JP7575681B2 - Vehicle battery unit and control method thereof - Google Patents

Description

The technology disclosed herein relates to a vehicle battery unit.

Patent Document 1 discloses a battery pack having multiple cell stacks connected in series. The cell stack includes multiple battery cells connected in series. A bypass path is connected in parallel to each of the multiple cell stacks, and a cooling element (Peltier element) is provided in the bypass path. The cooling element generates the Peltier effect only when a charging current flows through the bypass path.

Special Publication No. 2020-502969

In the battery pack of Patent Document 1, the cooling element is driven using the charging current for charging the battery cells. However, Patent Document 1 does not disclose or suggest anything about driving the cooling element (Peltier module) using the power of the battery cells (battery module).

The technology disclosed here has been developed in light of these issues, and its purpose is to drive multiple Peltier modules using the power of a battery module.

The technology disclosed herein relates to a vehicle battery unit, which includes a plurality of battery modules for a vehicle, a heat exchange unit, a plurality of Peltier modules provided between the plurality of battery modules and the heat exchange unit and promoting the transfer of heat by passing current through them, a first output terminal for outputting a first power supplied to the vehicle, a ground terminal, a battery circuit capable of switching the connection state of the plurality of battery modules to a state in which a battery module among the plurality of battery modules that serves as a first power source for outputting the first power is connected between the first output terminal and the ground terminal, and a Peltier circuit capable of switching the connection state of the plurality of Peltier modules to a state in which the plurality of Peltier modules are connected in parallel between the first output terminal and the ground terminal.

In the above configuration, the first power can be supplied to the vehicle by the battery module serving as the first power source. In addition, when the connection state of the multiple battery modules is "a state in which the battery module serving as the first power source among the multiple battery modules is connected between the first output terminal and the ground terminal," the connection state of the multiple Peltier modules can be changed to "a state in which the multiple Peltier modules are connected in parallel between the first output terminal and the ground terminal." This allows the multiple Peltier modules to be driven using the power of the battery module serving as the first power source.

The vehicle battery unit may include a second output terminal for outputting a second power that is supplied to the vehicle and is higher than the first power. The battery circuit may be capable of switching the connection state of the plurality of battery modules to a state in which a battery module that serves as the first power source among the plurality of battery modules is connected between the first output terminal and the ground terminal, and at least two of the plurality of battery modules are connected in series between the second output terminal and the ground terminal.

In the above configuration, a first power is supplied to the vehicle by a battery module serving as a first power source, and a second power is supplied to the vehicle by two or more battery modules connected in series.

In the vehicle battery unit, the battery circuit may be capable of switching the connection state of the multiple battery modules to a state in which the multiple battery modules are connected in parallel.

In the above configuration, the SOC of the multiple battery modules can be equalized by connecting the multiple battery modules in parallel. This reduces the variation in the SOC of the multiple battery modules.

In the vehicle battery unit, the battery circuit may be capable of switching the battery module that serves as the first power source among the plurality of battery modules.

In the above configuration, the battery module that serves as the first power source among the multiple battery modules can be prevented from being fixed. This makes it possible to reduce the variation in SOC among the multiple battery modules.

The vehicle battery unit may include a heat transfer switching mechanism that can switch the state of heat transfer between the plurality of battery modules and the heat exchange unit via the plurality of Peltier modules between a heat transfer permitted state in which the heat transfer is permitted and a heat transfer inhibited state in which the heat transfer is inhibited.

In the above configuration, by setting the state of heat transfer between the multiple battery modules and the heat exchange unit via the multiple Peltier modules to a heat transfer permitted state, heat can be transferred appropriately between the multiple battery modules and the heat exchange unit. In addition, by setting the state of heat transfer between the multiple battery modules and the heat exchange unit via the multiple Peltier modules to a heat transfer inhibited state, unnecessary heat transfer between the multiple battery modules and the heat exchange unit can be suppressed.

The technology disclosed herein relates to a method for controlling the vehicle battery unit, which includes an SOC detection step for detecting the SOC of each of the battery modules when the battery module serving as the first power source among the battery modules is connected between the first output terminal and the ground terminal, and a parallel connection step for controlling the battery circuit so that the battery modules are connected in parallel when the variation in SOC of the battery modules detected by the SOC detection step exceeds a threshold value.

In the above method, when the variation in SOC of multiple battery modules exceeds a threshold value, the variation in SOC of multiple battery modules can be effectively reduced by connecting the multiple battery modules in parallel.

The technology disclosed herein relates to a method for controlling the vehicle battery unit, which includes an SOC detection step for detecting the SOC of each of the battery modules when the battery module serving as the first power source among the battery modules is connected between the first output terminal and the ground terminal, and a power source switching step for controlling the battery circuit so that the battery module serving as the first power source among the battery modules is switched when the variation in the SOC of the battery modules detected by the SOC detection step exceeds a threshold value.

In the above method, when the variation in SOC of the multiple battery modules exceeds a threshold value, the variation in SOC of the multiple battery modules can be effectively reduced by switching the battery module that serves as the first power source among the multiple battery modules.

The technology disclosed herein relates to a method for controlling the vehicle battery unit, which includes a Peltier control step for controlling the energization and de-energization of each of the plurality of Peltier modules, and a heat transfer control step for controlling the heat transfer switching mechanism so that the heat transfer state becomes the heat transfer permissive state when at least one of the plurality of Peltier modules is energized, and for controlling the heat transfer switching mechanism so that the heat transfer state becomes the heat transfer inhibited state when the plurality of Peltier modules are not energized.

In the above method, when the multiple Peltier modules are energized, the heat transfer switching mechanism is controlled so that the heat transfer state is a heat transfer permitted state, thereby allowing heat to be transferred appropriately between the multiple battery modules and the heat exchange unit. In addition, when the multiple Peltier modules are not energized, the heat transfer switching mechanism is controlled so that the heat transfer state is a heat transfer inhibited state, thereby preventing unnecessary heat transfer between the multiple battery modules and the heat exchange unit.

The technology disclosed here makes it possible to drive multiple Peltier modules using the power of a battery module.

