Storage battery monitoring system and control program

Abstract

To correctly acquire a predetermined parameter to be used for estimation of a full charge capacity of a storage battery even when an interval between each energization of the storage battery and previous / subsequent energization is short.SOLUTION: In a storage battery monitoring system (10), a plurality of storage battery modules (30, 60) including a storage battery (31, 61) and a conversion circuit (40, 70) are connected in parallel to a charging device (29) and a load (21). A parameter acquisition unit (16c) acquires predetermined parameters before the start of energization of an estimation storage battery for which a full charge capacity is to be estimated and after the end of energization. When a request for energizing a storage battery is input, a control unit (16b) starts energization of at least one of non-estimated storage batteries for which the full charge capacity is not to be estimated, and after a lapse of a predetermined time since the energization request is input, starts energization after acquiring the predetermined parameters in the estimation storage battery, and controls the conversion circuits corresponding to the estimation storage battery and the non-estimated storage battery such that an energization time of the estimation storage battery is shorter than an energization time of the non-estimated storage battery.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a battery monitoring system. [Background technology]

[0002] For example, there is a system in which, among a plurality of battery blocks connected in parallel to a load, a battery block for estimating a full charge capacity (hereinafter referred to as an "estimation battery block") is disconnected from the parallel connection until polarization is eliminated, and the other battery blocks are used for discharging or charging, and the voltage before charging after polarization elimination of the estimated battery block is obtained, and after a predetermined charge amount is charged to the estimation block, the voltage after polarization elimination of the estimated battery block after charging is obtained (see Patent Document 1). The system described in Patent Document 1 obtains charging rates (predetermined parameters) before and after charging from the acquired voltages after polarization elimination of the estimated battery block before and after charging, respectively, and estimates the full charge capacity from these values ​​and the predetermined charge amount. According to the system described in Patent Document 1, the time for elimination of polarization of the estimated battery block is secured without interfering with the use of battery blocks other than the estimated battery block, and the full charge capacity of the estimated battery block can be accurately estimated. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-115127 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the system described in Patent Document 1, the timing for completing charging of a predetermined amount of charge in the estimated battery block is delayed by the time that the estimated battery block is left to deflate polarization (hereinafter referred to as "polarization deflation time") before charging (energizing) the estimated battery block. Therefore, when multiple battery blocks are used for discharging immediately after charging, it is difficult to ensure the polarization deflation time after charging the estimated battery block.

[0005] A similar problem may occur when calculating the charge rates before and after discharging (energizing) and estimating the full charge capacity from these values ​​and a predetermined discharge amount. That is, when a polarization elimination time is ensured before discharging the estimated battery block and multiple battery blocks are used for charging immediately after discharging the multiple battery blocks, it is difficult to ensure a polarization elimination time after discharging the estimated battery block.

[0006] The present invention has been made to solve the above-mentioned problems, and its main object is to accurately obtain, in a battery monitoring system, specified parameters used to estimate the full charge capacity of a battery, even when the interval between each current supply to the battery is short. [Means for solving the problem]

[0007] The first means for solving the above problem is A storage battery monitoring system (10, 210) in which a plurality of storage battery modules (30, 60, 90) including a storage battery (31, 61, 91) and a conversion circuit (40, 70, 100) that converts power input from the storage battery to a primary terminal pair (41, 42, 71, 72) and outputs the power from a secondary terminal pair (47, 48, 77, 78) are connected in parallel to at least one of a charging device (29) and a load (21), a parameter acquisition unit (16c, 31a, 51, 61a, 91a) that acquires predetermined parameters used for estimating a full charge capacity of the estimated battery before and after a current supply to the estimated battery is started and ended, the estimated battery being the battery whose full charge capacity is to be estimated; a control unit (16b) that controls the conversion circuits of the plurality of storage battery modules, thereby controlling a current-carrying state of the storage batteries of the plurality of storage battery modules, When a request for power supply to the multiple storage batteries is input, the control unit starts power supply to at least one of the non-estimation storage batteries, which are storage batteries whose full charge capacity is not estimated, while starting power supply to the estimated storage battery after a predetermined time has elapsed since the request for power supply was input and after the predetermined parameters have been acquired by the parameter acquisition unit, and controls the conversion circuit corresponding to the estimated storage battery and the conversion circuit corresponding to the non-estimation storage battery so that the power supply time of the estimated storage battery in response to the request for power supply is shorter than the power supply time of the non-estimation storage battery in response to the request for power supply.

[0008] According to the above configuration, in the power supply system, a plurality of storage battery modules each including a storage battery and a conversion circuit that converts power input from the storage battery to a primary terminal pair and outputs the power from a secondary terminal pair are connected in parallel to at least one of a charging device and a load. Therefore, the storage battery can be charged (energized) by the charging device, and the storage battery can be discharged (energized) to the load.

[0009] The parameter acquisition unit acquires predetermined parameters used to estimate the full charge capacity of the estimated storage battery before the start of current application to the estimated storage battery and after the end of current application. In order to accurately acquire the predetermined parameters, it is necessary to ensure a polarization elimination time in the estimated storage battery before acquiring the predetermined parameters. In addition, the control unit can control the current application states of the storage batteries of the multiple storage battery modules by controlling the conversion circuits of the multiple storage battery modules, respectively.

[0010] Here, the control unit starts energizing at least one of the non-estimated storage batteries when a request for energizing the plurality of storage batteries is input. Therefore, the request for energizing the plurality of storage batteries can be satisfied by at least one of the non-estimated storage batteries. Meanwhile, the control unit starts energizing the estimated storage battery after a predetermined time has elapsed since the input of the energizing request, and after the parameter acquisition unit acquires the predetermined parameter in the estimated storage battery. Therefore, even if the interval between the end of energizing immediately before the input of the energizing request and the input of the energizing request is short in the estimated storage battery, a predetermined time can be secured as a polarization elimination time for the estimated storage battery before acquiring the predetermined parameter. Then, energizing the estimated storage battery can be started after acquiring the predetermined parameter. However, the energizing start timing of the estimated storage battery is later than the energizing start timing of the non-estimated storage battery.

[0011] In this regard, the control unit controls the conversion circuit corresponding to the estimated storage battery and the conversion circuit corresponding to the non-estimated storage battery so that the current-carrying time of the estimated storage battery in response to the current-carrying request is shorter than the current-carrying time of the non-estimated storage battery in response to the current-carrying request. Therefore, the timing of ending the current-carrying of the estimated storage battery can be made earlier than when the current-carrying time of the estimated storage battery in response to the current-carrying request is longer than the current-carrying time of the non-estimated storage battery in response to the current-carrying request. Therefore, it is easier to ensure a polarization elimination time for the estimated storage battery after the current-carrying of the estimated storage battery is ended. Therefore, even if the interval between each current-carrying of the storage battery is short, the predetermined parameters used to estimate the full charge capacity of the storage battery can be accurately acquired.

[0012] Specifically, as in the second means, the predetermined parameter may be an open circuit voltage of the estimated battery measured when the time during which it can be assumed that no current flows through the estimated battery is equal to or longer than the predetermined time, or a charging rate of the estimated battery calculated based on the open circuit voltage. With this configuration, the full charge capacity of the estimated battery can be calculated with high accuracy based on the open circuit voltage of the estimated battery. For example, the full charge capacity can be calculated by the formula: full charge capacity = charging amount x 100 / (charging rate after charging - charging rate before charging).

[0013] In a third means, the multiple storage battery modules are connected in parallel to the charging device, and the request for power supply to the multiple storage batteries is a charging request for the multiple storage batteries, and the control unit controls the conversion circuit corresponding to the estimated storage battery and the conversion circuit corresponding to the non-estimated storage battery so that the charging time of the estimated storage battery in response to the charging request is shorter than the charging time of the non-estimated storage battery in response to the charging request, thereby making the average value of the current flowing to the estimated storage battery greater than the average value of the current flowing to the non-estimated storage battery from the start of charging to the end of charging of the multiple storage batteries.

[0014] According to the above configuration, when the power supply request is a charging request, the average value of the current flowing to the estimated storage battery and the non-estimated storage battery can be controlled, thereby easily making the charging time of the estimated storage battery shorter than the charging time of the non-estimated storage battery.

[0015] In a fourth aspect, the control unit controls the conversion circuit corresponding to the estimated battery and the conversion circuit corresponding to the non-estimated battery to make the charging end timing of the estimated battery earlier than the charging end timing of the non-estimated battery. With this configuration, even if the charging start timing of the estimated battery becomes later than the charging start timing of the non-estimated battery, the charging end timing of the estimated battery can be made earlier than the charging end timing of the non-estimated battery. Therefore, it becomes easier to ensure a polarization elimination time for the estimated battery after the charging of the estimated battery is completed.

[0016] In the fifth aspect, the positive and negative electrodes of the storage battery are respectively connected to the primary terminal pair of the conversion circuit, and the storage battery is connected in series to the secondary terminal pair of the conversion circuit.

[0017] According to the above configuration, the output voltage Vm of the storage battery module is the sum of the output voltage Vb of the storage battery and the output voltage Vo of the conversion circuit. Therefore, compared to a storage battery module in which a storage battery is connected in parallel to a secondary terminal pair of the conversion circuit, the output voltage Vo required of the conversion circuit when the output voltage Vm is required of the storage battery module can be reduced. Therefore, the rated voltage of the conversion circuit can be reduced, and the rated capacity of the conversion circuit can be reduced, thereby making it possible to miniaturize the conversion circuit.

[0018] In a sixth aspect, the control unit controls the conversion circuit corresponding to the estimated storage battery so as to make the current flowing through the estimated storage battery approach 0 from the start of charging of at least one of the non-estimated storage batteries until the start of charging of the estimated storage battery. With this configuration, even if the storage battery module corresponding to the estimated storage battery is not separated from the charging device by a relay or the like, the current flowing through the estimated storage battery can be made to approach 0, and polarization of the estimated storage battery can be suppressed.

