Remaining capacity calculation device and program

Abstract

To provide a residual capacity calculation device and a program capable of improving calculation accuracy of a residual capacity of a secondary battery.SOLUTION: A BMU 30 sequentially calculates a residual capacity of an electric cell 21 at a charge time and a discharge time of the electric cell 21 constituting a battery pack 20. The BMU 30 calculates a reference residual capacity of the electric cell 21 according to a correlation relation between an open circuit voltage and the residual capacity of the electric cell 21 at detection timing of the open circuit voltage of the electric cell 21, calculates a predetermined section including the reference residual capacity as a first capacity section. It then adds a changed portion of a current capacity due to charge / discharge of the electric cell 21 from a time of calculation of a past capacity section to a maximum residual capacity and a minimum residual capacity of the past capacity section calculated at detection timing of the open circuit voltage before a present time, respectively, to calculate a second capacity section, and calculates a section including an overlapped section of the first capacity section and the second capacity section at the detection timing of the open circuit voltage as a third capacity section including an actual residual capacity.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a remaining capacity calculation device and a program. [Background technology]

[0002] Conventionally, there are known techniques for calculating the remaining capacity of a storage battery. For example, Patent Document 1 describes a technique for calculating the SOC of a storage battery using an SOC-OCV map that indicates the correlation between the SOC and the open circuit voltage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-266221 Summary of the Invention [Problem to be solved by the invention]

[0004] It can be difficult to accurately calculate the remaining capacity of a storage battery. For example, in the plateau region of the correlation between the open-circuit voltage and remaining capacity of a storage battery, the change in open-circuit voltage associated with a change in remaining capacity is small, making it difficult to accurately calculate the remaining capacity from the open-circuit voltage. Also, for example, when calculating the remaining capacity by integrating the charge / discharge current of a storage battery, an integration error accumulates as the current integration period becomes longer, making it difficult to accurately calculate the remaining capacity from the integrated current value.

[0005] A primary object of the present invention is to provide a remaining capacity calculation device and program that can improve the accuracy of calculating the remaining capacity of a storage battery. [Means for solving the problem]

[0006] The present invention provides a remaining capacity calculation device (30) for calculating a remaining capacity of a storage battery (21) when the storage battery is being charged and discharged, comprising: a first interval calculation unit that calculates a reference remaining capacity of the storage battery based on a correlation between the open circuit voltage and the remaining capacity of the storage battery at a timing when an open circuit voltage of the storage battery is detected, and calculates a predetermined interval including the reference remaining capacity as a first capacity interval; a second section calculation unit that calculates a second capacity section by adding a capacity change amount, which is a change in current capacity due to charging and discharging of the storage battery since the calculation of the past capacity section, to the maximum remaining capacity and the minimum remaining capacity of the past capacity section calculated at the detection timing before the present time; a third interval calculation unit that calculates, at the detection timing, an interval including an overlapping interval between the first capacity interval and the second capacity interval as a third capacity interval including an actual remaining capacity; Equipped with.

[0007] At the timing of detecting the open circuit voltage of the battery, a reference remaining capacity of the battery is calculated based on the correlation between the open circuit voltage of the battery and the remaining capacity, and a first capacity interval is calculated as a predetermined interval including the reference remaining capacity. Furthermore, a second capacity interval is calculated by adding a capacity change, which is a change in current capacity due to charging and discharging of the battery since the calculation of the past capacity interval, to the maximum and minimum remaining capacities of a past capacity interval calculated at a timing of detecting the open circuit voltage of the battery prior to the current time. In this case, the first capacity interval is calculated taking into account variations in remaining capacity caused by the detection conditions of the open circuit voltage of the battery and the charging and discharging conditions of the battery, and the second capacity interval is calculated taking into account an integration error in the integrated value of current capacity. Furthermore, a third capacity interval is calculated as an interval including an overlapping interval of each capacity interval, thereby narrowing the range of the third capacity interval including the actual remaining capacity of the battery. Narrowing the range of the third capacity interval improves the accuracy of calculating the remaining capacity of the battery. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing a schematic configuration of a battery system according to a first embodiment. [Figure 2] FIG. 10 is a diagram showing a method for setting a first capacity section. [Figure 3] FIG. 10 is a diagram showing a method for setting a second capacity section. [Figure 4] FIG. 10 is a diagram showing a method for setting a third capacity section. [Figure 5] 1 is a flowchart showing the control procedure performed by the BMU. [Figure 6] FIG. 4 is a diagram showing an example of control for calculating a full charge capacity. [Figure 7] 10 is a flowchart showing a control procedure performed by a BMU according to the second embodiment. [Figure 8] FIG. 4 is a diagram showing an example of control for calculating a full charge capacity. DETAILED DESCRIPTION OF THE INVENTION

[0009] First Embodiment A first embodiment of a remaining capacity calculation device according to the present invention will be described below with reference to the drawings. In this embodiment, a specific configuration of a battery system mounted on an electrically powered vehicle such as an electric vehicle or a hybrid vehicle will be described.

[0010] 1 is a diagram showing a schematic configuration of a battery system according to this embodiment. The battery system includes a rotating electric machine 10 that serves as a power source for a vehicle, a battery pack 20 consisting of a plurality of cells 21, and a BMU (Battery Management Unit) 30 that monitors the state of the battery pack 20.

[0011] The battery pack 20 is used as a power source for the rotating electric machine 10 and is connected to the rotating electric machine 10. More specifically, the rotating electric machine 10 has an inverter that controls the current of each phase. The battery pack 20 is configured as a series connection of a plurality of cells 21. A positive power supply line 11 extending from the most positive terminal of each of the series-connected cells 21 is connected to the positive side of the inverter, and a negative power supply line 12 extending from the most negative terminal of each of the series-connected cells 21 is connected to the negative side of the inverter. This enables current to flow between the battery pack 20 and the rotating electric machine 10. Each cell 21 is a rechargeable storage battery, specifically a lithium-ion storage battery.

[0012] The BMU 30 is configured with a microcomputer including a CPU and various memories. The BMU 30 includes a voltage detection unit 31, a current detection unit 32, and a calculation unit 33. The voltage detection unit 31 is connected to both ends of each cell 21 via wiring such as a wire harness and detects the terminal voltage of each cell 21. In this embodiment, the voltage detection unit 31 detects the open-circuit voltage, which is the voltage between both terminals of the cell 21 when no load is applied to the cell 21 and the cell 21 is in an unpowered state, when the vehicle starts running or when the vehicle is being externally charged. For example, when the vehicle starts running, the voltage detection unit 31 detects the open-circuit voltage of the cell 21 before the ignition switch is turned on and power is supplied to the cell 21. Furthermore, when the vehicle is being externally charged, the voltage detection unit 31 detects the open-circuit voltage of the cell 21 before power is supplied to the battery pack 20 by an external charger provided outside the vehicle.

[0013] The current detection unit 32 detects the charge / discharge current of the battery pack 20 at predetermined time intervals. In Fig. 1, the current detection unit 32 acquires a detection signal from a current sensor 13 provided on the negative power supply line 12, and detects the charge / discharge current of the battery pack 20 based on the detection signal. The detection values ​​of the voltage detection unit 31 and the current detection unit 32 are input to a calculation unit 33.

[0014] The calculation unit 33 sequentially calculates the remaining capacity of each cell 21 constituting the battery pack 20 when the cell 21 is being charged and discharged. In this embodiment, the calculation unit 33 calculates the current capacity [Ah] as the remaining capacity of the cell 21. Note that the calculation unit 33 may calculate the power capacity [Wh] or the SOC [%] as the remaining capacity of the cell 21 instead of the current capacity [Ah].