1 is a schematic diagram illustrating a configuration of a vehicle power supply system according to a first embodiment; FIG. 2 is a circuit diagram illustrating an electrical configuration of the battery unit of the first embodiment. FIG. 2 is a circuit diagram illustrating a basic connection state of the battery module according to the first embodiment. FIG. 2 is a circuit diagram illustrating a parallel connection state of battery modules according to the first embodiment. FIG. 11 is a circuit diagram illustrating switching of a battery module serving as a low-voltage power source. 2 is a circuit diagram illustrating the configuration of a Peltier module and a Peltier circuit. FIG. 1 is a block diagram illustrating a configuration of a vehicle power supply system according to a first embodiment; 4 is a flowchart for illustrating control (Peltier control) of the battery unit according to the first embodiment. 4 is a flowchart for illustrating control (SOC control) of the battery unit according to the first embodiment. FIG. 11 is a schematic diagram illustrating the configuration of a battery unit according to a second embodiment. 11 is a schematic diagram illustrating a heat transfer permitted state of a battery unit according to a second embodiment. FIG. 10 is a flowchart for illustrating control (Peltier control) of a battery unit according to a second embodiment. 13 is a schematic diagram illustrating a configuration of a battery unit according to a modified example of the second embodiment. FIG. 13 is a schematic diagram illustrating a heat transfer permitted state of a battery unit according to a modified example of the second embodiment. FIG.

The following describes the embodiments in detail with reference to the drawings. Note that the same or corresponding parts in the drawings are given the same reference numerals and their description will not be repeated.

(Embodiment 1)
1 illustrates the configuration of a vehicle power supply system 1 according to a first embodiment. The vehicle power supply system 1 is provided in a vehicle and supplies power to devices such as an electric motor mounted on the vehicle. The vehicle power supply system 1 includes a vehicle battery unit 10, a plurality of temperature sensors 21, a plurality of SOC sensors 22, and a control device 30. In this example, the vehicle power supply system 1 includes a radiator 2, a first flow path 3, a second flow path 4, a pump 5, and a fan 6 in addition to these components.

Note that the temperature sensor 21 and the SOC sensor 22 are not shown in FIG. 1. In the following description, the vehicle battery unit 10 will simply be referred to as the "battery unit 10."

In the vehicle power supply system 1, the radiator 2 and the heat exchange section 12 of the battery unit 10 described below are connected by a first flow path 3 and a second flow path 4 to form a coolant circuit through which the coolant circulates. The coolant is an example of a heat exchange medium, and the coolant circuit is an example of a heat exchange medium circuit through which the heat exchange medium circulates.

The pump 5 circulates the coolant in the coolant circuit. The fan 6 adjusts the flow rate of air passing through the radiator 2. The radiator 2 exchanges heat between the coolant passing through the radiator 2 and the air. The coolant flowing out from the radiator 2 flows through the first flow path 3 and performs heat exchange (heat absorption in this example) in the heat exchange section 12 of the battery unit 10. The coolant flowing out from the heat exchange section 12 of the battery unit 10 flows through the second flow path 4 and performs heat exchange (heat dissipation in this example) in the radiator 2. The radiator 2 is an example of a heat exchanger.

The rotation speed of the pump 5 is variable. By increasing the rotation speed of the pump 5, the flow rate of the coolant circulating through the coolant circuit increases, and heat exchange in the heat exchange section 12 of the battery unit 10 and the radiator 2 is promoted. By decreasing the rotation speed of the pump 5, the flow rate of the coolant circulating through the coolant circuit decreases, and heat exchange in the heat exchange section 12 of the battery unit 10 and the radiator 2 is no longer promoted.

The rotation speed of the fan 6 is variable. Increasing the rotation speed of the fan 6 increases the flow rate of air passing through the radiator 2, promoting heat exchange in the radiator 2. As a result, heat exchange in the heat exchange section 12 of the battery unit 10 is also promoted. Decreasing the rotation speed of the fan 6 decreases the flow rate of air passing through the radiator 2, and heat exchange in the radiator 2 is no longer promoted. As a result, heat exchange in the heat exchange section 12 of the battery unit 10 is no longer promoted.

[Battery unit]
1, the battery unit 10 has a plurality of (specifically, four) vehicle battery modules 11, a heat exchanger 12, a plurality of (specifically, four) Peltier modules 13, a first output terminal 41, a second output terminal 42, a ground terminal 43, a battery circuit 45, and a Peltier circuit 70. These components of the battery unit 10 are housed in a housing.

In FIG. 1, the first output terminal 41, the second output terminal 42, and the ground terminal 43 are omitted from the illustration. In the following, the vehicle battery module 11 will simply be referred to as the "battery module 11."

<Battery module>
Each of the battery modules 11 stores electric power. The battery modules 11 have the same configuration. In this example, the battery modules 11 are formed in a flat rectangular parallelepiped shape. The battery modules 11 are arranged in a row such that the flat surfaces (surfaces with the largest areas) of two adjacent battery modules 11 face each other. For example, the battery modules 11 are lithium ion batteries.

<Heat exchange section>
The heat exchange unit 12 is provided to adjust the temperature of the multiple battery modules 11. The heat exchange unit 12 exchanges heat with a heat exchange medium. In this example, the coolant circulating in the coolant circuit flows through the heat exchange unit 12. The heat exchange unit 12 exchanges heat (dissipates heat in this example) with the coolant flowing through the heat exchange unit 12. For example, the heat exchange unit 12 is made of a material with high thermal conductivity. Examples of materials with high thermal conductivity include copper and aluminum.

<Peltier module>
The Peltier modules 13 are provided between the battery modules 11 and the heat exchange unit 12, and promote the transfer of heat when electricity is applied thereto.

In this example, the multiple Peltier modules 13 correspond one-to-one to the multiple battery modules 11. The Peltier module 13 is provided between the battery module 11 corresponding to that Peltier module 13 and the heat exchange unit 12, and is in contact with that battery module 11 and the heat exchange unit 12.

The Peltier module 13 is formed in a plate shape, and when electricity is applied, one surface becomes a heat absorption surface and the other surface becomes a heat dissipation surface. The heat absorption surface and heat dissipation surface of the Peltier module 13 are determined by the direction of the current flowing through the Peltier module 13. When the direction of the current flowing through the Peltier module 13 is reversed, the heat absorption surface and heat dissipation surface of the Peltier module 13 are reversed.

<Various terminals>
2, the first output terminal 41 is a terminal for outputting low-voltage power supplied to a low-voltage device of the vehicle. An example of the low-voltage device of the vehicle is an auxiliary device of the vehicle. The low-voltage power is an example of the first power supplied to the vehicle.

