Power supply system, control device, and control program

Abstract

To flexibly adjust temperatures of storage batteries while energizing between the storage batteries and a load in a power supply system with a plurality of storage batteries.SOLUTION: In a power supply system (10), a plurality of storage battery modules (30, 60, 90) comprising storage batteries (31, 61, 91) and conversion circuits (40, 70, 100) and a load (21) are connected in parallel with power supply buses (11, 12). Positive electrodes and negative electrodes of the storage batteries are connected with primary side terminal pairs (41, 42, 71, 72, 101, 102) of the conversion circuits, respectively, and the storage batteries are connected in series with secondary side terminal pairs (47, 48, 77, 78, 107, 108) of the conversion circuits. An energization operation of the storage batteries and the load and a temperature raising operation for raising temperatures of the storage batteries by charging / discharging among the plurality of storage batteries are simultaneously executed by controlling the conversion circuits of the plurality of storage battery modules, respectively.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power supply system. [Background technology]

[0002] For example, there is a power supply system in which a plurality of power conversion devices are provided corresponding to a plurality of power storage devices, the number of power storage devices to be operated is set based on the power required by the load device and the allowable charge / discharge power of each of the plurality of power storage devices, which is defined based on the state of each of the plurality of power storage devices, and power is exchanged between the load device and the set number of power storage devices (see Patent Document 1).The power supply system described in Patent Document 1 is said to be able to heat up the power storage devices quickly because the charge / discharge current per power storage device is larger and the amount of heat generated per power storage device is larger than when all of the power storage devices are used to exchange power with the load device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-11138 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the power supply system described in Patent Document 1, for example, when a set number of power storage devices (storage batteries) are discharged (powered) to load devices (loads) to raise the temperature of the power storage devices, the temperature of the power storage devices cannot be flexibly adjusted while discharging to the load devices. Also, when a set number of power storage devices are charged (powered) from the load devices to raise the temperature of the power storage devices, the temperature of the power storage devices cannot be flexibly adjusted while charging from the load devices.

[0005] The present invention has been made to solve the above-mentioned problems, and its main object is to make it possible to flexibly adjust the temperature of a storage battery while current is flowing between the storage batteries and a load in a power supply system having multiple storage batteries. [Means for solving the problem]

[0006] The first means for solving the above problem is A power supply system (10, 210) in which a plurality of storage battery modules (30, 60, 90) each 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, 101, 102) and outputs the power from a secondary terminal pair (47, 48, 77, 78, 107, 108) and a load (21) are connected in parallel to a power supply bus (11, 12), a positive electrode and a negative electrode 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; an energization execution unit (16c) that controls the conversion circuits of the plurality of storage battery modules to execute an energization operation between the storage battery and the load; a temperature-raising execution unit (16d) that controls each of the conversion circuits of the plurality of storage battery modules to perform a temperature-raising operation of raising the temperatures of the plurality of storage batteries by charging and discharging between the plurality of storage batteries, The current application operation by the current application execution unit and the temperature increase operation by the temperature increase execution unit are performed simultaneously.

[0007] 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, and a load are connected in parallel to a power supply bus. Therefore, the plurality of storage batteries can discharge power to the load via the power supply bus, and the load can charge the storage battery via the power supply bus. Note that the power supply bus is a power path (common power path) shared in the power supply system to connect a plurality of circuits, devices, and equipment to exchange power.

[0008] The positive and negative electrodes of the storage battery are connected to the primary terminal pair of the conversion circuit, respectively, and the storage battery is connected in series to the secondary terminal pair of the conversion circuit. With this configuration, the sum of the output voltage Vb of the storage battery and the output voltage Vo of the conversion circuit becomes the output voltage Vm of the storage battery module. Therefore, compared to a storage battery module in which the storage battery is connected in parallel to the 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.

[0009] Here, the current supply execution unit controls the conversion circuits of the plurality of storage battery modules, respectively, to perform a current supply operation between the storage battery and the load. Therefore, it is possible to heat up the storage battery that has performed a current supply operation with the load. Furthermore, the temperature increase execution unit controls the conversion circuits of the plurality of storage battery modules, respectively, to perform a temperature increase operation to increase the temperature of the plurality of storage batteries by charging and discharging between the plurality of storage batteries. Therefore, it is possible to increase the temperature of the plurality of storage batteries that have performed a temperature increase operation, in addition to the temperature increase of the storage battery due to the current supply operation between the storage battery and the load. Furthermore, the power supply system simultaneously performs the current supply operation by the current supply execution unit and the temperature increase operation by the temperature increase execution unit. Therefore, it is possible to flexibly adjust the temperature of the storage battery while current is being supplied between the storage battery and the load.

[0010] The second means includes a status acquisition unit (32, 62, 92) that acquires the status of the plurality of storage batteries, and the current supply execution unit adjusts the power ratio of the plurality of storage batteries in the current supply operation based on the status of the plurality of storage batteries acquired by the status acquisition unit. With this configuration, the power ratio of the plurality of storage batteries in the current supply operation is adjusted based on the status of the plurality of storage batteries, so that the temperature of the storage batteries can be further flexibly adjusted through the current supply operation by the current supply execution unit.

[0011] In a third aspect, the status acquisition unit acquires the charging rates of the multiple storage batteries as the status of the multiple storage batteries, and the energization execution unit adjusts the power ratio of the multiple storage batteries in the energization operation so as to reduce the difference in the charging rates of the multiple storage batteries acquired by the status acquisition unit. With this configuration, the energization operation by the energization execution unit can not only energize the storage batteries and the load, but also reduce the difference in the charging rates of the multiple storage batteries.

[0012] In a fourth aspect, the state acquisition unit acquires the health of the plurality of storage batteries as the state of the plurality of storage batteries, and the energization execution unit increases the power ratio in the energization operation for a storage battery having a higher health acquired by the state acquisition unit. With this configuration, not only can the energization operation by the energization execution unit energize the storage battery and the load, but also the difference in health of the plurality of storage batteries can be reduced. In other words, by increasing the energization power in the energization operation for a storage battery having a higher health, the difference in health of the storage batteries from the other storage batteries can be reduced. The state of health (SOH) [%] of a storage battery can be calculated by the formula: SOH [%] = current full charge capacity × 100 / full charge capacity at the time of manufacture.

[0013] The fifth means includes a status acquisition unit (16e) that acquires at least one of the status, physical arrangement, and power supply schedule of the plurality of storage batteries, and the temperature rise execution unit determines the storage battery for which the temperature rise operation is to be performed based on the status of the plurality of storage batteries acquired by the status acquisition unit. With this configuration, the storage battery for which the temperature rise operation is to be performed can be appropriately determined based on the status of the plurality of storage batteries. Note that acquiring the power supply schedule includes a case where the power supply schedule is received by communication or the like, and a case where the power supply schedule is predicted.

[0014] In a sixth aspect, the status acquisition unit acquires the health of the multiple storage batteries as the status of the multiple storage batteries, and the temperature rise execution unit determines the storage battery whose health status acquired by the status acquisition unit is higher than that of the other storage batteries as the execution target. With this configuration, the temperature rise execution unit not only raises the temperature of the multiple storage batteries but also reduces the difference in health of the multiple storage batteries. In other words, by actively executing the temperature rise operation on a storage battery whose health status is higher than that of the other storage batteries, the difference in health of the storage batteries from the other storage batteries can be reduced.

