It is a flowchart showing the process of the basic operation of the data interpolation system according to the embodiment.

[0022] Figure 7 It is a diagram showing an interpolation process example of a first interpolation method of the data interpolation system according to the embodiment.

[0023] Figure 8 It is a diagram showing a first specific example of a second interpolation method.

[0024] Figure 9 It is a diagram showing a second specific example of the second interpolation method.

[0025] Figure 10 It is a diagram showing a third specific example of the second interpolation method.

[0026] Figure 11 It is a diagram showing an interpolation processing example of the second interpolation method of the data interpolation system according to the embodiment.

[0027] Figure 12 (a) to (b) are diagrams showing an example of estimating the SOC in the defective section. DETAILED DESCRIPTION

[0028] Figure 1 This is a diagram for explaining a data interpolation system 10 for battery data. The data interpolation system 10 is a system for interpolating data of missing intervals when the collected battery data contains missing intervals as a pre-processing of the analysis process of the secondary battery 21 mounted on the electric vehicle 20. The data interpolation system 10 can be constructed, for example, on the company facilities of an operator who provides analysis services for the secondary battery 21 mounted on the electric vehicle 20 or on the company servers set up in the data center. In addition, the data interpolation system 10 can also be constructed on a cloud server based on the use of cloud services. In addition, the data interpolation system 10 can also be constructed on multiple servers dispersedly arranged in multiple bases (data centers, company facilities). The multiple servers can be any one of a combination of multiple company servers, a combination of multiple cloud servers, and a combination of company servers and cloud servers.

[0029] The secondary battery 21 mounted on the electric vehicle 20 supplies electric power to a driving motor (not shown). The secondary battery 21 is composed of a plurality of cells or a plurality of parallel cell blocks connected in series. Each parallel cell block is composed of a plurality of cells connected in parallel.

[0030] The cells may be lithium-ion battery cells, nickel-metal hydride battery cells, lead-acid battery cells, etc. In the following, this specification assumes an example of using lithium-ion battery cells (nominal voltage: 3.6-3.7 V). The number of cells or parallel cell blocks connected in series is determined according to the voltage of the driving motor.

[0031] The voltage sensor 22 detects the voltages at both ends of the series-connected cells or parallel cell blocks respectively. A shunt resistor is connected in series with a plurality of series-connected cells or a plurality of parallel cell blocks. The current sensor 23 detects the current flowing through the series-connected cells or parallel cell blocks based on the voltage across the shunt resistor. Additionally, a Hall element can also be used to replace the shunt resistor. The temperature sensor 24 detects the temperature of the plurality of cells or parallel cell blocks based on the thermistor provided in at least one of the plurality of cells or parallel cell blocks and the divided voltage of the resistor.

[0032] The control unit 25 is composed of the cooperation between the BMU (Battery Management Unit) and the ECU (Electronic Control Unit). The BMU combines the OCV method and the current integration method to estimate the SOC. The OCV method is a method of estimating the SOC based on the measured OCV of the cells and the SOC-OCV curve of the cells. The current integration method is a method of estimating the SOC based on the OCV at the start of charge and discharge of the cells and the integrated value of the measured current. As the charge and discharge time becomes longer, the current integration method gradually accumulates the measurement error of the current. Therefore, it is preferable to use the SOC estimated by the OCV method to correct the SOC estimated by the current integration method.

[0033] The BMU samples the voltage, current, temperature, and SOC of the plurality of cells or parallel cell blocks regularly (for example, at 10-second intervals). The BMU transmits the battery data including the voltage, current, temperature, and SOC of the plurality of cells or parallel cell blocks to the ECU via the in-vehicle network. As the in-vehicle network, for example, CAN (Controller Area Network) or LIN (Local Interconnect Network) can be used.

[0034] The vehicle speed sensor 27 generates a pulse signal proportional to the rotational speed of the axle and transmits it to the ECU. The ECU calculates the vehicle speed and the cumulative driving distance based on the received pulse signal. The ECU can obtain the gear position from the gear lever.

[0035] A GPS sensor can also be provided in the electric vehicle 20. The GPS sensor detects the current position (latitude, longitude) and transmits it to the ECU. The ECU can generate a driving history based on the received current position information. The received current position information can also be used for correcting the cumulative driving distance.

[0036] The communication unit 26 has a function of performing communication signal processing with the communication unit 33 of the charging station 30 and a function of performing wireless signal processing for connecting to the network 5. The communication unit 26 can access the network 5 using, for example, a mobile phone network (cellular network), wireless LAN, V2I (Vehicle-to-Infrastructure), V2V (Vehicle-to-Vehicle), ETC system (Electronic Toll Collection System), or DSRC (Dedicated Short Range Communications).

[0037] The network 5 is a general term for communication paths such as the Internet, dedicated lines, and VPNs (Virtual Private Networks), and there are no restrictions on its communication medium or protocol. As the communication medium, for example, a mobile phone network, wireless LAN, wired LAN, optical fiber network, ADSL network, or CATV network can be used. As the communication protocol, for example, TCP (Transmission Control Protocol) / IP (Internet Protocol), UDP (User Datagram Protocol) / IP, or Ethernet (registered trademark) can be used.

[0038] The ECU can either send the sampled battery data and vehicle data (e.g., vehicle speed, cumulative driving distance, gear position) to the data interpolation system 10 each time or store them in an internal memory and send the battery data and vehicle data stored in the memory to the data interpolation system 10 at a specified timing. In addition, when the electric vehicle 20 is connected to the charging station 30 via a charging cable, the ECU can also send the battery data and vehicle data stored in the memory to the data interpolation system 10 via the charging station 30.

[0039] By connecting the electric vehicle 20 to the charging station 30 with a charging cable, the secondary battery 21 in the electric vehicle 20 can be charged from the outside. The charging station 30 is connected to the commercial power system 2 to charge the secondary battery 21.

[0040] Generally speaking, for normal charging, AC is used for charging, and for fast charging, DC is used for charging. When charging with AC (such as single-phase 100 / 200V), the charging voltage or charging current is controlled by a charger (not shown) inside the electric vehicle 20. When charging with DC, the charging voltage or charging current is controlled by the power supply unit 31 of the charging station 30. The power supply unit 31 includes a rectifier circuit, a filter, and a DC / DC converter. The rectifier circuit performs full-wave rectification on the AC power supplied from the commercial power system 2, and the filter smooths it to generate DC power. The DC / DC converter controls the voltage or current of the generated DC power.