[0019] In a seventh means, the control unit controls the conversion circuit corresponding to the estimated battery and the conversion circuit corresponding to the non-estimated battery so that the voltage applied to the estimated battery from the conversion circuit corresponding to the estimated battery is higher than the voltage applied to the non-estimated battery from the conversion circuit corresponding to the non-estimated battery from the conversion circuit corresponding to the non-estimated battery. With this configuration, the current flowing through the estimated battery and the non-estimated battery can be easily controlled by controlling the voltage applied to the estimated battery and the non-estimated battery.

[0020] If the voltage difference between the output voltage of the non-estimated storage battery and the output voltage of the estimated storage battery becomes too large, it becomes difficult for the conversion circuit to adjust the output voltage of the storage battery module corresponding to the non-estimated storage battery to match the output voltage of the storage battery module corresponding to the estimated storage battery.

[0021] In this respect, in the eighth means, when the voltage difference between the output voltage of the non-estimated battery and the output voltage of the estimated battery is greater than a predetermined voltage difference from the start of charging to the end of charging the multiple storage batteries, the control unit controls the conversion circuit corresponding to the estimated battery and the conversion circuit corresponding to the non-estimated battery so as to increase the power or current input to at least one storage battery included in the non-estimated battery and the estimated battery with the lower output voltage from the current level, or to decrease the power or current input to at least one storage battery included in the non-estimated battery and the estimated battery with the higher output voltage from the current level. With this configuration, it is possible to prevent the voltage difference between the output voltage of the non-estimated battery and the output voltage of the estimated battery from becoming too large. Therefore, it is possible to maintain a state in which the conversion circuit can adjust the output voltage of the storage battery module corresponding to the non-estimated battery to match the output voltage of the storage battery module corresponding to the estimated battery.

[0022] In a ninth aspect, the control unit selects, as the estimated battery, at least one of the storage batteries that is predicted to be the most deteriorated and the storage battery that has not yet calculated the full charge capacity for the longest period of time among the storage batteries. With this configuration, it is possible to estimate the full charge capacity of a storage battery that is predicted to have a small full charge capacity or a storage battery that is predicted to have a large error in the recognized full charge capacity. Therefore, when controlling the power supply to the storage batteries using the full charge capacities of the storage batteries, the effect of control can be improved.

[0023] When energizing the non-estimation batteries, if the total power of the energized non-estimation batteries is significantly smaller than the available power of the battery monitoring system, the energization efficiency of the battery monitoring system may decrease.

[0024] In this regard, in the tenth aspect, the control unit determines the number of the storage batteries to be selected as the estimated storage batteries when power supply to the non-estimated storage batteries starts based on the available power of each storage battery and the available power of the storage battery monitoring system. With this configuration, the number of the storage batteries to be selected as the estimated storage batteries when power supply to the non-estimated storage batteries starts, and further the number of non-estimated storage batteries to be powered, can be determined in consideration of the available power of each storage battery and the available power of the storage battery monitoring system. Therefore, it is possible to suppress a decrease in the power supply efficiency of the storage battery monitoring system.

[0025] In an eleventh aspect, when the available power of the battery monitoring system is greater than the total available power of all the non-estimated batteries between the start of energization of all the non-estimated batteries and the start of energization of the estimated batteries, the control unit changes at least one of the batteries selected as the estimated batteries at the start of energization of the non-estimated batteries to the non-estimated batteries and starts energization. According to this configuration, when the available power of the battery monitoring system is not reached even when all the non-estimated batteries are energized, at least one of the batteries selected as the estimated batteries at the start of energization of the non-estimated batteries is changed to the non-estimated battery, so that the total available power of the non-estimated batteries can be increased. Therefore, even if too many batteries are selected as the estimated batteries at the start of energization of the non-estimated batteries, it is possible to suppress a decrease in the energization efficiency of the battery monitoring system.

[0026] If a next current supply request for multiple storage batteries is input between the start and end of current supply to the estimated storage battery, and current supply to the estimated storage battery is immediately started, it is not possible to ensure time for the estimated storage battery to depolarize and acquire specified parameters before current supply to the estimated storage battery begins in response to the next current supply request.

[0027] In this regard, in a twelfth means, the control unit ends energization of the estimated battery when a next energization request for the multiple storage batteries is input between the start and end of energization of the estimated battery, and starts energization after the predetermined time has elapsed since the end of energization of the estimated battery, and after the parameter acquisition unit acquires the predetermined parameters for the estimated battery. With this configuration, even if a next energization request for the multiple storage batteries is input between the start and end of energization of the estimated battery, it is possible to secure a predetermined time as a polarization elimination time for the estimated battery and acquire the predetermined parameters.

[0028] The thirteenth measure is: A control program applied to a storage battery monitoring system (10) in which a plurality of storage battery modules (30, 60, 90) including storage batteries (31, 61, 91) and conversion circuits (40, 70, 100) that convert power input from the storage batteries to primary terminal pairs (41, 42, 71, 72) and output the power from secondary terminal pairs (47, 48, 77, 78) are connected in parallel to at least one of a charging device (29) and a load (21), A process of acquiring predetermined parameters used for estimating a full charge capacity of an estimated battery before and after a current is applied to the estimated battery, the estimated battery being the battery whose full charge capacity is to be estimated; A process of controlling a current-carrying state of the storage batteries of the plurality of storage battery modules by controlling the conversion circuits of the plurality of storage battery modules, respectively; a process of starting current supply to at least one non-estimation battery, which is a storage battery for which a full charge capacity is not estimated, when a current supply request for the plurality of storage batteries is input, while starting current supply to the estimated storage battery after a predetermined time has elapsed since the current supply request was input and after the predetermined parameters have been acquired, and controlling the conversion circuit corresponding to the estimated storage battery and the conversion circuit corresponding to the non-estimation storage battery so that a current supply time of the estimated storage battery in response to the current supply request is shorter than a current supply time of the non-estimation storage battery in response to the current supply request; The computer (16) executes the above.

[0029] According to the above configuration, by causing a computer to execute a control program applied to the storage battery monitoring system, it is possible to achieve the same advantageous effects as the first means. [Brief description of the drawings]

[0030] [Figure 1] FIG. 1 is a circuit diagram of a power supply system according to a first embodiment. [Diagram 2] FIG. 4 is a circuit diagram showing an example of a conversion circuit. [Diagram 3] 5 is a time chart showing a manner of calculating a full charge capacity in an ideal use case. [Figure 4] 4 is a graph showing the relationship between OCV and SOC, and how SOC is acquired. [Diagram 5] FIG. 1 is a schematic diagram showing the relationship between use cases and whether or not SOH can be calculated. [Figure 6] FIG. 4 is a schematic diagram showing an outline of calculation of a full charge capacity in the first embodiment. [Figure 7] 4 is a flowchart showing a procedure for calculating a full charge capacity in the first embodiment. [Figure 8] 4 is a time chart showing a manner of calculating a full charge capacity in the first embodiment. [Figure 9] FIG. 13 is a schematic diagram showing an overview of a modified example of full charge capacity calculation. [Figure 10] FIG. 11 is a circuit diagram of a modified example of a power supply system. [Figure 11] FIG. 11 is a circuit diagram of a power supply system according to a second embodiment. [Figure 12] 10 is a flowchart showing a procedure for calculating a full charge capacity in a second embodiment. [Figure 13] 5 is a schematic diagram showing the relationship between the number of non-estimation batteries and estimation batteries and the chargeable current of the system. [Figure 14] FIG. 11 is a circuit diagram of another modified example of the power supply system. [Figure 15] FIG. 13 is a circuit diagram of a modified example of the conversion circuit. [Figure 16] FIG. 13 is a circuit diagram of another modified example of the conversion circuit. [Figure 17] FIG. 11 is a circuit diagram of a modified example of the storage battery module. [Figure 18]FIG. 11 is a circuit diagram of another modified example of the storage battery module. [Figure 19] FIG. 13 is a schematic diagram showing an overview of another modified example of full charge capacity calculation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] (First embodiment) A first embodiment of a power supply system that is mounted on a vehicle and supplies power to a load will be described below with reference to the drawings. The vehicle is, for example, a hybrid vehicle or an electric vehicle, and is equipped with a start switch (for example, an IG switch or a start switch) for starting the vehicle. The vehicle is put into an operating state (operating) by turning on the start switch (not shown), and is put into a stopped state (stopped) by turning off the start switch.

[0032] 1, power supply system 10 includes buses 11 and 12 (power supply buses), a first storage battery module 30, a second storage battery module 60, a voltage sensor 13, a current sensor 19, an ECU (Electronic Control Unit) 16, etc. The positive side of the buses is referred to as bus 11, and the negative side of the buses is referred to as bus 12. Bus 12 is grounded.

[0033] A first storage battery module 30 (storage battery module), a second storage battery module 60 (storage battery module), a load 21, an external charger 29, and a voltage sensor 13 are connected in parallel to the buses 11 and 12. The storage battery modules 30 and 60 input and output power to the buses 11 and 12. The load 21 inputs power from the buses 11 and 12, or inputs and outputs power to the buses 11 and 12. The external charger 29 charges the storage batteries 31 and 61 by inputting power to the buses 11 and 12. The voltage sensor 13 detects a bus voltage Vbus, which is a voltage between the buses 12 and 11. The current sensor 19 detects a current flowing through the bus 12 (the load 21 or the external charger 29).

[0034] The load 21 is, for example, a combination of an inverter and a motor generator (MG) (motor unit with inverter), an electric heater, a DC-DC converter, or the like. The motor generator (MG) drives, for example, an electric vehicle with power supplied from the inverter, or performs regenerative power generation with a rotational force applied from the electric vehicle. The inverter converts power between the buses 11, 12 and the MG. The electric heater generates heat with a voltage supplied from the buses 11, 12, for example, to warm the interior of the vehicle or the battery. The DC-DC converter converts, for example, DC power supplied from the buses 11, 12 to supply DC power, or converts DC power supplied from a solar panel or the like to supply DC power to the buses 11, 12. The load 21 may be a single load or a plurality of loads.