The second output terminal 42 is a terminal for outputting high-voltage power supplied to a high-voltage device of the vehicle. An example of a high-voltage device of the vehicle is an electric motor that serves as a drive source for the vehicle. The high-voltage power is an example of a second power that is supplied to the vehicle and is higher than the first power.

The ground terminal 43 is a terminal for connecting to the ground (earth).

For example, the power of the battery module 11 and the low voltage power are 12V power, and the high voltage power is 48V power.

<Battery circuit>
The battery circuit 45 is capable of switching the connection states of the multiple battery modules 11. As shown in Fig. 2, in this example, the battery circuit 45 has a power supply line 50 and multiple (specifically, 16) relays 60 provided on the power supply line 50.

For ease of explanation, in the following, the battery modules 11 are assigned branch numbers to distinguish between the multiple battery modules 11. The numbers written near the power supply symbol in FIG. 2 indicate the branch numbers assigned to the battery modules 11. Also, in order to distinguish between the multiple relays 60, branch numbers are assigned to the relays 60. The numbers in circles in FIG. 2 indicate the branch numbers assigned to the relays 60.

Power Line
The multiple power supply lines 50 include a first power supply line 51, a second power supply line 52, a third power supply line 53, and a fourth power supply line 54. The first power supply line 51 connects the positive electrodes of the multiple battery modules 11 to the first output terminal 41. The second power supply line 52 connects the negative electrodes of the multiple battery modules 11 to the ground terminal 43. The third power supply line 53 connects the multiple battery modules 11 in series and in a ring shape. The fourth power supply line 54 connects the positive electrodes of the multiple battery modules 11 to the second output terminal 42.

In FIG. 2, the portion of the third power supply line 53 that connects the positive electrode of the battery module _11-4 and the negative electrode of the battery module _11-1 is indicated by a dashed line and a thick black arrow, but in the subsequent figures, this dashed line is omitted to avoid cluttering the figures.

"relay"
The multiple relays 60 each have the same configuration. The relays 60 can be switched between an on state (closed state) and an off state (open state). When the relay 60 is in the on state, the power supply lines at both ends of the relay 60 are connected, and when the relay 60 is in the off state, the power supply lines at both ends of the relay 60 are disconnected. For example, the relay 60 is configured of a switching element such as a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor).

The multiple relays 60 include multiple first relays 61 provided on the first power line 51, multiple second relays 62 provided on the second power line 52, multiple third relays 63 provided on the third power line 53, and multiple fourth relays 64 provided on the fourth power line 54.

The multiple first relays 61 correspond one-to-one to the multiple battery modules 11. Each of the multiple first relays 61 switches the connection state between the battery module 11 corresponding to that first relay 61 and the first output terminal 41. In the example of Fig. 2, relays _60-1 , _60-3 , _60-5 , and _60-7 are the first relays 61.

The second relays 62 correspond one-to-one to the battery modules 11. Each of the second relays 62 switches the state of connection between the battery module 11 corresponding to that second relay 62 and the ground terminal 43. In the example of FIG. 2, relays _60-2 , _60-4 , _60-6 , and _60-8 are the second relays 62.

The multiple third relays 63 correspond one-to-one to the multiple battery modules 11. Each of the multiple third relays 63 switches the state of connection between the positive electrode of the battery module 11 corresponding to that third relay 63 and the negative electrode of the battery module 11 adjacent to that battery module on the third power supply line 53. In the example of Fig. 2, relays _60-9 , _60-10 , _60-11 , and _60-12 are the third relays 63.

The multiple fourth relays 64 correspond one-to-one to the multiple battery modules 11. Each of the multiple fourth relays 64 switches the state of connection between the positive electrode of the battery module 11 corresponding to that fourth relay 64 and the second output terminal 42. In the example of Fig. 2, relays _60-13 , _60-14 , _60-15 , and _60-16 are the fourth relays 64.

<Battery circuit operation: Basic connection state>
The battery circuit 45 can switch the connection state of the plurality of battery modules 11 to a state in which a battery module 11 serving as a low-voltage power source that outputs low-voltage power among the plurality of battery modules 11 is connected between the first output terminal 41 and the ground terminal 43. The low-voltage power source is an example of a first power source that outputs a first power.

In this example, the battery circuit 45 can switch the connection state of the multiple battery modules 11 to a state in which the battery module 11 that serves as a low-voltage power source among the multiple battery modules 11 is connected between the first output terminal 41 and the ground terminal 43, and at least two of the multiple battery modules 11 (in this example, all four battery modules 11) are connected in series between the second output terminal 42 and the ground terminal 43. Hereinafter, this connection state will be referred to as the "basic connection state."

As shown in Figures 3(a) to 3(d), there are four basic connection states. In Figures 3(a) to 3(d), the flow of electricity that outputs low-voltage power of 12 V is indicated by a dashed line PH, and the flow of electricity that outputs high-voltage power of 48 V is indicated by a dashed line PL. Also, among the multiple relays 60, relays 60 that are in the on state are indicated with a dotted pattern.

3(a), relays _60-1 , _60-2 , _60-9 , _60-10 , _60-11 , and _60-16 are in the ON state, and the other relays 60 are in the OFF state. In this state, battery modules _11-4 , _11-3 , _11-2 , and _11-1 are connected in series in this order between the second output terminal 42 and the ground terminal 43. In addition, battery module _11-1 serves as a low-voltage power _supply , and is connected between the first output terminal 41 and the ground terminal 43.

3(b), relays _60-3 , _60-4 , _60-10 , _60-11 , _60-12 , and _60-13 are in the ON state, and the other relays 60 are in the OFF state. In this state, battery modules _11-1 , _11-4 , _11-3 , and _11-2 are connected in series in this order between the second output terminal 42 and the ground terminal 43. In addition, battery module _11-2 serves as a low-voltage power _supply , and is connected between the first output terminal 41 and the ground terminal 43.

3(c), relays _60-5 , _60-6 , _60-9 , _60-11 , _60-12 , and _60-14 are in the ON state, and the other relays 60 are in the OFF state. In this state, battery modules _11-2 , _11-1 , _11-4 , and _11-3 are connected in series in this order between the second output terminal 42 and the ground terminal 43. In addition, battery module _11-3 serves as a low-voltage power _supply , and is connected between the first output terminal 41 and the ground terminal 43.

