Battery control device and program

Abstract

To accurately calculate the allowable input power of a storage battery and appropriately manage the storage battery.SOLUTION: A BMU 30 is a battery control device that calculates allowable input power Win of a battery pack 10. The BMU 30 comprises: a full charge determining section for determining that the storage battery 10 is fully charged; a discharge amount calculating section for calculating, as a discharge amount of the storage battery 10 relative to the full charge of the storage battery 10, a value obtained by adding a current or current capacity during discharge of the storage battery 10 and subtracting the current or current capacity during charging of the storage battery 10 to integrate the current or current capacity; and an input power calculating section for calculating the allowable input power Win of the storage battery 10 on the basis of the discharge amount calculated by the discharge amount calculating section.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a battery control device and a program. [Background technology]

[0002] There is a concern that overcharging of a storage battery may cause deterioration. Therefore, a technique is known in which an allowable input power (Win) is determined for the storage battery, and the input of power to the storage battery (charging of the storage battery) is limited based on the allowable input power. For example, a technique is known in which a SOC (State Of Charge), which indicates the ratio of the remaining capacity of the storage battery to the fully charged capacity of the storage battery, is calculated based on the OCV (Open Circuit Voltage) of the storage battery, and the allowable input power is calculated based on the SOC (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6970289 Summary of the Invention [Problem to be solved by the invention]

[0004] In a storage battery, the remaining capacity at which a steep increase in voltage occurs with respect to an increase in capacity in the voltage-capacity characteristic, which indicates the relationship between voltage and capacity, is the full charge capacity, and the input of power to the storage battery is limited with the full charge capacity as the upper limit. However, in this case, if the characteristics of the storage battery change near the full charge capacity due to deterioration, the accuracy of the SOC calculation by the OCV may decrease, and the accuracy of the calculation of the allowable input power by the SOC may decrease. In addition, if it becomes difficult to correctly grasp the capacity margin (charging margin) relative to the full charge capacity due to a change in the full charge capacity, the accuracy of the calculation of the allowable input power may also decrease. If the allowable input power is too high, there is a concern that the protection of the storage battery may be insufficient, and if the allowable input power is too low, the protection of the storage battery may be excessive.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a battery control device and program that can accurately calculate the allowable input power of a storage battery, and thereby properly manage the storage battery. [Means for solving the problem]

[0006] In order to solve the above problems, the first invention is: A battery control device that calculates an allowable input power in a storage battery, a full charge determination unit that determines whether the storage battery is fully charged; a discharge amount calculation unit that calculates a value of a current or a current capacity by adding a current or a current capacity when the storage battery is discharged and subtracting a current or a current capacity when the storage battery is charged, based on a fully charged state of the storage battery, as a discharge amount of the storage battery; an input power calculation unit that calculates the allowable input power of the storage battery based on the discharge amount calculated by the discharge amount calculation unit; Equipped with.

[0007] In the storage battery, the allowable input power of the storage battery is appropriately set to suppress deterioration due to overcharging. In this case, if a deviation in the full charge capacity occurs due to deterioration of the storage battery, there is a concern that the allowable input power cannot be calculated correctly. In consideration of this point, the storage battery is determined to be fully charged, and a value obtained by adding the current or current capacity of the storage battery when it is discharged and subtracting the current or current capacity of the storage battery when it is charged based on the full charge of the storage battery is calculated as the discharge amount of the storage battery. In addition, the allowable input power of the storage battery is calculated based on the discharge amount. In this case, even if the full charge capacity changes due to deterioration of the storage battery, the allowable input power according to the capacity margin degree with respect to the full charge can be properly calculated. As a result, the allowable input power of the storage battery can be accurately calculated, and the storage battery can be properly managed.

[0008] The second invention is, A battery control device that calculates an allowable input power in a storage battery, a full charge determination unit that determines whether the storage battery is fully charged; a discharge amount calculation unit that calculates a value of a current or a current capacity by adding a current or a current capacity when the storage battery is discharged and subtracting a current or a current capacity when the storage battery is charged, based on a fully charged state of the storage battery, as a discharge amount of the storage battery; a charge amount calculation unit that calculates a current or current capacity by adding a current or current capacity when the storage battery is charged and subtracting a current or current capacity when the storage battery is discharged based on a fully discharged state of the storage battery as a charge amount of the storage battery; a first power calculation unit that calculates the allowable input power of the storage battery as a first power based on the discharge amount calculated by the discharge amount calculation unit; a second power calculation unit that calculates the allowable input power of the storage battery as a second power based on the charged amount calculated by the charged amount calculation unit; a power control unit that selectively uses either the first power or the second power as the allowable input power based on a predetermined condition; Equipped with.

[0009] The storage battery is determined to be fully charged, and the discharge amount of the storage battery is calculated by integrating the charge and discharge amount (integration of current or current capacity) based on the full charge of the storage battery, and the allowable input power of the storage battery is calculated as the first power based on the discharge amount. In this case, even if the full charge capacity changes due to deterioration of the storage battery, the first power corresponds to the capacity margin for each full charge. Therefore, by using the first power as the allowable input power, the allowable input power can be set appropriately.

[0010] In addition, the charge amount of the storage battery is calculated by integrating charge and discharge (integration of current or current capacity) based on the full discharge of the storage battery, and the allowable input power of the storage battery is calculated as the second power based on the charge amount. Then, whether the first power or the second power is used as the allowable input power is selected based on a predetermined condition. In this case, even if the calculation accuracy of the first power calculated based on the discharge amount based on the full charge of the storage battery decreases, suitable support can be realized by using the second power calculated based on the charge amount based on the full discharge of the storage battery as the allowable input power. As a result, the allowable input power of the storage battery can be calculated with high accuracy, and the storage battery can be appropriately managed. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing the configuration of a power supply system. [Diagram 2] 6 is a diagram for explaining a deviation in full charge capacity when a battery is deteriorated. [Diagram 3] 4 is a diagram for explaining a first integrated capacitance ΔQ1 and a second integrated capacitance ΔQ2. [Figure 4] 4 is a diagram showing a relationship used in calculating a first power W1 and a second power W2. [Diagram 5] FIG. 1 shows the OCV-capacity characteristics of two single cells. [Figure 6] FIG. 13 is a graph showing the difference in first integrated capacity ΔQ1 between two cells. [Figure 7] 5 is a flowchart showing a procedure for calculating an allowable input power. [Figure 8] FIG. 1 is a diagram showing two-dimensional coordinates on which current and voltage are plotted. [Figure 9] 10 is a flowchart showing a procedure for calculating an allowable input power in another embodiment. [Figure 10] 10 is a flowchart showing a process of switching the allowable input power in another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a power supply system according to the present invention will be described with reference to the drawings. In this embodiment, a specific configuration of a power supply system mounted on an electrically powered vehicle such as an electric vehicle or a hybrid vehicle will be described.