[0041] As fast charging standards, for example, CHAdeMO (registered trademark), ChaoJi, GB / T, Combo (Combined Charging System) can be used. In CHAdeMO, ChaoJi, and GB / T, CAN is adopted as the communication method. In Combo, PLC (Power Line Communication) is adopted as the communication method.

[0042] In addition to the power line, the charging cable adopting the CAN method also includes a communication line. When connecting the electric vehicle 20 and the charging station 30 with this charging cable, the control unit 25 of the electric vehicle 20 establishes a communication channel with the control unit 32 of the charging station 30. In addition, in the charging cable adopting the PLC method, the communication signal is superimposed on the power line for transmission.

[0043] The communication unit 33 of the charging station 30 has the function of performing communication signal processing with the communication unit 26 of the electric vehicle 20 and the function of performing signal processing for connecting to the network 5. The communication unit 33 can access the network 5 using, for example, a wired LAN, a wireless LAN, or a mobile phone network.

[0044] The data interpolation system 10 includes a control unit 11, a storage unit 12, and a communication unit 13. The communication unit 13 is a communication interface (such as a NIC: Network Interface Card) for connecting to the network 5 by wire or wirelessly.

[0045] The control unit 11 includes a data acquisition unit 111, an operation state determination unit 112, a defect determination unit 113, an interpolation method selection unit 114, an interpolation unit 115, and a validity determination unit 116. The functions of the control unit 11 can be implemented through the cooperation of hardware resources and software resources or only through hardware resources. As hardware resources, a CPU, ROM, RAM, GPU (Graphics Processing Unit), ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), or other LSI can be used. As software resources, an operating system, applications, or other programs can be used.

[0046] The storage unit 12 includes non-volatile recording media such as HDDs and SSDs, and stores various data. The storage unit 12 includes a battery data holding unit 121 and a vehicle data holding unit 122.

[0047] The data acquisition unit 111 acquires battery data and vehicle data from the electric vehicle 20 or the charging station 30, stores the acquired battery data in the battery data holding unit 121, and stores the acquired vehicle data in the vehicle data holding unit 122. Hereinafter, in the present embodiment, it is assumed that the vehicle data related to the operation of the electric vehicle 20 includes time series data of vehicle speed and cumulative driving distance. It is assumed that the battery data of the secondary battery 21 includes time series data of voltage, current, temperature, and SOC.

[0048] Based on the battery data and the vehicle data, the operation state determination unit 112 determines the operation state of the secondary battery 21 and the operation state of the electric vehicle 20 at each sampling time. The operation state of the vehicle data at least includes an operation state and a stop state. Hereinafter, in the present embodiment, the operation state of the vehicle data is classified into five states: "power running", "regenerative running", "parking (IG ON)", "idling (IG OFF)", and "parking charging". "Parking charging" means a state in which charging is performed while connected to the charging station 30. The operation state of the secondary battery 21 at least includes a "charging state", a "discharging state", and an "idling state". Hereinafter, in the present embodiment, the operation state of the secondary battery 21 is classified into these three states. Hereinafter, the case where the current is positive is set as the discharging state, the case where the current is negative is set as the charging state, and the case where the current is 0 is set as the idling state. In the case where data cannot be acquired correctly, invalid values such as blanks and hexadecimal "FFFF" are obtained, but all invalid values are set as NaN.

[0049] Figure 2This represents an example of a condition table for determining the operating state of the electric vehicle 20. When the vehicle speed is positive, the current is 0, positive, or NaN, the operating state determination unit 112 determines the operating state of the electric vehicle 20 as power running. When the vehicle speed is positive and the current is negative, the operating state determination unit 112 determines the operating state of the electric vehicle 20 as regenerative running. When the vehicle speed is 0 and the current is positive, the operating state determination unit 112 determines the operating state of the electric vehicle 20 as stopped. When the vehicle speed is 0 and the current is 0, the operating state determination unit 112 determines the operating state of the electric vehicle 20 as at rest. When the vehicle speed is 0 and the current is negative, the operating state determination unit 112 determines the operating state of the electric vehicle 20 as charging while stopped.

[0050] When the vehicle speed is NaN, the current is positive or 0, and the cumulative driving distance has a positive change, the operating state determination unit 112 determines the operating state of the electric vehicle 20 as power running. When the vehicle speed is NaN, the current is negative, and the cumulative driving distance has a positive change, the operating state determination unit 112 determines the operating state of the electric vehicle 20 as regenerative running. When the vehicle speed is NaN, the current is positive, and the cumulative driving distance does not change, the operating state determination unit 112 determines the operating state of the electric vehicle 20 as stopped. When the vehicle speed is NaN, the current is 0, and the cumulative driving distance does not change, the operating state determination unit 112 determines the operating state of the electric vehicle 20 as at rest. When the vehicle speed is NaN, the current is negative, and the cumulative driving distance does not change, the operating state determination unit 112 determines the operating state of the electric vehicle 20 as charging while stopped.

[0051] When the vehicle speed is 0, the current is NaN, and the SOC has a positive change, the operating state determination unit 112 determines the operating state of the electric vehicle 20 as charging while stopped. When the vehicle speed is 0, the current is NaN, and the SOC does not change, the operating state determination unit 112 determines the operating state of the electric vehicle 20 as at rest. When the vehicle speed is 0, the current is NaN, and the SOC has a negative change, the operating state determination unit 112 determines the operating state of the electric vehicle 20 as stopped. Additionally, when both the current and the vehicle speed are NaN or the change amount of the cumulative driving distance and the change amount of the SOC are abnormal values (such as negative values, etc.), the operating state of the electric vehicle 20 is set to the previous value. Furthermore, when sufficient data for state determination cannot be obtained (specifically, in the case of initial data without a previous value), the state of NaN (no state) is maintained.

[0052] Return Figure 1The defect determination unit 113 determines whether the battery data includes a defective section. When the change amount of continuous data (for example, time stamp, cumulative driving distance, SOC, temperature, etc.) exceeds a specified threshold value, the defect determination unit 113 determines it as a defective section that does not satisfy the specified sampling interval.