[0015] However, it may be difficult to accurately calculate the remaining capacity of the cell 21. Specifically, the correlation between the open-circuit voltage and the remaining capacity may include a plateau region in which the open-circuit voltage is stable over a wide range of remaining capacity. In the plateau region, the change in open-circuit voltage with changes in remaining capacity is small, making it difficult to accurately calculate the remaining capacity from the open-circuit voltage. Furthermore, when calculating the remaining capacity by integrating the charge / discharge current of the cell 21, an integration error accumulates over a long current integration period, making it difficult to accurately calculate the remaining capacity from the integrated current value. In this embodiment, a lithium-ion battery is used as the cell 21. In lithium-ion batteries, lithium iron phosphate is sometimes used as the positive electrode active material and graphite is sometimes used as the negative electrode active material. In this case, the presence of a plateau region in the correlation between the open-circuit voltage and the remaining capacity of the cell 21 becomes prominent, raising concerns that it may become difficult to accurately calculate the remaining capacity of the cell 21.

[0016] In view of this, in this embodiment, the calculation unit 33 calculates a capacity range within which the remaining capacity of each of the cells 21 constituting the battery pack 20 can be assumed, and narrows the range of the capacity range to improve the accuracy of calculating the remaining capacity. The method for calculating the capacity range of the cell 21 will be described below.

[0017] The calculation unit 33 uses a plurality of predefined correlations between the open circuit voltage of the cell 21 and the remaining capacity at the timing of detecting the open circuit voltage of the cell 21, calculates a plurality of reference remaining capacities corresponding to the open circuit voltage of the cell 21 for each correlation, and calculates a section including each of the reference remaining capacities as a first capacity section A. In this embodiment, as shown in FIG. 2 , the calculation unit 33 predefines a charge characteristic M1 that indicates the correlation between the open circuit voltage of the cell 21 and the remaining capacity during charging, and a discharge characteristic M2 that indicates the correlation between the open circuit voltage of the cell 21 and the remaining capacity during discharging, and calculates the reference remaining capacity using the charge characteristic M1 and the discharge characteristic M2. The calculation unit 33 determines the reference remaining capacity corresponding to the detected value Vr of the open circuit voltage of the cell 21 in the charge characteristic M1 as the minimum remaining capacity A_min of the first capacity section A, and determines the reference remaining capacity corresponding to the detected value Vr of the open circuit voltage of the cell 21 in the discharge characteristic M2 as the maximum remaining capacity A_max of the first capacity section A. In this case, the calculation unit 33 calculates the section defined by the maximum remaining capacity A_max and the minimum remaining capacity A_min as the first capacity section A. The calculation unit 33 may use a value calculated based on the detection value of the voltage detection unit 31 as the detection value Vr of the open circuit voltage of the cell 21.

[0018] The charge characteristic M1 and discharge characteristic M2 of the cell 21 are predetermined based on the open-circuit voltage measured as follows, for example, before shipping from the factory, and are stored in a memory unit included in the BMU 30. The open-circuit voltage that defines the discharge characteristic M2 is measured each time a predetermined capacity is discharged from the cell 21, after a predetermined rest period has elapsed since the discharge was stopped. The open-circuit voltage that defines the discharge characteristic M2 is measured repeatedly from a fully charged state in which the open-circuit voltage of the cell 21 is equal to or greater than an upper limit voltage, until the open-circuit voltage of the cell 21 falls below a lower limit voltage. The open-circuit voltage that defines the charge characteristic M1 is measured each time a predetermined capacity is charged to the cell 21, after a predetermined rest period has elapsed since the charging was stopped. The open-circuit voltage that defines the charge characteristic M1 is measured repeatedly from a state in which the open-circuit voltage of the cell 21 falls below the lower limit voltage, until the cell 21 is fully charged. From the viewpoint of noise reduction, it is preferable that the cell 21 be charged and discharged at a low current.

[0019] The calculation unit 33 calculates the second capacity section B by adding the change in current capacity due to charging and discharging of the cell 21 since the calculation of the past capacity section to the maximum and minimum remaining capacities of the past capacity section calculated at the detection timing of the open circuit voltage before the current time. FIG. 3 shows an example of a case where the first capacity section A calculated at the previous detection timing of the open circuit voltage is used as the past capacity section to calculate the second capacity section B. The calculation unit 33 calculates the maximum remaining capacity B_max of the second capacity section B by adding the integrated value IS of the current capacity since the calculation of the first capacity section A to the maximum remaining capacity A_max of the previous first capacity section A. The calculation unit 33 calculates the minimum remaining capacity B_min of the second capacity section B by adding the integrated value IS of the current capacity since the calculation of the first capacity section A to the minimum remaining capacity A_min of the previous first capacity section A. In this embodiment, when the integrated value IS of the current capacity is positive, the remaining capacities A_max and A_min shift to the charging side, and when the integrated value IS of the current capacity is negative, the remaining capacities A_max and A_min shift to the discharging side.

[0020] The calculation unit 33 calculates the third capacity interval C based on the current first capacity interval A and the current second capacity interval B at the timing of detecting the open circuit voltage of the cell 21. Here, in calculating the third capacity interval C, the calculation unit 33 may set the remaining capacity between the maximum remaining capacity A_max of the first capacity interval A and the maximum remaining capacity B_max of the second capacity interval B as the maximum remaining capacity C_max of the third capacity interval C, and may set the remaining capacity between the minimum remaining capacity A_min of the first capacity interval A and the minimum remaining capacity B_min of the second capacity interval B as the minimum remaining capacity C_min of the third capacity interval C. Furthermore, the calculation unit 33 may set the overlapping interval of the first capacity interval A and the second capacity interval B as the third capacity interval C. In this case, for example, in Figure 4, the calculation unit 33 calculates the maximum remaining capacity B_max of the second capacity section B as the maximum remaining capacity C_max of the third capacity section C, and calculates the minimum remaining capacity A_min of the first capacity section A as the minimum remaining capacity C_min of the third capacity section C.

[0021] 3 above, an example has been described in which the calculation unit 33 calculates the second capacity interval B using the previous first capacity interval A. However, the previous third capacity interval C may be used as the past capacity interval instead of the previous first capacity interval A. In this case, the calculation unit 33 calculates the maximum remaining capacity B_max and minimum remaining capacity B_min of the current second capacity interval B by adding the integrated value IS of the current capacity since the calculation of the third capacity interval C to the maximum remaining capacity C_max and minimum remaining capacity C_min of the third capacity interval C calculated at the timing of the previous detection of the open circuit voltage.

[0022] By calculating the above-described sections A, B, and C, it is possible to narrow down the range of the third capacity section C using the first capacity section A and the second capacity section B calculated using different methods.

[0023] The calculation unit 33 calculates the full charge capacity using the third capacity section C of the cell 21. In this embodiment, the calculation unit 33 determines whether the cell 21 is in a fully charged state, and calculates the full charge capacity if it determines that the cell 21 is in a fully charged state. For example, when the battery pack 20 is being charged by an external charger, the calculation unit 33 determines that the cell 21 is in a fully charged state if it determines that the terminal voltage of the cell 21 has reached a full charge voltage value. Furthermore, when the battery pack 20 is being charged by regenerative power generation of the rotating electric machine 10 and the cell 21 is in a fully charged state, the calculation unit 33 determines that the cell 21 is in a fully charged state if it determines that the open circuit voltage of the cell 21 is equal to or greater than the full charge voltage value at the time the open circuit voltage of the cell 21 is detected.