[0015] In a seventh means, the status acquisition unit acquires the physical arrangement of the multiple storage batteries as the status of the multiple storage batteries, and the heating execution unit determines, based on the physical arrangement of the multiple storage batteries acquired by the status acquisition unit, as the execution target a storage battery that is less susceptible to receiving heat from the outside than other storage batteries, or a storage battery that is more likely to dissipate heat to the outside than other storage batteries.

[0016] According to the above configuration, the temperature-raising execution unit determines the storage battery that is less susceptible to receiving heat from the outside than the other storage batteries as the execution target. Therefore, it is possible to heat up the storage battery that is less susceptible to heating up than the other storage batteries or that is more susceptible to cooling than the other batteries in advance. Alternatively, the temperature-raising execution unit determines the storage battery that is more susceptible to dissipating heat to the outside than the other storage batteries as the execution target. Therefore, it is possible to heat up the storage battery that is more susceptible to cooling than the other storage batteries in advance.

[0017] In the eighth means, the temperature increase execution unit executes the temperature increase operation so as to keep the temperature of the storage battery determined as the execution target at or above a specified temperature when the outside air temperature is lower than the temperatures of the plurality of storage batteries. With this configuration, for example, even if the outside air temperature is lower than the temperatures of the plurality of storage batteries after the end of the current supply operation between the storage battery and the load, the temperature of the storage battery can be kept at or above a specified temperature by the temperature increase operation. Therefore, when a charge / discharge request is made to the power supply system, charging / discharging in response to the charge / discharge request can be quickly executed.

[0018] In a ninth aspect, the status acquisition unit acquires the states and the energization schedule of the multiple storage batteries as the status of the multiple storage batteries, and the temperature increase execution unit determines the storage battery to be the target of the temperature increase operation based on the states and the energization schedule of the multiple storage batteries acquired by the status acquisition unit. With this configuration, the storage battery to be the target of the temperature increase operation can be appropriately determined in consideration of the states and the energization schedule of the multiple storage batteries. For example, by determining a storage battery that is scheduled to be energized with a load and needs to be heated as the target of the temperature increase operation, the current operation with the load can be started quickly.

[0019] In a tenth aspect, the temperature rise execution unit determines, as the execution target, the storage battery having a larger increase in the available power of the storage battery before and after the execution of the temperature rise operation than the other storage batteries. With this configuration, the available power of the storage battery can be effectively increased by the temperature rise operation, and the current carrying capacity of the power supply system can be effectively improved.

[0020] In an eleventh aspect, the temperature rise execution unit sets the charging rate of the storage battery determined as the execution target higher than the charging rates of the other storage batteries by charging from the load or the other storage batteries before executing the temperature rise operation. With this configuration, even if the charging rate of the execution target storage battery decreases due to the temperature rise operation, it is possible to prevent the difference in charging rates of the multiple storage batteries from becoming large. The twelfth measure is: A control device (16) applied to a power supply system (10, 210) in which a plurality of storage battery modules (30, 60, 90) including storage batteries (31, 61, 91) and a conversion circuit (40, 70, 100) that converts power input from the storage batteries to a pair of primary terminals (41, 42, 71, 72, 101, 102) and outputs the power from a pair of secondary terminals (47, 48, 77, 78, 107, 108) and a load (21) are connected in parallel to a power supply bus (11, 12), and positive and negative electrodes of the storage batteries are connected to the pair of primary terminals of the conversion circuit, respectively, and the storage batteries are connected in series to the pair of secondary terminals of the conversion circuit, an energization execution unit (16c) that controls the conversion circuits of the plurality of storage battery modules to execute an energization operation between the storage battery and the load; a temperature-raising execution unit (16d) that controls each of the conversion circuits of the plurality of storage battery modules to perform a temperature-raising operation of raising the temperatures of the plurality of storage batteries by charging and discharging between the plurality of storage batteries, The current application operation by the current application execution unit and the temperature increase operation by the temperature increase execution unit are performed simultaneously. According to the above configuration, the control device applied to the power supply system can achieve the same effects as the first aspect.

[0021] The thirteenth measure is: A control program applied to a power supply system (10, 210) in which a plurality of storage battery modules (30, 60, 90) including storage batteries (31, 61, 91) and a conversion circuit (40, 70, 100) that converts power input from the storage batteries to a pair of primary terminals (41, 42, 71, 72, 101, 102) and outputs the power from a pair of secondary terminals (47, 48, 77, 78, 107, 108) and a load (21) are connected in parallel to a power supply bus (11, 12), positive and negative electrodes of the storage batteries are respectively connected to the pair of primary terminals of the conversion circuit, and the storage batteries are connected in series to the pair of secondary terminals of the conversion circuit, A process of controlling the conversion circuits of the plurality of storage battery modules to perform a current supply operation between the storage battery and the load; a process of performing a temperature raising operation of raising temperatures of the storage batteries by charging and discharging between the storage batteries by controlling the conversion circuits of the storage battery modules, respectively; are simultaneously executed by a computer (16).

[0022] According to the above configuration, by causing a computer to execute a control program applied to the power supply system, it is possible to achieve the same advantageous effects as the first means. [Brief description of the drawings]

[0023] [Figure 1] Circuit diagram of the power supply system. [Diagram 2] FIG. 4 is a circuit diagram showing an example of a conversion circuit. [Diagram 3] 4 is a flowchart showing the procedure of a current application operation and a temperature increase operation. [Figure 4] 1 is a graph showing the relationship between the internal resistance of a storage battery and the AC frequency. [Diagram 5] 1 is a graph showing the relationship between the amount of heat generated and the current amplitude. [Figure 6] 5A and 5B are schematic diagrams showing an example of performing a current application operation and a temperature increase operation. [Figure 7] 4 is a time chart showing the current of the storage batteries of each storage battery module. [Figure 8] 4 is a time chart showing changes in the operating state, battery temperature, and battery SOC of each storage battery module; [Figure 9] 5 is a time chart showing changes in the operating state, battery temperature, and battery SOC of each storage battery module in a comparative example. [Figure 10] 13A and 13B are schematic diagrams showing another example of the current application operation and the temperature increasing operation. [Figure 11] 13A and 13B are schematic diagrams showing another example of the current application operation and the temperature increasing operation. [Figure 12] 13A and 13B are schematic diagrams showing another example of the current application operation and the temperature increasing operation. [Figure 13] 13A and 13B are schematic diagrams showing another example of the current application operation and the temperature increasing operation. [Figure 14] 13A and 13B are schematic diagrams showing another example of the current application operation and the temperature increasing operation. [Figure 15] FIG. 4 is a schematic diagram showing an example of performing a temperature increasing operation. [Figure 16] FIG. 11 is a schematic diagram showing another example of performing the temperature increasing operation. [Figure 17] FIG. 11 is a circuit diagram of a modified example of a power supply system. [Figure 18] FIG. 13 is a circuit diagram of a modified example of the conversion circuit. [Figure 19] FIG. 13 is a circuit diagram of another modified example of the conversion circuit. [Figure 20] FIG. 11 is a circuit diagram of a modified example of the storage battery module. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an embodiment of a power supply system for inputting and outputting power to and from a load will be described with reference to the drawings.

[0025] 1, a 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 third storage battery module 90, 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.