[0013] 1 is a diagram showing a schematic configuration of a power supply system in this embodiment. The power supply system includes a storage battery 10, a rotating electrical machine unit 20 as an electric load to which power is supplied from the storage battery 10, and a BMU 30 (Battery Management Unit) that monitors the state of the storage battery 10. The storage battery 10 is configured as a battery pack in which a plurality of single cells 11 are connected in series. The single cells 11 are, for example, lithium ion storage batteries, and more specifically, LFP batteries (lithium iron phosphate storage batteries, LiFePO4 batteries) that use lithium, iron, and phosphorus as positive electrode active materials. The single cells 11 may be, for example, a plurality of battery cells connected in series.

[0014] A current sensor 13 is provided on the electrical path 12 connected to the storage battery 10. The storage battery 10 also has a voltage sensor 14 that detects the voltage across each of the cells 11. The voltage sensor 14 detects the terminal voltage of each of the cells 11.

[0015] The rotating electric machine unit 20 includes a rotating electric machine 21 having a multi-phase (e.g., three-phase) stator winding, and an inverter 22 that adjusts the input and output of electric power to and from the rotating electric machine 21. The rotating electric machine 21 is provided as a running power source for the vehicle, and has a power running function and a regenerative power generation function. The inverter 22 has a plurality of switching elements that control the energization of each phase of the stator winding, and the energization current of each phase is controlled by controlling the switching of each switching element by an MG control device (not shown). Note that an electric load other than the rotating electric machine unit 20 is also connected to the storage battery 10, but illustration and description thereof will be omitted here.

[0016] The storage battery 10 can be externally charged by an external charging facility. Specifically, a charging device 40 can be connected to the positive and negative electric paths 12 of the storage battery 10 via a cable, and the storage battery 10 is charged by the charging device 40 while the vehicle is stopped.

[0017] The BMU 30 is an electronic control device equipped with a microcomputer having a CPU and various memories, and detection signals are appropriately input to the BMU 30 from various sensors such as the above-mentioned current sensor 13 and voltage sensor 14. The BMU 30 executes various arithmetic processing related to the storage battery 10 based on a program stored in the memory. Specifically, the BMU 30 acquires a detection signal from the voltage sensor 14, and detects the terminal voltage of each cell 11 as an OCV (open circuit voltage) when the storage battery 10 is not energized, i.e., when the energizing current is zero. The BMU 30 also acquires a detection signal from the current sensor 13 at a predetermined time period, and detects the charge / discharge current of the storage battery 10.

[0018] Furthermore, the BMU 30 calculates the power that can be input (charged) to the storage battery 10 as the allowable input power Win, and performs power control so that the input power to the storage battery 10 is within the allowable input power Win in order to prevent overcharging of the storage battery 10. In this embodiment, the BMU 30 corresponds to a "battery control device." The allowable input power Win is also referred to as the upper limit input power, the maximum charging power, or the target charging power. Furthermore, assuming a constant voltage, the allowable input power Win may be specified as the allowable input current or a value equivalent thereto.

[0019] However, if a deviation in the full charge capacity occurs due to deterioration of the storage battery 10, there is a concern that the allowable input power Win cannot be calculated correctly. The deviation in the full charge capacity during deterioration will be explained with reference to FIG. 2. FIG. 2(a) is a diagram showing the OCV-capacity characteristic which is the correlation between the OCV and the capacity in the storage battery 10, and FIG. 2(b) is a diagram showing the OCV-SOC characteristic which is the correlation between the OCV and the SOC in the storage battery 10. In FIGS. 2(a) and 2(b), the solid line shows the initial characteristic, and the dashed line shows the characteristic after deterioration. In addition, in the plateau region where the change in OCV relative to the change in capacity is small, a characteristic having a sudden change region X where the voltage changes suddenly with respect to the capacity is shown in FIGS. 2(a) and 2(b). The plateau region is a region where the change in OCV relative to the change in capacity is small compared to the lower capacity side and the higher capacity side of the region. The sudden change region X is a step region sandwiched between two plateau regions on the lower capacity side and the higher capacity side.

[0020] In the OCV-capacity characteristic of Fig. 2(a), when the storage battery 10 deteriorates, the full charge capacity decreases and shifts to the lower capacity side. In this case, due to the shift in the full charge capacity, it becomes difficult to correctly grasp the capacity margin (charging margin) relative to the full charge. Note that there is no shift in the characteristics on the lower capacity side than the sudden change region X at the middle position of the plateau region.

[0021] 2(b), when the storage battery 10 deteriorates, the full charge capacity decreases and the entire characteristic line shifts to the higher SOC side. In this case, an error occurs in the SOC value relative to the OCV as shown in the figure.

[0022] Therefore, in this embodiment, the fully charged state of the storage battery 10 is used as a reference, the discharge amount of the storage battery 10 is calculated by integrating the current to the discharge side, and the allowable input power Win of the storage battery 10 is calculated based on the discharge amount. Also, in this embodiment, a first power W1 and a second power W2 are calculated by two types of calculation methods as power equivalent to the allowable input power Win, and the allowable input power Win is determined by using the first power W1 and the second power W2 appropriately, and the configuration thereof will be described in detail below.

[0023] As shown in FIG. 1, the BMU 30 has, as components related to the calculation of the allowable input power Win, a full charge determination unit 31, a first integrated capacity calculation unit 32, a second integrated capacity calculation unit 33, a first power calculation unit 34, a second power calculation unit 35, and a power control unit 36.

[0024] The full charge determination unit 31 determines whether the storage battery 10 is fully charged. At this time, it is determined that the battery 10 is fully charged to a high capacity range equivalent to a full charge. Specifically, it is preferable that the battery 10 is fully charged when any of the following conditions is met: A prescribed charge end condition is reached. The charge end condition is, for example, that the CCV (closed circuit voltage) during charging by the charging device 40 becomes larger than a prescribed value, or that the charging current during constant voltage charging becomes smaller than a prescribed value. The OCV of the storage battery 10 is higher than the threshold voltage for determining whether the battery is fully charged. The amount of discharge after it is determined that the battery is fully charged is less than a specified value.

[0025] The first integrated capacity calculation unit 32 calculates the first integrated capacity ΔQ1 by integrating the current to the discharge side with the full charge of the storage battery 10 as a reference. As shown in FIG. 3(a), the first integrated capacity ΔQ1 is calculated as the discharge amount with the full charge as a reference. In FIG. 3(a), the initial characteristic and the characteristic at the time of deterioration are shown in a state where the capacity of the full charge is matched. The first integrated capacity calculation unit 32 calculates the first integrated capacity ΔQ1 by sequentially adding the current capacity at the time of discharge and sequentially subtracting the current capacity at the time of charge at a predetermined period from the specified value reset when the full charge is determined. The first integrated capacity calculation unit 32 corresponds to the "discharge amount calculation unit".