[0024] When the calculation unit 33 determines that the cell 21 is in a fully charged state, it calculates a full charge capacity section of the cell 21 based on the previous third capacity section C and the change in current capacity due to charging and discharging of the cell 21 since the calculation of the third capacity section C, and calculates the full charge capacity using the full charge capacity section. Specifically, the calculation unit 33 adds the integrated value IS of the current capacity due to charging and discharging of the cell 21 since the calculation of the third capacity section C to the maximum remaining capacity C_max and minimum remaining capacity C_min of the previous third capacity section C to calculate the maximum and minimum values ​​of the full charge capacity section, and determines the section determined by these maximum and minimum values ​​as the full charge capacity section. The calculation unit 33 calculates the capacity within the full charge capacity section as the full charge capacity of the cell 21. For example, the calculation unit 33 calculates the full charge capacity of the battery 21 as the maximum value of the full charge capacity section or a value obtained by shifting that maximum value toward the discharge side by a predetermined value, the minimum value of the full charge section or a value obtained by shifting that minimum value toward the charge side by a predetermined value, or the arithmetic mean or weighted mean value of the maximum and minimum values ​​of the full charge section.

[0025] 5 shows a control procedure in which the above-described methods for calculating the first, second, and third capacity ranges A, B, and C and the full charge capacity are applied to the calculation of the SOH, which indicates the state of deterioration of the battery pack 20. This control is repeatedly executed by the BMU 30 at a predetermined control period.

[0026] In step S10, it is determined whether a reset condition for the third capacity interval C is met. In this embodiment, it is determined whether a period during which the third capacity interval C is not calculated continues for a predetermined time or more (for example, several tens of hours or several days). A situation in which the third capacity interval C is not calculated may be a situation in which the vehicle is left unattended and the ignition switch is left off for a long time. Alternatively, it may be determined that the reset condition for the third capacity interval C is met when it is determined that the elapsed time since the last calculation of the third capacity interval C cannot be measured due to some malfunction. If the determination in step S10 is affirmative, the process proceeds to step S11. In step S11, the third capacity interval C is reset to a predetermined initial interval. For example, the first capacity interval A calculated at a time when the open circuit voltage was detected before the current time may be used as the initial interval for the third capacity interval C. After the process in step S11, the process proceeds to step S12. On the other hand, if the determination in step S10 is negative, the process proceeds to step S12 without performing the process in step S11. The process of step S10 corresponds to a "period determination unit", and the process of step S11 corresponds to a "reset unit".

[0027] In step S12, it is determined whether or not the open circuit voltage of the battery cell 21 can be detected. In this embodiment, it is determined that the open circuit voltage of the battery cell 21 can be detected before current begins to flow through the battery cell 21 when the vehicle starts running or when the vehicle is being externally charged, and it is determined that the open circuit voltage of the battery cell 21 cannot be detected in other cases. If a negative determination is made in step S12, the process proceeds to step S19.

[0028] In step S19, the current capacity due to charging and discharging of the battery 21 from the previous timing of detecting the open circuit voltage is integrated to calculate an integrated value IS. The current capacity due to charging and discharging of the battery 21 may be calculated based on the detection value of the current sensor 13. After processing in step S19, the process proceeds to step S20.

[0029] On the other hand, if the determination in step S12 is affirmative, the process proceeds to step S13. In step S13, the open circuit voltage of the cell 21 is detected. For example, the open circuit voltage of the cell 21 may be detected by regarding the terminal voltage of the cell 21 after a predetermined time has elapsed since the cell 21 was turned off as the open circuit voltage, or by estimating the open circuit voltage from the terminal voltage of the cell 21 in a powered state. The value detected by the voltage detection unit 31 may be used as the terminal voltage of the cell 21.

[0030] In step S14, the first capacity section A is calculated. In this embodiment, a charge characteristic M1 indicating the correlation between the open circuit voltage of the battery cell 21 and the remaining capacity during charging and a discharge characteristic M2 indicating the correlation between the open circuit voltage of the battery cell 21 and the remaining capacity during discharging are used to calculate the maximum remaining capacity A_max and the minimum remaining capacity A_min of the first capacity section A from the detected open circuit voltage of the battery cell 21. Note that the calculation of the first capacity section A is not limited to using two correlations between the open circuit voltage and the remaining capacity. For example, it is also possible to calculate the first capacity section A using one correlation between the open circuit voltage of the battery cell 21 and the remaining capacity. In this case, a detection error of the open circuit voltage is determined in advance, and two correction values ​​of the open circuit voltage are calculated by decreasing and increasing the detection error amount with respect to the detected open circuit voltage. The maximum remaining capacity A_max and the minimum remaining capacity A_min of the first capacity section A are then calculated from the two correction values. Furthermore, for example, the first capacity interval A may be calculated using three or more correlations between the open circuit voltage and remaining capacity of the cell 21. The process of step S14 corresponds to a "first interval calculation unit."

[0031] In step S15, the second capacity section B is calculated. In this embodiment, the second capacity section B is calculated by adding the integrated value IS of the current capacity due to the charging and discharging of the single battery 21 since the calculation of the third capacity section C to the maximum remaining capacity and minimum remaining capacity of the third capacity section C at the timing of the previous open circuit voltage detection. In the processing of step S15, the integrated value IS of the current capacity may be the value calculated in the processing of step S19. In this embodiment, the processing of steps S15 and S19 corresponds to the "second section calculation unit."

[0032] In step S16, it is determined whether or not to calculate the third capacity interval C. For example, if it is determined that the calculated first capacity interval A is wider than the predetermined range, it is determined that it is difficult to narrow down the range of the third capacity interval C, and it is determined not to calculate the third capacity interval C. Also, for example, if it is within a predetermined time from the timing of the previous open circuit voltage detection, it is determined that the change from the previous third capacity interval C is small, and it is determined not to calculate the third capacity interval C this time. In cases other than those described above, it is determined to calculate the third capacity interval C. If the determination in step S16 is affirmative, the process proceeds to step S17.

[0033] In step S17, a third capacity interval C is calculated. In this embodiment, the overlapping interval between the first capacity interval A and the second capacity interval B calculated by the processing of steps S14 and S15 is calculated as the third capacity interval C. The processing of step S17 corresponds to the "third interval calculation unit."

[0034] The integrated value IS of the current capacity calculated in the above-described sections A to C and in the processing of step S19 may be stored in a backup memory provided in the BMU 30. This allows the integrated value IS of the current capacity and the sections A to C to be saved even after the ignition switch is turned off, making it possible to calculate the third capacity section C over multiple trips.

[0035] In step S18, the integrated value IS of the current capacity due to charging and discharging of the battery 21 is reset to 0, and the process proceeds to step S20. If the determination in step S16 is negative, the process proceeds to step S20 without performing the processes in steps S17 and S18.

[0036] In step S20, it is determined whether the cell 21 is in a fully charged state. If the determination in step S20 is affirmative, the process proceeds to step S21. On the other hand, if the determination in step S20 is negative, the process proceeds to step S24. The process in step S20 corresponds to the "full charge determination unit."

[0037] In step S21, it is determined whether the full charge capacity is reliable. In this embodiment, the third capacity section C of the cell 21 is used to calculate the full charge capacity section, and the capacity within this full charge capacity section is calculated as the full charge capacity. In this case, the narrower the width of the third capacity section C, the higher the calculation accuracy of the full charge capacity and the higher the reliability of the full charge capacity. Therefore, the width of the third capacity section C is used as a determination parameter for determining the reliability of the full charge capacity, and the reliability of the full charge capacity is determined based on this determination parameter. Specifically, if the width of the third capacity section C is equal to or less than a predetermined width, it is determined that the calculation accuracy of the full charge capacity is ensured and the full charge capacity is reliable. In this case, the process proceeds to step S22. On the other hand, if the width of the third capacity section C is wider than the predetermined width, it is determined that the calculation accuracy of the full charge capacity is not ensured and the full charge capacity is unreliable. In this case, the process proceeds to step S24. The process of step S21 corresponds to the "reliability determination unit."