[0053] The interpolation method selection unit 114 selects an interpolation method for the battery data of the defective section according to the operation state of the electric vehicle 20 and the operation state of the secondary battery 21. The interpolation unit 115 interpolates the battery data of the defective section using the selected interpolation method, based on at least the battery data outside the defective section. For example, the interpolation unit 115 may also interpolate the battery data of the defective section based on the battery data outside the defective section and the vehicle data.

[0054] The interpolation method selection unit 114 selects an interpolation method according to the combination of the state changes of the electric vehicle 20 and the secondary battery 21 before and after the defective section. First, the first interpolation method for the current data will be described.

[0055] Figure 3 is a diagram showing a first specific example of the first interpolation method. When the cumulative driving distance at the moment immediately after the end of the defective section is greater than a specified threshold value (for example, 3 km) or more than the cumulative driving distance at the moment immediately before the start of the defective section, the interpolation method selection unit 114 determines that the defective section includes a discharge state. The interpolation method selection unit 114 confirms the operation state of the secondary battery 21 before and after the defective section. Figure 3 In the example shown, the operation state of the secondary battery 21 before the defective section is a discharge state, and the operation state of the secondary battery 21 after the defective section is a rest state. In this case, the interpolation method selection unit 114 selects the following first interpolation algorithm.

[0056] During the discharge period before the defective section, the interpolation unit 115 determines the moment when the SOC becomes the maximum value within a specified period (for example, 6 hours) in the past direction from the start moment of the defective section. The interpolation unit 115 sets the range from the moment when the SOC becomes the maximum value to the start moment of the defective section as the discharge reference section.

[0057] The interpolation unit 115 calculates the reduction value of the SOC in the discharge reference section. The interpolation unit 115 calculates the reduction value of the SOC per unit time (e.g., 10 seconds) (the time slope of the SOC) based on the reduction value of the SOC in the discharge reference section and the time of the discharge reference section. The interpolation unit 115 calculates the increase value of the cumulative driving distance per unit time (the slope of the cumulative driving distance) based on the increase value of the cumulative driving distance in the discharge reference section and the time of the discharge reference section. The interpolation unit 115 calculates the reduction value of the SOC per unit distance (e.g., 1 km) (the distance slope of the SOC) based on the time slope of the SOC and the slope of the cumulative driving distance in the discharge reference section.

[0058] The interpolation unit 115 calculates the discharge end time within the missing section based on the cumulative driving distance at the moment immediately before the start of the missing section, the distance slope of the SOC, and the cumulative driving distance at the moment immediately after the end of the missing section. The interpolation unit 115 calculates the SOC at the discharge end time within the missing section based on the moment when the SOC in the discharge reference section becomes the maximum value, the discharge end time within the missing section, the maximum value of the SOC, and the time slope of the SOC. The interpolation unit 115 calculates the SOC at the start time of the missing section based on the SOC at the discharge end time within the missing section, the time from the start time of the missing section to the discharge end time within the missing section, and the time slope of the SOC.

[0059] The interpolation unit 115 divides the discharge amount corresponding to the difference between the SOC at the start time of the missing section and the SOC at the discharge end time within the missing section by the time from the start time of the missing section to the discharge end time within the missing section to calculate the estimated value of the discharge current.

[0060] As the battery data at each moment from the start time of the missing section to the discharge end time within the missing section, the interpolation unit 115 interpolates the estimated value of the discharge current (dashed line). As the battery data at each moment from the discharge end time within the missing section to the end time of the missing section, the interpolation unit 115 interpolates 0 (dashed line). In addition, the interpolation unit 115 may also interpolate the cumulative driving distance from the start time of the missing section to the discharge end time within the missing section based on the slope of the cumulative driving distance in the discharge reference section.

[0061] Figure 4 It is a diagram showing a second specific example of the first interpolation method. The interpolation method selection unit 114 confirms the operating states of the secondary battery 21 before and after the missing section. Figure 4 In the example shown, the operating state of the secondary battery 21 before the missing section is the rest state, and the operating state of the secondary battery 21 after the missing section is the discharge state. In this case, the interpolation method selection unit 114 selects the following second interpolation algorithm.

[0062] During the discharge period after the missing section, the interpolation unit 115 determines the time when the SOC becomes the minimum value within a specified period (e.g., 6 hours) in the future direction from the end time of the missing section. The interpolation unit 115 sets the range from the time when the SOC becomes the minimum value to the end time of the missing section as the discharge reference section.

[0063] The interpolation unit 115 calculates the reduction value of the SOC in the discharge reference section. The interpolation unit 115 calculates the time slope of the SOC based on the reduction value of the SOC in the discharge reference section and the time of the discharge reference section. The interpolation unit 115 calculates the slope of the cumulative driving distance based on the increase value of the cumulative driving distance in the discharge reference section and the time of the discharge reference section. The interpolation unit 115 calculates the distance slope of the SOC based on the time slope of the SOC and the slope of the cumulative driving distance in the discharge reference section.

[0064] The interpolation unit 115 calculates the discharge start time in the missing section based on the cumulative driving distance at the moment immediately after the end of the missing section, the distance slope of the SOC, and the cumulative driving distance at the moment immediately before the start of the missing section. The interpolation unit 115 calculates the SOC at the discharge start time in the missing section based on the time when the SOC becomes the minimum value in the discharge reference section, the discharge start time in the missing section, the minimum value of the SOC, and the time slope of the SOC. The interpolation unit 115 calculates the SOC at the end time of the missing section based on the SOC at the discharge start time in the missing section, the time from the discharge start time in the missing section to the end time of the missing section, and the time slope of the SOC.

[0065] The interpolation unit 115 divides the discharge amount corresponding to the difference between the SOC at the discharge start time in the missing section and the SOC at the end time of the missing section by the time from the discharge start time in the missing section to the end time of the missing section to calculate the estimated value of the discharge current. In addition, the interpolation unit 115 can also simply divide the discharge amount corresponding to the difference between the SOC at the moment immediately before the start of the missing section and the SOC at the moment immediately after the end of the missing section included in the battery data by the time from the discharge start time in the missing section to the end time of the missing section to calculate the estimated value of the discharge current.