3(d), relays _60-7 , _60-8 , _60-9 , _60-10 , _60-12 , and _60-15 are in the ON state, and the other relays 60 are in the OFF state. In this state, battery modules _11-3 , _11-2 , _11-1 , and _11-4 are connected in series in this order between the second output terminal 42 and the ground terminal 43. In addition, battery module _11-4 serves as a low-voltage power _supply , and is connected between the first output terminal 41 and the ground terminal 43.

<Battery circuit operation: parallel connection state>
Furthermore, the battery circuit 45 can switch the connection state of the multiple battery modules 11 to a state in which the multiple battery modules 11 are connected in parallel.

In this example, the battery circuit 45 can switch the connection state of the multiple battery modules 11 to a state in which the multiple battery modules are connected in parallel between the first output terminal 41 and the ground terminal 43. Hereinafter, this connection state will be referred to as the "parallel connection state."

4, in the parallel connection state, the relays _60-1 , _60-2 , _60-3 , _60-4 , _60-5 , 60-6, _60-7 , _{and 60-8} are in the ON state, and the other relays 60 are in the OFF state. In this state, the SOCs of the four battery modules 11 are equalized. In addition, low-voltage power is supplied by the four battery modules 11 connected in parallel.

<Battery circuit operation: switching of battery module as low-voltage power source>
Furthermore, the battery circuit 45 is capable of switching between the battery modules 11 that serve as the low-voltage power source among the plurality of battery modules 11 .

5(a) to 5(e), switching of the battery module 11 that serves as the low-voltage power source will be described. In the following, an example is given of switching the battery module 11 that serves as the low-voltage power source from "battery module _11-1 " to "battery module _11-2 ."

As shown in Fig. 5(a), the relays _60-1 and _60-2 corresponding to the battery module _11-1 are in the ON state. This connects the battery module _11-1 , which is a low-voltage power supply, between the first output terminal 41 and the ground terminal 43. In addition, the relays _60-9 , _60-10 , _60-11 , and _60-16 are in the ON state. This causes high-voltage power to be output. The other relays 60 are in the OFF state.

5B, the relays _60-9 , _60-10 , and _60-11 are then turned off, thereby stopping the supply of high-voltage power.

5(c), the relays _60-3 and _60-4 corresponding to the battery module _11-2 are turned on, so that the battery module _11-2, which becomes the next low-voltage power supply, is connected between the first output terminal 41 and the ground terminal 43.

5(d), the relays _60-1 and _60-2 corresponding to the battery module _11-1 are turned off, thereby disconnecting the battery module _11-1 , which was previously a low-voltage power supply, from the first output terminal 41 and the ground terminal 43.

5(e), the relays _60-10 , _60-11 , and _60-12 are then turned on, thereby restarting the supply of high-voltage power.

When switching the battery module 11 to be the low-voltage power source, the state shown in FIG. 4 (parallel connection state) may be used instead of the state shown in FIG. 5(c). In other words, after multiple battery modules 11 are connected in parallel, the battery module 11 to be the low-voltage power source among the multiple battery modules 11 may be switched.

<Peltier circuit>
The Peltier circuit 70 is capable of switching the connection state of the multiple Peltier modules 13. As shown in Fig. 2, in this example, the Peltier circuit 70 has a first connection line 71, a second connection line 72, and multiple switches 73 that correspond one-to-one to the multiple Peltier modules 13.

The first connection line 71 is connected to the first output terminal 41. The second connection line 72 is connected to the ground terminal 43. Each of the multiple switches 73 can switch the connection state of the Peltier module 13 corresponding to that switch 73.

<Operation of Peltier Circuit>
The Peltier circuit 70 is capable of switching the connection state of the multiple Peltier modules 13 to a state in which the multiple Peltier modules 13 are connected in parallel between the first output terminal 41 and the ground terminal 43 .

In this example, the Peltier circuit 70 can switch the connection state of each of the multiple Peltier modules 13 between a first current-carrying state, a second current-carrying state, and a non-current-carrying state. Specifically, as shown in FIG. 6, the switch 73 can switch the connection state of the Peltier module 13 corresponding to that switch 73 between a first current-carrying state (the state shown by the solid line in FIG. 6), a second current-carrying state (the state shown by the dashed line in FIG. 6), and a non-current-carrying state.

<<First energized state>>
In the first current-carrying state, the positive side of the Peltier module 13 is connected to the first connection line 71 connected to the first output terminal 41, and the negative side of the Peltier module 13 is connected to the second connection line 72 connected to the ground terminal 43. This causes the Peltier module 13 to be electrically connected, with the surface of the Peltier module 13 facing the battery module 11 becoming a "heat absorbing surface" and the surface of the Peltier module 13 facing the heat exchanger 12 becoming a "heat releasing surface." As a result, the transfer of heat in the direction indicated by the outlined solid arrow in FIG. 6 is promoted.

<<Second energized state>>
In the second current-carrying state, the positive side of the Peltier module 13 is connected to the first connection line 71 connected to the first output terminal 41 and the positive side of the Peltier module 13, and the negative side of the Peltier module 13 is connected to the second connection line 72 connected to the ground terminal 43. This causes the Peltier module 13 to be current-carrying, with the surface of the Peltier module 13 facing the heat exchanger 12 becoming a "heat absorbing surface" and the surface of the Peltier module 13 facing the battery module 11 becoming a "heat releasing surface." As a result, the transfer of heat in the direction indicated by the outlined dashed arrow in FIG. 6 is promoted.

<<De-energized state>>
In the non-energized state, the positive side and the negative side of the Peltier module 13 are not connected to either the first connection line 71 or the second connection line 72. This causes the Peltier module 13 to be de-energized, and the transfer of heat in the Peltier module 13 is not promoted.

[Temperature sensor]
The multiple temperature sensors 21 correspond one-to-one to the multiple battery modules 11. Each of the multiple temperature sensors 21 detects the temperature of the battery module 11 corresponding to that temperature sensor 21. Note that the temperature sensor 21 may directly detect the temperature of the battery module 11, or may indirectly detect the temperature of the battery module 11.

[SOC sensor]
The multiple SOC sensors 22 correspond one-to-one to the multiple battery modules 11. Each of the multiple SOC sensors 22 detects the SOC (State of Charge) of the battery module 11 corresponding to the SOC sensor 22. Note that the SOC sensor 22 may directly detect the SOC of the battery module 11, or may indirectly detect the SOC of the battery module 11.