[0038] In step S22, the full charge capacity section FCC of the cell 21 is calculated. Here, the maximum remaining capacity C_max and minimum remaining capacity C_min of the third capacity section C are added to the integrated value IS of the current capacity due to charging and discharging of the cell 21 since the calculation of the third capacity section C to calculate the maximum and minimum values ​​of the full charge capacity section FCC, and the section determined by these maximum and minimum values ​​is set as the full charge capacity section FCC. The integrated value IS of the current capacity may be the value calculated in the process of step S19. In step S23, the capacity within the full charge capacity section FCC is calculated as the full charge capacity of the cell 21. The processes of steps S22 and S23 correspond to a "full charge capacity calculation unit."

[0039] In step S24, it is determined whether or not the calculation of the full charge capacity of each cell 21 constituting the battery pack 20 has been completed. If the full charge capacity of each cell 21 has been calculated, the process proceeds to step S25. On the other hand, if there is a cell among the cells 21 constituting the battery pack 20 for which the full charge capacity has not been calculated, this control ends.

[0040] In step S25, the SOH of the battery pack 20 is calculated. The SOH [%] of the battery pack 20 is expressed as (current full charge capacity of the battery pack 20 / reference full charge capacity of the battery pack 20) ​​× 100. The reference full charge capacity of the battery pack 20 indicates the dischargeable capacity of the battery pack 20, and is, for example, a capacity specified at the time of designing the battery pack 20 or during vehicle testing. The current full charge capacity of the battery pack 20 is, for example, the product of the smallest full charge capacity of the cells 21 constituting the battery pack 20, the number of series connections of the battery pack 20, and a specified voltage. The specified voltage may be an average voltage when the battery pack 20 is discharged, and may be specified at the time of designing the vehicle. Note that the current full charge capacity of the battery pack 20 may be corrected taking into account variations in the remaining capacity of the cells 21 and deterioration of the battery pack 20.

[0041] In step S26, the calculated SOH of the battery pack 20 is notified to other devices. In this case, for example, the SOH of the battery pack 20 may be displayed on the vehicle's instrument panel or on the vehicle's car navigation system, or the SOH of the battery pack 20 may be notified to a server outside the vehicle or a mobile terminal such as a smartphone.

[0042] An example of control for calculating the third capacity section C and the full charge capacity section FCC is shown in Fig. 6. In Fig. 6, the discharge of the battery pack 20 and the detection of the open circuit voltage are performed in the order of (a), (b), and (c), and in (d), the battery pack 20 is charged from the state (c) to the fully charged state.

[0043] In FIG. 6(a), an initial section is set as the third capacity section C of the cell 21. In this case, for example, the width of the third capacity section C is wider than the plateau region in the correlation between the open circuit voltage of the cell 21 and the remaining capacity, which raises concerns about low accuracy in calculating the remaining capacity. In FIG. 6(b), the third capacity section C is calculated as an overlapping section of the first capacity section A and the second capacity section B, which are calculated using different methods. This allows the range of the third capacity section C to be accurately narrowed, and the range of the third capacity section C in FIG. 6(b) is narrower than that in FIG. 6(a).

[0044] In this embodiment, the current second capacity interval B is calculated using the third capacity interval C at the timing of the previous detection of the open circuit voltage of the cell 21, and the current third capacity interval C is calculated based on the current first and second capacity intervals A and B. As a result, the previous third capacity interval C is carried over to the calculation of the current third capacity interval C, so the range of the current third capacity interval C can be accurately narrowed. Therefore, the range of the third capacity interval C in (c) of FIG. 6 is narrowed compared to (b). Then, the width of the third capacity interval C in FIG. 6(c) becomes equal to or less than a predetermined width, and it is determined that the full charge capacity is reliable. As a result, calculation of the full charge capacity interval FCC is permitted.

[0045] In Fig. 6(d), the full charge capacity section FCC is calculated by adding the integrated value IS of the current capacity due to charging of the cell 21 since the calculation of the third capacity section C to the maximum remaining capacity C_max and minimum remaining capacity C_min of the third capacity section C in Fig. 6(c). In this case, the range of the full charge capacity section FCC is narrowed, which can improve the accuracy of calculating the full charge capacity.

[0046] According to the present embodiment described above in detail, the following effects can be obtained.

[0047] At the timing of detecting the open circuit voltage of the cell 21, a reference remaining capacity of the cell 21 is calculated based on the correlation between the open circuit voltage of the cell 21 and the remaining capacity, and a first capacity interval A is calculated as a predetermined interval including the reference remaining capacity. Furthermore, a second capacity interval B is calculated by adding a capacity change, which is a change in current capacity due to charging and discharging of the cell 21 since the calculation of the past capacity interval, to the maximum and minimum remaining capacities of a past capacity interval calculated at a timing of detecting the open circuit voltage of the cell 21 prior to the present. In this case, the first capacity interval A is calculated taking into account the variation in remaining capacity caused by the detection conditions of the open circuit voltage of the cell 21 and the charging and discharging conditions of the cell 21, and the second capacity interval B is calculated taking into account the integration error of the integrated value IS of the current capacity. In addition, a third capacity interval C is calculated as an interval including an overlapping interval of the capacity intervals A and B, thereby narrowing the range of the third capacity interval C including the actual remaining capacity of the cell 21. By narrowing the range of the third capacity section C, the accuracy of calculating the remaining capacity of the single cell 21 can be improved.

[0048] By calculating the first capacity interval A using multiple correlations between the open circuit voltage and the remaining capacity, it is possible to properly calculate the first capacity interval A while assuming that there is variation in the charge / discharge characteristics of the actual cells 21. In addition to the above, multiple correlations with different degrees of deterioration of the cells 21 may be used. Alternatively, multiple correlations determined within the range of allowable tolerance for the cells 21 may be used.

[0049] The width of the third capacity section C is used as a determination parameter for determining the reliability of the full charge capacity, and the reliability of the full charge capacity is determined based on the determination parameter. If the full charge capacity is determined to be reliable, calculation of the full charge capacity is permitted. This allows the full charge capacity of the cell 21 to be calculated with high accuracy.

[0050] If a long period of time has passed without calculation of the third capacity interval C, it is considered that the reliability of the already calculated third capacity interval C has decreased. Therefore, according to this embodiment, if it is determined that a period of time has passed without calculation of the third capacity interval C, the third capacity interval C is reset to a predetermined initial interval. This makes it possible to prevent the second capacity interval B from being calculated using a third capacity interval C with low reliability.

[0051] <Modification of the first embodiment> The first embodiment may be modified as follows.

[0052] The calculation unit 33 may calculate the second capacity section B by adding an integrated current capacity value IS obtained by subtracting and correcting the amount of current capacity detection error from the minimum remaining capacity in a past capacity section (e.g., the previous third capacity section C) and adding an integrated current capacity value IS obtained by subtracting and correcting the amount of current capacity detection error from the maximum remaining capacity in the past capacity section. Specifically, in step S19 of FIG. 5 , the calculation unit 33 may calculate an integrated current capacity value IS1 obtained by subtracting and correcting the amount of current capacity detection error, and an integrated current capacity value IS2 obtained by increasing and correcting the amount of current capacity detection error. For example, the integrated current capacity value IS1 obtained by subtracting and correcting the amount of detection error from the detection error may be calculated using the following formula (A), and the integrated current capacity value IS2 obtained by increasing and correcting the amount of detection error from the detection error may be calculated using the following formula (B). Note that the amount of current capacity detection error may be determined in advance.