[0066] As the battery data at each moment from the discharge start time in the missing section to the end time of the missing section, the interpolation unit 115 interpolates the estimated value of the discharge current (dashed line). As the battery data at each moment from the start time of the missing section to the discharge start time in the missing section, the interpolation unit 115 interpolates 0 (dashed line). In addition, the interpolation unit 115 can also interpolate the cumulative driving distance from the discharge start time in the missing section to the end time of the missing section based on the slope of the cumulative driving distance in the discharge reference section.

[0067] Figure 5 This is a diagram showing the third specific example of the first interpolation method. The interpolation method selection unit 114 confirms the operating states of the secondary battery 21 before and after the defective section. Figure 5 In the example shown, the operating state of the secondary battery 21 before the defective section is the discharging state, and the operating state of the secondary battery 21 after the defective section is also the discharging state. In this case, the interpolation method selection unit 114 selects the following third interpolation algorithm.

[0068] The interpolation unit 115 calculates the estimated value of the discharge current by dividing the discharge amount corresponding to the difference in SOC between the moment immediately before the start of the defective section and the moment immediately after the end of the defective section by the time of the defective section. As the battery data for each moment from the start time of the defective section to the end time of the defective section, the interpolation unit 115 interpolates the estimated value of the discharge current (dashed line). In addition, the interpolation unit 115 can also simply divide the discharge amount corresponding to the difference in SOC between the moment immediately before the start of the defective section and the moment immediately after the end of the defective section included in the battery data by the time from the start time of the defective section to the discharge end time within the defective section to calculate the estimated value of the discharge current. Additionally, the discharge current can be estimated either based on the average current value of the discharge reference section or by using machine learning or the like to estimate the discharge current according to past driving data.

[0069] In addition, the interpolation method selection unit 114 may not select the third interpolation algorithm but select the first interpolation algorithm. When the first interpolation algorithm is applied in the third specific example, it is not necessary to calculate the discharge end time within the defective section. The interpolation unit 115 calculates the SOC at the end time of the defective section based on the time when the SOC in the discharge reference section becomes the maximum value, the end time of the defective section, the maximum value of this SOC, and the time slope of the SOC. The interpolation unit 115 calculates the SOC at the start time of the defective section based on the SOC at the end time of the defective section, the time of the defective section, and the time slope of the SOC. The subsequent processing is the same as that in the first specific example.

[0070] In addition, the interpolation method selection unit 114 may select the second interpolation algorithm. When the second interpolation algorithm is applied in the third specific example, it is not necessary to calculate the discharge start time within the defective section. The interpolation unit 115 calculates the SOC at the start time of the defective section based on the time when the SOC in the discharge reference section becomes the minimum value, the start time of the defective section, the minimum value of this SOC, and the time slope of the SOC. The interpolation unit 115 calculates the SOC at the end time of the defective section based on the SOC at the start time of the defective section, the time of the defective section, and the time slope of the SOC. The subsequent processing is the same as that in the second specific example.

[0071] Figure 6It is a flowchart showing the basic operation process of the data interpolation system 10 according to the embodiment. The data acquisition unit 111 acquires battery data and vehicle data from the electric vehicle 20 or the charging station 30 (S10). The operation state determination unit 112 determines the operation state of the secondary battery 21 and the operation state of the electric vehicle 20 at each sampling time based on the battery data and the vehicle data (S20). The defect determination unit 113 determines whether there is a defect interval in the current data included in the battery data (S30). When there is a defect interval in the current data (Yes in S30), the interpolation method selection unit 114 and the interpolation unit 115 perform data interpolation processing for the defect interval (S40). When there is no defect interval in the current data (No in S30), the interpolation processing in step S40 is skipped.

[0072] Figure 7 An example of the interpolation process of the first interpolation method of the data interpolation system 10 according to the embodiment. In Figure 7 In the flowchart of the subroutine shown, it is premised that the operation state of the electric vehicle 20 is a non-idle state. The interpolation method selection unit 114 determines whether the state of the secondary battery 21 after the defect interval is state A (S41). When the state of the secondary battery 21 after the defect interval is state A (Yes in S41), the interpolation method selection unit 114 determines whether the state of the secondary battery 21 before the defect interval is state A (S42).

[0073] When the state of the secondary battery 21 before the defect interval and the state of the secondary battery 21 after the defect interval are state A (Yes in S42), the interpolation method selection unit 114 selects a method of interpolating based on the battery data before and after the defect interval. When state A is a discharge state, the interpolation unit 115 refers to the battery data before and after the defect interval and linearly interpolates the battery data of the defect interval based on the battery data before and after it in a manner that maintains the continuity of the discharge state before and after (S43). When state A is a charge state, the interpolation unit 115 refers to the battery data before and after the defect interval and linearly interpolates the battery data of the defect interval based on the battery data before and after it in a manner that maintains the continuity of the charge state before and after (S43).

[0074] When the state of the secondary battery 21 before the defective section is not state A and the state of the secondary battery 21 after the defective section is state A (No in S42), the interpolation method selection unit 114 selects a method of interpolating based on the battery data after the defective section. When state A is a discharging state and the state changes from a resting state to a discharging state before and after the defective section, the interpolation unit 115 refers to the battery data after the defective section and interpolates the battery data of the defective section based on the subsequent battery data in a manner that maintains the continuity with the subsequent discharging state (S44). When state A is a charging state and the state changes from a resting state to a charging state before and after the defective section, the interpolation unit 115 refers to the battery data after the defective section and interpolates the battery data of the defective section based on the subsequent battery data in a manner that maintains the continuity with the subsequent charging state (S44).

[0075] When the state of the secondary battery 21 after the defective section is not state A (No in S41), the interpolation method selection unit 114 determines whether the state of the secondary battery 21 before the defective section is state A (S45). When the state of the secondary battery 21 before the defective section is state A and the state of the secondary battery 21 after the defective section is not state A (Yes in S45), the interpolation method selection unit 114 selects a method of interpolating based on the battery data before the defective section. When state A is a discharging state and the state changes from a discharging state to a resting state before and after the defective section, the interpolation unit 115 refers to the battery data before the defective section and interpolates the battery data of the defective section based on the previous battery data in a manner that maintains the continuity with the previous discharging state (S46). When state A is a charging state and the state changes from a charging state to a resting state before and after the defective section, the interpolation unit 115 refers to the battery data before the defective section and interpolates the battery data of the defective section based on the previous battery data in a manner that maintains the continuity with the previous charging state (S46).