[Control device]
The control device 30 controls each part of the vehicle power supply system 1. As shown in Fig. 7, in this example, the control device 30 is connected by signal lines to a plurality of temperature sensors 21, a plurality of SOC sensors 22, a pump 5, a fan 6, a battery circuit 45, a Peltier circuit 70, etc. The control device 30 has a storage unit 31 and a control unit 32.

The memory unit 31 stores various types of information. For example, the memory unit 31 stores information used to control each part of the vehicle power supply system 1. Examples of information used to control each part of the vehicle power supply system 1 include values detected by various sensors and thresholds used for various controls.

The control unit 32 controls each part of the vehicle power supply system 1. For example, the control unit 32 is composed of a processor and a memory that stores programs and data for operating the processor.

[Battery unit control (Peltier control)]
Next, the Peltier control will be described with reference to Fig. 8. The Peltier control is a process for controlling the Peltier module 13 so that the temperature of the battery module 11 becomes an appropriate temperature. The control unit 32 repeatedly performs the following process for each of the plurality of Peltier modules 13.

When this Peltier control is performed, the connection state of the multiple battery modules 11 is the basic connection state shown in Figures 3(a) to 3(d) or the parallel connection state shown in Figure 4. In the following, an example will be described with one Peltier module 13, one battery module 11 corresponding to that Peltier module 13, and one temperature sensor 21 that detects the temperature of that battery module 11.

<Step S11>
First, the control unit 32 acquires the temperature of the battery module 11 detected by the temperature sensor 21 .

<Step S12>
The control unit 32 determines whether the temperature of the battery module 11 is an appropriate temperature. For example, when the temperature of the battery module 11 is a predetermined target temperature, the control unit 32 determines that the temperature of the battery module 11 is an appropriate temperature. Note that the target temperature may be a value with a certain range (i.e., a target range).

If the temperature of the battery module 11 is appropriate, step S13 is performed; if not, step S14 is performed.

<Step S13>
When the temperature of the battery module 11 is appropriate, the control unit 32 controls the Peltier circuit 70 to stop the flow of current to the Peltier module 13. This stops the Peltier module 13. Note that when the flow of current to the Peltier module 13 has already been stopped, the control unit 32 controls the Peltier circuit 70 to keep the flow of current to the Peltier module 13 stopped.

<Step S14>
On the other hand, when the temperature of the battery module 11 is not appropriate, the control unit 32 determines whether or not it is necessary to cool the Peltier module 13. For example, when the temperature of the Peltier module 13 exceeds the target temperature (or the upper limit of the target range), the control unit 32 determines that it is necessary to cool the Peltier module 13. Also, when the temperature of the Peltier module 13 falls below the target temperature (or the lower limit of the target range), the control unit 32 determines that it is necessary to heat the Peltier module 13.

If cooling of the battery module 11 is required, step S15 is performed; if not (if heating of the battery module 11 is required), step S16 is performed.

<Step S15>
When cooling of the battery module 11 is required, the control unit 32 controls the Peltier circuit 70 so that a current flows in the Peltier module 13 in a direction such that the surface on the battery module 11 side becomes a heat absorbing surface and the surface on the heat exchange unit 12 side becomes a heat releasing surface. This drives the Peltier module 13, and promotes the transfer of heat from the battery module 11 to the heat exchange unit 12 via the Peltier module 13. As a result, the temperature of the battery module 11 drops. Note that if the above-mentioned current is already being applied to the Peltier module 13, the control unit 32 controls the Peltier circuit 70 so that the current continues to be applied.

<Step S16>
On the other hand, when the battery module 11 does not need to be cooled but needs to be heated, the control unit 32 controls the Peltier circuit 70 so that a current flows in the Peltier module 13 in a direction such that the surface on the heat exchange unit 12 side becomes a heat absorbing surface and the surface on the battery module 11 side becomes a heat releasing surface. This drives the Peltier module 13, and promotes the transfer of heat from the heat exchange unit 12 to the battery module 11 via the Peltier module 13. As a result, the temperature of the battery module 11 rises. Note that if the above-mentioned current is already being applied to the Peltier module 13, the control unit 32 controls the Peltier circuit 70 so that the current continues to be applied.

[Battery unit control (SOC control)]
Next, the SOC control will be described with reference to Fig. 9. The SOC control is a process for managing the SOC of the multiple battery modules 11. The control unit 32 repeatedly performs the following process. At the start of the SOC control, the connection state of the multiple battery modules 11 is the basic connection state shown in Figs. 3(a) to 3(d).

<Step S21 (SOC detection step)>
First, the control unit 32 acquires the SOCs of the multiple battery modules 11 detected by the multiple SOC sensors 22, respectively.

<Step S22>
The control unit 32 determines whether the SOCs of the multiple battery modules 11 are unbalanced. Specifically, the control unit 32 determines whether the variation in the SOCs of the multiple battery modules 11 exceeds a threshold. For example, the control unit 32 determines that the variation in the SOCs of the multiple battery modules 11 exceeds a threshold when a value obtained by subtracting the "SOC of the battery module 11 that is a low-voltage power source" from the "average value of the SOCs of the battery modules 11 other than the battery module 11 that is a low-voltage power source among the multiple battery modules 11" exceeds a predetermined allowable value.

If the SOCs of the multiple battery modules 11 are unbalanced, processing in step S24 is performed; otherwise, processing in step S23 is performed.

<Step S23>
When the SOCs of the battery modules 11 are not unbalanced, the control unit 32 determines whether the Peltier modules 13 are in operation. When at least one of the Peltier modules 13 is in operation, the process of step S24 is performed, and when not, the process ends.

<Step S24>
When the SOCs of the battery modules 11 are unbalanced or when the Peltier modules 13 are in operation, the control unit 32 determines whether or not it is possible to cut off the supply of high-voltage power. For example, when there is no need to operate a high-voltage device mounted on the vehicle, the control unit 32 determines that it is possible to cut off the supply of high-voltage power.

If it is possible to cut off the power supply to the high-voltage system, processing in step S25 is performed; if not, processing ends.

<Step S25 (parallel connection step)>
When it is possible to cut off the supply of power to the high voltage system, the control unit 32 controls the battery circuit 45 so that the connection state of the multiple battery modules 11 changes from the "basic connection state" to the "parallel connection state (see FIG. 4)." As a result, the multiple battery modules 11 are connected in parallel, and the SOCs of the multiple battery modules 11 are gradually equalized.