[0053] IS1 (current value) = IS1 (previous value) + (current capacity - detection error) (Formula A) IS2 (current value) = IS2 (previous value) + (current capacity + detection error) (Formula B) In this case, in step S15, the second capacity section B may be calculated by adding the integrated value IS1 to the minimum remaining capacity of the past capacity section and adding the integrated value IS2 to the maximum remaining capacity of the past capacity section.

[0054] According to the above configuration, the minimum remaining capacity in the past capacity section is added slightly lower, taking into account the detection error of the current capacity. On the other hand, the maximum remaining capacity in the past capacity section is added slightly higher, taking into account the detection error of the current capacity. This allows the second capacity section B to be calculated appropriately, taking into account the fact that the detection value of the current capacity includes sensor error, etc.

[0055] In step S22, the full charge capacity section FCC may be calculated by adding the integrated value IS1, which has been corrected by subtracting the detection error, to the minimum remaining capacity C_min of the third capacity section C, and adding the integrated value IS2, which has been corrected by increasing the detection error, to the maximum remaining capacity C_max of the third capacity section C.

[0056] The calculation unit 33 may update the second capacity section B each time the open circuit voltage of the battery cell 21 is detected in step S19 of Fig. 5 instead of calculating the second capacity section B at that time. In this case, step S15 does not need to be performed. The integrated value IS of the current capacity calculated in step S19 may be used to calculate the full charge capacity section FCC.

[0057] In the processing of step S17 in FIG. 5, the minimum remaining capacity C_min of the third capacity section C may be calculated using the following formula (C), and the maximum remaining capacity C_max of the third capacity section C may be calculated using the following formula (D).

[0058] C_min=(α×A_min+β×B_min) / (α+β) (Formula C) C_max=(γ×A_max+ε×B_max) / (γ+ε) (Formula D) Here, α, β, γ, and ε are weighting coefficients. The coefficients α, β, γ, and ε may be set to fixed values ​​(specifically, α = β = γ = ε = 1) or may be variably set according to the remaining capacity of the battery 21. For example, when the remaining capacity of the battery 21 (specifically, the remaining capacities A_min, A_max, B_min, and B_max) is low, the ratio of the coefficients β and ε of the second capacity range B to the coefficients α and γ of the first capacity range A (in other words, the coefficient ratio β / α,ε / γ) may be set to be larger than when the remaining capacity of the battery 21 is high. In this case, the second capacity range B is reflected more than the first capacity range A, and the third capacity range C is calculated. The BMU 30 may also detect the temperature of the battery pack 20 and variably set the coefficients α, β, γ, and ε according to the temperature of the battery pack 20.

[0059] In the process of step S21 in Fig. 5, a parameter other than the width of the third capacity interval C may be used as the judgment parameter. For example, the difference between the third capacity interval C and the second capacity interval B when the third capacity interval C is calculated may be used as the judgment parameter, and whether the full charge capacity is reliable may be determined based on the judgment parameter. In this case, for example, if the following formulas (E), (F), and (G) are satisfied, it may be determined that the full charge capacity is reliable.

[0060] C_min-B_min ≧ predetermined amount (Formula E) B_max-C_max≧predetermined amount (Formula F) (C_min-B_min)+(B_max-C_max)≧predetermined amount (Formula G) Here, the left side of each of equations (E), (F), and (G) is the degree of limitation indicating the extent to which the range of the third capacity range C is limited relative to the second capacity range B. If the degree of limitation is equal to or greater than a predetermined amount, it is determined that the calculation accuracy of the full charge capacity is ensured, and the full charge capacity is determined to be reliable. On the other hand, if the degree of limitation is less than a predetermined amount, it is determined that the calculation accuracy of the full charge capacity is not ensured, and the full charge capacity is determined to be unreliable. As the degree of limitation, a value indicating the extent to which the third capacity range C is limited relative to the first capacity range A may be calculated instead of the second capacity range B. Alternatively, the integrated value of the left side of each of equations (E), (F), and (G) may be calculated, and the reliability of the full charge capacity may be determined based on whether the integrated value is equal to or greater than a predetermined amount.

[0061] Alternatively, for example, at least one of the width of the full charge capacity section, the maximum capacity value of the full charge capacity section, and the minimum capacity value of the full charge capacity section may be used as a determination parameter, and the reliability of the full charge capacity may be determined based on the determination parameter. In this case, after the process of step S20, the process of step S22 may be performed before the process of step S21. Specifically, if the width of the full charge capacity section is equal to or less than a predetermined width, the full charge capacity is determined to be reliable. If the width of the full charge capacity section is greater than the predetermined width, the full charge capacity is determined to be unreliable. If the maximum capacity value of the full charge capacity section is equal to or less than a first predetermined value, the full charge capacity is determined to be reliable. If the minimum capacity value of the full charge capacity section is equal to or greater than a second predetermined value, the full charge capacity is determined to be reliable. If the minimum capacity value of the full charge capacity section is smaller than the second predetermined value, the full charge capacity is determined to be unreliable. Note that the first predetermined value is greater than the second predetermined value.

[0062] In FIG. 5, the processes of steps S10, S11, and S16 do not have to be performed.

[0063] 5, other processes may be performed instead of the processes of steps S25 and S26. For example, if a positive determination is made in step S24, the SOC of the battery pack 20 may be calculated. The SOC [%] of the battery pack 20 is expressed as (current remaining capacity of the battery pack 20 / current full charge capacity of the battery pack 20) ​​× 100. The full charge capacity of each cell 21 calculated in the process of step S23 may be used as the current full charge capacity of the battery pack 20. The current remaining capacity of the battery pack 20 may be calculated based on the third capacity section C of each cell 21 calculated in the process of step S17. Furthermore, the processes of steps S24 to S26 may not be performed.

[0064] 5, the remaining capacity of each cell 21 may be calculated using the third capacity interval C. In this case, for example, the calculation unit 33 may calculate, as the remaining capacity of each cell 21, the maximum remaining capacity C_max or a value obtained by shifting the maximum remaining capacity C_max in the third capacity interval C toward the discharge side by a predetermined value, the minimum remaining capacity C_min or a value obtained by shifting the minimum remaining capacity C_min in the third capacity interval C toward the charge side by a predetermined value, or the arithmetic mean or weighted mean value of the maximum remaining capacity C_max and the minimum remaining capacity C_min in the third capacity interval C. Furthermore, after the processing of step S17 in FIG. 5, the third capacity interval C may be used to set the maximum power (i.e., Win, Wout) that can be input / output to / from the battery pack 20. When the third capacity interval C is used to calculate the remaining capacity of each cell 21 or to set the maximum power that can be input / output to / from the battery pack 20, the processing of steps S20 to S26 may not be performed.

[0065] Second Embodiment The second embodiment will be described below with reference to the drawings, focusing on differences from the first embodiment. In this embodiment, the full charge capacity is calculated when the open circuit voltage of the cell 21 is detected, instead of when it is determined that the cell 21 is fully charged.

[0066] Fig. 7 shows the control procedure for calculating the full charge capacity. This control is repeatedly executed at a predetermined control period by the BMU 30. For convenience, the same processes as those shown in Fig. 5 are denoted by the same reference numerals in Fig. 7.

[0067] In step S30, it is determined whether the cells 21 are fully charged. In this embodiment, assuming a situation in which the battery pack 20 is being charged by an external charger, if it is determined that the terminal voltage of a cell 21 has reached a full charge voltage value, it is determined that the cell 21 is fully charged. If the determination in step S30 is negative, the process proceeds to step S31. If the determination in step S32 is positive, the process proceeds to step S32.