[0076] When the state of the secondary battery 21 before the defective section and the state of the secondary battery 21 after the defective section are not state A (No in S45), the battery data of the defective section is skipped from the interpolation process regardless of the discharging state or the charging state.

[0077] In addition, in step S42, when the state of the secondary battery 21 before the defective section and the state of the secondary battery 21 after the defective section are state A (Yes in S42), the interpolation method selection unit 114 may also select a method of interpolating based on the battery data before the defective section. In this case, the interpolation unit 115 refers to the battery data before the defective section and interpolates the battery data of the defective section based on the previous battery data in a manner that maintains the continuity with the previous state A.

[0078] In addition, when the operating state of the electric vehicle 20 is in a rest state and at least one of the secondary batteries 21 before and after the defective section is in a discharged state, the interpolation method selection unit 114 skips the interpolation process. When changing from the rest state to the charging state before and after the defective section, the interpolation unit 115 refers to the battery data after the defective section and interpolates the battery data of the defective section based on the rear battery data in such a way as to maintain the continuity with the subsequent charging state. When changing from the charging state to the rest state before and after the defective section, the interpolation unit 115 refers to the battery data before the defective section and interpolates the battery data of the defective section based on the front battery data in such a way as to maintain the continuity with the previous charging state.

[0079] When the states of the secondary batteries 21 before and after the defective section are both in the charging state, the interpolation unit 115 refers to the battery data before and after the defective section and linearly interpolates the battery data of the defective section based on the battery data before and after in such a way as to maintain the continuity with the charging states before and after. In addition, the interpolation unit 115 may also refer to the battery data before the defective section and interpolate the battery data of the defective section based on the front battery data in such a way as to maintain the continuity with the previous charging state.

[0080] Next, the second interpolation method will be described. The second interpolation method is an interpolation method effective when the state of at least one of the secondary batteries 21 before and after the defective section is in the charging state. In particular, it is an interpolation method effective when the states of the secondary batteries 21 before and after the defective section are in the charging state.

[0081] In the second interpolation method, when at least one of the front and rear of the defective section is in the charging state, the interpolation unit 115 interpolates the current data of the defective section so that the discharge amount during the charge-discharge period from the SOC of the charging state immediately after the defective section to the SOC corresponding to the SOC in the past direction is corresponding to the charge amount. Or, when at least one of the front and rear of the defective section is in the charging state, the interpolation unit 115 interpolates the current data of the defective section so that the discharge amount during the charge-discharge period from the SOC of the charging state immediately before the defective section to the SOC corresponding to the SOC in the future direction is corresponding to the charge amount.

[0082] The validity determination unit 116 determines the validity of the interpolation process based on the charge amount or charge time of the defective section based on the capacity difference between the discharge amount and the charge amount calculated from the battery data included in the charge-discharge period.

[0083] Figure 8This is a diagram showing the first specific example of the second interpolation method. In the second interpolation method, the state of charge of the secondary battery 21 is set to the charging state when the electric vehicle 20 is parked and charging. The interpolation method selection unit 114 confirms the operating states of the secondary battery 21 before and after the missing section. Figure 8 In the example shown, the operating state of the secondary battery 21 before the missing section is the charging state, and the operating state of the secondary battery 21 after the missing section is also the charging state. In this case, the interpolation method selection unit 114 selects the following fourth interpolation algorithm.

[0084] The interpolation unit 115 determines the moment closest to the end moment of the missing section in the past direction from the end moment of the missing section, at which the SOC at the moment immediately after the end of the missing section becomes the same SOC. The interpolation unit 115 sets the range from the closest moment with the same SOC to the end moment of the missing section as the charge and discharge reference section. The interpolation unit 115 accumulates the positive current values within the charge and discharge reference section to calculate the cumulative discharge amount (1), and accumulates the negative current values within the charge and discharge reference section to calculate the cumulative charge amount (2). The interpolation unit 115 subtracts the cumulative charge amount (2) from the cumulative discharge amount (1) to calculate the missing charge amount (3).

[0085] The interpolation unit 115 determines the maximum value (4) of the charging current (the minimum value as current data) within the range of a specified period (e.g., 24 hours) in the future direction from the end moment of the missing section. In addition, the interpolation unit 115 may also determine the maximum value (4) of the charging current within the charge and discharge reference section. Additionally, the interpolation unit 115 may also determine the maximum value (4) of the charging current within both the charge and discharge reference section and the range of a specified period in the future direction from the end moment of the missing section.

[0086] The interpolation unit 115 divides the missing charge amount (3) by the time of the missing section to calculate the estimated value (5) of the charging current for the missing section. As the current data for each moment from the start moment to the end moment of the missing section, the interpolation unit 115 interpolates the estimated value (5) of the charging current (dashed line).

[0087] Figure 9 This is a diagram showing the second specific example of the second interpolation method. The interpolation method selection unit 114 confirms the operating states of the secondary battery 21 before and after the missing section. Figure 9 In the example shown, the operating state of the secondary battery 21 before the missing section is the discharging state, and the operating state of the secondary battery 21 after the missing section is the charging state. In this case, the interpolation method selection unit 114 selects the following fifth interpolation algorithm.

[0088] The interpolation unit 115 determines the moment closest to the end moment of the missing section in the past direction from the end moment of the missing section, at which the SOC at the moment immediately after the end of the missing section becomes the same SOC. The interpolation unit 115 sets the range from the closest moment when the SOC becomes the same to the end moment of the missing section as the charge / discharge reference section. The interpolation unit 115 accumulates the positive current values within the charge / discharge reference section to calculate the accumulated discharge amount (1). In the second specific example, the accumulated charge amount (2) within the charge / discharge reference section is 0.

[0089] The interpolation unit 115 determines the maximum value of the charging current (4) (the minimum value as current data) within a specified period (for example, 24 hours) in the future direction from the end moment of the missing section. In addition, the interpolation unit 115 may also determine the maximum value of the charging current (4) within the charge / discharge reference section. Further, the interpolation unit 115 may also determine the maximum value of the charging current (4) within both the charge / discharge reference section and the specified period in the future direction from the end moment of the missing section.