<Step S26>
Next, the control unit 32 determines whether or not the parallel connection state can be continued. For example, the control unit 32 determines that the parallel connection state can be continued when there is no need to supply high-voltage power to the high-voltage system devices of the vehicle.

If the parallel connection state can be continued, step S25 is performed; if not, step S27 is performed.

<Step S27 (power supply switching step)>
If the parallel connection state cannot be continued, the control unit 32 controls the battery circuit 45 so that the connection state of the multiple battery modules 11 changes from the "parallel connection state" to the "basic connection state (see Figures 3(a) to 3(d))." At this time, the control unit 32 controls the battery circuit 45 so that the battery module 11 that serves as the low-voltage power source among the multiple battery modules 11 is switched.

For example, if the low-voltage power source in the "basic connection state" before switching to the "parallel connection state" in step S25 is "battery module _11-1 ," the low-voltage power source in the "basic connection state" after switching from the "parallel connection state" in step S27 will be another battery module 11 (e.g., battery module _11-2 ) other than "battery module _11-1 ."

[Effects of the First Embodiment]
As described above, the battery circuit 45 can switch the connection state of the multiple battery modules 11 to a state in which the battery module 11 that serves as a low-voltage power supply among the multiple battery modules 11 is connected between the first output terminal 41 and the ground terminal 43. The Peltier circuit 70 can switch the connection state of the multiple Peltier modules 13 to a state in which the multiple Peltier modules 13 are connected in parallel between the first output terminal 41 and the ground terminal 43.

With this configuration, low-voltage power can be supplied to the vehicle by the battery module 11, which serves as a low-voltage power source. In addition, when the connection state of the multiple battery modules 11 is "a state in which the battery module 11 serving as a low-voltage power source among the multiple battery modules 11 is connected between the first output terminal 41 and the ground terminal 43," the connection state of the multiple Peltier modules 13 can be changed to "a state in which the multiple Peltier modules 13 are connected in parallel between the first output terminal 41 and the ground terminal 43." This allows the multiple Peltier modules 13 to be driven using the power of the battery module 11, which serves as a low-voltage power source.

In the first embodiment, the battery circuit 45 can switch the connection state of the multiple battery modules 11 to a state in which the battery module 11 that serves as a low-voltage power source among the multiple battery modules 11 is connected between the first output terminal 41 and the ground terminal 43, and at least two of the multiple battery modules 11 (in this example, all of them) are connected in series between the second output terminal 42 and the ground terminal 43. With this configuration, the battery module 11 that serves as a low-voltage power source can supply low-voltage power to the vehicle, and two or more battery modules (in this example, all of them) that are connected in series can supply high-voltage power to the vehicle.

In addition, in the first embodiment, the battery circuit 45 can switch the connection state of the multiple battery modules 11 to a state in which the multiple battery modules 11 are connected in parallel. With this configuration, the multiple battery modules 11 can be connected in parallel to equalize the SOC of the multiple battery modules 11. This makes it possible to reduce the variation in the SOC of the multiple battery modules 11.

Specifically, in the first embodiment, when the battery module 11 serving as a low-voltage power source among the multiple battery modules 11 is connected between the first output terminal 41 and the ground terminal 43, the SOC of each of the multiple battery modules 11 is detected. Then, when the detected SOC variation of the multiple battery modules 11 exceeds a threshold value, the battery circuit 45 is controlled so that the multiple battery modules 11 are connected in parallel. Through such control, the SOC variation of the multiple battery modules 11 can be effectively reduced.

In addition, in the first embodiment, the battery circuit 45 can switch the battery module 11 that serves as the low-voltage power source among the multiple battery modules 11. With this configuration, it is possible to prevent the battery module 11 that serves as the low-voltage power source from being fixed among the multiple battery modules 11. This makes it possible to reduce the variation in SOC of the multiple battery modules 11.

Specifically, in the first embodiment, when the battery module 11 serving as a low-voltage power source among the multiple battery modules 11 is connected between the first output terminal 41 and the ground terminal 43, the SOC of each of the multiple battery modules 11 is detected. Then, when the variation in the detected SOC of the multiple battery modules 11 exceeds a threshold value, the battery circuit 45 is controlled so that the battery module 11 serving as the low-voltage power source among the multiple battery modules 11 is switched. By such control, the variation in the SOC of the multiple battery modules 11 can be effectively reduced.

If, in the battery pack of Patent Document 1, one were to use the power of the battery cells contained in the multiple cell stacks to drive the cooling elements (Peltier elements) connected in parallel to each of the multiple cell stacks, the cooling elements connected in parallel to each of the multiple cell stacks would have to be individually grounded (earthed).

In the battery unit 10 of the first embodiment, multiple Peltier modules 13 can be connected in parallel between the first output terminal 41 and the ground terminal 43, so there is no need to ground (earth) the multiple Peltier modules 13 individually.

(Embodiment 2)
Fig. 10 illustrates the configuration of the battery unit 10 of embodiment 2. The battery unit 10 of embodiment 2 includes a plurality of (specifically, four) heat transfer members 14 and a heat transfer switching mechanism 15 in addition to the configuration of the battery unit 10 of embodiment 1 shown in Fig. 1.

<Heat transfer material>
The plurality of heat transfer members 14 are provided between the plurality of battery modules 11 and the plurality of Peltier modules 13 .

In this example, the heat transfer members 14 correspond one-to-one to the battery modules 11. The heat transfer members 14 also correspond one-to-one to the Peltier modules 13. Each of the heat transfer members 14 is formed in an L-shaped bent plate shape, and has a first surface portion that faces the flat surface (the surface with the largest area) of the battery module 11 corresponding to the heat transfer member 14, and a second surface portion that contacts the Peltier module 13 corresponding to the heat transfer member 14. The battery modules 11 and the heat transfer members 14 are arranged in a row so that the battery modules 11 and the first surfaces of the heat transfer members 14 are arranged alternately. The Peltier modules 13 are fixed to the second surfaces of the heat transfer members 14, respectively.

<Heat transfer switching mechanism>
The heat transfer switching mechanism 15 is capable of switching the state of heat transfer between the multiple battery modules 11 and the heat exchange section 12 via the multiple Peltier modules 13 between a heat transfer permissive state in which heat transfer is permitted, and a heat transfer inhibited state in which heat transfer is inhibited.

In the second embodiment, the heat transfer switching mechanism 15 can switch the state of heat transfer between the battery module 11 and the heat transfer member 14 between a heat transfer permitted state (the state shown in FIG. 11) and a heat transfer inhibited state (the state shown in FIG. 10). In the second embodiment, the heat exchange unit 12 and the multiple Peltier modules 13 are in contact with each other.