[0026] The second integrated capacity calculation unit 33 calculates the second integrated capacity ΔQ2 by integrating the current to the charging side with the full discharge of the storage battery 10 as a reference. The capacity of the full discharge is, for example, zero remaining capacity. As shown in FIG. 3(b), the second integrated capacity ΔQ2 is calculated as a charge amount based on the full discharge. In FIG. 3(b), the initial characteristic and the characteristic at the time of deterioration are shown in a state where the capacity of the full discharge is matched. The second integrated capacity calculation unit 33 calculates a base value of the second integrated capacity ΔQ2 based on the remaining capacity corresponding to the OCV when the OCV is detected, and calculates the second integrated capacity ΔQ2 by sequentially adding the current capacity at the time of charging to the base value and sequentially subtracting the current capacity at the time of discharging from the base value at a predetermined period. The second integrated capacity calculation unit 33 corresponds to the "charge amount calculation unit".

[0027] The first power calculation unit 34 calculates the allowable input power Win of the storage battery 10 as the first power W1 based on the first integrated capacity ΔQ1 calculated by the first integrated capacity calculation unit 32. The first power calculation unit 34 calculates the first power W1 using, for example, the relationship shown in Fig. 4(a). In Fig. 4(a), a relationship is defined in which the larger the first integrated capacity ΔQ1, the larger the first power W1.

[0028] The second power calculation unit 35 calculates the allowable input power Win of the storage battery 10 as the second power W2 based on the second integrated capacity ΔQ2 calculated by the second integrated capacity calculation unit 33. The second power calculation unit 35 calculates the second power W2 using, for example, the relationship shown in Fig. 4(b). In Fig. 4(b), a relationship is defined in which the second power W2 increases as the second integrated capacity ΔQ2 increases.

[0029] The power control unit 36 ​​uses either the first power W1 or the second power W2 as the allowable input power Win based on a predetermined condition. The predetermined condition will be described in detail later, but for example, the result of determining the reliability of the first integrated capacity ΔQ1 is used as the predetermined condition, and if it is determined that the reliability is low, the second power W2 is used as the allowable input power Win instead of the first power W1.

[0030] In the storage battery 10, the OCV-capacity characteristics of the individual cells 11 are different from each other, and it is considered that differences occur in the first integrated capacity ΔQ1 and the second integrated capacity ΔQ2 of each cell 11. In consideration of this point, in this embodiment, the first power calculation unit 34 and the second power calculation unit 35 calculate the first power W1 and the second power W2 by taking into account the variation in characteristics of each cell 11. The calculation of the first power W1 and the second power W2 will be described below. Note that the full charge determination unit 31 determines that each cell 11 is fully charged as the full charge determination of the storage battery 10. In addition, the first integrated capacity calculation unit 32 calculates the first integrated capacity ΔQ1 for each cell 11 based on full charge, and the second integrated capacity calculation unit 33 calculates the second integrated capacity ΔQ2 for each cell 11 based on full discharge.

[0031] FIG. 5 shows the OCV-capacity characteristics of two cells 11 in a storage battery 10. FIG. 5(a) shows the characteristics of cell A, and FIG. 5(b) shows the characteristics of cell B. Cells A and B have different capacities at full charge (full charge capacity), with cell A having a full charge capacity of Cfa and cell B having a full charge capacity of Cfb. In this case, if the full charge capacities of cells A and B are different, the first integrated capacity ΔQ1 of cells A and B will be different. This will be explained using FIG. 6. In FIG. 6, the cells change over time from state (a), to state (b), to state (c).

[0032] In FIG. 6, in the state (a), the first integrated capacity ΔQ1 of the cells A and B is ΔQ1a and ΔQ1b (ΔQ1a<ΔQ1b), respectively, and is changed to the state (b) by charging X [Ah] from that state. In the state (b), the cell A is fully charged, and the first integrated capacity ΔQ1 is reset to 0, while the first integrated capacity ΔQ1 of the cell B becomes "ΔQ1b-X". Also, the state (c) is changed to the state (c) by discharging Y [Ah] from the state (b). In the state (c), the first integrated capacity ΔQ1 of the cell A becomes "Y", and the first integrated capacity ΔQ1 of the cell B becomes "ΔQ1b-X+Y".

[0033] In this case, the first power calculation unit 34 calculates the first power W1 based on the smallest first integrated capacity ΔQ1 among the first integrated capacities ΔQ1 of the multiple single cells 11. In Fig. 6, it is preferable that the first power W1 is calculated based on the first integrated capacity ΔQ1a among the first integrated capacities ΔQ1a and ΔQ1b of the single cells A and B.

[0034] 5(a) and (b), the remaining capacity corresponding to the OCV differs in each of the single cells A and B. In this case, the second power calculation unit 35 calculates the second power W2 based on the largest second integrated capacity ΔQ2 among the second integrated capacities ΔQ2 of the multiple single cells 11. In FIG. 5(a) and (b), it is preferable to calculate the second power W2 based on the second integrated capacity ΔQ2 corresponding to the larger remaining capacity Ca among the remaining capacities Ca and Cb (e.g., remaining capacities corresponding to the OCV) of the single cells A and B.

[0035] By calculating the first power W1 and the second power W2 as described above, the allowable input power Win is prevented from being calculated as an excessively large value, thereby making it possible to appropriately suppress deterioration of the storage battery 10.

[0036] Fig. 7 is a flowchart showing the procedure for calculating the allowable input power Win, and this process is repeatedly executed at a predetermined cycle by the BMU 30 in the system operating state after the vehicle power switch (IG switch) is turned on. In this embodiment, the functions of the full-charge determination unit 31, the first integrated capacity calculation unit 32, the second integrated capacity calculation unit 33, the first power calculation unit 34, the second power calculation unit 35, and the power control unit 36 ​​described above are realized by the process of Fig. 7.

[0037] 7, in step S11, the current capacity that has increased or decreased due to charging or discharging the storage battery 10 is calculated based on the current detected by the current sensor 13. At this time, the current capacity is calculated, for example, with the current during charging being positive.

[0038] In step S12, a first integrated capacity ΔQ1 based on the full charge of the storage battery 10 is calculated, and a second integrated capacity ΔQ2 based on the full discharge of the storage battery 10 is calculated. Specifically, the current capacity calculated in step S11 is subtracted from the previous value of the first integrated capacity ΔQ1 to calculate the current value of the first integrated capacity ΔQ1. At this time, the current capacity to the discharge side is integrated as the current integration from the full charge of the storage battery 10 to the discharge side. In addition, the current capacity calculated in step S11 is added to the previous value of the second integrated capacity ΔQ2 to calculate the current value of the second integrated capacity ΔQ2. At this time, the current capacity to the charge side is integrated as the current integration from the full discharge of the storage battery 10 to the charge side.

[0039] Then, in step S13, it is determined whether or not the storage battery 10 is fully charged. If it is fully charged, the process proceeds to step S14, and if it is not fully charged, the process proceeds to step S16.

[0040] In step S14, the first integrated capacity ΔQ1 is reset to a specified value. The specified value is a reference value for calculating the discharge amount from full charge, and is, for example, 0. However, when full charge determination is performed based on the OCV, the specified value may be changed according to the OCV value. For example, it is preferable to set the specified value to a larger value as the OCV is lower. In addition, since resistance increases at low temperatures of the storage battery 10 and full charge is difficult to achieve, the specified value may be changed according to the battery temperature. In this case, the specified value may be set to be larger as the temperature decreases.