[0026] A first storage battery module 30 (storage battery module), a second storage battery module 60 (storage battery module), a third storage battery module 90 (storage battery module), a load 21, and a voltage sensor 13 are connected in parallel to the buses 11 and 12. The storage battery modules 30, 60, and 90 input and output power to and from the buses 11 and 12. The load 21 includes a plurality of loads, and inputs and outputs power to and from 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 (load 21).

[0027] 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, an external charger (charging device), or the like. The motor generator (MG) drives, for example, an electric vehicle by power supplied from the inverter, or performs regenerative power generation by a rotational force given by the electric vehicle. The inverter converts power between the buses 11, 12 and the MG. The electric heater generates heat by a high voltage (voltage) supplied from the buses 11, 12, for example, and warms the interior of the vehicle, the battery, or the like. 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 external charger charges the storage batteries 31, 61, 91 by inputting power to the buses 11, 12.

[0028] 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 and 40b, a BMU 32 (Battery Management Unit), 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 and 40b disconnect and connect the storage battery module 30 to the buses 11 and 12, respectively. The first storage battery 31 (storage battery) may be a secondary battery that is not a high voltage battery. A detection value by the first current sensor 33 may be input to the BMU 32.

[0029] 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.

[0030] The BMU 32 (status acquisition unit) includes a temperature sensor, a storage device, a computing device, and the like. The temperature sensor detects the temperature (status) of the first storage battery 31. The storage device (storage unit) stores the characteristics of the first storage battery 31. The characteristics of the first storage battery 31 include, for example, the relationship between the internal resistance of the first storage battery 31 and the AC current frequency (see FIG. 4), the relationship between the amount of heat generated, the current amplitude, and the current flow constraint of the first storage battery 31 (see FIG. 5), and the relationship between the open circuit voltage OCV (open circuit voltage) and the SOC of the first storage battery 31. The BMU 32 calculates (acquires) the SOC (status) of the first storage battery 31 by applying the open circuit voltage OCV detected by the voltage sensor 51 to a graph or map that specifies the relationship between the open circuit voltage OCV and the SOC. The BMU 32 updates the SOC calculated based on the open circuit voltage OCV based on an integrated value of the current detected by the first current sensor 33. The BMU 32 estimates (acquires) the SOH (State Of Health) of the first storage battery 31 as follows. For example, the BMU 32 calculates (acquires) the full charge capacity (state) of the first storage battery 31 using the formula: Full charge capacity [Ah] = Charge amount x 100 / (SOC after charging - SOC before charging). The charge amount is an integrated value of the current from the start to the end of charging, and can be calculated, for example, by integrating the current detected by the current sensor 33. For example, the BMU 32 calculates (acquires) the SOH [%] (state) of the first storage battery 31 using the formula: SOH [%] = Current full charge capacity x 100 / Full charge capacity at the time of manufacture. The status acquisition unit 16e (ECU 16) may calculate (acquire) the SOC and SOH of the first storage battery 31, or the status acquisition unit 16e (ECU 16) may receive (acquire) the SOC and SOH of the first storage battery 31 from the BMU 32.

[0031] The second storage battery module 60 has the same configuration as 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, a BMU 62, and the like. The second conversion circuit 70 (conversion circuit) has the same configuration as 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 the same as that of the first storage battery module 30, and therefore the above description of the first storage battery module 30 is also applicable. The BMU 62 (status acquisition unit) has the same configuration as the BMU 32, and therefore the above description of the BMU 32 is also applicable. 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.

[0032] The third storage battery module 90 has the same configuration as the first storage battery module 30, and includes a third storage battery 91 (storage battery), a third current sensor 93 (current sensor), a third drive circuit 95 (drive circuit), a third conversion circuit 100, relays 100a and 100b, a BMU 92, and the like. The third conversion circuit 100 (conversion circuit) has the same configuration as the first conversion circuit 40, and includes a primary side positive terminal 101 and a negative terminal 102, which are a primary side terminal pair, and a secondary side positive terminal 107 and a negative terminal 108, which are a secondary side terminal pair. The connection manner of these is also the same as the first storage battery module 30, and therefore the above description of the first storage battery module 30 is applicable. The BMU 92 (status acquisition unit) has the same configuration as the BMU 32, and therefore the above description of the BMU 32 is applicable. Although the first storage battery module 30 and the third storage battery module 90 have configurations having similar functions, the ratings and withstand voltages of the respective configurations may be different from each other.

[0033] 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 of the first storage battery 31. The current sensor 52 detects the input current Ii 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 of the first conversion circuit 40. The current sensor 58 detects the current flowing through the reactor 56, i.e., the output current Io 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. The detection value of the voltage sensor 51 may be input to the BMU 32.

[0034] The ECU 16 (control device) is configured as a microcomputer (computer) equipped with, for example, a CPU, a ROM, a RAM, a storage device, and an input / output interface. The ECU 16 controls the states of the relays 40a, 40b, 70a, 70b, 100a, and 100b 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 current supply execution unit 16c, a temperature rise execution unit 16d, a status acquisition unit 16e, and the like. The BMUs 32, 62, and 92 and the ECU 16 can communicate with each other by wire or wirelessly.

[0035] 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.

[0036] The control unit 16b controls the output voltages Vo1, Vo2, and Vo3 of the conversion circuits 40, 70, and 100 so that the output voltages Vm1, Vm2, and Vm3 of the storage battery modules 30, 60, and 90 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*). More specifically, 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). Similarly, the control unit 16b controls the third output voltage Vo3 of the third conversion circuit 100 to become the third output voltage request value Vo3* (approach the third output voltage request value Vo3*). More specifically, the third output voltage request value Vo3* is set to a voltage obtained by subtracting the third output voltage Vb3 of the third storage battery 91 from the bus voltage request value Vbus* (Vo3*=Vbus*-Vb3).

[0037] The current supply execution unit 16c controls the conversion circuits 40, 70, 100 of the storage battery modules 30, 60, 90, respectively, to supply current between the storage batteries 31, 61, 91 and the load 21. The current supply operation includes a discharge operation from the storage batteries 31, 61, 91 to the load 21 (e.g., a motor unit with an inverter) and a charge operation from the load 21 (e.g., an external charger) to the storage batteries 31, 61, 91. The current supply execution unit 16c passes a DC load current between the storage batteries 31, 61, 91 and the load 21 in the current supply operation.

[0038] The temperature rise execution unit 16d controls the conversion circuits 40, 70, 100 of the storage battery modules 30, 60, 90, respectively, to perform a temperature rise operation for raising the temperatures of the storage batteries 31, 61, 91 by charging and discharging between the storage batteries 31, 61, 91. The temperature rise execution unit 16d flows an AC heat generating current between the storage batteries 31, 61, 91 in the temperature rise operation.

[0039] The status acquisition unit 16e acquires the status of the storage battery 31, 61, 91. The status of the storage battery 31, 61, 91 includes, for example, the above-mentioned state of the storage battery 31, 61, 91 acquired by the BMU 32, 62, 92. The status of the storage battery 31, 61, 91 includes, for example, the physical arrangement of the storage battery 31, 61, 91. The physical arrangement is the position of the storage battery 31, 61, 91 in the vehicle, the positional relationship between the storage battery 31, 61, 91 and other devices, and is stored, for example, in a storage device of the ECU 16. The status of the storage battery 31, 61, 91 includes, for example, a power supply schedule of the storage battery 31, 61, 91. The power supply schedule is, for example, the next charging timing or the next discharging timing of the storage battery 31, 61, 91, and can be received (acquired) from the ECU or predicted (acquired) from the state of the vehicle.