[0035] The external charger 29 (charging device) is a well-known DC charger installed outside the vehicle. The rated charging power (chargeable power) of the external charger 29 is determined in advance according to the specifications of the external charger 29. For example, the external charger 29 has a rated voltage of 400 [V] and a rated power of 150 [kW]. The external charger 29 is connected to the buses 11 and 12 (vehicle) via charging cables 29a and 29b, and outputs charging power to the buses 11 and 12. The external charger 29 can communicate with the ECU 16. The external charger 29 transmits information related to charging, such as its own rated charging power, to the ECU 16. When the charging cables 29a and 29b are connected to the buses 11 and 12, the external charger 29 transmits a signal indicating the connection to the ECU 16.

[0036] The first storage battery module 30 includes a first storage battery 31, a first current sensor 33, a first drive circuit 35, a first conversion circuit 40, relays 40a, 40b, and the like. The first storage battery 31 (storage battery) is a high-voltage secondary battery using, for example, a lithium-ion battery, a nickel-metal hydride battery, or the like, and the type is arbitrary. The first current sensor 33 (current sensor) detects a current flowing through the first storage battery 31. A detection value by the first current sensor 33 is input to the ECU 16 and is used, for example, to calculate the charging rate (SOC: State Of Charge) [%] of the first storage battery 31. The first drive circuit 35 (drive circuit) drives a switching element (described later) included in the first conversion circuit 40 to turn on and off. The first drive circuit 35 is controlled by the ECU 16. The relays 40a, 40b disconnect and connect the storage battery module 30 to and from the buses 11, 12, respectively. The first storage battery 31 (storage battery) may be a secondary battery that is not a high voltage battery.

[0037] The first conversion circuit 40 (conversion circuit) includes a primary side positive terminal 41 and a negative terminal 42, which are a primary side terminal pair, and a secondary side positive terminal 47 and a negative terminal 48, which are a secondary side terminal pair. The negative electrode of the first storage battery 31 is connected to the bus 12. The primary side positive terminal 41 is connected to the positive electrode of the first storage battery 31, and the primary side negative terminal 42 is connected to the negative electrode of the first storage battery 31. In addition, the secondary side negative terminal 48 is connected to the positive electrode of the first storage battery 31. The secondary side positive terminal 47 is connected to the bus 11. That is, the positive electrode and the negative electrode of the first storage battery 31 are connected to the primary side terminal pair 41, 42 of the first conversion circuit 40, respectively, and the first storage battery 31 is connected in series to the secondary side terminal pair 47, 48 of the first conversion circuit 40. The first conversion circuit 40 converts the power input from the first storage battery 31 to the primary side terminal pair 41, 42 and outputs it from the secondary side terminal pair 47, 48. The first conversion circuit 40 is a bidirectional conversion circuit that can also convert the power input to the secondary side terminal pair 47, 48 and output it from the primary side terminal pair 41, 42.

[0038] The second storage battery module 60 has a similar configuration to the first storage battery module 30, and includes a second storage battery 61 (storage battery), a second current sensor 63 (current sensor), a second drive circuit 65 (drive circuit), a second conversion circuit 70, relays 70a, 70b, etc. The second conversion circuit 70 (conversion circuit) has a similar configuration to the first conversion circuit 40, and includes a primary side positive terminal 71 and a negative terminal 72, which are a primary side terminal pair, and a secondary side positive terminal 77 and a negative terminal 78, which are a secondary side terminal pair. The connection manner of these is also similar to that of the first storage battery module 30, so the above description of the first storage battery module 30 is used. Note that although the first storage battery module 30 and the second storage battery module 60 have configurations having similar functions, the ratings and withstand voltages of the respective configurations may be different from each other.

[0039] FIG. 2 shows an example of the first conversion circuit 40. The first conversion circuit 40 is a well-known center-tapped insulated DC-DC converter. The first conversion circuit 40 includes switching elements 43 to 46, 54, and 55, smoothing capacitors 50 and 57, a transformer 53, a reactor 56, voltage sensors 51 and 59, and current sensors 52 and 58. The switching elements 43 to 46, 54, and 55 are, for example, MOSFETs and IGBTs (Insulated Gate Bipolar Transistors). The switching elements 43 to 46 form a full bridge circuit. A connection point between the switching element 43 and the switching element 44 and a connection point between the switching element 45 and the switching element 46 are connected to both ends of the primary coil of the transformer 53, respectively. The switching elements 54 and 55 are connected between both ends of the secondary coil of the transformer 53 and the reactor 56, respectively. The voltage sensor 51 detects the voltage between the negative terminal 42 and the positive terminal 41 on the primary side, i.e., the output voltage Vb (primary side voltage) of the first storage battery 31. The current sensor 52 detects the input current Ii (primary side current) which is a current input to the primary side circuit. The voltage sensor 59 detects the voltage between the negative terminal 48 and the positive terminal 47 on the secondary side, i.e., the output voltage Vo (secondary side voltage) of the first conversion circuit 40. The current sensor 58 detects the current flowing through the reactor 56, i.e., the output current Io (secondary side current) of the first conversion circuit 40. The detection values ​​of the voltage sensors 51, 59 and the current sensors 52, 58 are input to the ECU 16.

[0040] The ECU 16 (control device) is configured as a microcomputer (computer) including, for example, a CPU, a ROM, a RAM, and an input / output interface. The ECU 16 controls the states of the relays 40a, 40b, 70a, and 70b and the state of the load 21. Furthermore, the ECU 16 executes a control program applied to the power supply system 10 to realize functions of a bus voltage setting unit 16a, a control unit 16b, a parameter acquisition unit 16c, and the like. The storage battery modules 30 and 60, the control unit 16b, and the parameter acquisition unit 16c form a storage battery monitoring system.

[0041] The bus voltage setting unit 16a sets a bus voltage request value Vbus*, which is a voltage that is requested to be supplied from the buses 11 and 12 to the load 21. The bus voltage setting unit 16a sets the bus voltage request value Vbus* based on the state of the load 21.

[0042] The control unit 16b controls the output voltages Vo1 and Vo2 of the conversion circuits 40 and 70 so that the output voltages Vm1 and Vm2 of the storage battery modules 30 and 60 become the bus voltage request value Vbus* (approach the bus voltage request value Vbus*). For example, the control unit 16b controls the switching elements 43-46, 54, and 55 based on the detection values ​​of the voltage sensors 51 and 59 and the current sensors 52 and 58, thereby controlling the first output voltage Vo1 of the first conversion circuit 40 to become the first output voltage request value Vo1* (approach the first output voltage request value Vo1*). In more detail, the first output voltage request value Vo1* is set to a voltage obtained by subtracting the first output voltage Vb1 of the first storage battery 31 from the bus voltage request value Vbus* (Vo1*=Vbus*-Vb1). Similarly, the control unit 16b controls the second output voltage Vo2 of the second conversion circuit 70 to become the second output voltage request value Vo2* (approach the second output voltage request value Vo2*). In detail, the second output voltage request value Vo2* is set to a voltage obtained by subtracting the second output voltage Vb2 of the second storage battery 61 from the bus voltage request value Vbus* (Vo2*=Vbus*-Vb2).

[0043] Furthermore, if the voltage difference between the first output voltage Vb1 of the first storage battery 31 and the second output voltage Vb2 of the second storage battery 61 becomes too large, it becomes difficult for the conversion circuits 40, 70 to adjust the output voltage Vm1 of the first storage battery module 30 and the second output voltage Vm2 of the second storage battery module 60 so that they match.

[0044] FIG. 3 is a time chart showing the manner of calculating the full charge capacity in the ideal use case. When the vehicle stops traveling at timing t11, the polarization of the storage batteries 31, 61 gradually disappears. When the voltage of the storage batteries 31, 61 becomes stable at timing t12, the parameter acquisition unit 16c causes the voltage sensor 51 to detect the pre-charge OCV (Open Circuit Voltage) with the circuit of the storage batteries 31, 61 open. Thereafter, the control unit 16b charges the storage batteries 31, 61 with the charging power from the external charger 29 by controlling the conversion circuits 40, 70. When the charging of the storage batteries 31, 61 ends at timing t13, the polarization of the storage batteries 31, 61 gradually disappears. When the voltage of the storage batteries 31, 61 becomes stable at timing t14, the parameter acquisition unit 16c causes the voltage sensor 51 to detect the post-charge OCV of the storage batteries 31, 61. The pre-charge OCV and the post-charge OCV correspond to predetermined parameters used to estimate the full charge capacity of the storage batteries 31, 61.

[0045] FIG. 4 is a graph showing the relationship between OCV and SOC, and the acquisition mode of SOC. The parameter acquisition unit 16c stores the graph of FIG. 4 that specifies the relationship between OCV and SOC in a stable state. The relationship between OCV and SOC in a stable state can be acquired in advance based on a test or the like. The parameter acquisition unit 16c calculates the pre-charge SOC (predetermined parameter) by applying the pre-charge OCV detected at timing t12 in FIG. 3 to the graph of FIG. 4. The parameter acquisition unit 16c calculates the post-charge SOC (predetermined parameter) by applying the post-charge OCV detected at timing t14 in FIG. 3 to the graph of FIG. 4. Then, the parameter acquisition unit 16c (ECU 16) calculates the full charge capacity by the formula: full charge capacity [Ah]=charge amount×100 / (post-charge SOC−pre-charge SOC). The charge amount is an integrated value of the current from the start to the end of charging, and can be calculated by, for example, integrating the currents detected by the current sensors 33 and 63, respectively. The parameter acquisition unit 16c (ECU 16) calculates the SOH of the storage batteries 31, 61 using the formula: State of Health (SOH) [%] of storage battery = current full charge capacity × 100 / full charge capacity at time of manufacture. If the pre-charge OCV (post-charge OCV) is detected when the voltage of the storage batteries 31, 61 is not stable, the pre-charge OCV (post-charge OCV) applied to the graph in Fig. 4 cannot be accurately detected. In that case, the full charge capacity of the storage batteries 31, 61 cannot be accurately estimated, and therefore the SOH of the storage batteries 31, 61 cannot be accurately estimated.

[0046] Figure 5 is a schematic diagram showing the relationship between use cases and whether or not the SOH can be calculated. Note that the star marks indicate the timing at which the OCV can be detected after stabilization.