[0041] Then, in step S15, a flag FW indicating that the first power W1 is to be preferentially used as the allowable input power Win is set to 1. Note that the flag FW is set to 1 as an initial value when the system is started up, and if FW=1 is already set, this state is maintained.

[0042] In step S16, it is determined whether or not it is currently time to detect the OCV, and if it is, the OCV is acquired in step S17. At this time, for example, if it is immediately after the vehicle is started (immediately after the power switch is turned on) and before the start of current supply to the storage battery 10, it is determined that it is time to detect the OCV, and the OCV detected by the voltage sensor 14 is acquired. Note that the OCV detection condition may include a condition that the vehicle has been left unused for a predetermined period of time or longer since the last time the vehicle was stopped. The OCV may be the OCV of a predetermined cell 11.

[0043] Alternatively, the OCV may be detected at predetermined intervals (for example, a period of several seconds to several minutes) while the vehicle power switch is on (while the vehicle is running). In this case, as shown in FIG. 8, the current and voltage of the storage battery 10 are periodically acquired and plotted on a two-dimensional coordinate system. The voltage at the voltage axis intercept of an approximate straight line on the two-dimensional coordinate system is then calculated as the OCV. Note that if the current change within the predetermined period is small, or if charging or discharging occurs unevenly within the predetermined period, there is a concern that the OCV detection accuracy may decrease, and therefore it is preferable not to perform OCV detection.

[0044] Thereafter, in step S18, it is determined whether the OCV of the storage battery 10 is at a voltage on the lower capacity side than the sudden change region X of the OCV-capacity characteristic. In this case, a voltage threshold corresponding to the sudden change region X may be determined in advance, and if the OCV is lower than the voltage threshold, it may be determined that the OCV is at a voltage on the lower capacity side than the sudden change region X, and if the OCV is higher than the voltage threshold, it may be determined that the OCV is at a voltage on the higher capacity side than the sudden change region X. Then, if the OCV of the storage battery 10 is at a voltage on the lower capacity side than the sudden change region X, the process proceeds to step S19, and if the OCV of the storage battery 10 is at a voltage on the higher capacity side than the sudden change region X, the process proceeds to step S21.

[0045] In step S19, the remaining capacity corresponding to the OCV is calculated using the correlation between the OCV and the capacity, and the remaining capacity is set as the second integrated capacity ΔQ2 (the second integrated capacity ΔQ2 is reset).

[0046] Meanwhile, in step S21, it is determined whether the first integrated capacity ΔQ1 calculated in step S12 is larger than a current capacity ΔQA from the full charge capacity of the storage battery 10 to the sudden change region X. The current capacity ΔQA may be a current capacity from the full charge capacity to the sudden change region X in the initial characteristics. However, assuming deterioration of the storage battery 10, the current capacity ΔQA may be a current capacity smaller than the current capacity from the full charge capacity to the sudden change region X in the initial characteristics.

[0047] If step S21 is negative, step S22 is skipped, and if step S21 is positive, the process proceeds to step S22. In step S22, the first integrated capacity ΔQ1 is updated to a decreasing value. At this time, the first integrated capacity ΔQ1 may be subtracted by a current capacity ΔQA from the full charge capacity to the sudden change region X. Alternatively, the first integrated capacity ΔQ1 may be subtracted by a predetermined capacity.

[0048] Thereafter, in step S23, it is determined whether or not the reliability of the first integrated capacity ΔQ1 is low. The reliability of the first integrated capacity ΔQ1 may be determined by at least one of the following determination methods. The reliability may be determined based on whether an integration period T1, which is a period of current integration of the storage battery 10 after it is determined that the storage battery 10 is fully charged, is longer than a predetermined period. If it is determined that the integration period T1 is longer than the predetermined time, it is determined that the reliability is low. Specifically, if the elapsed time (on time) with the power switch in the on state after it is determined that the storage battery 10 is fully charged is equal to or longer than a predetermined time, it is determined that the integration error of the current sensor value has increased, and it is determined that the reliability of the first integrated capacity ΔQ1 is low. The reliability may be determined based on whether or not the period T2 during which the charge / discharge control of the storage battery 10 is stopped after it is determined that the storage battery 10 is fully charged is longer than a predetermined period. If it is determined that the period T2 during which the charge / discharge control is stopped is longer than the predetermined time, it is determined that the reliability is low. Specifically, if the time during which the vehicle is left unused, that is, the time elapsed with the power switch in the off state (off time), is equal to or longer than a predetermined time, it is determined that a large amount of discharge not detected by the current sensor 13 has occurred due to battery self-discharge or the like, and it is determined that the reliability of the first integrated capacity ΔQ1 is low. The reliability may be determined based on whether the combined period of the integration period T1 and the period T2 during which charging and discharging is stopped, i.e., the time that has elapsed since it was determined that the storage battery 10 is fully charged, is longer than a predetermined period. If it is determined that the time that has elapsed since the full charge determination (T1+T2) is longer than the predetermined period, it may be determined that the reliability is low.

[0049] The first integrated capacity ΔQ1 is reset when the battery is fully charged, and the second integrated capacity ΔQ2 is reset when the OCV is detected. In this case, the first integrated capacity ΔQ1 is used in Win calculation with priority over the second integrated capacity ΔQ2, and the first integrated capacity ΔQ1 is likely to be reset less frequently than the second integrated capacity ΔQ2. Therefore, it is preferable to perform a reliability determination on the first integrated capacity ΔQ1 based on the current integration period.

[0050] If it is determined in step S23 that the reliability of the first integrated capacity ΔQ1 is low, the process proceeds to step S24. In step S24, the flag FW is reset to 0.

[0051] Then, in step S25, it is determined whether or not the flag FW is set to 1. If the flag FW is set to 1, the process proceeds to step S26. In step S26, the first power W1 is calculated based on the first integrated capacity ΔQ1 using the relationship in FIG. 4(a). Then, this first power W1 is set as the allowable input power Win. Here, if it is determined that the storage battery 10 is fully charged (if step S13 is YES), the flag FW is set to 1, and the first power W1 is preferentially used to calculate the allowable input power Win.

[0052] If the flag FW is not set to 1, the process proceeds to step S27. In step S27, the second power W2 is calculated based on the second integrated capacity ΔQ2 using the relationship in FIG. 4(b). Then, the second power W2 is set as the allowable input power Win. According to steps S25 to S27, the first power W1 and the second power W2 are used differently based on the information of the flag FW. In this case, the first power W1 is preferentially used as the allowable input power Win at least after it is determined that the storage battery 10 is fully charged. Furthermore, if it is determined in step S23 that the reliability of the first integrated capacity ΔQ1 is low, the second power W2 is used as the allowable input power Win instead of the first power W1.