[0040] 3 is a flowchart showing the procedure of the current supply operation and the temperature increase operation. This series of processes is repeatedly executed at a predetermined cycle by the ECU 16. Note that the current supply operation includes the discharge operation and the charge operation of the storage batteries 31, 61, 91, but the discharge operation will be mainly described here as an example.

[0041] First, the status of each storage battery 31, 61, 91 is acquired (S10). The status of each storage battery 31, 61, 91 includes the temperature of each storage battery 31, 61, 91, the above characteristics, SOC [%], SOH [%], the above physical arrangement, the above power supply schedule, etc. Based on the acquired temperature of each storage battery 31, 61, 91, it is determined whether or not the temperature variation of the storage batteries 31, 61, 91 is equal to or less than a preset value (S11). For example, it is determined whether or not the difference between the temperature of the storage battery with the highest temperature and the temperature of the storage battery with the lowest temperature is equal to or less than a preset value. The power upper limit value (current supplyable power) as the power supply constraint of the storage batteries 31, 61, 91 becomes smaller as the temperature of the storage battery becomes lower. Therefore, the preset value is set to a value that can determine that the difference in current supplyable power of the storage batteries becomes undesirable, for example. In this determination, when it is determined that the temperature variation of the storage batteries 31, 61, 91 is equal to or less than the preset value (S11: YES), the system transitions to a no-heat-creation mode (S12). The no-heat-creation mode is a mode in which the above-mentioned current application operation is performed, but the above-mentioned temperature increase operation is not performed.

[0042] Next, based on the acquired SOC [%] of each storage battery 31, 61, 91, it is determined whether the SOC variation of the storage batteries 31, 61, 91 is equal to or less than a preset value (S13). For example, it is determined whether the difference between the SOC [%] of the storage battery with the highest SOC [%] and the SOC [%] of the storage batteries 31, 61, 91 is equal to or less than a preset value. If the voltage difference of the output voltages Vb of the storage batteries 31, 61, 91 becomes too large, it becomes difficult to adjust the output voltages Vm of the storage battery modules 30, 60, 90 by the conversion circuits 40, 70, 100 so as to match them. Therefore, the preset value is set to a value that can determine, for example, that the voltage difference of the output voltages Vb of the storage batteries 31, 61, 91 becomes too large. In this determination, if it is determined that the SOC variation of the storage batteries 31, 61, 91 is equal to or less than the preset value (S13: YES), the process proceeds to S14.

[0043] In the process of S14, it is determined whether or not the SOH variation of the storage batteries 31, 61, 91 is equal to or less than a preset value based on the acquired SOH [%] of each storage battery 31, 61, 91. For example, it is determined whether or not the difference between the SOH [%] of the storage battery 31, 61, 91 with the highest SOH [%] and the SOH [%] of the storage battery 31, 61, 91 with the lowest SOH [%] is equal to or less than a preset value. The SOH [%] of the storage batteries 31, 61, 91 correlates with the deterioration degree of the storage batteries 31, 61, 91, and further with the life of the storage batteries 31, 61, 91. Therefore, the preset value is set to a value that can determine that the difference in the deterioration degree of the storage batteries 31, 61, 91 becomes undesirable, for example. In this determination, when it is determined that the SOH variation of the storage batteries 31, 61, 91 is equal to or less than the preset value (S14: YES), the process proceeds to S15.

[0044] In the process of S15, an evenly distributed value that evenly distributes the load current (discharge current or charge current) required for the load 21 is commanded to each storage battery module 30, 60, 90 as each current command value. At this time, if each current command value exceeds the DC Win / Wout constraint of FIG. 5, each current command value is corrected to be within the DC Win / Wout constraint. For example, the DC power upper limit value as the DC Win / Wout constraint during discharge of the storage battery 31, 61, 91 increases as the temperature increases up to the upper limit of the appropriate temperature range of the storage battery 31, 61, 91. Also, the higher the SOC [%] of the storage battery 31, 61, 91, the smaller the upper limit value of the DC Win becomes and the larger the upper limit value of the DC Wout becomes. Then, each conversion circuit 40, 70, 100 of each storage battery module 30, 60, 90 is controlled so that each current flowing between each storage battery module 30, 60, 90 and the load 21 becomes each current command value. After that, this series of processes is temporarily terminated (END).

[0045] On the other hand, if it is determined that the SOC variation of the storage batteries 31, 61, 91 is not equal to or less than the predetermined value (S13: NO), or if it is determined that the SOH variation of the storage batteries 31, 61, 91 is not equal to or less than the predetermined value (S14: NO), the process proceeds to S16.

[0046] In the process of S16, an unequal distribution value that unevenly distributes the load current (discharge current or charge current) required for the load 21 is commanded to each storage battery module 30, 60, 90 as each current command value. Specifically, if the SOC variation of the storage batteries 31, 61, 91 is not equal to or less than a preset value (S13: NO), the unequal distribution value is set so as to reduce the difference in SOC [%]. For example, when discharging from the storage batteries 31, 61, 91 to the load, the unequal distribution value is set to be larger for the storage battery with a higher SOC [%]. When charging the storage batteries 31, 61, 91 from the load, the unequal distribution value is set to be larger for the storage battery with a lower SOC [%]. In other words, based on the acquired SOC [%] of each storage battery 31, 61, 91, the power ratio of the storage batteries 31, 61, 91 in the current application operation is adjusted so as to reduce the difference in SOC [%] of the storage batteries 31, 61, 91. Also, if the SOH variation of the storage batteries 31, 61, 91 is not equal to or less than the preset value (S14: NO), the unequal distribution value is increased for a storage battery with a higher SOH [%]. That is, based on the acquired SOH [%] of each storage battery 31, 61, 91, the power ratio of the storage battery in the energization operation (discharging operation and charging operation) is increased for a storage battery with a higher SOH [%]. Note that, if each current command value exceeds the DC Win / Wout constraint in FIG. 5, each current command value is corrected to within the DC Win / Wout constraint. Then, each conversion circuit 40, 70, 100 of each storage battery module 30, 60, 90 is controlled so that each energization current between each storage battery module 30, 60, 90 and the load 21 becomes each current command value. After that, this series of processes is temporarily terminated (END).

[0047] Furthermore, when it is determined in S11 that the temperature variation of the storage batteries 31, 61, 91 is not equal to or less than the preset value (S11: NO), the system transitions to a heat generation mode (S17). The heat generation mode is a mode in which the above-mentioned current application operation and temperature increase operation are performed. A heat generation target battery is selected (S18). The heat generation target battery is a battery for which the temperature increase operation is to be performed. For example, the temperature of the battery with the highest temperature among the storage batteries 31, 61, 91 is set as a reference temperature, and a battery whose temperature difference from the reference temperature is greater than a preset value is selected as the heat generation target battery.

[0048] Next, it is determined whether the number of heat generation target batteries is two or more (S19). If it is determined that the number of heat generation target batteries is not two or more (S19: NO), the process proceeds to S16. In this case, in the process of S16, the unequal distribution value to be distributed to the storage battery module corresponding to the heat generation target storage battery is set to be greater than the unequal distribution value to be distributed to the other storage battery modules. That is, the power ratio of the storage batteries 31, 61, 91 in the current supply operation is adjusted based on the temperature of each storage battery 31, 61, 91 acquired by the processes of S11, S18, and S16.