[0047] In an ideal use case, after the vehicle has finished traveling, a time for leaving the storage batteries 31, 61 to eliminate the polarization (polarization elimination time) can be secured, and the stabilized pre-charge OCV can be detected at timing t21. Even after the storage batteries 31, 61 have finished charging, a polarization elimination time can be secured, and the stabilized post-charge OCV can be detected at timing t25. Therefore, the SOH can be accurately estimated.

[0048] In the problematic use case, the user charges the storage battery 31, 61 immediately after the vehicle has finished running. Therefore, the polarization elimination time of the storage battery 31, 61 cannot be secured, and the pre-charge OCV after the storage battery 31, 61 has stabilized cannot be detected. Therefore, the SOH cannot be accurately estimated.

[0049] In the comparative example, when the user performs a charging operation on the storage batteries 31, 61 at timing t21 immediately after the vehicle has finished traveling, for example, charging of the first storage battery 31, for which the full charge capacity is estimated, is prohibited from timing t21 to timing t22. Therefore, at timing t22, the pre-charge OCV after stabilization can be detected. However, the charging end timing t24 of the first storage battery 31 is later than the charging end timing t23 of, for example, the second storage battery 61, which starts charging immediately when the charging operation is performed. Therefore, when the user requests traveling at timing t25, the polarization elimination time of the first storage battery 31 cannot be secured, and the post-charge OCV after stabilization of the first storage battery 31 cannot be detected. Therefore, the SOH cannot be accurately estimated.

[0050] FIG. 6 is a schematic diagram showing an outline of the calculation of the full charge capacity in this embodiment. In this embodiment, when the user performs a charging operation on the storage batteries 31, 61 at timing t31 immediately after the vehicle has finished traveling, charging of the non-estimated storage battery, which is a storage battery whose full charge capacity is not estimated, is started. At this time, charging is performed, for example, with the rated charging power of the external charger 29. On the other hand, the estimated storage battery, which is a storage battery whose full charge capacity is estimated, is left to eliminate polarization from timing t31 to timing t32. Therefore, at timing t32, the pre-charge OCV after stabilization can be detected. After detecting the pre-charge OCV, charging of the estimated storage battery is started, and the charging power of the non-estimated storage battery and the estimated storage battery is controlled. At this time, the charging power of the estimated storage battery is made larger than the charging power of each non-estimated storage battery. This makes it possible to make the charging time Te2 of the estimated storage battery shorter than the charging time Te1 of the non-estimated storage battery. As a result, for example, at timing t33, the estimated storage battery is fully charged. After that, the estimated storage battery is left to eliminate polarization. Then, when the user requests to drive at timing t34, the polarization elimination time of the estimated battery is ensured, and the post-charge OCV after the estimated battery has stabilized can be detected, and therefore the SOH can be accurately estimated.

[0051] 7 is a flowchart showing the procedure for calculating the full charge capacity in this embodiment. This series of processes is repeatedly executed at a predetermined cycle by the ECU 16. Here, a case where the first storage battery 31 is determined to be the estimated storage battery and the second storage battery 61 is determined to be the non-estimated storage battery will be described as an example.

[0052] First, it is determined whether it is time to start charging (S10). For example, when the charging cables 29a, 29b are connected to the buses 11, 12, if a signal indicating the connection is received from the external charger 29, it is determined that it is time to start charging (there is a charging request, there is a power supply request). If it is determined that it is time to start charging (S10: YES), a non-estimated battery and an estimated battery are determined (S11). Specifically, at least one of the battery that is predicted to be the most degraded among the multiple batteries 31, 61 and the battery that has not calculated the full charge capacity for the longest period among the multiple batteries 31, 61 is selected as the estimated battery. For example, the battery with the smallest most recently estimated full charge capacity is selected as the battery predicted to be the most degraded. For example, the battery that has been elapsed the longest since the most recently calculated full charge capacity is selected as the battery that has not calculated the full charge capacity for the longest period. Then, of the multiple storage batteries 31, 61, for example, the first storage battery 31 selected as the estimated storage battery is determined to be the estimated storage battery, and the remaining second storage battery 61 not selected as the estimated storage battery is determined to be the non-estimated storage battery. If the storage battery predicted to be most degraded and the storage battery for which the full charge capacity has not been calculated for the longest period are selected and are different, one of them may be determined to be the estimated storage battery. Also, the storage battery with the highest SOC among the multiple storage batteries 31, 61 may be selected as the estimated storage battery, or the estimated storage battery may be selected randomly. Next, charging of the non-estimated storage battery is started (S12).

[0053] On the other hand, when it is determined in the determination of S10 that it is not the timing to start charging (S10: NO), it is determined whether or not the elapsed time from the start of charging is equal to a predetermined time (S13). Specifically, it is determined whether or not the elapsed time from the start of charging is equal to a time threshold value set to be longer than the standing time (standby time) required for the polarization of the first storage battery 31 (storage battery) to be eliminated and the OCV to be stabilized. The time threshold value may be a variable value, and may be set to be longer as the temperature of the estimated storage battery is lower. In addition, if the estimated storage battery has already been left for a time Te3 before the timing to start charging, the time obtained by subtracting the time Te3 from the time threshold value may be set as a new time threshold. The elapsed time from the start of charging may be, for example, the elapsed time from the time it is determined in the process of S13 that it is the timing to start charging, or may be the time elapsed from the time charging of the non-estimated storage battery is started in the process of S12. When it is determined in this determination that the elapsed time from the start of charging is equal to the predetermined time (S13: YES), the pre-charge OCV (predetermined parameter) of the estimated storage battery is acquired (S14). Specifically, in a state where the circuit of the estimated battery is open (a state where it can be considered that no current flows through the estimated battery), the output voltage Vb of the estimated battery is detected by the voltage sensor 51. Then, charging of the estimated battery is started (S15).

[0054] In addition, when it is determined in the determination of S13 that the elapsed time from the start of charging is not equal to the predetermined time (S13: NO), it is determined whether or not there is a storage battery that satisfies the charging end condition (S16). Specifically, among the non-estimated storage battery and the estimated storage battery, a storage battery whose output voltage Vb has reached the full charge voltage threshold is determined to be a storage battery that satisfies the charging end condition. The full charge voltage threshold is set to a value that allows determination that the storage battery 31, 61 is fully charged. In this determination, when it is determined that there is a storage battery that satisfies the charging end condition (S16: YES), the charging of the storage battery that satisfies the charging end condition is terminated (S17). To terminate the charging of the storage battery, for example, the conversion circuits 40, 70 may be controlled so that no current flows through the storage batteries 31, 61, or the storage batteries 31, 61 may be disconnected from the buses 11, 12 by the relays 40a, 40b, 70a, 70b, respectively. On the other hand, if it is determined that no storage battery satisfies the charging end condition (S16: NO), the process proceeds to S18.

[0055] Next, the charging power of each storage battery 31, 61 is controlled according to the state of the storage battery that has started or ended charging (S18). Here, for example, in a state where charging of the non-estimated storage battery 61 has started and the estimated storage battery 31 has been left for polarization elimination, the conversion circuit 70 corresponding to the non-estimated storage battery 61 is controlled to charge the non-estimated storage battery 61 with the rated charging power of the external charger 29. At this time, for example, the conversion circuit 40 corresponding to the estimated storage battery 31 is controlled so that it can be considered that no current flows through the estimated storage battery 31 (the current flowing through the estimated storage battery is brought close to zero), or the estimated storage battery 31 is disconnected from the buses 11, 12 by the relays 40a, 40b, respectively. The ECU 16 can acquire the rated charging power of the external charger 29 by communicating with the external charger 29. In addition, in a state where the charging of the estimated battery 31 is also started and the non-estimated battery 61 and the estimated battery 31 are being charged, the conversion circuit 40 corresponding to the estimated battery 31 and the conversion circuit 70 corresponding to the non-estimated battery 61 are controlled so that the charging time of the estimated battery 31 for the connection (charging request) of the charging cables 29a, 29b is shorter than the charging time of the non-estimated battery 61 for the charging request. Specifically, by controlling the conversion circuit 40 corresponding to the estimated battery 31 and the conversion circuit 70 corresponding to the non-estimated battery 61, the average value of the current flowing through the estimated battery 31 is made larger than the average value of the current flowing through the non-estimated battery 61 from the start of charging to the end of charging the multiple batteries 31, 61. In more detail, the conversion circuit 40 corresponding to the estimated battery 31 and the conversion circuit 70 corresponding to the non-estimated battery 61 are controlled so that the output voltage Vo applied from the conversion circuit 40 corresponding to the estimated battery 31 to the estimated battery 31 is higher than the output voltage Vo applied from the conversion circuit 70 corresponding to the non-estimated battery 61 to the non-estimated battery 61. Then, when the charging termination condition of the non-estimated battery 61 or the estimated battery 31 is satisfied and only one of the non-estimated battery 61 and the estimated battery 31 is being charged, the one of the batteries being charged is charged using the rated charging power of the external charger 29.

[0056] Next, it is determined whether or not the charging of the estimated battery is completed and the above-mentioned predetermined time or more has elapsed since the charging of the estimated battery is completed (S19). If the determination is negative (S19: NO), this series of processes is temporarily terminated (END). On the other hand, if the determination is positive (S19: YES), the post-charge OCV (predetermined parameter) of the estimated battery is acquired (S20). Based on the acquired pre-charge OCV and post-charge OCV, and the charge amount from the start to the end of charging the estimated battery, the pre-charge SOC and post-charge SOC, and the full charge capacity are calculated (S21). Specifically, the pre-charge SOC (predetermined parameter) and post-charge SOC (predetermined parameter) are calculated by applying the acquired pre-charge OCV and post-charge OCV to the graph of FIG. 4. Then, the full charge capacity is calculated by the formula: full charge capacity [Ah]=charge amount×100 / (post-charge SOC-pre-charge SOC). After that, this series of processes is terminated.

[0057] The processes of S14, S20, and S21 correspond to the processes performed by the parameter acquisition unit 16c, and the processes of S12, S15, and S18 correspond to the processes performed by the control unit 16b.