In this example, the heat transfer switching mechanism 15 changes the thermal resistance between the two members whose state of heat transfer is to be changed, thereby switching the state of heat transfer between the two members between a heat transfer permitted state and a heat transfer inhibited state. Note that in the first embodiment, the two members whose state of heat transfer is to be changed are a plurality of Peltier modules 13 and a plurality of heat transfer members 14.

For example, by decreasing the thermal resistance between two components, the state of heat transfer between the two components can be changed from a "heat transfer inhibited state" to a "heat transfer permitted state." Also, by increasing the thermal resistance between two components, the state of heat transfer between the two components can be changed from a "heat transfer permitted state" to a "heat transfer inhibited state."

Specifically, in this example, the heat transfer switching mechanism 15 has a plurality of heat transfer plates 101, a plurality of insulating members 102, and a drive unit 110.

The heat transfer plate 101 is formed in a corrugated shape and is placed between two components between which the state of heat transfer is to be changed. When an external force is applied to the two components to move them toward each other, the heat transfer plate 101 is pushed by the two components and deforms from a corrugated shape (the shape shown in FIG. 10) to a flat shape (the shape shown in FIG. 11). When the application of the external force is released, the heat transfer plate 101 returns from the flat shape to the corrugated shape due to a restoring force. For example, the heat transfer plate 101 is made of a material with high thermal conductivity.

The multiple heat insulating members 102 are formed in elongated plate shapes and are attached to the heat transfer plate 101 so as to follow the vertices of the corrugated plate shape that face the battery module 11. The heat insulating members 102 are made of a material that has heat insulating properties. Examples of materials that have heat insulating properties include expanded polystyrene and wood. Note that the heat insulating members 102 are not shown in FIG. 11.

The driving unit 110 applies the above-mentioned external force (external force for moving the two members in a direction toward each other) to the two members that are intended to change the state of heat transfer. When the external force is applied by the driving unit 110, the heat transfer plate 101 is pushed by the two members and deforms from a corrugated plate shape to a flat plate shape. Then, when the application of the external force by the driving unit 110 is released, the heat transfer plate 101 returns from the flat plate shape to the corrugated plate shape due to a restoring force.

In this example, the driving unit 110 is fixed to the housing 10a. The driving unit 110 presses one of the two members (e.g., the heat transfer member 14) in a direction toward the other of the two members (e.g., the battery module 11), thereby deforming the heat transfer plate 101 disposed between the two members from a corrugated shape to a flat shape. In addition, the driving unit 110 releases the pressure on one of the two members, thereby causing the heat transfer plate 101 to return from the flat shape to the corrugated shape by the restoring force of the heat transfer plate 101. For example, the driving unit 110 is an electromagnetic solenoid.

When the heat transfer plate 101 placed between two components between which the state of heat transfer is to be changed is corrugated, a gap (air layer) is formed between the two components and the corrugated heat transfer plate 101, resulting in a larger thermal resistance between the two components than when the heat transfer plate 101 is flat.

In addition, in this example, the insulating member 102 is attached so as to fit along the apex portion of the corrugated shape of the heat transfer plate 101. Therefore, when the heat transfer plate 101 has a corrugated shape, the insulating member 102 is interposed between the apex portion of the corrugated shape of the heat transfer plate 101 and a member (a member that is intended to change the state of heat transfer), thereby improving the insulation between the two members that are intended to change the state of heat transfer. This makes it possible to inhibit the transfer of heat between the two members.

In addition, when the heat transfer plate 101, which is placed between two components between which the state of heat transfer is to be changed, is pressed by the two components into a flat plate shape, the heat transfer plate 101 and the components (the components between which the state of heat transfer is to be changed) come into contact, and the thermal resistance between the two components is smaller than when the heat transfer plate 101 is in a corrugated plate shape.

In this example, the shape (particularly the thickness) of the insulating member 102 attached to the heat transfer plate 101 is designed so that when the heat transfer plate 101 is pressed by two members into a flat plate shape, the heat transfer plate 101 can come into contact with a member (a member that is intended to change the state of heat transfer).

Therefore, by applying an external force to the two components whose heat transfer state is to be changed in a direction toward each other and changing the heat transfer plate 101 from a corrugated shape to a flat shape, the thermal resistance between the two components can be reduced and the state of heat transfer between the two components can be changed from a "heat transfer inhibited state" to a "heat transfer permitted state." In addition, by releasing the external force applied to the two components and changing the heat transfer plate 101 from a flat shape to a corrugated shape, the thermal resistance between the two components can be increased and the state of heat transfer between the two components can be changed from a "heat transfer permitted state" to a "heat transfer inhibited state."

[Battery unit control (Peltier control)]
Next, the Peltier control in the second embodiment will be described with reference to Fig. 12. The control unit 32 repeatedly performs the following process.

<Step S31>
First, the control unit 32 acquires the temperatures of the plurality of battery modules 11 detected by the plurality of temperature sensors 21. In this example, the control unit 32 acquires the temperatures of four battery modules 11.

<Step S32>
The control unit 32 determines whether the temperatures of the battery modules 11 are appropriate. For example, when each of the temperatures of the battery modules 11 is a predetermined target temperature, the control unit 32 determines that the temperatures of the battery modules 11 are appropriate. Note that the target temperature may be a value with a range (i.e., a target range). When the temperatures of the battery modules 11 are appropriate, the process of step S35 is performed, and when they are not appropriate (when the temperature of at least one battery module 11 is not appropriate), the process of step S33 is performed.

<Step S33 (Heat Transfer Control Step)>
If the temperature of at least one battery module 11 is not appropriate, the control unit 32 controls the heat transfer switching mechanism 15 so that the state of heat transfer between the multiple battery modules 11 and the heat exchange unit 12 via the multiple Peltier modules 13 becomes a "heat transfer permissible state."

In this example, the control unit 32 controls the drive unit 110 so that an external force (an external force for moving the battery modules 11 and the heat transfer members 14 in a direction toward each other) is applied to the battery modules 11 and the heat transfer members 14 that are intended to change the state of heat transfer.

If the state of heat transfer between the multiple battery modules 11 and the heat exchange unit 12 via the multiple Peltier modules 13 is already in a "heat transfer permitted state," the control unit 32 controls the heat transfer switching mechanism 15 so that the heat transfer permitted state is maintained.