[0049] On the other hand, when it is determined that the number of heat generation target batteries is two or more (S19: YES), the AC heat generation current of the heat generation target batteries is determined (S20). Specifically, the required heat generation amount is calculated based on the temperature difference between the above-mentioned reference temperature and the temperature of the heat generation target batteries. Then, the AC heat generation current of the heat generation target batteries is calculated based on the calculated required heat generation amount. For example, when the number of heat generation target batteries is two, AC current is exchanged between the two heat generation target batteries, and the maximum current value allowed by the battery module corresponding to the two heat generation target batteries is selected. The maximum current value allowed is the smaller current value of either the maximum current value that can be input / output by the conversion circuit corresponding to the heat generation target batteries or the maximum current value that can be input / output by the heat generation target batteries. Next, the required internal resistance value of the battery required to satisfy the required heat generation amount with the selected current value is obtained. Furthermore, the AC current frequency that can satisfy the obtained required battery internal resistance value is selected with reference to the graph of the "internal resistance-frequency" characteristic in FIG. 4. The current amplitude is selected from the required amount of heat generation by referring to the graph of the "amount of heat generation - current amplitude" characteristic in FIG. 5 at the selected AC current frequency. However, in the "amount of heat generation - current amplitude" characteristic in FIG. 5, the amount of heat generation must be within the AC Win / Wout constraint, which is the characteristic of the storage battery. For example, the AC Win / Wout constraint of the storage batteries 31, 61, 91 increases as the temperature increases up to the upper limit of the appropriate temperature range of the storage batteries 31, 61, 91. Also, the higher the SOC [%] of the storage batteries 31, 61, 91, the smaller the upper limit value of AC Win and the larger the upper limit value of AC Wout. If the AC Win / Wout constraint is exceeded, the AC frequency is increased (a frequency with a small internal resistance of the storage battery is used) or the current amplitude is reduced to correct it to within the AC Win / Wout constraint. In this way, the AC heat generation current is determined by selecting the AC frequency and the AC amplitude. Note that, if the number of storage batteries to be subjected to heat generation is three, AC current may be exchanged between the three storage batteries to be subjected to heat generation. In addition, when the number of heat generation target batteries is four, AC current may be exchanged between the four heat generation target batteries, or two pairs of AC current may be formed between two heat generation target batteries. Note that the AC heat generation current of the batteries that are not heat generation target batteries is determined to be 0.

[0050] The processes of S21 and S22 are the same as the processes of S13 and S 14. If it is determined in S22 that the SOH variations of the storage batteries 31, 61, and 91 are equal to or smaller than the predetermined value (S22: YES), the process proceeds to S23.

[0051] In the process of S23, a current obtained by adding the AC heat generation current to an evenly distributed value obtained by evenly distributing the load current (discharging current or charging current) required for the load 21 is commanded as each current command value to each storage battery module 30, 60, 90. Then, each conversion circuit 40, 70, 100 of each storage battery module 30, 60, 90 is controlled so that each current flowing between each storage battery module 30, 60, 90 and the load 21 becomes each current command value. After that, this series of processes is temporarily terminated (END).

[0052] On the other hand, if it is determined that the SOC variation of the storage batteries 31, 61, 91 is not equal to or less than the predetermined value (S21: NO), or if it is determined that the SOH variation of the storage batteries 31, 61, 91 is not equal to or less than the predetermined value (S22: NO), the process proceeds to S24.

[0053] In the process of S24, a current obtained by adding the AC heat generation current to an unequal distribution value obtained by unevenly distributing the load current (discharging current or charging current) required for the load 21 is commanded as each current command value to each storage battery module 30, 60, 90. The method of setting the unequal distribution value is the same as the process of S16. Then, each conversion circuit 40, 70, 100 of each storage battery module 30, 60, 90 is controlled so that each current flowing between each storage battery module 30, 60, 90 and the load 21 becomes each current command value. After that, this series of processes is temporarily terminated (END).

[0054] The process of S10 corresponds to the process performed by the status acquisition unit 16e, the processes of S15, S16, S23, and S24 correspond to the process performed by the current application execution unit, and the processes of S23 and S24 correspond to the process performed by the temperature increase execution unit.

[0055] FIG. 6 is a schematic diagram showing an example of the execution of a discharging operation (current application operation) and a temperature increase operation. In the figure, the current due to the discharging operation is represented by a solid arrow, and the current due to the temperature increase operation is represented by a hollow arrow. The same representation will be used in the following figures. The third storage battery module 90 executes only the discharging operation, and the storage battery modules 30 and 60 execute the discharging operation and the temperature increase operation. In detail, the storage battery module 90 is commanded to have an equal distribution value as a current command value (AC heat generation current = 0), and the storage battery modules 30 and 60 are commanded to have a current command value of the equal distribution value plus the AC heat generation current. In this case, the current shown in FIG. 7 flows through each storage battery 31, 61, 91 of each storage battery module 30, 60, 90.

[0056] Fig. 8 is a time chart showing the transition of the operating state, battery temperature, and battery SOC [%] of each storage battery module 30, 60, 90 in the case of Fig. 6 and Fig. 7. As shown in Fig. 8(b), the temperature of the first storage battery 31 shown by the solid line and the temperature of the second storage battery 61 shown by the dashed line rise more rapidly than the temperature of the third storage battery 91 shown by the dashed line. As shown in Fig. 8(c), the SOC [%] of the storage batteries 31, 61, 91 decreases evenly, and a state in which the SOC variation is small is maintained. As a result, it becomes easier to use up the remaining capacity of all the storage batteries 31, 61, 91.

[0057] FIG. 9 is a time chart showing the transition of the operating state, battery temperature, and battery SOC [%] of each storage battery module 30, 60, 90 in the comparative example. In the comparative example, as shown in FIG. 9(a), the third storage battery module 90 is stopped at first, and the storage battery modules 30, 60 discharge to the load 21. As a result, as shown in FIG. 9(b), the temperature of the first storage battery 31 shown by the solid line and the temperature of the second storage battery 61 shown by the dashed line rise, and the temperature of the third storage battery 91 shown by the dashed line becomes constant. At this time, as shown in FIG. 9(c), the SOC [%] of the storage batteries 31, 61 decreases, and the SOC [%] of the third storage battery 91 does not change, so the SOC variation increases. After that, as shown in FIG. 9(b), when the temperature of the storage batteries 31, 61 becomes equal to the temperature of the third storage battery 91, the third storage battery module 90 starts discharging to the load 21, as shown in FIG. 9(a). As a result, although the temperatures of the storage batteries 31, 61, and 91 rise evenly, the SOC variation remains large as shown in FIG. 9(c).

[0058] 10 is a schematic diagram showing another example of the execution of the current application operation and the temperature increase operation. The storage battery modules 30 and 60 execute only the temperature increase operation, and the third storage battery module 90 executes only the discharge operation. For example, when only the third storage battery 91 is at a temperature at which it is possible to discharge to the load 21, only the third storage battery 91 is discharging, and the temperature of the third storage battery 91 is higher than the temperatures of the storage batteries 31 and 61 by a specified value or more, the operation shown in the figure is executed.