[0058] FIG. 8 is a time chart showing the manner of calculating the full charge capacity in this embodiment. When a charging request is input at timing t41, charging of the non-estimated battery is started, and the estimated battery is left without charging. When the elapsed time from the start of charging reaches a time threshold at timing t42, the OCV of the estimated battery is acquired. Then, charging of the estimated battery is started, and the charging current of the estimated battery is controlled to be larger than the charging current of the non-estimated battery. At timing t43, the output voltage Vb of the estimated battery reaches the full receiving voltage threshold, and charging of the estimated battery is terminated. At timing t44, the output voltage Vb of the non-estimated battery reaches the full receiving voltage threshold, and charging of the non-estimated battery is terminated. That is, the control unit 16b controls the conversion circuit corresponding to the estimated battery and the conversion circuit corresponding to the non-estimated battery to make the charging end timing t43 of the estimated battery earlier than the charging end timing t44 of the non-estimated battery. When the vehicle is started for traveling at timing t45, the time threshold equivalent to the predetermined time has elapsed since the charging end timing t43 of the estimated battery, and the OCV of the estimated battery is acquired.

[0059] The present embodiment described above in detail has the following advantages.

[0060] When the control unit 16b receives a charging request for the multiple storage batteries 31 and 61, the control unit 16b starts charging, for example, the non-estimated storage battery 61. Therefore, the non-estimated storage battery 61 can respond to the charging request for the multiple storage batteries 31 and 61. On the other hand, the control unit 16b starts charging after a predetermined time has elapsed since the charging request was received, for example, after the parameter acquisition unit 16c acquires a predetermined parameter for the estimated storage battery 31. Therefore, even if the interval between the charging end timing immediately before the input of the charging request and the input of the charging request is short in the estimated storage battery 31, a predetermined time can be secured as a polarization elimination time for the estimated storage battery 31 before acquiring the predetermined parameter. Then, charging of the estimated storage battery 31 can be started after acquiring the predetermined parameter.

[0061] The control unit 16b controls the conversion circuit 40 corresponding to the estimated battery 31 and the conversion circuit 70 corresponding to the non-estimated battery 61 so that the charging time of the estimated battery 31 in response to the charging request is shorter than the charging time of the non-estimated battery 61 in response to the charging request. Therefore, the charging end timing t43 of the estimated battery 31 can be made earlier than when the charging time of the estimated battery 31 in response to the charging request is longer than the charging time of the non-estimated battery 61 in response to the charging request. Therefore, it is easier to ensure a polarization elimination time for the estimated battery 31 after the charging of the estimated battery 31 is completed. Therefore, even if the interval between the discharge before and after the charging of the batteries 31 and 61 is short, the predetermined parameters used to estimate the full charge capacity of the batteries 31 and 61 can be accurately acquired.

[0062] The predetermined parameters are the OCV of the estimated battery 31, which is measured when the time during which it can be assumed that no current flows through the estimated battery 31 is equal to or longer than a predetermined time, and the SOC of the estimated battery 31, which is calculated based on the OCV. With this configuration, the full charge capacity of the estimated battery 31 can be calculated with high accuracy based on the OCV of the estimated battery 31.

[0063] By controlling the average values ​​of the currents flowing through the estimated battery 31 and the non-estimated battery 61, the charging time of the estimated battery 31 can be easily made shorter than the charging time of the non-estimated battery 61.

[0064] The control unit 16b controls, for example, the conversion circuit 40 corresponding to the estimated battery 31 and the conversion circuit 70 corresponding to the non-estimated battery 61 to make the charging end timing t43 of the estimated battery 31 earlier than the charging end timing t44 of the non-estimated battery 61. With this configuration, even if the charging start timing t42 of the estimated battery 31 is later than the charging start timing t41 of the non-estimated battery 61, the charging end timing t43 of the estimated battery 31 can be made earlier than the charging end timing t44 of the non-estimated battery 61. Therefore, it becomes easier to ensure a polarization elimination time for the estimated battery 31 after the charging of the estimated battery 31 is completed.

[0065] The output voltage Vm of the storage battery module 30, 60 is the sum of the output voltage Vb of the storage battery 31, 61 and the output voltage Vo of the conversion circuit 40, 70. Therefore, compared to a storage battery module in which the storage battery 31, 61 is connected in parallel to the secondary side terminal pairs 47, 48, 77, 78 of the conversion circuit 40, 70, it is possible to reduce the output voltage Vo required of the conversion circuit 40, 70 when the output voltage Vm is required of the storage battery module 30, 60. Therefore, the rated voltage of the conversion circuit 40, 70 can be lowered, and the rated capacity of the conversion circuit 40, 70 can be reduced, thereby making it possible to miniaturize the conversion circuit 40, 70.

[0066] The control unit 16b controls the conversion circuit 40 corresponding to the estimated battery 31 so as to make the current flowing through the estimated battery 31 approach zero, for example, from when charging of the non-estimated battery 61 starts until charging of the estimated battery 31 starts. With this configuration, even if the battery module 30 corresponding to the estimated battery 31 is not disconnected from the external charger 29 by the relays 40a, 40b, the current flowing through the estimated battery 31 can be made approach zero, and polarization of the estimated battery 31 can be suppressed.

[0067] The control unit 16b controls the conversion circuit 40 corresponding to the estimated battery 31 and the conversion circuit 70 corresponding to the non-estimated battery 61 so that the voltage applied from the conversion circuit 40 corresponding to the estimated battery 31 to the estimated battery 31 is higher than the voltage applied from the conversion circuit 70 corresponding to the non-estimated battery 61 to the non-estimated battery 61, for example, from the start of charging the estimated battery 31 to the end of charging. With this configuration, by controlling the voltage applied to the estimated battery 31 and the non-estimated battery 61, the current flowing through the estimated battery 31 and the non-estimated battery 61 can be easily controlled.

[0068] The control unit 16b selects at least one of the storage batteries 31, 61 that is predicted to be the most deteriorated and the storage battery that has not yet calculated the full charge capacity for the longest period of time among the storage batteries 31, 61 as the estimated storage battery. This configuration makes it possible to estimate the full charge capacity of a storage battery that is predicted to have a low full charge capacity or a storage battery that is predicted to have a large error in the recognized full charge capacity. Therefore, when controlling the power supply to the storage batteries 31, 61 using the full charge capacities of the storage batteries 31, 61, the effect of control can be improved.

[0069] The above-mentioned advantageous effects can be achieved by causing the ECU 16 (computer) to execute a control program applied to the storage battery monitoring system (power supply system 10).

[0070] The first embodiment can be modified as follows: The same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof will be incorporated herein.

[0071] The charging end timing t44 of the non-estimated battery 61 may be earlier than the charging end timing t43 of the estimated battery 31. Even in this case, if the charging time of the estimated battery 31 in response to a charging request is shorter than the charging time of the non-estimated battery 61 in response to a charging request, it becomes easier to ensure a polarization elimination time for the estimated battery 31 after charging of the estimated battery 31 is completed.

[0072] Whether or not the non-estimation battery 61 is charged by the external charger 29 can be switched by opening and closing the relays 70a and 70b.

[0073] 9, the parameter acquisition unit 16c acquires the OCV at timing t52 after a predetermined time has elapsed since the input of a charge request at timing t51. Then, it is assumed that a traveling request (a discharge request for the multiple storage batteries 31, 61, a next current request) is input between the start and end of current supply to the estimated storage battery. In this case, if discharging of the estimated storage battery is immediately started, it is not possible to secure a polarization elimination time for the estimated storage battery and acquire the OCV (predetermined parameter) before the start of discharging of the estimated storage battery in response to the traveling request.

[0074] Therefore, the control unit 16b may control as follows when a travel request is input between the start and end of charging (energization) of the estimated battery. That is, the control unit 16b may end charging of the estimated battery when the travel request is input at timing t53, and may start discharging (energization) of the estimated battery after a predetermined time has elapsed since the end of charging of the estimated battery, after the parameter acquisition unit 16c acquires the OCV (predetermined parameter) of the estimated battery at timing t54. With this configuration, even if a travel request is input between the start and end of charging of the estimated battery, the OCV can be acquired by securing a predetermined time as the polarization elimination time of the estimated battery. Note that the control unit 16b may not execute the above control when it has not been able to acquire the stabilized pre-charge OCV.

[0075] 10, the power supply system 10 may include a path 22 that connects the positive electrode side (positive side) of the first storage battery module 30 to the bus 11, a path 24 that connects the negative electrode side (negative side) of the second storage battery module 60 to the bus 12, and a path 23 that connects the path 22 and the path 24. The path 22 is provided with a relay 25 (switch) that disconnects and connects the path 22 between a connection point N1 between the path 22 and the path 23 and a connection point N2 between the path 22 and the bus 11. The path 23 is provided with a relay 26 (switch) that disconnects and connects the path 23. The path 24 is provided with a relay 27 (switch) that disconnects and connects the path 24 between a connection point N3 between the path 24 and the path 23 and a connection point N4 between the path 24 and the bus 12. The relays 25 to 27 are controlled by the ECU 16. The paths 22 to 24 and the relays 25 to 27 form a switching circuit.

[0076] According to the above configuration, the ECU 16 can switch the first storage battery module 30 and the second storage battery module 60 to a parallel connection with respect to the buses 11 and 12 by turning on (connecting) the relays 25 and 27 and turning off (disconnecting) the relay 26. The ECU 16 can also switch the first storage battery module 30 and the second storage battery module 60 to a series connection with respect to the buses 11 and 12 by turning off (disconnecting) the relays 25 and 27 and turning on (connecting) the relay 26. That is, the switching circuit switches the storage battery modules 30 and 60 (plurality of storage battery modules) between a series connection and a parallel connection with respect to the buses 11 and 12. When the storage battery modules 30 and 60 are switched to a parallel connection by the switching circuit, power can be supplied from the storage battery modules 30 and 60 to the buses 11 and 12. For this reason, the storage battery modules 30 and 60 can be used as redundant power sources. Then, in a state in which the storage battery modules 30, 60 are switched to a parallel connection by the switching circuit, the ECU 16 can execute the above-mentioned control of the power supply system 10 and control similar to the modified example thereof. When the storage battery modules 30, 60 are switched to a series connection by the switching circuit, a voltage obtained by adding up the output voltages Vm1, Vm2 of the storage battery modules 30, 60 can be supplied to the buses 11, 12. Therefore, the storage battery modules 30, 60 can be used as a higher voltage power source.