[0068] In step S31, the current capacity resulting from charging and discharging the cells 21 from the time when the cells 21 are determined to be in a fully charged state is integrated to calculate an integrated value IS. The current capacity resulting from charging and discharging the cells 21 may be calculated based on the detection value of the current sensor 13. In step S32, the integrated value IS of the current capacity calculated in the processing of step S31 is reset to 0. After the processing of steps S31 and S32, the process proceeds to step S12.

[0069] The processes of steps S12 to S17, and S19 are the same as those in the first embodiment. After the process of step S17, the process proceeds to step S22. The processes of steps S22 and S23 are the same as those in the first embodiment. Note that the process of step S16 is omitted in FIG. 7. In this embodiment, the process of step S31 corresponds to the "integrated value calculation unit", and the processes of steps S22 and S23 correspond to the "full charge capacity calculation unit".

[0070] After the process of step S23, the process proceeds to step S33. In step S33, the integrated value IS of the current capacity calculated in the process of step S19 is reset to 0. The integrated value IS of the current capacity calculated in the process of step S19 is the integrated value IS of the current capacity due to charging and discharging of the single battery 21 from the timing of the previous detection of the open circuit voltage. After the process of step S33, this control ends.

[0071] 8 shows an example of calculation of the third capacity section C and the full charge capacity section FCC. In Fig. 8, the discharge of the battery pack 20 and the detection of the open circuit voltage are performed in the order of (a), (b), and (c).

[0072] 8(a), a third capacity section C is set when the cell 21 is in a fully charged state. The third capacity section C when the cell 21 is in a fully charged state may be any initial set section that is set in advance.

[0073] In Figures 8(b) and (c), the third capacity section C is updated using the current first capacity section A and second capacity section B, and the full charge capacity section FCC is calculated using the third capacity section C.

[0074] 8(b), in calculating the second capacity section B, the integrated value ISA of the current capacity due to charging and discharging of the cell 21 during the period from the timing of FIG. 8(a) to the timing of FIG. 8(b) is added to the maximum remaining capacity C_max and minimum remaining capacity C_min of the third capacity section C, which is a set section. In calculating the full charge capacity section FCC, the integrated value ISA of the current capacity due to charging and discharging of the cell 21 during the period from the timing of FIG. 8(a) to the timing of FIG. 8(b) is added to the maximum remaining capacity C_max and minimum remaining capacity C_min of the third capacity section C at the timing of FIG. 8(b).

[0075] In FIG. 8(c), in calculating the second capacity section B, an integrated value ISB of the current capacity due to charging and discharging of the cell 21 during the period from the timing of FIG. 8(b) to the timing of FIG. 8(c) is added to the maximum remaining capacity C_max and minimum remaining capacity C_min of the third capacity section C in FIG. 8(b). Here, the integrated value ISB of the current capacity may be calculated in the process of step S19 in FIG. 7. In calculating the full charge capacity section FCC, an integrated value ISA+ISB of the current capacity due to charging and discharging of the cell 21 during the period from the timing of FIG. 8(a) to the timing of FIG. 8(c) is added to the maximum remaining capacity C_max and minimum remaining capacity C_min of the third capacity section C in FIG. 8(c). Here, the integrated value ISA+ISB of the current capacity may be calculated in the process of step S31 in FIG.

[0076] According to the above configuration, the full charge capacity of the cell 21 can be calculated at each timing when the open circuit voltage of the cell 21 is detected.

[0077] 7, the process of calculating the SOH and SOC of the battery pack 20 may be performed similarly to the first embodiment. Furthermore, after the process of step S17 in Fig. 7, the remaining capacity of each cell 21 may be calculated and the maximum power that can be input / output to / from the battery pack 20 may be set using the third capacity section C similarly to the first embodiment.

[0078] <Other embodiments> The above-described embodiments may be modified as follows.

[0079] The calculation unit 33 may calculate the SOH of the cell 21 using the third capacity section C instead of the full charge capacity. In this case, in the process of step S23 in Fig. 5 , the capacity within the full charge capacity section FCC is calculated as the full charge capacity of the cell 21, and the SOH of the cell 21 is calculated by dividing the full charge capacity by the reference full charge capacity of the cell 21. The reference full charge capacity of the cell 21 is a capacity that was specified when the cell 21 was designed or when a vehicle test was performed.

[0080] In the above embodiment, the battery system has been described as a battery system for a vehicle, but it may also be a battery system for a moving body other than a vehicle, such as an aircraft or a ship. It may also be a battery system for a body other than a moving body, i.e., a stationary battery system. Specifically, it can be applied to a battery system provided in association with a building such as a house, a store, or a public facility.

[0081] The vehicle control device and method described herein may be implemented by a special-purpose computer configured with a processor and memory programmed to execute one or more functions embodied in a computer program. Alternatively, the vehicle control device and method described herein may be implemented by a special-purpose computer configured with a processor comprising one or more dedicated hardware logic circuits. Alternatively, the vehicle control device and method described herein may be implemented by one or more special-purpose computers configured with a combination of a processor and memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by the computer.

[0082] The following describes characteristic configurations extracted from the above-described embodiments. [Configuration 1] A remaining capacity calculation device (30) for calculating a remaining capacity of a storage battery (21) when the storage battery (21) is being charged and discharged, a first interval calculation unit that calculates a reference remaining capacity of the storage battery based on a correlation between the open circuit voltage and the remaining capacity of the storage battery at a timing when an open circuit voltage of the storage battery is detected, and calculates a predetermined interval including the reference remaining capacity as a first capacity interval; a second section calculation unit that calculates a second capacity section by adding a capacity change amount, which is a change in current capacity due to charging and discharging of the storage battery since the calculation of the past capacity section, to the maximum remaining capacity and the minimum remaining capacity of the past capacity section calculated at the detection timing before the present time; a third interval calculation unit that calculates, at the detection timing, an interval including an overlapping interval between the first capacity interval and the second capacity interval as a third capacity interval including an actual remaining capacity; A remaining capacity calculation device comprising: [Configuration 2] The remaining capacity calculation device according to configuration 1, wherein the first interval calculation unit uses a plurality of correlations defined as the correlations at the detection timing, calculates a plurality of reference remaining capacities corresponding to the open circuit voltage for each correlation, and calculates an interval including each of the reference remaining capacities as the first capacity interval. [Configuration 3] The remaining capacity calculation device according to configuration 1 or 2, wherein the second interval calculation unit defines the third capacity interval calculated by the third interval calculation unit before the present time as the past capacity interval, and calculates the second capacity interval by adding the capacity change due to charging and discharging of the storage battery since the calculation of the third capacity interval to the maximum remaining capacity and minimum remaining capacity of the third capacity interval. [Configuration 4] The storage capacity calculation device according to any one of configurations 1 to 3, wherein, in calculating the third capacity section, the third section calculation unit determines the remaining capacity between the maximum remaining capacity of the first capacity section and the maximum remaining capacity of the second capacity section as the maximum remaining capacity of the third capacity section, and determines the remaining capacity between the minimum remaining capacity of the first capacity section and the minimum remaining capacity of the second capacity section as the minimum remaining capacity of the third capacity section. [Configuration 5] 4. The storage capacity calculation device according to any one of configurations 1 to 3, wherein the third interval calculation unit determines an overlapping interval between the first capacity interval and the second capacity interval as the third capacity interval. [Configuration 6] The second section calculation unit calculates the second capacity section by adding the capacity change amount obtained by subtracting and correcting the detection error of the current capacity to the minimum remaining capacity of the past capacity section, and by adding the capacity change amount obtained by subtracting and correcting the detection error of the current capacity to the maximum remaining capacity of the past capacity section. [Configuration 7] a full charge determination unit that determines whether the storage battery is in a fully charged state; and a full charge capacity calculation unit that, when it is determined that the storage battery is in the fully charged state, calculates a full charge capacity range of the storage battery based on the third capacity range calculated at the previous detection timing and a change in current capacity due to charging and discharging of the storage battery since the calculation of the third capacity range, and calculates a full charge capacity from the full charge capacity range. [Configuration 8] an integrated value calculation unit that calculates an integrated value of current capacity due to charging and discharging of the storage battery from a time when the storage battery is fully charged as a capacity integrated value; and a full charge capacity calculation unit that calculates a full charge capacity range of the storage battery based on the third capacity range calculated by the third range calculation unit and the capacity integrated value calculated by the integrated value calculation unit at the detection timing, and calculates a full charge capacity from the full charge capacity range. [Configuration 9] a reliability determination unit that uses at least one of the width of the third capacity range calculated by the third range calculation unit, the width of the full charge capacity range calculated by the full charge capacity calculation unit, the maximum capacity value or the minimum capacity value of the full charge capacity range, the difference between the third capacity range and the first capacity range when the third capacity range is calculated, and the difference between the third capacity range and the second capacity range when the third capacity range is calculated as a determination parameter, and determines the reliability of the full charge capacity calculated by the full charge capacity calculation unit based on the determination parameters; 9. The remaining capacity calculation device according to claim 7, further comprising: a permission unit that permits the full charge capacity calculation unit to calculate the full charge capacity on condition that the reliability determination unit has determined that the remaining charge capacity is reliable. [Configuration 10] a period determination unit that determines whether a period during which the calculation of the third capacity section is not performed continues for a predetermined time or more; The remaining capacity calculation device according to any one of configurations 1 to 9, further comprising a reset unit that resets the third capacity section when it is determined that a period during which calculation of the third capacity section is not performed continues for a predetermined time or longer. [Explanation of symbols]