[0053] Then, in step S28, it is determined whether or not it is a predetermined period immediately after the transition from a state in which the first power W1 is used as the allowable input power Win to a state in which the second power W2 is used as the allowable input power Win. If it is a predetermined period immediately after the transition, the process proceeds to step S29. In step S29, the allowable input power Win is limited with the first power immediately before the transition as the upper limit value. That is, the allowable input power Win (second power W2) is limited so as not to be larger than the first power W1. In addition, in the following step S30, the allowable input power Win is gradually changed from the first power W1 immediately before the transition to the second power W2 after the transition. At this time, it is preferable to determine the allowable input power Win by performing an averaging calculation of the current value and past values ​​(for example, values ​​for the most recent predetermined number of times) of the allowable input power Win. The predetermined period may be a predetermined time. Alternatively, the predetermined period may be a period until the limitation (gradual change) of the second power W2 by the averaging calculation is eliminated.

[0054] According to the present embodiment described above in detail, the following excellent effects can be obtained.

[0055] It is determined that the storage battery 10 is fully charged, and the allowable input power Win of the storage battery 10 is calculated as the first power W1 based on the first integrated capacity ΔQ1, which is the discharge amount based on the full charge of the storage battery 10. In this case, even if the full charge capacity changes due to deterioration of the storage battery 10, the first power W1 corresponds to the capacity margin degree for each full charge. Therefore, by using the first power W1 as the allowable input power Win, it is possible to appropriately set the allowable input power Win.

[0056] In addition, the allowable input power Win of the storage battery 10 is calculated as the second power W2 based on the second integrated capacity ΔQ2, which is the charge amount based on the full discharge of the storage battery 10, and whether the first power W1 or the second power W2 is used as the allowable input power Win is selected based on a predetermined condition. In this case, even if the calculation accuracy of the first power W1 calculated based on the first integrated capacity ΔQ1 decreases, the second power W2 calculated based on the second integrated capacity ΔQ2 is used as the allowable input power Win, thereby achieving suitable support. As a result, the allowable input power Win of the storage battery 10 can be calculated with high accuracy, and the charging and discharging of the storage battery 10 can be appropriately managed.

[0057] Due to a characteristic change associated with deterioration of the storage battery 10, a calculation error of the first integrated capacity ΔQ1, etc., even if the OCV of the storage battery 10 is at a voltage on the higher capacity side than the sudden change region X of the OCV-capacity characteristic, the first integrated capacity ΔQ1 (discharge amount from full charge) may become larger than the current capacity from the full charge capacity to the sudden change region X of the storage battery 10. In consideration of this point, when it is determined that the OCV of the storage battery 10 is at a voltage on the higher capacity side than the sudden change region X and the first integrated capacity ΔQ1 is larger than the current capacity (ΔQA) from the full charge capacity to the sudden change region X, the first integrated capacity ΔQ1 is updated to a value on the decreasing side. This improves the calculation accuracy of the first integrated capacity ΔQ1, and therefore the allowable input power Win can be calculated with high accuracy.

[0058] At the timing when the OCV of the storage battery 10 is detected, the remaining capacity corresponding to the OCV is set as the second integrated capacity ΔQ2. In this case, the second integrated capacity ΔQ2 can be reset every time the OCV is detected in the storage battery 10, so that the second integrated capacity ΔQ2 can be maintained with high accuracy, which in turn contributes to improving the calculation accuracy of the allowable input power Win.

[0059] At the timing when the OCV of the storage battery 10 is detected, the remaining capacity corresponding to the OCV is set as the second integrated capacity ΔQ2 on the condition that the OCV is at a voltage on the lower capacity side than the sudden change region X of the OCV-capacity characteristic. In this case, although there is a risk of a characteristic change occurring due to the influence of deterioration of the storage battery 10 on the higher capacity side than the sudden change region X in the OCV-capacity characteristic, it is possible to suppress a decrease in the calculation accuracy of the second integrated capacity ΔQ2 caused by the characteristic change.

[0060] When it is determined that the storage battery 10 is fully charged, the flag FW is set, and out of the first power W1 and the second power W2, the first power W1 is preferentially set as the allowable input power Win. This makes it possible to appropriately set the allowable input power Win when the storage battery 10 is close to being fully charged.

[0061] The result of the reliability judgment of the first integrated capacity ΔQ1 is used as a predetermined condition, and when it is judged that the reliability of the first integrated capacity ΔQ1 is low, the second power W2 is used as the allowable input power Win instead of the first power W1. This makes it possible to appropriately select the first power W1 and the second power W2 as the allowable input power Win.

[0062] When current integration of the storage battery 10 is performed, it is considered that the longer the integration period, the more errors in current detection are accumulated. In consideration of this point, when it is determined that the time between current integration from the full charge determination of the storage battery 10 is longer than a predetermined period, the second power W2 is used as the allowable input power Win instead of the first power W1. This makes it possible to suppress inconveniences such as a decrease in calculation accuracy of the first integrated capacity ΔQ1 due to an integration error in current detection, which results in a decrease in calculation accuracy of Win.

[0063] The first integrated capacity ΔQ1 is calculated for each cell 11 based on full charge, and the first power W1 is calculated based on the smallest first integrated capacity ΔQ1 among the first integrated capacities ΔQ1 of the multiple cells 11. Also, the second integrated capacity ΔQ2 is calculated for each cell 11 based on full discharge, and the second power W2 is calculated based on the largest second integrated capacity ΔQ2 among the second integrated capacities ΔQ2 of the multiple cells 11. In this case, the first power W1 and the second power W2 are calculated using appropriate information from the multiple cells 11, and thus it is possible to prevent the allowable input power Win from being calculated as an excessively large value.

[0064] When transitioning from a state in which the first power W1 is used as the allowable input power Win to a state in which the second power W2 is used as the allowable input power Win, there is a concern that the difference between the first power W1 and the second power W2 may affect power control. In consideration of this, a configuration is adopted in which, when transitioning from the first power W1 to the second power W2, the allowable input power Win is limited by setting the first power W1 immediately before the transition as the upper limit. This makes it possible to prevent inconveniences such as an unintentional increase in the allowable input power Win that may cause a user to feel uncomfortable.

[0065] When transitioning from a state in which the first power W1 is used as the allowable input power Win to a state in which the second power W2 is used as the allowable input power Win, the allowable input power Win is gradually changed from the first power W1 immediately before the transition to the second power W2 after the transition. This makes it possible to prevent inconveniences such as a sudden change in the allowable input power Win that makes the user feel uncomfortable.

[0066] (Other embodiments) The above embodiment may be modified, for example, as follows.

[0067] The following conditions may be defined as the predetermined conditions for selectively using the first power W1 and the second power W2.

[0068] At the timing when the OCV of the storage battery 10 is detected, it is determined whether or not the OCV is at a voltage that is lower in capacity than the sudden change region X (voltage determination unit), and the determination result is used as a predetermined condition. If the OCV is at a voltage that is lower in capacity than the sudden change region X, the second power W2 may be used as the allowable input power Win instead of the first power W1.

[0069] Specifically, the Win calculation process shown in Fig. 9 may be executed. Fig. 9 is a partial modification of Fig. 7, and the same process is given the same step number. In Fig. 9, when it is the timing to detect the OCV and it is determined that the OCV is at a voltage that is lower in capacity than the sudden change region X (when both steps S16 and S18 are YES), the flag FW is reset to 0 in step S41. As a result, in step S27, the second power W2 is calculated based on the second integrated capacity ΔQ2.