[0077] Furthermore, the load 28 may be connected in parallel to the second storage battery 61 (storage battery) of the second storage battery module 60 (storage battery module). In this case, the charge amount of the second storage battery 61 can be reduced by supplying power from the second storage battery 61 to the load 28. For this reason, the second output voltage Vb2 of the second storage battery 61 of the second storage battery module 60 can be made lower than the first output voltage Vb1 of the first storage battery 31 of the first storage battery module 30. Therefore, it becomes easier to perform control to add the second output voltage Vo2 of the second conversion circuit 70 to the second output voltage Vb2 of the second storage battery 61 of the second storage battery module 60, and it becomes easier to adjust the second output voltage Vm2 of the second storage battery module 60 to the bus voltage request value Vbus*.

[0078] Second embodiment The second embodiment will be described below, focusing on the differences from the first embodiment. Note that the same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof will be repeated.

[0079] In this embodiment, as shown in Fig. 11, the power supply system 210 includes three or more storage battery modules 30, 60, 90. Here, an example will be described in which the power supply system 210 includes three storage battery modules 30, 60, 90. Note that in Fig. 11, the connection state of the conversion circuits 40, 70, 100 (PPC: Partial Power Converter, partial boost converter) is shown in a simplified manner. The storage battery modules 30, 60, 90 include voltage sensors 31a, 61a, 91a that detect the voltages of the storage batteries 31, 61, 91, respectively, and relays 40a, 40b, 70a, 70b, 100a, 100b (switches) that disconnect and connect the storage battery modules 30, 60, 90 to the buses 11, 12, respectively.

[0080] 12 is a flowchart showing a procedure for calculating the full charge capacity according to this embodiment. This series of processes is repeatedly executed by the ECU 16 at a predetermined interval.

[0081] The process of S30 is the same as the process of S10 in FIG. 7. In this determination, when it is determined that it is the timing to start charging (S30: YES), the number of non-estimated storage batteries and estimated storage batteries is determined (S31). Specifically, the number of storage batteries to be selected as non-estimated storage batteries is determined based on the chargeable current (chargeable power) of the power supply system 10. The chargeable current of the power supply system 10 (system) can be, for example, a current upper limit value determined by the specifications of the external charger 29 or a current upper limit value determined by the specifications of the conversion circuits 40, 70, 100, etc., acquired by communication or the like and used. The relationship between the chargeable current of the power supply system 10 and the number of storage batteries to be selected as non-estimated storage batteries can be specified in advance based on tests or the like (for example, a table or graph is stored in the ECU 16). For example, the larger the chargeable current of the power supply system 10, the more storage batteries to be selected as non-estimated storage batteries. Here, the number of storage batteries to be selected as non-estimated storage batteries can also be specified taking into consideration the chargeable current (chargeable power) of each storage battery described later. Then, the number of batteries to be selected as estimated batteries is determined by subtracting the number of batteries selected as non-estimated batteries from the total number N of batteries. That is, the number of batteries to be selected as estimated batteries when charging of the non-estimated batteries starts is determined based on the chargeable power (current carrying capacity) of each battery and the chargeable power of the power supply system 10. When the number of batteries to be selected as estimated batteries is determined, the method of determining the batteries to be preferentially selected as estimated batteries is the same as the process of S11 in Fig. 7. Next, charging of all non-estimated batteries starts (S32).

[0082] The processing of S33 to S35 is similar to the processing of S13 to S35 in Fig. 7. However, the processing of S34 and S35 targets all the estimated batteries.

[0083] The processes of S36 and S37 are similar to the processes of S16 and S17 in Fig. 7. However, the processes of S36 and S37 are targeted at all of the storage batteries 31, 61, and 91 (all of the storage battery modules 30, 60, and 90).

[0084] The process of S38 is the same as the process of S18 in FIG. 7. However, the process of S38 targets all the storage batteries 31, 61, 91 (all storage battery modules 30, 60, 90). For example, in a state where charging of the non-estimated storage batteries is started and the estimated storage batteries are left to be depolarized, the conversion circuits corresponding to all the non-estimated storage batteries are controlled to distribute the rated charging power of the external charger 29 to all the non-estimated storage batteries. In addition, in a state where charging of the estimated storage batteries is also started and the non-estimated storage batteries and the estimated storage batteries are being charged, the conversion circuits corresponding to all the estimated storage batteries and the conversion circuits corresponding to all the non-estimated storage batteries are controlled so that the charging time of the estimated storage batteries for the connection (charging request) of the charging cables 29a, 29b is shorter than the charging time of the non-estimated storage batteries for the charging request. In a state where the charging end conditions of some of the non-estimated storage batteries and some of the estimated storage batteries are satisfied and only some of the non-estimated storage batteries and the estimated storage batteries are being charged, the rated charging power of the external charger 29 is distributed to some of the charging batteries.

[0085] Next, it is determined whether the chargeable current of the power supply system 10 is greater than the total chargeable current of the non-estimated batteries (S39). The chargeable current of the non-estimated batteries (storage batteries) can be specified in advance based on tests or the like (for example, a map is stored in the ECU 16). For example, the higher the temperature of the storage battery, the greater the chargeable current of the storage battery, and the lower the SOC of the storage battery, the greater the chargeable current. Then, the chargeable current of the storage battery is calculated by referring to the map and applying the temperature and SOC of the storage battery. In this determination, if it is determined that the chargeable current of the power supply system 10 is greater than the total chargeable current of the non-estimated batteries (S39: YES), one of the batteries selected as the estimated battery is changed to a non-estimated battery and charging is started (S40). As shown in FIG. 13, when charging the non-estimated batteries, if the total current of the non-estimated batteries to be charged is significantly smaller than the chargeable current of the power supply system 10 (for example, the number of non-estimated batteries=1), the charging efficiency of the storage battery in the power supply system 10 decreases. For example, the charging time required to charge all the non-estimated batteries becomes longer. Here, the batteries cannot be charged with a current larger than the chargeable current of the power supply system 10. If a current larger than the chargeable current of each battery is passed through each battery, each battery will deteriorate. For this reason, the charging current is the smaller of the sum of the chargeable current of the power supply system 10 and the chargeable current of the non-estimated batteries. For example, when the number of non-estimated batteries is 4, the sum of the chargeable currents of the non-estimated batteries is slightly larger than the chargeable current of the power supply system 10. In this case, in the process of S38, the chargeable current of the power supply system 10 is distributed to the four non-estimated batteries for charging, thereby improving the charging efficiency of the batteries in the power supply system 10. Furthermore, the number of estimated batteries=N-4 can be made as large as possible. When the number of non-estimated batteries=5, the number of estimated batteries=N-5 becomes smaller. Therefore, in the process of S40, one of the batteries selected as the estimated battery is changed to a non-estimated battery and charging is started.

[0086] Next, it is determined whether the voltage difference between the output voltage Vb of the non-estimated battery and the output voltage Vb of the estimated battery is greater than a predetermined voltage difference (S41). When there are multiple non-estimated batteries, the maximum value, average value, minimum value, etc. of the output voltage Vb of the multiple non-estimated batteries can be appropriately used for the determination. Similarly, when there are multiple estimated batteries, the maximum value, average value, minimum value, etc. of the output voltage Vb of the multiple estimated batteries can be appropriately used for the determination. The predetermined voltage difference is set to a value that makes it possible to determine that it is difficult to adjust the output voltage Vm of the battery module corresponding to the non-estimated battery and the output voltage Vm of the battery module corresponding to the estimated battery so that they match. In this determination, when it is determined that the voltage difference between the output voltage Vb of the non-estimated battery and the output voltage Vb of the estimated battery is greater than the predetermined voltage difference (S41: YES), the charging power of the battery being charged is adjusted (S42). Specifically, the conversion circuit corresponding to the estimated battery and the conversion circuit corresponding to the non-estimated battery are controlled so as to increase the power or current input to at least one battery included in the non-estimated battery and the estimated battery with the lower output voltage from the current level. For example, the power or current input to the battery with the lowest output voltage included in the non-estimated battery and the estimated battery with the lower output voltage is increased from the current level. Alternatively, the conversion circuit corresponding to the estimated battery and the conversion circuit corresponding to the non-estimated battery are controlled so as to decrease the power or current input to at least one battery included in the non-estimated battery and the estimated battery with the higher output voltage from the current level. For example, the power or current input to the battery with the highest output voltage included in the non-estimated battery and the estimated battery with the higher output voltage is decreased from the current level.

[0087] The processing of S43 to S45 is similar to the processing of S19 to S21 in Fig. 7. However, the processing of S43 to S45 targets all the estimated batteries.

[0088] The processes of S34, S44, and S45 correspond to the processes performed by the parameter acquisition unit 16c, and the processes of S32, S35, S38, S40, and S42 correspond to the processes performed by the control unit 16b.

[0089] The present embodiment described above in detail has the following advantages in addition to the advantages of the first embodiment.

[0090] When the voltage difference between the output voltage Vb of the non-estimated battery and the output voltage Vb of the estimated battery is greater than a predetermined voltage difference from the start to the end of charging of the multiple batteries 31, 61, 91, the control unit 16b controls the conversion circuit corresponding to the estimated battery and the conversion circuit corresponding to the non-estimated battery to reduce the voltage difference. With this configuration, it is possible to prevent the voltage difference between the output voltage Vb of the non-estimated battery and the output voltage Vb of the estimated battery from becoming too large. Therefore, it is possible to maintain a state in which the output voltage Vm of the battery module corresponding to the non-estimated battery and the output voltage Vm of the battery module corresponding to the estimated battery can be adjusted by the conversion circuit so as to match each other.

[0091] The control unit 16b determines the number of storage batteries to be selected as estimated storage batteries when charging of the non-estimated storage batteries starts, based on the chargeable power of each storage battery and the chargeable power of the power supply system 10. With this configuration, the number of non-estimated storage batteries to be charged can be determined in consideration of the chargeable power of each storage battery and the chargeable power of the power supply system 10. Therefore, it is possible to suppress a decrease in the charging efficiency of the power supply system 10.