[0090] The interpolation unit 115 divides the missing charge amount (= accumulated discharge amount (1) - 0) by the maximum value of the charging current (4) to calculate the charging time within the missing section. The interpolation unit 115 sets the moment obtained by tracing back the charging time within the missing section in the past direction from the end moment of the missing section as the charging start moment within the missing section. As the battery data for each moment from the charging start moment within the missing section to the end moment of the missing section, the interpolation unit 115 interpolates the maximum value of the charging current (4) (dotted line). As the battery data for each moment from the start moment within the missing section to the charging start moment within the missing section, the interpolation unit 115 interpolates 0 (dotted line).

[0091] Figure 10 This is a diagram showing the third specific example of the second interpolation method. The interpolation method selection unit 114 confirms the operation states of the secondary battery 21 before and after the missing section. Figure 10 In the example shown, the operation state of the secondary battery 21 before the missing section is the charging state, and the operation state of the secondary battery 21 after the missing section is the discharging state. In this case, the interpolation method selection unit 114 selects the following sixth interpolation algorithm.

[0092] The interpolation unit 115 determines the moment closest to the start moment of the missing section in the future direction, at which the SOC at the moment immediately before the start of the missing section becomes the same SOC. The interpolation unit 115 sets the range from the closest moment when the SOC becomes the same to the start moment of the missing section as the charge / discharge reference section. The interpolation unit 115 accumulates the positive current values within the charge / discharge reference section to calculate the cumulative discharge amount (1). In the third specific example, the cumulative charge amount (2) within the charge / discharge reference section is 0.

[0093] The interpolation unit 115 determines the maximum value of the charging current (4) (the minimum value as current data) within a specified period (e.g., 24 hours) in the past direction from the start moment of the missing section. In addition, the interpolation unit 115 may determine the maximum value of the charging current (4) within the charge / discharge reference section. Further, the interpolation unit 115 may determine the maximum value of the charging current (4) within both the charge / discharge reference section and the specified period in the past direction from the start moment of the missing section.

[0094] The interpolation unit 115 divides the missing charge amount (= cumulative discharge amount (1) - 0) by the maximum value of the charging current (4) to calculate the charging time within the missing section. The interpolation unit 115 sets the moment advanced by the charging time within the missing section in the future direction from the start moment of the missing section as the charging end moment within the missing section. As the battery data for each moment from the start moment of the missing section to the charging end moment within the missing section, the interpolation unit 115 interpolates the maximum value of the charging current (4) (dashed line). As the battery data for each moment from the charging end moment within the missing section to the end moment of the missing section, the interpolation unit 115 interpolates 0 (dashed line).

[0095] Figure 11 An interpolation processing example showing the second interpolation method of the data interpolation system 10 according to the embodiment. The interpolation method selection unit 114 determines whether the state of the secondary battery 21 after the missing section is a charging state (S410). When the state of the secondary battery 21 after the missing section is a charging state (Yes in S410), the interpolation method selection unit 114 determines whether the state of the secondary battery 21 before the missing section is a charging state (S411).

[0096] When the state of the secondary battery 21 before the missing section and the state of the secondary battery 21 after the missing section are both in the charging state (Yes in S411), the interpolation unit 115 sets the range from the SOC at the moment immediately after the end of the missing section to the same SOC in the past direction as the charge / discharge reference period for one cycle. The interpolation unit 115 obtains the maximum value of the charging current (4) from within the charge / discharge reference period for one cycle (S412). In Figure 11In the flowchart, the maximum value (4) of the charging current is an absolute value.

[0097] The interpolation unit 115 calculates the missing charge amount (3) by subtracting the cumulative charge amount (2) from the cumulative discharge amount (1) within the charge-discharge reference period (S413). The interpolation unit 115 divides the missing charge amount (3) by the time of the missing period to calculate the estimated value (5) of the charging current (S414). In Figure 11 the flowchart, the estimated value (5) of the charging current is an absolute value.

[0098] The validity determination unit 116 compares the estimated value (5) of the charging current with the maximum value (4) of the charging current (S415). When the estimated value (5) of the charging current is less than or equal to the maximum value (4) of the charging current (Yes in S415), the interpolation unit 115 interpolates the estimated value (5) of the charging current for the missing period (S416). When the estimated value (5) of the charging current exceeds the maximum value (4) of the charging current (No in S415), the validity determination unit 116 determines that the interpolation current value is inappropriate and skips the interpolation process.

[0099] When the state of the secondary battery 21 before the missing period is a discharge state or a rest state and the state of the secondary battery 21 after the missing period is a charge state (No in S411), the interpolation unit 115 sets the range from the SOC at the moment immediately after the end of the missing period to the SOC that becomes the same in the past direction as one cycle of the charge-discharge reference period. The interpolation unit 115 obtains the maximum value (4) of the charging current from within one cycle of the charge-discharge reference period (S417).

[0100] The interpolation unit 115 calculates the missing charge amount (3) by subtracting the cumulative charge amount (2) from the cumulative discharge amount (1) within the charge-discharge reference period (S418). The interpolation unit 115 divides the missing charge amount (3) by the maximum value (4) of the charging current to calculate the charging time within the missing period (S419).

[0101] The validity determination unit 116 compares the charging time within the missing period with the time of the entire missing period (S420). When the charging time within the missing period is less than or equal to the time of the entire missing period (Yes in S420), the interpolation unit 115 interpolates the maximum value (4) of the charging current for the charging period of the missing period (S421). When the charging time within the missing period exceeds the time of the entire missing period (No in S420), the validity determination unit 116 determines that the charging time within the missing period is inappropriate and skips the interpolation process.

[0102] When the state of the secondary battery 21 after the missing section is not the charging state (No in S410), the interpolation method selection unit 114 determines whether the state of the secondary battery 21 before the missing section is the charging state (S421). When the state of the secondary battery 21 before the missing section is the discharging state or the resting state and the state of the secondary battery 21 after the missing section is the charging state (Yes in S421), the interpolation unit 115 sets the range from the SOC at the moment immediately before the start of the missing section to the SOC that becomes the same in the future direction as one cycle of charge-discharge reference period. The interpolation unit 115 obtains the maximum value of the charging current (4) from within one cycle of charge-discharge reference period (S422).

[0103] The interpolation unit 115 calculates the missing charge amount (3) by subtracting the cumulative charge amount (2) from the cumulative discharge amount (1) within the charge-discharge reference interval (S423). The interpolation unit 115 divides the missing charge amount (3) by the maximum value of the charging current (4) to calculate the charging time within the missing section (S424).