[0083] 21...Diameter battery, 30...BMU.

Claims

1. A remaining capacity calculation device (30) that calculates the remaining capacity of a storage battery (21) when the storage battery is being charged and discharged, a first interval calculation unit that calculates a reference remaining capacity of the storage battery based on a correlation between the open circuit voltage and the remaining capacity of the storage battery at a timing when an open circuit voltage of the storage battery is detected, and calculates a predetermined interval including the reference remaining capacity as a first capacity interval; a second section calculation unit that calculates a second capacity section by adding a capacity change amount, which is a change in current capacity due to charging and discharging of the storage battery since the calculation of the past capacity section, to the maximum remaining capacity and the minimum remaining capacity of the past capacity section calculated at the detection timing before the present time; a third interval calculation unit that calculates, at the detection timing, an interval including an overlapping interval between the first capacity interval and the second capacity interval as a third capacity interval including an actual remaining capacity; Equipped with The first interval calculation unit uses a plurality of correlations defined as the correlations at the detection timing, calculates a plurality of reference remaining capacities corresponding to the open circuit voltage for each correlation, and calculates an interval including each of the reference remaining capacities as the first capacity interval.

2. A remaining capacity calculation device (30) that calculates the remaining capacity of a storage battery (21) when the storage battery is being charged and discharged, a first interval calculation unit that calculates a reference remaining capacity of the storage battery based on a correlation between the open circuit voltage and the remaining capacity of the storage battery at a timing when an open circuit voltage of the storage battery is detected, and calculates a predetermined interval including the reference remaining capacity as a first capacity interval; a second section calculation unit that calculates a second capacity section by adding a capacity change amount, which is a change in current capacity due to charging and discharging of the storage battery since the calculation of the past capacity section, to the maximum remaining capacity and the minimum remaining capacity of the past capacity section calculated at the detection timing before the present time; a third interval calculation unit that calculates, at the detection timing, an interval including an overlapping interval between the first capacity interval and the second capacity interval as a third capacity interval including an actual remaining capacity; Equipped with The second interval calculation unit defines the third capacity interval calculated by the third interval calculation unit before the present time as the past capacity interval, and calculates the second capacity interval by adding the capacity change due to charging and discharging of the storage battery since the calculation of the third capacity interval to the maximum remaining capacity and minimum remaining capacity of the third capacity interval.

3. A remaining capacity calculation device (30) that calculates the remaining capacity of a storage battery (21) when the storage battery is being charged and discharged, a first interval calculation unit that calculates a reference remaining capacity of the storage battery based on a correlation between the open circuit voltage and the remaining capacity of the storage battery at a timing when an open circuit voltage of the storage battery is detected, and calculates a predetermined interval including the reference remaining capacity as a first capacity interval; a second section calculation unit that calculates a second capacity section by adding a capacity change amount, which is a change in current capacity due to charging and discharging of the storage battery since the calculation of the past capacity section, to the maximum remaining capacity and the minimum remaining capacity of the past capacity section calculated at the detection timing before the present time; a third interval calculation unit that calculates, at the detection timing, an interval including an overlapping interval between the first capacity interval and the second capacity interval as a third capacity interval including an actual remaining capacity; Equipped with The third section calculation unit, in calculating the third capacity section, sets the remaining capacity between the maximum remaining capacity of the first capacity section and the maximum remaining capacity of the second capacity section as the maximum remaining capacity of the third capacity section, and sets the remaining capacity between the minimum remaining capacity of the first capacity section and the minimum remaining capacity of the second capacity section as the minimum remaining capacity of the third capacity section.

4. The remaining capacity calculation device according to claim 1 , wherein the third interval calculation unit determines an overlapping interval between the first capacity interval and the second capacity interval as the third capacity interval.

5. The second section calculation unit calculates the second capacity section by adding the capacity change amount obtained by subtracting and correcting the detection error of the current capacity to the minimum remaining capacity of the past capacity section, and by adding the capacity change amount obtained by subtracting and correcting the detection error of the current capacity to the maximum remaining capacity of the past capacity section.

6. A remaining capacity calculation device (30) that calculates the remaining capacity of a storage battery (21) when the storage battery is being charged and discharged, a first interval calculation unit that calculates a reference remaining capacity of the storage battery based on a correlation between the open circuit voltage and the remaining capacity of the storage battery at a timing when an open circuit voltage of the storage battery is detected, and calculates a predetermined interval including the reference remaining capacity as a first capacity interval; a second section calculation unit that calculates a second capacity section by adding a capacity change amount, which is a change in current capacity due to charging and discharging of the storage battery since the calculation of the past capacity section, to the maximum remaining capacity and the minimum remaining capacity of the past capacity section calculated at the detection timing before the present time; a third interval calculation unit that calculates, at the detection timing, an interval including an overlapping interval between the first capacity interval and the second capacity interval as a third capacity interval including an actual remaining capacity; a full charge determination unit that determines whether the storage battery is in a fully charged state; a full charge capacity calculation unit that, when it is determined that the storage battery is in the fully charged state, calculates a full charge capacity range of the storage battery based on the third capacity range calculated at the previous detection timing and a change in current capacity due to charging and discharging of the storage battery since the calculation of the third capacity range, and calculates a full charge capacity from the full charge capacity range; A remaining capacity calculation device comprising:

7. A remaining capacity calculation device (30) that calculates the remaining capacity of a storage battery (21) when the storage battery is being charged and discharged, a first interval calculation unit that calculates a reference remaining capacity of the storage battery based on a correlation between the open circuit voltage and the remaining capacity of the storage battery at a timing when an open circuit voltage of the storage battery is detected, and calculates a predetermined interval including the reference remaining capacity as a first capacity interval; a second section calculation unit that calculates a second capacity section by adding a capacity change amount, which is a change in current capacity due to charging and discharging of the storage battery since the calculation of the past capacity section, to the maximum remaining capacity and the minimum remaining capacity of the past capacity section calculated at the detection timing before the present time; a third interval calculation unit that calculates, at the detection timing, an interval including an overlapping interval between the first capacity interval and the second capacity interval as a third capacity interval including an actual remaining capacity; an integrated value calculation unit that calculates an integrated value of current capacity due to charging and discharging of the storage battery from a time when the storage battery is fully charged as a capacity integrated value; a full charge capacity calculation unit that calculates a full charge capacity range of the storage battery based on the third capacity range calculated by the third range calculation unit and the integrated capacity value calculated by the integrated value calculation unit at the detection timing, and calculates a full charge capacity from the full charge capacity range; A remaining capacity calculation device comprising:

8. a reliability determination unit that uses at least one of the width of the third capacity range calculated by the third range calculation unit, the width of the full charge capacity range calculated by the full charge capacity calculation unit, the maximum capacity value or the minimum capacity value of the full charge capacity range, the difference between the third capacity range and the first capacity range when the third capacity range is calculated, and the difference between the third capacity range and the second capacity range when the third capacity range is calculated as a determination parameter, and determines the reliability of the full charge capacity calculated by the full charge capacity calculation unit based on the determination parameters; 8. The remaining capacity calculation device according to claim 6, further comprising: a permission unit that permits the full charge capacity calculation unit to calculate the full charge capacity on condition that the reliability determination unit determines that the remaining charge capacity is reliable.

9. a period determination unit that determines whether a period during which the calculation of the third capacity section is not performed continues for a predetermined time or more; A remaining capacity calculation device as described in any one of claims 1 to 3, 6, and 7, further comprising a reset unit that resets the third capacity section when it is determined that a period in which calculation of the third capacity section is not performed continues for a predetermined time or longer.

10. A program that causes a computer (30) to execute a process of calculating a remaining capacity of a storage battery (21) when the storage battery (21) is charged and discharged, a first interval calculation step of calculating a reference remaining capacity of the storage battery based on a correlation between the open circuit voltage and the remaining capacity of the storage battery at a timing when an open circuit voltage of the storage battery is detected, and calculating a predetermined interval including the reference remaining capacity as a first capacity interval; a second interval calculation step of calculating a second capacity interval by adding a capacity change amount, which is a change in current capacity due to charging and discharging of the storage battery since the calculation of the past capacity interval, to the maximum remaining capacity and the minimum remaining capacity of the past capacity interval calculated at the detection timing before the present time; a third interval calculation step of calculating an interval including an overlapping interval between the first capacity interval and the second capacity interval at the detection timing as a third capacity interval including an actual remaining capacity; causing the computer to execute In the first interval calculation step, a program is provided that, at the detection timing, a plurality of correlations defined as the correlation are used to calculate a plurality of reference remaining capacities corresponding to the open circuit voltage for each correlation, and an interval including each of the reference remaining capacities is calculated as the first capacity interval.

11. A program that causes a computer (30) to execute a process of calculating a remaining capacity of a storage battery (21) when the storage battery (21) is charged and discharged, a first interval calculation step of calculating a reference remaining capacity of the storage battery based on a correlation between the open circuit voltage and the remaining capacity of the storage battery at a timing when an open circuit voltage of the storage battery is detected, and calculating a predetermined interval including the reference remaining capacity as a first capacity interval; a second interval calculation step of calculating a second capacity interval by adding a capacity change amount, which is a change in current capacity due to charging and discharging of the storage battery since the calculation of the past capacity interval, to the maximum remaining capacity and the minimum remaining capacity of the past capacity interval calculated at the detection timing before the present time; a third interval calculation step of calculating an interval including an overlapping interval between the first capacity interval and the second capacity interval at the detection timing as a third capacity interval including an actual remaining capacity; causing the computer to execute In the second interval calculation step, the third capacity interval calculated in the third interval calculation step before the present time is set as the past capacity interval, and the change in capacity due to charging and discharging of the storage battery since the calculation of the third capacity interval is added to the maximum remaining capacity and minimum remaining capacity of the third capacity interval, respectively, to calculate the second capacity interval.

12. A program that causes a computer (30) to execute a process of calculating a remaining capacity of a storage battery (21) when the storage battery (21) is charged and discharged, a first interval calculation step of calculating a reference remaining capacity of the storage battery based on a correlation between the open circuit voltage and the remaining capacity of the storage battery at a timing when an open circuit voltage of the storage battery is detected, and calculating a predetermined interval including the reference remaining capacity as a first capacity interval; a second interval calculation step of calculating a second capacity interval by adding a capacity change amount, which is a change in current capacity due to charging and discharging of the storage battery since the calculation of the past capacity interval, to the maximum remaining capacity and the minimum remaining capacity of the past capacity interval calculated at the detection timing before the present time; a third interval calculation step of calculating an interval including an overlapping interval between the first capacity interval and the second capacity interval at the detection timing as a third capacity interval including an actual remaining capacity; causing the computer to execute In the third section calculation step, when calculating the third capacity section, the remaining capacity between the maximum remaining capacity of the first capacity section and the maximum remaining capacity of the second capacity section is set to the maximum remaining capacity of the third capacity section, and the remaining capacity between the minimum remaining capacity of the first capacity section and the minimum remaining capacity of the second capacity section is set to the minimum remaining capacity of the third capacity section.

13. A program that causes a computer (30) to execute a process of calculating a remaining capacity of a storage battery (21) when the storage battery (21) is charged and discharged, a first interval calculation step of calculating a reference remaining capacity of the storage battery based on a correlation between the open circuit voltage and the remaining capacity of the storage battery at a timing when an open circuit voltage of the storage battery is detected, and calculating a predetermined interval including the reference remaining capacity as a first capacity interval; a second interval calculation step of calculating a second capacity interval by adding a capacity change amount, which is a change in current capacity due to charging and discharging of the storage battery since the calculation of the past capacity interval, to the maximum remaining capacity and the minimum remaining capacity of the past capacity interval calculated at the detection timing before the present time; a third interval calculation step of calculating an interval including an overlapping interval between the first capacity interval and the second capacity interval at the detection timing as a third capacity interval including an actual remaining capacity; a full charge determination step of determining whether the storage battery is in a fully charged state; a full charge capacity calculation step of calculating a full charge capacity range of the storage battery based on the third capacity range calculated at the previous detection timing and a change in current capacity due to charging and discharging of the storage battery since the calculation of the third capacity range, when it is determined that the storage battery is in the fully charged state, and calculating a full charge capacity from the full charge capacity range; A program that causes the computer to execute the above.

14. A program that causes a computer (30) to execute a process of calculating a remaining capacity of a storage battery (21) when the storage battery (21) is charged and discharged, a first interval calculation step of calculating a reference remaining capacity of the storage battery based on a correlation between the open circuit voltage and the remaining capacity of the storage battery at a timing when an open circuit voltage of the storage battery is detected, and calculating a predetermined interval including the reference remaining capacity as a first capacity interval; a second interval calculation step of calculating a second capacity interval by adding a capacity change amount, which is a change in current capacity due to charging and discharging of the storage battery since the calculation of the past capacity interval, to the maximum remaining capacity and the minimum remaining capacity of the past capacity interval calculated at the detection timing before the present time; a third interval calculation step of calculating an interval including an overlapping interval between the first capacity interval and the second capacity interval at the detection timing as a third capacity interval including an actual remaining capacity; an integrated value calculation step of calculating an integrated value of current capacity due to charging and discharging of the storage battery from a fully charged state of the storage battery as a capacity integrated value; a full charge capacity calculation step of calculating a full charge capacity range of the storage battery based on the third capacity range calculated in the third range calculation step and the integrated capacity value calculated in the integrated value calculation step at the detection timing, and calculating a full charge capacity from the full charge capacity range; A program that causes the computer to execute the above.

Images