[0092] When the chargeable current of the power supply system 10 is greater than the sum of the chargeable currents of all the non-estimated batteries between the start of charging of all the non-estimated batteries and the start of charging of the estimated battery, the control unit 16b changes one of the batteries selected as the estimated battery at the start of charging of the non-estimated batteries to a non-estimated battery and starts charging it. With this configuration, when the chargeable current of the power supply system 10 does not reach even if all the non-estimated batteries are charged, the sum of the charging currents of the non-estimated batteries can be increased. Therefore, even if too many batteries are selected as estimated batteries at the start of charging of the non-estimated batteries, a decrease in the charging efficiency of the power supply system 10 can be suppressed.

[0093] The second embodiment can be modified as follows: The same parts as those in the first and second embodiments are denoted by the same reference numerals and the description thereof will be incorporated herein.

[0094] The process of S31 in FIG. 12 may be executed before the series of processes in FIG. 12 is started.

[0095] In the process of S38 in FIG. 12, when charging of the non-estimated batteries has been started and the estimated batteries have been left to depolarize, if an uncharged battery is included in the non-estimated batteries, charging of one of the uncharged non-estimated batteries may be started instead of the process of S40.

[0096] As shown in FIG. 14, the power supply system 210 may include a path 211 that connects a connection point N7 between the third conversion circuit 100 and the relay 100a of the third storage battery module 90 and a connection point N8 between the first storage battery 31 and the relay 40b of the first storage battery module 30. Furthermore, the power supply system 210 may include a path 213 that connects a connection point N9 between the first conversion circuit 40 and the relay 40a of the first storage battery module 30 and a connection point N10 between the second storage battery 61 and the relay 70b of the second storage battery module 60. The path 211 is provided with a relay 212 (switch) that disconnects and connects the path 211. The path 213 is provided with a relay 214 (switch) that disconnects and connects the path 213. The relays 212 and 214 are controlled by the ECU 16. The paths 211 and 213 and the relays 212 and 214 form a switching circuit. That is, the power supply system 210 may include three or more storage battery modules (a plurality of storage battery modules), and the switching circuit may switch the three or more storage battery modules between series connection and parallel connection with the buses 11 and 12.

[0097] The first and second embodiments can be modified as follows: The same parts as those in the first and second embodiments are denoted by the same reference numerals and the description thereof will be incorporated herein.

[0098] To determine whether the charging end condition is met, a voltage threshold value lower than the full charge voltage threshold value (for example, corresponding to a predetermined SOC) may be used.

[0099] The load 21 may be, for example, a combination of an inverter and a motor generator (MG) (motor unit with inverter), and two or more of these may be connected in parallel to the buses 11 and 12. In this case, the number of storage battery modules connected to the buses 11 and 12 may be increased as the number of motor units with inverter increases.

[0100] As shown in Fig. 15, in the first conversion circuit 40 (conversion circuit), the switching elements 54, 55 in Fig. 2 may be connected between the transformer 53 and the negative terminal 48. With such a configuration, it is possible to achieve the same effects as the first conversion circuit 40 in Fig. 2. The same is true for the second conversion circuit 70 and the third conversion circuit 100, etc. (conversion circuits).

[0101] 16, the first conversion circuit 40 (conversion circuit) may be a well-known insulated DC-DC converter including a non-center-tapped transformer 153 and a secondary-side full-bridge circuit composed of switching elements 143 to 146. The switching elements 143 to 146 are, for example, MOSFETs and IGBTs (Insulated Gate Bipolar Transistors). The switching elements 143 to 146 are controlled by the ECU 16. The same applies to the second conversion circuit 70 and the third conversion circuit 100 (conversion circuit).

[0102] A resonant DC-DC converter may be used as the first conversion circuit 40 (conversion circuit). A non-isolated DC-DC converter such as a buck converter may be used as the first conversion circuit 40 (conversion circuit). The same applies to the second conversion circuit 70 and the third conversion circuit 100 (conversion circuit).

[0103] The storage battery modules 30, 60 may be configured as shown in FIG. 17. That is, the positive electrode of the first storage battery 31 is connected to the bus 11. The positive electrode of the first storage battery 31 is connected to the positive terminal 41 of the primary side of the first conversion circuit 40, and the negative electrode of the first storage battery 31 is connected to the negative terminal of the first storage battery 31. The positive terminal 47 of the secondary side of the first conversion circuit 40 is connected to the negative terminal of the first storage battery 31. The negative terminal 48 of the secondary side of the first conversion circuit 40 is connected to the bus 12. In this case, the positive and negative electrodes of the first storage battery 31 are connected to the primary terminal pair 41, 42 of the first conversion circuit 40, respectively, and the first storage battery 31 is connected in series to the secondary terminal pair 47, 48 of the first conversion circuit 40. With such a configuration, the same effects as those of the above embodiment can be achieved. The same applies to the second storage battery module 60, the third storage battery module 90, etc. (storage battery modules).

[0104] 18, a general DC-DC converter other than a PPC (partial boost converter) may be adopted as the conversion circuits 240 and 270. A secondary terminal 48 of the conversion circuit 240 is connected to the negative electrode of the first storage battery 31. That is, the first storage battery 31 may be connected in parallel to the secondary terminal pair 47 and 48 of the first conversion circuit 40. The same applies to the second storage battery module 60 and the third storage battery module 90 (storage battery modules).

[0105] The parameter acquisition unit 16c can also acquire the OCV (predetermined parameter) and SOC (predetermined parameter) used to estimate the full charge capacity of the estimated battery before and after discharging (energization) of the estimated battery. As shown in FIG. 19, when the control unit 16b inputs a travel request (a request to discharge a plurality of batteries) at timing t61, the control unit 16b starts traveling of the vehicle by discharging at least one of the non-estimated batteries. On the other hand, at timing t62, a predetermined time after the input of the travel request, the control unit 16b acquires the pre-discharge OCV of the estimated battery by the parameter acquisition unit 16c and then starts discharging. The control unit 16b controls the conversion circuit corresponding to the estimated battery and the conversion circuit corresponding to the non-estimated battery so that the discharge time Te2 of the estimated battery for the travel request is shorter than the discharge time Te1 of the non-estimated battery for the discharge request. When the voltage of the estimated battery is stabilized at timing t64, the parameter acquisition unit 16c acquires the post-discharge OCV of the estimated battery. Then, the parameter acquisition unit 16c calculates the pre-discharge SOC and the post-discharge SOC by applying the pre-discharge OCV and the post-discharge OCV to the graph in Fig. 4. The parameter acquisition unit 16c (ECU 16) then calculates the full charge capacity using the formula: Full charge capacity [Ah] = Discharge amount x 100 / (Pre-discharge SOC - Post-discharge SOC). The discharge amount is the integrated value of the current from the start to the end of discharge. With this configuration, it is possible to achieve the same effects as the first and second embodiments and their modifications.

[0106] At least one of the functions of the bus voltage setting unit 16a, the control unit 16b, and the parameter acquisition unit 16c of the ECU 16 can be realized by, for example, a BMU (Battery Management Unit) provided for each storage battery and managing the state of the storage battery, a power control ECU (Electronic Control Unit) that controls the power of the electric vehicle, or a vehicle control ECU (host ECU) that comprehensively controls the electric vehicle. In addition, when the power supply system 10, 210 is used as, for example, a fixed power source, the functions of the bus voltage setting unit 16a, the control unit 16b, and the parameter acquisition unit 16c of the ECU 16 can be realized by a fixed power source control ECU (control device) that controls the fixed power source.

[0107] The ECU 16 and the method described herein may be implemented by a special-purpose computer provided by configuring a processor and a memory programmed to execute one or more functions (instructions) embodied in a computer program. Alternatively, the ECU 16 and the method described herein may be implemented by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the ECU 16 and the method described herein may be implemented 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. Also, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by the computer.

[0108] The above-described embodiment and each modified example may be combined to the extent possible.