[0104] The validity determination unit 116 compares the charging time within the missing section with the time of the entire missing section (S425). When the charging time within the missing section is less than or equal to the time of the entire missing section (Yes in S425), the interpolation unit 115 interpolates the maximum value of the charging current (4) for the charging section of the missing section (S426). When the charging time within the missing section exceeds the time of the entire missing section (No in S425), the validity determination unit 116 determines that the charging time within the missing section is inappropriate and skips the interpolation process.

[0105] When the states of the secondary battery 21 before and after the missing section are not the charging state (No in S421), the battery data of the missing section is independent of the charging state, and the interpolation process is skipped.

[0106] In the above steps S413, S418, and S423, when the calculated cumulative discharge amount (1) or cumulative charge amount (2) within the charge-discharge reference interval exceeds the rated capacity of the secondary battery 21, the validity determination unit 116 may also determine that the interpolation process is inappropriate and skip the subsequent interpolation process. The rated capacity of the secondary battery 21 is the current full charge capacity, and the current full charge capacity is calculated by multiplying the initial full charge capacity by the SOH (State Of Health).

[0107] Figure 12 (a) - (b) are diagrams showing an example of estimating the SOC of the missing section. Figure 12(a) The example shown is an example of charge and discharge in which the defective section includes two cycles. In the above-described second interpolation method, the defective section is recognized as one cycle of charge and discharge. Therefore, as shown in Figure 12 (b), the transition of the SOC due to the recognition of the charge and discharge in the defective section is shown. In this case, due to the discharge in the defective section, the SOC becomes less than 0%. In this case, an inappropriate interpolation process is performed. By comparing the discharge amount or charge amount in the charge and discharge reference section with the rated capacity of the secondary battery 21, an inappropriate interpolation process can be avoided.

[0108] In the above steps S413, S418, and S423, when the cumulative charge amount (2) in the calculated charge and discharge reference section exceeds the cumulative discharge amount (1), the validity determination unit 116 may also determine that the interpolation process is inappropriate and skip the subsequent interpolation process.

[0109] In the above description, the interpolation method selection unit 114 may first interpolate the current data of the discharge state in the defective section using the first interpolation method, and then interpolate the current data of the charge state in the defective section using the second interpolation method.

[0110] According to the present embodiment described above, by accurately interpolating the defective section of the battery data, the usefulness of the battery data can be improved. In the first interpolation method, by changing the interpolation method according to the operation state of the electric vehicle 20, inappropriate interpolation can be avoided and the accuracy of the interpolated data can be improved.

[0111] In the second interpolation method, since the SOC is relatively used, the SOC error and the influence of the rated capacity caused by the deterioration of the secondary battery 21 can be eliminated. Specifically, the shape of the SOC-OCV curve of the secondary battery 21 changes due to deterioration. In the method of calculating the difference in SOC based on the OCV measured at the moment immediately before the start and immediately after the end of the defective section, and multiplying the difference in SOC by the rated capacity of the secondary battery 21 to calculate the charge amount in the defective section, the error caused by the influence of the SOC error and the rated capacity becomes large.

[0112] In addition, the current sensor 23 has a measurement error, and the measurement error is also accumulated in the charge amount obtained by accumulating the current. The longer the data period, the greater the measurement error. In this regard, in the second interpolation method, by using the capacity difference between the discharge amount and the charge amount in the charge and discharge reference section, the measurement errors of discharge and charge can be canceled. The measurement error becomes an error corresponding only to the defective section.

[0113] In particular, when the states of the secondary battery 21 before and after the missing section are in the charged state, by selecting the second interpolation method, interpolation can be performed with high precision. In addition, by determining the appropriateness of the interpolated charging current value, it is possible to avoid performing interpolation processing with low precision and ensure the precision of the interpolation processing.

[0114] As described above, the present disclosure has been described based on the embodiments. Those skilled in the art should understand that the embodiments are merely examples, and various variations can be made to the combinations of their respective constituent elements and processing procedures, and such variations are also within the scope of the present disclosure.

[0115] The above data interpolation system 10 can also be installed in the control unit 25 of the electric vehicle 20 or the control unit 32 of the charging station 30.

[0116] In the above embodiment, as the electric vehicle 20, a four-wheeled electric vehicle is envisioned. In this regard, it can also be an electric motorcycle (electric two-wheeler), an electric bicycle, or an electric scooter. In addition, the electric vehicle includes not only full-standard electric vehicles but also low-speed electric vehicles such as golf carts and land vehicles. In addition, the device equipped with the secondary battery 21 is not limited to the electric vehicle 20. Devices equipped with the secondary battery 21 also include electric moving bodies such as electric ships, railway vehicles, and multi-rotor aircraft (drones), fixed-type energy storage systems, and civilian electronic devices (smartphones, laptop PCs, etc.). In addition, when the secondary battery 21 is mounted on a fixed-type energy storage system or a civilian electronic device, the operating state of the device does not include the regenerative charging state.

[0117] In addition, the embodiments can also be specified by the following items.

[0118] [Item 1]

[0119] A data interpolation system (10), characterized by comprising:

[0120] A data acquisition unit (111) that acquires battery data of time-series data including at least current and SOC (State Of Charge),

[0121] A defect determination unit (113) that determines whether the battery data includes a missing section, and

[0122] An interpolation unit (115) that interpolates the battery data of the missing section based on at least the battery data outside the missing section;

[0123] When at least one of the front and rear of the defect interval is in a charging state, the interpolation unit (115) interpolates the current data of the defect interval so that the charge and discharge periods from the SOC in the charging state immediately after the defect interval to the corresponding SOC in the past direction, or from the SOC in the charging state immediately before the defect interval to the corresponding SOC in the future direction, have the discharge amount corresponding to the charge amount.

[0124] Thereby, the defect interval of the battery data can be interpolated with high precision.

[0125] [Item 2]

[0126] The data interpolation system (10) described in Item 1 is characterized in that

[0127] It further includes a validity determination unit (116) that determines the validity of the interpolation process based on the charge amount or charge time of the defect interval based on the capacity difference between the discharge amount and the charge amount calculated from the battery data included in the charge and discharge period.