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

[0060] The positive and negative electrodes of the storage battery 31, 61, 91 are connected to the primary terminal pair 41, 42, 71, 72, 101, 102 of the conversion circuit 40, 70, 100, respectively, and the storage battery 31, 61, 91 is connected in series to the secondary terminal pair 47, 48, 77, 78, 107, 108 of the conversion circuit 40, 70, 100. According to this configuration, the output voltage Vb of the storage battery 31, 61, 91 plus the output voltage Vo of the conversion circuit 40, 70, 100 becomes the output voltage Vm of the storage battery module 30, 60, 90. Therefore, compared to a storage battery module in which storage batteries 31, 61, 91 are connected in parallel to secondary side terminal pairs 47, 48, 77, 78, 107, 108 of the conversion circuit 40, 70, 100, it is possible to reduce the output voltage Vo required of the conversion circuit 40, 70, 100 when an output voltage Vm is required of the storage battery module 30, 60, 90. Therefore, the rated voltage of the conversion circuit 40, 70, 100 can be lowered, and therefore the rated capacity of the conversion circuit 40, 70, 100 can be reduced, thereby making it possible to miniaturize the conversion circuit 40, 70, 100.

[0061] The energization execution unit 16c controls the conversion circuits 40, 70, 100 of the multiple storage battery modules 30, 60, 90, respectively, to perform energization between the storage batteries 31, 61, 91 and the load 21. This allows the temperature of the storage battery that has performed the energization with the load 21 to be increased. The temperature increase execution unit 16d controls the conversion circuits 40, 70, 100 of the multiple storage battery modules 30, 60, 90, respectively, to perform a temperature increase operation to increase the temperature of the multiple storage batteries 31, 61, 91 by charging and discharging between the multiple storage batteries 31, 61, 91. This allows the temperature of the multiple storage batteries that have performed the temperature increase operation to be increased, in addition to the temperature increase of the storage batteries 31, 61, 91 due to the energization between the storage batteries 31, 61, 91 and the load 21. Furthermore, the power supply system 10 simultaneously performs the energization operation by the energization execution unit 16c and the temperature increase operation by the temperature increase execution unit 16d. Therefore, the temperature of the storage battery 31, 61, 91 can be flexibly adjusted while current is being passed between the storage battery 31, 61, 91 and the load 21. In particular, for example, while the storage battery 31, 61, 91 is discharging to the load 21, the temperature of the storage battery 31, 61, 91 can be made uniform or increased quickly.

[0062] The energization execution unit 16c adjusts the power ratio of the multiple storage batteries 31, 61, 91 in the energization operation based on the states of the multiple storage batteries 31, 61, 91 acquired by the BMUs 32, 62, 92. With this configuration, the power ratio of the multiple storage batteries 31, 61, 91 in the energization operation is adjusted based on the states of the multiple storage batteries 31, 61, 91, so that the temperature of the storage batteries 31, 61, 91 can be adjusted more flexibly through the energization operation by the energization execution unit 16c.

[0063] The current supply execution unit 16c adjusts the power ratios of the multiple storage batteries 31, 61, 91 in the current supply operation so as to reduce the difference in SOC [%] among the multiple storage batteries 31, 61, 91 acquired by the BMUs 32, 62, 92. With this configuration, the current supply operation by the current supply execution unit 16c not only supplies current between the storage batteries 31, 61, 91 and the load 21, but also reduces the difference in SOC [%] among the multiple storage batteries 31, 61, 91.

[0064] The energization execution unit 16c increases the power ratio in energization operation for a storage battery having a higher SOH [%] acquired by the BMU 32, 62, 92. With this configuration, the energization operation by the energization execution unit 16c not only energizes the storage battery 31, 61, 91 and the load 21, but also reduces the difference in SOH [%] between the multiple storage batteries 31, 61, 91. In other words, by increasing the energization power in energization operation for a storage battery with a higher SOH [%], the difference in SOH [%] between the storage batteries and the other storage batteries can be reduced.

[0065] The temperature increase execution unit 16d determines the heat generation target battery based on the status of the multiple storage batteries 31, 61, 91 acquired by the status acquisition unit 16e. With this configuration, the heat generation target battery can be appropriately determined based on the status of the multiple storage batteries 31, 61, 91.

[0066] The above-mentioned advantageous effects can be achieved by causing a computer to execute the control program applied to the power supply system 10.

[0067] The above embodiment can be modified as follows: The same parts as those in the above embodiment are denoted by the same reference numerals and the description thereof will be omitted.

[0068] The status acquisition unit 16e may acquire the states and energization schedule of the multiple storage batteries 31, 61, 91 as the status of the multiple storage batteries 31, 61, 91, and the temperature increase execution unit 16d may determine the heat generation target storage battery based on the states and energization schedule of the multiple storage batteries 31, 61, 91 acquired by the status acquisition unit 16e. With this configuration, the heat generation target storage battery can be appropriately determined in consideration of the states and energization schedule of the multiple storage batteries 31, 61, 91. In FIG. 11, the first storage battery module 30 performs only the warming operation, the second storage battery module 60 performs the discharging operation and the warming operation, and the third storage battery module 90 performs only the discharging operation. For example, by determining the first storage battery 31, which is scheduled to be discharged to the load 21 and requires warming, as the heat generation target storage battery, the discharge operation from the first storage battery 31 to the load 21 can be started quickly. 12, the storage battery modules 30, 60 perform only a temperature increase operation, and the third storage battery module 90 performs a discharge operation and a temperature increase operation. For example, by determining the storage battery 31, 61 that is scheduled to be discharged to the load 21 and requires temperature increase as a heat generation target storage battery, it is possible to promptly start a discharge operation from the storage battery 31, 61 to the load 21.

[0069] The temperature increase execution unit 16d may determine, as the heat generation target battery, a battery in which the increase in the power upper limit value (transmittable power) as the current constraint Win / Wout of the battery before and after the execution of the temperature increase operation is greater than the increase in the other batteries. In FIG. 13, the first battery module 30 is stopped, and the battery modules 60, 90 are executing the discharge operation and the temperature increase operation. For example, when the increase in the transmittable power of the battery 61, 91 before and after the execution of the temperature increase operation for a predetermined time is greater than the increase in the first battery 31, the operation shown in the figure is executed. With this configuration, the transmittable power of the battery 61, 91 can be effectively increased by the temperature increase operation, and the current carrying capacity of the power supply system 10 can be effectively improved.

[0070] The status acquisition unit 16e may acquire the SOH [%] of the multiple storage batteries 31, 61, 91 as the status of the multiple storage batteries 31, 61, 91, and the temperature increase execution unit 16d may determine the storage battery having the SOH [%] acquired by the status acquisition unit 16e higher than the other storage batteries as the execution target. In FIG. 14, the first storage battery module 30 executes only the temperature increase operation, the second storage battery module 60 executes the discharge operation and the temperature increase operation, and the third storage battery module 90 is stopped. For example, when the SOH [%] of the first storage battery 31 is higher than the SOH [%] of the third storage battery 91, the operation shown in the figure is executed. With this configuration, the temperature increase operation by the temperature increase execution unit 16d can not only increase the temperature of the storage batteries 31, 61, but also reduce the difference in SOH [%] between the multiple storage batteries 31, 61, 91. That is, by actively performing a temperature-raising operation on a storage battery whose SOH [%] is higher than the other storage batteries, the difference in SOH [%] with the other storage batteries can be reduced.