[0070] In the OCV-capacity characteristics of the storage battery 10, it is considered that the accuracy of the first integrated capacity ΔQ1 decreases as the remaining capacity of the storage battery 10 is farther from the full charge capacity. In consideration of this point, when the OCV of the storage battery 10 is at a voltage that is lower than the sudden change region X, the second power W2 is used as the allowable input power Win instead of the first power W1. This makes it possible to suppress the inconvenience of a decrease in the accuracy of calculation of the first integrated capacity ΔQ1 resulting from a decrease in the accuracy of calculation of Win.

[0071] In the reliability determination of the first integrated capacity ΔQ1 in step S23, the following process may be performed. That is, it is determined whether the first integrated capacity ΔQ1 is larger than a predetermined value, and if it is determined that the first integrated capacity ΔQ1 is larger than the predetermined value, it is determined that the reliability of the first integrated capacity ΔQ1 is low. In this case, on the condition that it is determined that the first integrated capacity ΔQ1 is larger than the predetermined value, the second power W2 is used as the allowable input power Win instead of the first power W1. Note that the predetermined value may be a value larger than the current capacity ΔQA from the full charge capacity of the storage battery 10 to the sudden change region X.

[0072] The predetermined condition for selectively using the first power W1 and the second power W2 may be specified as follows. Here, in a configuration in which the vehicle's power switch (IG switch) is used as the system switch of the power supply system, the satisfaction of the predetermined condition is determined based on the on time, off time, and the combined time of the on time and off time of the power switch. Turning the power switch on allows current to flow through the storage battery 10, and turning the power switch off prevents current from flowing through the storage battery 10. The on time is the accumulated time that the power switch has been in the on state since it was previously determined that the storage battery 10 was fully charged. The off time is the accumulated time that the power switch has been in the off state since it was previously determined that the storage battery 10 was fully charged. The on time, off time, and combined time correspond to the "determination time."

[0073] Specifically, the process shown in Fig. 10 may be executed by the BMU 30. In Fig. 10, in step S51, it is determined whether the ON time is less than a predetermined time TH1, in step S52, it is determined whether the OFF time is less than a predetermined time TH2, and in step S53, it is determined whether the total time of the ON time and the OFF time is less than a predetermined time TH3. Then, if all of steps S31 to S53 are positive (i.e., if the predetermined condition is satisfied), the process proceeds to step S54, where the first power W1 is set as the allowable input power Win. If any one of steps S31 to S53 is negative (i.e., if the predetermined condition is not satisfied), the process proceeds to step S55, where the second power W2 is set as the allowable input power Win.

[0074] When the ON time of the power switch becomes longer, or when the OFF time of the power switch becomes longer, the calculation accuracy of the first integrated capacity ΔQ1 decreases due to the accumulation of current detection errors, etc. In this regard, by switching between the first power W1 and the second power W2 as described above, it is possible to suppress the inconvenience of a decrease in the calculation accuracy of Win due to a decrease in the accuracy of the first integrated capacity ΔQ1.

[0075] 10, any one or any two of steps S51 to S53 may be executed. The process of FIG. 10 may be executed in combination with the process of FIG.

[0076] 7, when it is the timing to detect the OCV and the remaining capacity corresponding to the OCV is on the lower capacity side than the sudden change region X of the OCV-capacity characteristic, the remaining capacity corresponding to the OCV is set as the second integrated capacity ΔQ2, but this may be changed. For example, when it is the timing to detect the OCV, the remaining capacity corresponding to the OCV may be set as the second integrated capacity ΔQ2 regardless of whether the remaining capacity equivalent to the OCV is on the lower capacity side than the sudden change region X (i.e., without performing the determination of step S18).

[0077] In the above embodiment, in the storage battery 10, it is determined that each cell 11 is fully charged, and the first integrated capacity ΔQ1 from full charge and the second integrated capacity ΔQ2 from full discharge are calculated for each cell 11, but this may be changed. For example, when any cell 11 is determined to be fully charged, the first integrated capacity ΔQ1 from full charge and the second integrated capacity ΔQ2 from full discharge of the storage battery 10 may be calculated without distinguishing between the cells 11.

[0078] In the above embodiment, the allowable input power Win is determined by using the first power W1 calculated based on the first integrated capacity ΔQ1 and the second power W2 calculated based on the second integrated capacity ΔQ2 appropriately. However, this configuration may be modified so that the second power W2 is not calculated and the first power W1 is always used as the allowable input power Win.

[0079] Instead of calculating the first integrated capacity ΔQ1 by integrating the current capacity [Ah] acquired at a predetermined cycle as the discharge amount based on the full charge of the storage battery 10, the integrated current from the full charge may be calculated by integrating the current [A] acquired at a predetermined cycle. Also, instead of calculating the second integrated capacity ΔQ2 by integrating the current capacity [Ah] acquired at a predetermined cycle as the charge amount based on the full discharge of the storage battery 10, the integrated current from the full discharge may be calculated by integrating the current [A] acquired at a predetermined cycle.

[0080] The power supply system is not limited to being mounted on a vehicle, but may be mounted on other moving objects such as aircraft, ships, etc. Also, the power supply system is not limited to being mounted on a moving object, but may be a stationary system.

[0081] The control unit and the method described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. Alternatively, the control unit and the method described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described in the present disclosure may be realized by one or more special-purpose computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. In addition, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by a computer.