[0109] Characteristic configurations extracted from the above-described embodiment and modified examples will be described below. [Configuration 1] A storage battery monitoring system (10, 210) in which a plurality of storage battery modules (30, 60, 90) including a storage battery (31, 61, 91) and a conversion circuit (40, 70, 100) that converts power input from the storage battery to a primary terminal pair (41, 42, 71, 72) and outputs the power from a secondary terminal pair (47, 48, 77, 78) are connected in parallel to at least one of a charging device (29) and a load (21), a parameter acquisition unit (16c, 31a, 51, 61a, 91a) that acquires predetermined parameters used for estimating a full charge capacity of the estimated battery before and after a current supply to the estimated battery is started and ended, the estimated battery being the battery whose full charge capacity is to be estimated; a control unit (16b) that controls the conversion circuits of the plurality of storage battery modules, thereby controlling a current-carrying state of the storage batteries of the plurality of storage battery modules, The control unit, when receiving a request for power supply to the multiple storage batteries, starts power supply to at least one of the non-estimation storage batteries, which are storage batteries whose full charge capacity is not estimated, while starting power supply to the estimated storage battery after a predetermined time has elapsed since the request for power supply was received and after the parameter acquisition unit has acquired the predetermined parameters for the estimated storage battery, and controls the conversion circuit corresponding to the estimated storage battery and the conversion circuit corresponding to the non-estimation storage battery so that the power supply time of the estimated storage battery in response to the request for power supply is shorter than the power supply time of the non-estimation storage battery in response to the request for power supply. [Configuration 2] The battery monitoring system of configuration 1, wherein the specified parameter is an open circuit voltage of the estimated battery measured when the time during which it can be assumed that no current is flowing through the estimated battery is equal to or longer than the specified time, or a charging rate of the estimated battery calculated based on the open circuit voltage. [Configuration 3] The storage battery modules are connected in parallel to the charging device, the energization request for the plurality of storage batteries is a charging request for the plurality of storage batteries, The control unit controls the conversion circuit corresponding to the estimated storage battery and the conversion circuit corresponding to the non-estimated storage battery so that the charging time of the estimated storage battery in response to the charging request is shorter than the charging time of the non-estimated storage battery in response to the charging request, thereby making the average value of the current flowing to the estimated storage battery greater than the average value of the current flowing to the non-estimated storage battery from the start of charging to the end of charging of the multiple storage batteries. [Configuration 4] The control unit controls the conversion circuit corresponding to the estimated storage battery and the conversion circuit corresponding to the non-estimated storage battery to make the charging end timing of the estimated storage battery earlier than the charging end timing of the non-estimated storage battery. [Configuration 5] A battery monitoring system as described in configuration 3 or 4, wherein the positive and negative electrodes of the storage battery are respectively connected to the primary side terminal pair of the conversion circuit, and the storage battery is connected in series to the secondary side terminal pair of the conversion circuit. [Configuration 6] The control unit controls the conversion circuit corresponding to the estimated battery so as to bring the current flowing to the estimated battery closer to zero from the time charging of at least one of the non-estimated batteries is started until charging of the estimated battery is started. [Configuration 7] The control unit controls the conversion circuit corresponding to the estimated battery and the conversion circuit corresponding to the non-estimated battery so that the voltage applied to the estimated battery from the conversion circuit corresponding to the estimated battery is higher than the voltage applied to the non-estimated battery from the conversion circuit corresponding to the non-estimated battery from the start of charging of the estimated battery to the end of charging. [Configuration 8] The control unit controls the conversion circuit corresponding to the estimated battery and the conversion circuit corresponding to the non-estimated battery so as to increase the power or current input to at least one storage battery included in the non-estimated storage battery and the estimated storage battery having the lower output voltage from the current level, or to decrease the power or current input to at least one storage battery included in the non-estimated storage battery and the estimated storage battery having the higher output voltage from the current level, when a voltage difference between the output voltage of the non-estimated storage battery and the output voltage of the estimated storage battery is greater than a predetermined voltage difference from the start of charging to the end of charging of the multiple storage batteries. [Configuration 9] A battery monitoring system described in any one of configurations 1 to 8, wherein the control unit selects at least one of the storage batteries that is predicted to be the most deteriorated among the multiple storage batteries and the storage battery that has not had its full charge capacity calculated for the longest period among the multiple storage batteries as the estimated storage battery. [Configuration 10] A battery monitoring system described in any one of configurations 1 to 9, wherein the control unit determines the number of batteries to be selected as the estimated batteries when power supply to the non-estimated batteries begins based on the available power of each battery and the available power of the battery monitoring system. [Configuration 11] The control unit of the battery monitoring system of configuration 10 changes at least one of the batteries selected as the estimated battery at the time when power supply to the non-estimated battery starts to the non-estimated battery to the non-estimated battery and starts power supply when the available power of the battery monitoring system is greater than the total available power of all of the non-estimated batteries between the time when power supply to all of the non-estimated batteries starts to start to the estimated battery. [Configuration 12] The control unit terminates energization of the estimated storage battery when a next energization request for the multiple storage batteries is input between the start and end of energization of the estimated storage battery, and starts energization after the specified time has elapsed since the end of energization of the estimated storage battery and after the specified parameters are acquired in the estimated storage battery by the parameter acquisition unit. [Explanation of symbols]

[0110] 10...power supply system, 16b...control unit, 16c...parameter acquisition unit, 21...load, 29...external charger, 30...first storage battery module, 31...first storage battery, 31a...voltage sensor, 40...first conversion circuit, 41...positive terminal (primary side terminal pair), 42...negative terminal (primary side terminal pair), 47...positive terminal (secondary side terminal pair), 48...negative terminal (secondary side terminal pair), 51...voltage sensor, 60...second storage battery module, 61...second storage battery, 61a...voltage sensor, 70...second conversion circuit, 71...positive terminal (primary side terminal pair), 72...negative terminal (primary side terminal pair), 77...positive terminal (secondary side terminal pair), 78...negative terminal (secondary side terminal pair), 90...third storage battery module, 91...third storage battery, 91a...voltage sensor, 100...third conversion circuit, 210...power supply system.

Claims

1. A storage battery monitoring system (10, 210) in which a plurality of storage battery modules (30, 60, 90) including a storage battery (31, 61, 91) and a conversion circuit (40, 70, 100) that converts power input from the storage battery to a primary side terminal pair (41, 42, 71, 72) and outputs the power from a secondary side terminal pair (47, 48, 77, 78) are connected in parallel to at least one of a charging device (29) and a load (21), a parameter acquisition unit (16c, 31a, 51, 61a, 91a) that acquires predetermined parameters used for estimating a full charge capacity of the estimated battery before and after a current supply to the estimated battery is started and ended, the estimated battery being the battery whose full charge capacity is to be estimated; a control unit (16b) that controls the conversion circuits of the plurality of storage battery modules, thereby controlling a current-carrying state of the storage batteries of the plurality of storage battery modules, The control unit, when a request for power supply to a plurality of the storage batteries is input, starts power supply to at least one of the non-estimation storage batteries, which are storage batteries whose full charge capacity is not estimated, while starting power supply to the estimated storage battery after a predetermined time has elapsed since the request for power supply was input and after the predetermined parameters have been acquired in the estimated storage battery by the parameter acquisition unit, and controls the conversion circuit corresponding to the estimated storage battery and the conversion circuit corresponding to the non-estimation storage battery so that the power supply time of the estimated storage battery in response to the power supply request is shorter than the power supply time of the non-estimation storage battery in response to the power supply request.

2. The battery monitoring system of claim 1, wherein the specified parameter is an open circuit voltage of the estimated battery measured when the time during which it can be assumed that no current is flowing through the estimated battery is equal to or longer than the specified time, or a charging rate of the estimated battery calculated based on the open circuit voltage.

3. The storage battery modules are connected in parallel to the charging device, the energization request for the plurality of storage batteries is a charging request for the plurality of storage batteries, The control unit controls the conversion circuit corresponding to the estimated storage battery and the conversion circuit corresponding to the non-estimated storage battery so that the charging time of the estimated storage battery in response to the charging request is shorter than the charging time of the non-estimated storage battery in response to the charging request, thereby making the average value of the current flowing through the estimated storage battery greater than the average value of the current flowing through the non-estimated storage battery from the start of charging to the end of charging of the multiple storage batteries.

4. The battery monitoring system of claim 3, wherein the control unit controls the conversion circuit corresponding to the estimated battery and the conversion circuit corresponding to the non-estimated battery to make the charging end timing of the estimated battery earlier than the charging end timing of the non-estimated battery.

5. The battery monitoring system according to claim 3 , wherein the positive and negative electrodes of the storage battery are respectively connected to the primary terminal pair of the conversion circuit, and the storage battery is connected in series to the secondary terminal pair of the conversion circuit.

6. The battery monitoring system of claim 5, wherein the control unit controls the conversion circuit corresponding to the estimated battery so as to bring the current flowing to the estimated battery closer to zero from the time charging of at least one of the non-estimated batteries is started until charging of the estimated battery is started.

7. The battery monitoring system of claim 5, wherein the control unit controls the conversion circuit corresponding to the estimated battery and the conversion circuit corresponding to the non-estimated battery so that the voltage applied to the estimated battery from the conversion circuit corresponding to the estimated battery is higher than the voltage applied to the non-estimated battery from the conversion circuit corresponding to the non-estimated battery from the start of charging of the estimated battery to the end of charging.

8. The battery monitoring system of claim 5, wherein the control unit controls the conversion circuit corresponding to the estimated battery and the conversion circuit corresponding to the non-estimated battery so as to increase the power or current input to at least one storage battery among the non-estimated battery and the estimated battery having the lower output voltage from the current level when the voltage difference between the output voltage of the non-estimated battery and the output voltage of the estimated battery is greater than a predetermined voltage difference from the start of charging to the end of charging of the multiple storage batteries, or to decrease the power or current input to at least one storage battery among the non-estimated battery and the estimated battery having the higher output voltage from the current level.

9. The battery monitoring system of claim 1 or 2, wherein the control unit selects as the estimated battery at least one of the storage batteries that is predicted to be the most degraded among the plurality of storage batteries and the storage battery that has not had its full charge capacity calculated for the longest period among the plurality of storage batteries.

10. The battery monitoring system of claim 1 or 2, wherein the control unit determines the number of batteries to be selected as the estimated batteries when power supply to the non-estimated batteries begins based on the available power of each battery and the available power of the battery monitoring system.

11. The battery monitoring system of claim 10, wherein when the available power of the battery monitoring system is greater than the sum of the available power of all the non-estimated batteries between the start of power supply to all the non-estimated batteries and the start of power supply to the estimated battery, the control unit changes at least one of the batteries selected as the estimated battery at the start of power supply to the non-estimated batteries to the non-estimated battery and starts power supply.

12. The control unit terminates energization of the estimated storage battery when a next energization request for multiple storage batteries is input between the start and end of energization of the estimated storage battery, and starts energization after the specified time has elapsed since the end of energization of the estimated storage battery, and after the specified parameters are acquired in the estimated storage battery by the parameter acquisition unit.

13. A control program applied to a storage battery monitoring system (10) in which a storage battery module (30, 60, 90) including a storage battery (31, 61, 91) and a conversion circuit (40, 70, 100) that converts power input from the storage battery to a primary terminal pair (41, 42, 71, 72) and outputs the power from a secondary terminal pair (47, 48, 77, 78) is connected in parallel to at least one of a charging device (29) and a load (21), A process of acquiring predetermined parameters used for estimating a full charge capacity of an estimated battery before and after a current is applied to the estimated battery, the estimated battery being the battery whose full charge capacity is to be estimated; A process of controlling a current-carrying state of the storage batteries of the plurality of storage battery modules by controlling the conversion circuits of the plurality of storage battery modules, respectively; a process of starting current supply to at least one non-estimation battery, which is a storage battery for which a full charge capacity is not estimated, when a current supply request for the plurality of storage batteries is input, while starting current supply to the estimated storage battery after a predetermined time has elapsed since the current supply request was input and after the predetermined parameters have been acquired, and controlling the conversion circuit corresponding to the estimated storage battery and the conversion circuit corresponding to the non-estimation storage battery so that a current supply time of the estimated storage battery in response to the current supply request is shorter than a current supply time of the non-estimation storage battery in response to the current supply request; A control program for causing a computer (16) to execute the above.

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