[0071] The status acquisition unit 16e acquires the physical arrangement of the multiple storage batteries 31, 61, 91 as the status of the multiple storage batteries 31, 61, 91, and the temperature increase execution unit 16d may determine a storage battery that is less likely to receive heat from the outside than the other storage batteries or that is more likely to radiate heat to the outside than the other storage batteries as a heat generation target storage battery based on the physical arrangement of the multiple storage batteries 31, 61, 91 acquired by the status acquisition unit 16e. In FIG. 15, the storage battery modules 30, 60 perform only a temperature increase operation, and the third storage battery module 90 is stopped. For example, when the storage battery 31, 61 is less likely to receive heat from the outside than the third storage battery 91, the operation shown in the figure is executed. With this configuration, the storage battery 31, 61 that is less likely to warm up than the third storage battery 91 or that is more likely to cool down than the third storage battery 91 can be heated in advance. Or, when the storage battery 31, 61 is more likely to radiate heat to the outside than the third storage battery 91, the operation shown in the figure is executed. According to this configuration, the storage batteries 31, 61, which are more likely to cool than the third storage battery 91, can be heated in advance.

[0072] The temperature increase execution unit 16d may perform a temperature increase operation to keep the temperature of the heat generation target storage battery at or above a specified temperature when the outside air temperature is lower than the temperatures of the multiple storage batteries 31, 61, 91. The outside air temperature can be detected by an outside air temperature sensor provided in the vehicle. The specified temperature is set to, for example, a temperature at which the storage batteries 31, 61, 91 can exert a standard current carrying capacity. In FIG. 16, the storage battery modules 30, 60, 90 perform only a temperature increase operation. For example, when the outside air temperature is lower than the temperature of the storage batteries 31, 61, 91, the operation shown in the figure is performed. With this configuration, for example, even if the outside air temperature is lower than the temperature of the multiple storage batteries 31, 61, 91 after the current carrying operation between the storage batteries 31, 61, 91 and the load 21 is completed, the temperature of the storage batteries 31, 61, 91 can be kept at or above the specified temperature by the temperature increase operation. Therefore, when a current carrying request is made to the power supply system 10, current carrying in response to the current carrying request can be promptly performed.

[0073] The temperature increase execution unit 16d may make the SOC [%] of the storage battery determined as the heat generation target storage battery higher than the SOC [%] of the other storage batteries by charging from the load 21 or other storage batteries before executing the temperature increase operation. With this configuration, even if the SOC [%] of the heat generation target storage battery decreases due to the temperature increase operation, it is possible to prevent the difference in SOC [%] of the multiple storage batteries 31, 61, 91 from becoming large.

[0074] As shown in FIG. 17, 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 second storage battery 61 and the relay 70b of the second storage battery module 60. Furthermore, the power supply system 210 may include a path 213 that connects a connection point N9 between the second conversion circuit 70 and the relay 70a of the second storage battery module 60 and a connection point N10 between the first storage battery 31 and the relay 40b of the first storage battery module 30. 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 respect to the buses 11 and 12. When the storage battery modules 30, 60, and 90 are switched to parallel connection by the switching circuit, power can be supplied from the storage battery modules 30, 60, and 90 to the buses 11 and 12. Therefore, the storage battery modules 30, 60, and 90 can be used as redundant power sources. When the storage battery modules 30, 60, and 60 are switched to 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, and 90 are switched to series connection by the switching circuit, a voltage obtained by adding up the output voltages Vm1, Vm2, and Vm3 of the storage battery modules 30, 60, and 90 can be supplied to the buses 11 and 12. Therefore, the storage battery modules 30, 60, and 90 can be used as higher voltage power sources.

[0075] The number of storage battery modules included in the power supply system 10, 210 may be two, or may be four or more.

[0076] 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.

[0077] As shown in Fig. 18, 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).

[0078] 19, 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).

[0079] 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).

[0080] 20, the storage battery modules 30, 60, 90 may be configured. 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).

[0081] At least one of the functions of the bus voltage setting unit 16a, the control unit 16b, the energization execution unit 16c, the temperature increase execution unit 16d, and the status acquisition unit 16e of the ECU 16 can be realized by the BMU 32, 62, 92, the drive circuit 35, 65, 95, a power control ECU (Electronic Control Unit) that controls the power of the electric vehicle, or a vehicle control ECU (higher ECU) that comprehensively controls the electric vehicle. In addition, when the power supply system 10, 210 is used as a fixed power source, for example, the functions of the bus voltage setting unit 16a, the control unit 16b, the energization execution unit 16c, the temperature increase execution unit 16d, and the status acquisition unit 16e of the ECU 16 can be realized by a fixed power source control ECU (control device) that controls the fixed power source.

[0082] 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.

[0083] The above-described embodiment and each modified example may be combined to the extent possible.

[0084] Characteristic configurations extracted from the above-described embodiment and modified examples will be described below. [Configuration 1] A power supply system (10, 210) in which a plurality of storage battery modules (30, 60, 90) each 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, 101, 102) and outputs the power from a secondary terminal pair (47, 48, 77, 78, 107, 108) and a load (21) are connected in parallel to a power supply bus (11, 12), a positive electrode and a negative electrode 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; an energization execution unit (16c) that controls the conversion circuits of the plurality of storage battery modules to execute an energization operation between the storage battery and the load; a temperature-raising execution unit (16d) that controls each of the conversion circuits of the plurality of storage battery modules to perform a temperature-raising operation of raising the temperatures of the plurality of storage batteries by charging and discharging between the plurality of storage batteries, The power supply system further comprises: a power supply execution unit that executes the current application operation and a temperature increase execution unit that executes the temperature increase operation simultaneously. [Configuration 2] A status acquisition unit (32, 62, 92) that acquires the status of the plurality of storage batteries, 2. The power supply system according to claim 1, wherein the energization execution unit adjusts a power ratio of the plurality of storage batteries in the energization operation based on the states of the plurality of storage batteries acquired by the state acquisition unit. [Configuration 3] the state acquisition unit acquires charging rates of the plurality of storage batteries as the states of the plurality of storage batteries; The power supply system according to configuration 2, wherein the power supply execution unit adjusts the power ratio of the multiple storage batteries in the power supply operation so as to reduce the difference in the charging rates of the multiple storage batteries acquired by the status acquisition unit. [Configuration 4] the status acquisition unit acquires health statuses of the plurality of storage batteries as the statuses of the plurality of storage batteries; 4. The power supply system according to claim 2, wherein the energization execution unit sets a higher power ratio in the energization operation for a storage battery whose health status acquired by the status acquisition unit is higher. [Configuration 5] a status acquisition unit (16e) that acquires at least one of a state, a physical arrangement, and a power supply schedule of the plurality of storage batteries; The power supply system according to any one of configurations 1 to 4, wherein the temperature rise execution unit determines the storage battery for which the temperature rise operation is to be performed based on the status of the plurality of storage batteries acquired by the status acquisition unit. [Configuration 6] the status acquisition unit acquires health statuses of the plurality of storage batteries as the statuses of the plurality of storage batteries; 6. The power supply system according to claim 5, wherein the temperature increase execution unit determines, as the execution target, the storage battery whose health status acquired by the status acquisition unit is higher than that of other storage batteries. [Configuration 7] the status acquisition unit acquires a physical arrangement of the storage batteries as the status of the storage batteries; The power supply system of configuration 5, wherein the heating execution unit determines, as the execution target, a storage battery that is less likely to receive heat from the outside than other storage batteries, or a storage battery that is more likely to radiate heat to the outside than other storage batteries, based on the physical arrangement of the multiple storage batteries acquired by the status acquisition unit. [Configuration 8] The power supply system according to configuration 7, wherein the temperature rise execution unit executes the temperature rise operation so as to keep the temperature of the storage battery determined as the execution target at or above a specified temperature when the outside air temperature is lower than the temperatures of the plurality of storage batteries. [Configuration 9] the status acquisition unit acquires the states and the energization schedule of the plurality of storage batteries as the statuses of the plurality of storage batteries; The power supply system of configuration 5, wherein the heating execution unit determines the storage battery to be subjected to the heating operation based on the states and the power supply schedule of the multiple storage batteries acquired by the status acquisition unit. [Configuration 10] The power supply system according to configuration 9, wherein the temperature rise execution unit determines, as the storage battery to be subjected to the temperature rise operation, the storage battery in which the increase in the available power of the storage battery before and after the temperature rise operation is performed is greater than that of other storage batteries. [Configuration 11] The power supply system according to any one of configurations 5 to 10, wherein the temperature rise execution unit sets the charging rate of the storage battery determined to be the execution target higher than the charging rates of the other storage batteries by charging from the load or the other storage batteries before executing the temperature rise operation. [Explanation of symbols]