[0082] The technical ideas extracted from the above-described embodiments will be described below. [Configuration 1] A battery control device (30) that calculates an allowable input power (Win) of a storage battery (10), a full charge determination unit that determines whether the storage battery is fully charged; a discharge amount calculation unit that calculates a value of a current or a current capacity by adding a current or a current capacity when the storage battery is discharged and subtracting a current or a current capacity when the storage battery is charged, based on a fully charged state of the storage battery, as a discharge amount of the storage battery; a power calculation unit that calculates the allowable input power of the storage battery based on the discharge amount calculated by the discharge amount calculation unit; A battery control device comprising: [Configuration 1-1] The storage battery has a plateau region in a voltage-capacity characteristic showing the relationship between voltage and capacity, and has a sudden change region within the plateau region where the voltage changes suddenly with respect to the capacity, a voltage determination unit that determines whether or not an open circuit voltage of the storage battery is a voltage on a higher capacity side than the sudden change region at a timing when the open circuit voltage of the storage battery is detected; a discharge amount determination unit that determines whether the discharge amount calculated by the discharge amount calculation unit is greater than a current capacity from a full charge capacity of the storage battery to the sudden change region, The battery control device according to configuration 1, wherein the discharge amount calculation unit updates the discharge amount to a decreasing value when it is determined that the open circuit voltage is a voltage on the higher capacity side than the sudden change region and the discharge amount is greater than a current capacity from the full charge capacity to the sudden change region. [Configuration 2] A battery control device (30) that calculates an allowable input power (Win) of a storage battery (10), a full charge determination unit that determines whether the storage battery is fully charged; a discharge amount calculation unit that calculates a value of a current or a current capacity by adding a current or a current capacity when the storage battery is discharged and subtracting a current or a current capacity when the storage battery is charged, based on a fully charged state of the storage battery, as a discharge amount of the storage battery; a charge amount calculation unit that calculates a current or current capacity by adding a current or current capacity when the storage battery is charged and subtracting a current or current capacity when the storage battery is discharged based on a fully discharged state of the storage battery as a charge amount of the storage battery; a first power calculation unit that calculates the allowable input power of the storage battery as a first power based on the discharge amount calculated by the discharge amount calculation unit; a second power calculation unit that calculates the allowable input power of the storage battery as a second power based on the charged amount calculated by the charged amount calculation unit; a power control unit that selectively uses either the first power or the second power as the allowable input power based on a predetermined condition; A battery control device comprising: [Configuration 3] The storage battery has a plateau region in a voltage-capacity characteristic showing the relationship between voltage and capacity, and has a sudden change region within the plateau region where the voltage changes suddenly with respect to the capacity, a voltage determination unit that determines whether or not an open circuit voltage of the storage battery is a voltage on a higher capacity side than the sudden change region at a timing when the open circuit voltage of the storage battery is detected; a discharge amount determination unit that determines whether the discharge amount calculated by the discharge amount calculation unit is greater than a current capacity from a full charge capacity of the storage battery to the sudden change region, The battery control device according to configuration 2, wherein the discharge amount calculation unit updates the discharge amount to a decreasing value when it is determined that the open circuit voltage is a voltage on the higher capacity side than the sudden change region and the discharge amount is greater than a current capacity from the full charge capacity to the sudden change region. [Configuration 4] 3. The battery control device according to configuration 2, wherein the charge amount calculation unit sets a remaining capacity corresponding to an open circuit voltage of the storage battery as the charge amount at a timing when the open circuit voltage of the storage battery is detected. [Configuration 5] The storage battery has a plateau region in a voltage-capacity characteristic showing the relationship between voltage and capacity, and has a sudden change region within the plateau region where the voltage changes suddenly with respect to the capacity, a voltage determination unit that determines whether or not an open circuit voltage of the storage battery is a voltage that is on the lower capacity side than the sudden change region at a timing when the open circuit voltage of the storage battery is detected; The battery control device according to configuration 4, wherein the charge amount calculation unit sets a remaining capacity corresponding to the open circuit voltage as the charge amount on condition that the voltage determination unit determines that the open circuit voltage is a voltage that is on the lower capacity side than the sudden change region. [Configuration 6] The battery control device of any one of configurations 2 to 5, wherein the power control unit uses the full charge determination unit's determination that the storage battery is fully charged as the specified condition, and after it is determined that the storage battery is fully charged, prioritizes the first power of the first power and the second power as the allowable input power. [Configuration 7] a reliability determination unit that determines the reliability of the discharge amount calculated by the discharge amount calculation unit, The battery control device of any one of configurations 2 to 6, wherein the power control unit uses the judgment result of the reliability judgment unit as the specified condition, and when it is judged that the reliability of the discharge amount is low, the second power is used as the allowable input power instead of the first power. [Configuration 8] an integration period determination unit that determines whether an integration period, which is a period of current integration of the storage battery after it is determined that the storage battery is fully charged, is longer than a predetermined period; The battery control device according to any one of configurations 2 to 6, wherein the power control unit uses a judgment result of the integration period judgment unit as the specified condition, and when it is judged that the integration period is longer than the specified period, the power control unit uses the second power as the allowable input power instead of the first power. [Configuration 9] The storage battery has a plateau region in a voltage-capacity characteristic showing the relationship between voltage and capacity, and has a sudden change region within the plateau region where the voltage changes suddenly with respect to the capacity, a voltage determination unit that determines whether or not an open circuit voltage of the storage battery is a voltage that is on the lower capacity side than the sudden change region at a timing when the open circuit voltage of the storage battery is detected; The battery control device of any one of configurations 2 to 6, wherein the power control unit uses the judgment result of the voltage judgment unit as the specified condition, and when it is judged that the open circuit voltage is a voltage that is on the lower capacity side than the sudden change region, the power control unit uses the second power as the allowable input power instead of the first power. [Configuration 10] a battery control device that is applied to a power supply system including the storage battery, wherein in the power supply system, when a system switch is turned on, the storage battery can be energized, and when the system switch is turned off, the storage battery cannot be energized; The battery control device of any one of configurations 2 to 6, wherein the power control unit uses as the specified condition that a determination time, which is at least one of the on time, off time, and the combined time of the on time and off time of the system switch since the storage battery was last determined to be fully charged, is less than a specified time, and when the specified condition is met, the first power is used as the allowable input power, and when the specified condition is not met, the second power is used as the allowable input power. [Configuration 11] The storage battery is an assembled battery including a plurality of cells (11) connected in series, the full charge determination unit determines whether each of the cells is fully charged, the discharge amount calculation unit calculates the discharge amount for each of the single cells based on a fully charged state; 11. The battery control device according to any one of configurations 2 to 10, wherein the first power calculation unit calculates the first power based on the smallest discharge amount among the discharge amounts of the plurality of single cells. [Configuration 12] The storage battery is an assembled battery including a plurality of cells (11) connected in series, the charge amount calculation unit calculates the charge amount for each of the single cells based on a fully discharged state; 12. The battery control device according to any one of configurations 2 to 11, wherein the second power calculation unit calculates the second power based on the largest charge amount among the charge amounts of the plurality of single cells. [Configuration 13] 13. A battery control device according to any one of configurations 2 to 12, comprising a power limiting unit that, when transitioning from a state in which the first power is used as the allowable input power to a state in which the second power is used as the allowable input power, limits the allowable input power by setting the first power immediately before the transition as an upper limit value. [Configuration 14] 14. The battery control device according to any one of configurations 2 to 13, further comprising a power gradual change unit that, when transitioning from a state in which the first power is used as the allowable input power to a state in which the second power is used as the allowable input power, gradually changes the allowable input power from the first power immediately before the transition to the second power after the transition. [Explanation of symbols]

[0083] 10...Storage battery, 30...BMU.