[0128] Thereby, inappropriate interpolation can be avoided.

[0129] [Item 3]

[0130] The data interpolation system (10) described in Item 2 is characterized in that

[0131] When the discharge amount or the charge amount during the charge and discharge period exceeds the rated capacity of the battery (21), the validity determination unit (116) determines the interpolation process as inappropriate.

[0132] Thereby, inappropriate interpolation can be avoided.

[0133] [Item 4]

[0134] The data interpolation system (10) described in Item 2 is characterized in that

[0135] When the charge amount during the charge and discharge period exceeds the discharge amount, the validity determination unit (116) determines the interpolation process as inappropriate.

[0136] Thereby, inappropriate interpolation can be avoided.

[0137] [Item 5]

[0138] The data interpolation system (10) described in Item 2 is characterized in that

[0139] When the estimated value of the charging current obtained based on the capacity difference and the time of the missing section is greater than the maximum value of the charging current during the charging period before or after the missing section, the interpolation process is determined to be inappropriate by the validity determination unit (116).

[0140] Thereby, inappropriate interpolation can be avoided.

[0141] [Item 6]

[0142] A data interpolation method, characterized by comprising:

[0143] A step of obtaining battery data of time series data including at least current and SOC (State Of Charge),

[0144] A step of determining whether the battery data contains a missing section, and

[0145] A step of interpolating the battery data of the missing section based at least on the battery data other than the missing section;

[0146] In the step of performing interpolation, when at least one of the front and rear of the missing section is in a charging state, the current data of the missing section is interpolated so that the charge and discharge amounts during the charge and discharge period from the SOC in the charging state immediately after the missing section to the corresponding SOC in the past direction, or from the SOC in the charging state immediately before the missing section to the corresponding SOC in the future direction, correspond to each other.

[0147] Thereby, the missing section of the battery data can be interpolated with high accuracy.

[0148] [Item 7]

[0149] A data interpolation program product, characterized by causing a computer to execute the following processing:

[0150] A process of obtaining battery data of time series data including at least current and SOC (State Of Charge),

[0151] A process of determining whether the battery data contains a missing section, and

[0152] A process of interpolating the battery data of the missing section based at least on the battery data other than the missing section;

[0153] When the interpolation process is performed with at least one of the front and rear of the defective section in a charged state, the current data of the defective section is interpolated so that the charge and discharge periods from the SOC in the charged state immediately after the defective section to the corresponding SOC in the past direction, or from the SOC in the charged state immediately before the defective section to the corresponding SOC in the future direction, have the discharge amount corresponding to the charge amount.

[0154] Thereby, it is possible to interpolate the defective section of the battery data with high accuracy.

[0155] [Industrial Applicability]

[0156] The present disclosure can be used for a battery analysis system constructed on a cloud server.

[0157] [Description of Reference Numerals]

[0158] 2 Commercial power system, 5 Network, 10 Data interpolation system, 11 Control unit, 12 Storage unit, 13 Communication unit, 20 Electric vehicle, 21 Secondary battery, 22 Voltage sensor, 23 Current sensor, 24 Temperature sensor, 25 Control unit, 26 Communication unit, 27 Vehicle speed sensor, 30 Charging station, 31 Power supply unit, 32 Control unit, 33 Communication unit, 111 Data acquisition unit, 112 Operating state determination unit, 113 Defect determination unit, 114 Interpolation method selection unit, 115 Interpolation unit, 116 Validity determination unit, 121 Battery data holding unit, 122 Vehicle data holding unit.

Claims

1. A data interpolation system, characterized in that, it comprises: a data acquisition unit that acquires battery data which is time-series data including at least current and SOC (State Of Charge); a defect determination unit that determines whether the battery data contains a defective section, and an interpolation unit that interpolates the battery data of the defective section based at least on the battery data outside the defective section; when at least one of the front and rear of the defective section is in a charging state, the interpolation unit interpolates the current data of the defective section so that the discharge amount and the charge amount correspond during the charge-discharge period from the SOC in the charging state immediately after the defective section to the corresponding SOC in the past direction, or during the charge-discharge period from the SOC in the charging state immediately before the defective section to the corresponding SOC in the future direction.

2. The data interpolation system according to claim 1, characterized in that, it further comprises a validity determination unit that determines the validity of the interpolation process according to the charge amount or charge time of the defective section based on the capacity difference between the discharge amount and the charge amount calculated from the battery data included in the charge-discharge period.

3. The data interpolation system according to claim 2, characterized in that, when the discharge amount or the charge amount during the charge-discharge period exceeds the rated capacity of the battery, the validity determination unit determines that the interpolation process is inappropriate.

4. The data interpolation system according to claim 2, characterized in that, when the charge amount during the charge-discharge period exceeds the discharge amount, the validity determination unit determines that the interpolation process is inappropriate.

5. The data interpolation system according to claim 2, characterized in that, when the estimated value of the charging current obtained from the capacity difference and the time of the defective section is greater than the maximum value of the charging current during the charging period in front of or behind the defective section, the validity determination unit determines that the interpolation process is inappropriate.

6. A data interpolation method, characterized in that, it has: a step of acquiring battery data which is time-series data including at least current and SOC (State Of Charge), a step of determining whether the battery data contains a defective section, and a step of interpolating the battery data of the defective section based at least on the battery data outside the defective section; when at least one of the front and rear of the defective section is in a charging state, the step of performing interpolation interpolates the current data of the defective section so that the discharge amount and the charge amount correspond during the charge-discharge period from the SOC in the charging state immediately after the defective section to the corresponding SOC in the past direction, or during the charge-discharge period from the SOC in the charging state immediately before the defective section to the corresponding SOC in the future direction.

7. A data interpolation program product, characterized in that, it causes a computer to execute the following processing: Processing for obtaining battery data including time series data of at least current and SOC (State Of Charge), processing for determining whether the battery data includes a missing section, and processing for interpolating the battery data of the missing section based at least on the battery data outside the missing section; In the case where at least one of the front and rear of the missing section is in a charging state during the processing for interpolation, the current data of the missing section is interpolated so that the discharge amount corresponds to the charge amount during the charge-discharge period from the SOC in the charging state immediately after the missing section to the corresponding SOC in the past direction, or during the charge-discharge period from the SOC in the charging state immediately before the missing section to the corresponding SOC in the future direction.

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