[0085] 10...power supply system, 11...bus, 12...bus, 16b...control unit, 16c...energization execution unit, 16d...heat rise execution unit, 21...load, 30...first storage battery module, 31...first storage battery, 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), 60...second storage battery module, 61...second storage battery, 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, 100...third conversion circuit, 101...positive terminal (primary side terminal pair), 102...negative terminal (primary side terminal pair), 107...positive terminal (secondary side terminal pair), 108...negative terminal (secondary side terminal pair), 210...power supply system.

Claims

1. A power supply system (10, 210) in which a plurality of storage battery modules (30, 60, 90) each 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, 101, 102) and outputs the power from a secondary side terminal pair (47, 48, 77, 78, 107, 108) and a load (21) are connected in parallel to a power supply bus (11, 12), a positive electrode and a negative electrode 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; an energization execution unit (16c) that controls each of the conversion circuits of the plurality of storage battery modules to execute an energization operation between the storage battery and the load; a temperature-raising execution unit (16d) that controls each of the conversion circuits of the plurality of storage battery modules to perform a temperature-raising operation of raising the temperatures of the plurality of storage batteries by charging and discharging between the plurality of storage batteries, The power supply system further comprises: a power supply execution unit that executes the current application operation and a temperature increase execution unit that executes the temperature increase operation simultaneously.

2. A status acquisition unit (32, 62, 92) that acquires the status of the plurality of storage batteries, The power supply system according to claim 1 , wherein the energization execution unit adjusts a power ratio of the plurality of storage batteries in the energization operation based on the states of the plurality of storage batteries acquired by the state acquisition unit.

3. the state acquisition unit acquires charging rates of the plurality of storage batteries as the states of the plurality of storage batteries; The power supply system according to claim 2 , wherein the energization execution unit adjusts the power ratio of the plurality of storage batteries in the energization operation so as to reduce a difference in the charging rates of the plurality of storage batteries acquired by the state acquisition unit.

4. the status acquisition unit acquires health statuses of the plurality of storage batteries as the statuses of the plurality of storage batteries; The power supply system according to claim 2 , wherein the energization execution unit increases the power ratio in the energization operation for a battery having a higher health status acquired by the state acquisition unit.

5. a status acquisition unit (16e) that acquires at least one of a state, a physical arrangement, and a power supply schedule of the plurality of storage batteries; The power supply system according to any one of claims 1 to 3, wherein the temperature rise execution unit determines the storage battery to be subjected to the temperature rise operation based on the status of the plurality of storage batteries acquired by the status acquisition unit.

6. the status acquisition unit acquires health statuses of the plurality of storage batteries as the statuses of the plurality of storage batteries; The power supply system according to claim 5 , wherein the temperature increase execution unit determines, as the execution target, the storage battery whose health state acquired by the status acquisition unit is higher than other storage batteries.

7. the status acquisition unit acquires a physical arrangement of the storage batteries as the status of the storage batteries; The power supply system of claim 5, wherein the temperature increase execution unit determines, based on the physical arrangement of the multiple storage batteries acquired by the status acquisition unit, as the execution target a storage battery that is less likely to receive heat from the outside than other storage batteries, or a storage battery that is more likely to radiate heat to the outside than other storage batteries.

8. The power supply system according to claim 7 , wherein the temperature rise execution unit executes the temperature rise operation so as to keep the temperature of the storage battery determined as the execution target at or above a specified temperature when an outside air temperature is lower than temperatures of the plurality of storage batteries.

9. the status acquisition unit acquires the states and the energization schedule of the plurality of storage batteries as the statuses of the plurality of storage batteries; The power supply system according to claim 5 , wherein the temperature rise execution unit determines the storage battery to be the target of the temperature rise operation based on the states and the power supply schedule of the plurality of storage batteries acquired by the status acquisition unit.

10. The power supply system according to claim 9 , wherein the temperature increase execution unit determines, as the execution target, the storage battery in which an increase in available power of the storage battery before and after the execution of the temperature increase operation is greater than other storage batteries.

11. The power supply system according to claim 5, wherein the temperature rise execution unit sets the charging rate of the storage battery determined to be the execution target higher than the charging rates of the other storage batteries by charging from the load or the other storage batteries before executing the temperature rise operation.

12. A control device (16) applied to a power supply system (10, 210) in which a plurality of storage battery modules (30, 60, 90) including storage batteries (31, 61, 91) and a conversion circuit (40, 70, 100) that converts power input from the storage batteries to primary side terminal pairs (41, 42, 71, 72, 101, 102) and outputs the power from secondary side terminal pairs (47, 48, 77, 78, 107, 108) and a load (21) are connected in parallel to a power supply bus (11, 12), positive and negative electrodes of the storage batteries are respectively connected to the primary side terminal pairs of the conversion circuit, and the storage batteries are connected in series to the secondary side terminal pairs of the conversion circuit, an energization execution unit (16c) that controls each of the conversion circuits of the plurality of storage battery modules to execute an energization operation between the storage battery and the load; a temperature-raising execution unit (16d) that controls each of the conversion circuits of the plurality of storage battery modules to perform a temperature-raising operation of raising the temperatures of the plurality of storage batteries by charging and discharging between the plurality of storage batteries, a control device that simultaneously executes the current application operation by the current application execution unit and the temperature increase operation by the temperature increase execution unit.

13. A control program applied to a power supply system (10, 210) in which a plurality of storage battery modules (30, 60, 90) including storage batteries (31, 61, 91) and a conversion circuit (40, 70, 100) that converts power input from the storage batteries to primary side terminal pairs (41, 42, 71, 72, 101, 102) and outputs the power from secondary side terminal pairs (47, 48, 77, 78, 107, 108) and a load (21) are connected in parallel to a power supply bus (11, 12), positive and negative electrodes of the storage batteries are respectively connected to the primary side terminal pairs of the conversion circuit, and the storage batteries are connected in series to the secondary side terminal pairs of the conversion circuit, A process of controlling the conversion circuits of the plurality of storage battery modules to perform a current supply operation between the storage battery and the load; a process of performing a temperature raising operation of raising temperatures of the storage batteries by charging and discharging between the storage batteries by controlling the conversion circuits of the storage battery modules, respectively; A control program that causes a computer (16) to execute the above simultaneously.

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