Claims

1. A battery control device (30) that calculates an allowable input power (Win) in a storage battery (10), a full charge determination unit that determines whether the storage battery is fully charged; a discharge amount calculation unit that calculates a value of a current or a current capacity by adding a current or a current capacity when the storage battery is discharged and subtracting a current or a current capacity when the storage battery is charged, based on a fully charged state of the storage battery, as a discharge amount of the storage battery; a power calculation unit that calculates the allowable input power of the storage battery based on the discharge amount calculated by the discharge amount calculation unit; A battery control device comprising:

2. A battery control device (30) that calculates an allowable input power (Win) in a storage battery (10), a full charge determination unit that determines whether the storage battery is fully charged; a discharge amount calculation unit that calculates a value of a current or a current capacity by adding a current or a current capacity when the storage battery is discharged and subtracting a current or a current capacity when the storage battery is charged, based on a fully charged state of the storage battery, as a discharge amount of the storage battery; a charge amount calculation unit that calculates a current or current capacity by adding a current or current capacity when the storage battery is charged and subtracting a current or current capacity when the storage battery is discharged based on a fully discharged state of the storage battery as a charge amount of the storage battery; a first power calculation unit that calculates the allowable input power of the storage battery as a first power based on the discharge amount calculated by the discharge amount calculation unit; a second power calculation unit that calculates the allowable input power of the storage battery as a second power based on the charged amount calculated by the charged amount calculation unit; a power control unit that selectively uses either the first power or the second power as the allowable input power based on a predetermined condition; A battery control device comprising:

3. The storage battery has a plateau region in a voltage-capacity characteristic showing the relationship between voltage and capacity, and has a sudden change region within the plateau region where the voltage changes suddenly with respect to the capacity, a voltage determination unit that determines whether or not an open circuit voltage of the storage battery is a voltage on a higher capacity side than the sudden change region at a timing when the open circuit voltage of the storage battery is detected; a discharge amount determination unit that determines whether the discharge amount calculated by the discharge amount calculation unit is greater than a current capacity from a full charge capacity of the storage battery to the sudden change region, 3. The battery control device according to claim 1, wherein the discharge amount calculation unit updates the discharge amount to a decreasing value when it is determined that the open circuit voltage is a voltage on the higher capacity side than the sudden change region and the discharge amount is greater than a current capacity from the full charge capacity to the sudden change region.

4. 3 . The battery control device according to claim 2 , wherein the charge amount calculation unit sets, at a timing when an open circuit voltage of the storage battery is detected, a remaining capacity corresponding to the open circuit voltage as the charge amount.

5. The storage battery has a plateau region in a voltage-capacity characteristic showing the relationship between voltage and capacity, and has a sudden change region within the plateau region where the voltage changes suddenly with respect to the capacity, a voltage determination unit that determines whether or not an open circuit voltage of the storage battery is a voltage that is on the lower capacity side than the sudden change region at a timing when the open circuit voltage of the storage battery is detected; 5. The battery control device according to claim 4, wherein the charge amount calculation unit sets the remaining capacity corresponding to the open circuit voltage as the charge amount on condition that the voltage determination unit determines that the open circuit voltage is a voltage that is on the lower capacity side than the sudden change region.

6. 3. The battery control device according to claim 2, wherein the power control unit uses the full charge determination unit's determination that the storage battery is fully charged as the specified condition, and after it is determined that the storage battery is fully charged, prioritizes the first power of the first power and the second power as the allowable input power.

7. a reliability determination unit that determines the reliability of the discharge amount calculated by the discharge amount calculation unit, 3. The battery control device according to claim 2, wherein the power control unit uses a judgment result of the reliability judgment unit as the specified condition, and when it is judged that the reliability of the discharge amount is low, the power control unit uses the second power as the allowable input power instead of the first power.

8. an integration period determination unit that determines whether an integration period, which is a period of current integration of the storage battery after it is determined that the storage battery is fully charged, is longer than a predetermined period; 3. The battery control device according to claim 2, wherein the power control unit uses a judgment result of the integration period judgment unit as the predetermined condition, and when it is judged that the integration period is longer than the predetermined period, uses the second power as the allowable input power instead of the first power.

9. The storage battery has a plateau region in a voltage-capacity characteristic showing the relationship between voltage and capacity, and has a sudden change region within the plateau region where the voltage changes suddenly with respect to the capacity, a voltage determination unit that determines whether or not an open circuit voltage of the storage battery is a voltage that is on the lower capacity side than the sudden change region at a timing when the open circuit voltage of the storage battery is detected; 3. The battery control device according to claim 2, wherein the power control unit uses a judgment result of the voltage judgment unit as the predetermined condition, and when it is judged that the open circuit voltage is a voltage that is on the lower capacity side than the sudden change region, uses the second power instead of the first power as the allowable input power.

10. a battery control device that is applied to a power supply system including the storage battery, wherein in the power supply system, when a system switch is turned on, the storage battery can be energized, and when the system switch is turned off, the storage battery cannot be energized; 3. The battery control device according to claim 2, wherein the power control unit uses as the specified condition that a determination time, which is at least one of the on time, off time, and the combined time of the on time and off time of the system switch since the storage battery was last determined to be fully charged, is less than a specified time, and when the specified condition is met, the first power is used as the allowable input power, and when the specified condition is not met, the second power is used as the allowable input power.

11. The storage battery is a battery pack formed by connecting a plurality of single cells (11) in series, the full charge determination unit determines whether each of the cells is fully charged, the discharge amount calculation unit calculates the discharge amount for each of the single cells based on a fully charged state; The battery control device according to claim 2 , wherein the first power calculation unit calculates the first power based on a smallest discharge amount among the discharge amounts of the plurality of single cells.

12. The storage battery is a battery pack formed by connecting a plurality of single cells (11) in series, the charge amount calculation unit calculates the charge amount for each of the single cells based on a fully discharged state; The battery control device according to claim 2 , wherein the second power calculation unit calculates the second power based on a largest charge amount among the charge amounts of the plurality of single cells.

13. 3. The battery control device according to claim 2, further comprising a power limiting unit that, when transitioning from a state in which the first power is used as the allowable input power to a state in which the second power is used as the allowable input power, limits the allowable input power by setting the first power immediately before the transition as an upper limit value.

14. 3. The battery control device according to claim 2, further comprising a power gradual change unit that, when transitioning from a state in which the first power is used as the allowable input power to a state in which the second power is used as the allowable input power, gradually changes the allowable input power from the first power immediately before the transition to the second power after the transition.

15. A program executed by a control device to calculate an allowable input power (Win) in a storage battery (10), a full charge determination process for determining whether the storage battery is fully charged; a discharge amount calculation process for calculating, as a discharge amount of the storage battery, a value obtained by adding a current or current capacity of the storage battery when the storage battery is discharged and subtracting a current or current capacity of the storage battery when the storage battery is charged, based on a fully charged state of the storage battery; an input power calculation process for calculating the allowable input power of the storage battery based on the discharge amount calculated by the discharge amount calculation process; A program that includes:

16. A program executed by a control device to calculate an allowable input power (Win) in a storage battery (10), a full charge determination process for determining whether the storage battery is fully charged; a discharge amount calculation process for calculating, as a discharge amount of the storage battery, a value obtained by adding a current or current capacity of the storage battery when the storage battery is discharged and subtracting a current or current capacity of the storage battery when the storage battery is charged, based on a fully charged state of the storage battery; a charge amount calculation process for calculating, as a charge amount of the storage battery, a value obtained by adding a current or current capacity when the storage battery is charged and subtracting a current or current capacity when the storage battery is discharged, based on a fully discharged state of the storage battery; a first power calculation process of calculating the allowable input power of the storage battery as a first power based on the discharge amount calculated by the discharge amount calculation process; a second power calculation process of calculating the allowable input power of the storage battery as a second power based on the charged amount calculated by the charged amount calculation process; a power control process for selectively using either the first power or the second power as the allowable input power based on a predetermined condition; A program that includes:

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