<Step S34 (Peltier Control Step)>
Next, the control unit 32 performs Peltier control (processing for controlling the Peltier modules 13 so that the temperature of the battery module 11 becomes an appropriate temperature) for each of the plurality of Peltier modules 13 .

The Peltier control performed for each of the multiple Peltier modules 13 is similar to the Peltier control (steps S11 to S16) in embodiment 1. Note that step S11 may be omitted here. In this case, in step S12, the control unit 32 performs the process of step S12 based on the temperature of the battery module 11 acquired in step S31.

<Step S35 (Heat Transfer Control Step and Peltier Control Step)>
On the other hand, when the temperatures of all of the multiple battery modules 11 are appropriate, the control unit 32 controls the heat transfer switching mechanism 15 so that the state of heat transfer between the multiple battery modules 11 and the heat exchange unit 12 via the multiple Peltier modules 13 becomes a "heat transfer inhibited state."

In this example, the control unit 32 controls the drive unit 110 so that the application of an external force (an external force for moving the battery modules 11 and the heat transfer members 14 in a direction toward each other) to change the state of heat transfer is released.

If the state of heat transfer between the multiple battery modules 11 and the heat exchange unit 12 via the multiple Peltier modules 13 is already in a "heat transfer inhibited state," the control unit 32 controls the heat transfer switching mechanism 15 so that the heat transfer inhibited state is maintained.

[Effects of the Second Embodiment]
As described above, in the second embodiment, the heat transfer switching mechanism 15 can switch the state of heat transfer between the multiple battery modules 11 and the heat exchange unit 12 via the multiple Peltier modules 13 between a "heat transfer permitted state in which heat transfer is permitted" and a "heat transfer inhibited state in which heat transfer is inhibited." By setting the above-mentioned heat transfer state to the "heat transfer permitted state," heat can be appropriately transferred between the multiple battery modules 11 and the heat exchange unit 12. In addition, by setting the above-mentioned heat transfer state to the "heat transfer inhibited state," unnecessary heat transfer between the multiple battery modules 11 and the heat exchange unit 12 can be suppressed.

Specifically, in the second embodiment, the current flow and non-current flow of each of the multiple Peltier modules 13 is controlled. When at least one of the multiple Peltier modules 13 is current flowing, the heat transfer switching mechanism 15 is controlled so that the heat transfer state described above becomes a "heat transfer permitted state". This control allows heat to be transferred appropriately between the multiple battery modules 11 and the heat exchange unit. In addition, when the multiple Peltier modules 13 are not current flowing, the heat transfer switching mechanism 15 is controlled so that the heat transfer state described above becomes a "heat transfer inhibited state". This control allows unnecessary heat transfer between the multiple battery modules 11 and the heat exchange unit 12 to be suppressed.

(Modification of the second embodiment)
Fig. 13 illustrates the configuration of a battery unit 10 according to a modification of embodiment 2. In the battery unit 10 according to the modification of embodiment 2, the heat transfer member 14 shown in Fig. 10 is omitted. The battery unit 10 according to the modification of embodiment 2 differs from the battery unit 10 according to embodiment 2 in the configuration of the heat transfer switching mechanism 15. The other configurations of the battery unit 10 according to the modification of embodiment 2 are similar to those of the battery unit 10 according to embodiment 2.

<Heat transfer switching mechanism>
In a modification of the second embodiment, the heat transfer switching mechanism 15 can switch the state of heat transfer between the heat exchange unit 12 and the multiple Peltier modules 13 between a heat transfer permitted state (the state shown in FIG. 14) and a heat transfer inhibited state (the state shown in FIG. 13). In this example, the heat transfer switching mechanism 15 can switch the above-mentioned heat transfer state individually for each Peltier module 13. Note that in the first modification of the second embodiment, the multiple battery modules 11 and the multiple Peltier modules 13 are in contact with each other.

In this example, the heat transfer switching mechanism 15 switches the state of heat transfer between the heat exchange unit 12 and the Peltier module 13 between a heat transfer permitted state and a heat transfer inhibited state by changing the thermal resistance between the heat exchange unit 12 and the Peltier module 13, which are intended to change the state of heat transfer. Note that in the first modification of the second embodiment, the two components intended to change the state of heat transfer are the heat exchange unit 12 and the Peltier module 13.

Specifically, the heat transfer switching mechanism 15 has a plurality of heat transfer plates 201 that correspond one-to-one with the plurality of Peltier modules 13, a plurality of insulating members 202, and a plurality of drive units 210 that correspond one-to-one with the plurality of Peltier modules 13.

Each of the multiple heat transfer plates 201 is disposed between the Peltier module 13 corresponding to that heat transfer plate 201 and the heat exchange unit 12. The configuration of the heat transfer plate 201 is similar to the configuration of the heat transfer plate 101 shown in FIG. 10. The multiple heat insulating members 202 are formed in elongated plate shapes and are attached so as to fit along the vertices of the corrugated shape of the heat transfer plate 201.

Each of the multiple drive units 210 applies an external force (an external force for moving the two members in a direction toward each other) to the heat exchange unit 12 and Peltier module 13 corresponding to that drive unit 210. When the external force is applied by the drive unit 210, the heat transfer plate 201 is pushed by the heat exchange unit 12 and the Peltier module 13 and deforms from a corrugated plate shape to a flat plate shape. Then, when the application of the external force by the drive unit 210 is released, the heat transfer plate 201 returns from the flat plate shape to the corrugated plate shape due to a restoring force.

(Supplementary Note on Modification of the Second Embodiment)
In the battery unit 10 of the modified example of the second embodiment, the heat transfer plates 201 may be disposed between the battery modules 11 and the Peltier modules 13. That is, the heat transfer switching mechanism 15 may be capable of switching the state of heat transfer between the battery modules 11 and the Peltier modules 13 between a heat transfer permitted state and a heat transfer inhibited state. Specifically, the heat transfer switching mechanism 15 may switch the state of heat transfer between the battery module 11 and the Peltier module 13 between a heat transfer permitted state and a heat transfer inhibited state by changing the thermal resistance between the battery module 11 and the Peltier module 13, the state of heat transfer of which is to be changed. In this case, the two members whose state of heat transfer is to be changed are the battery module 11 and the Peltier module 13.

Other Embodiments
In the above description, a case where a heat insulating member (e.g., heat insulating member 102) is attached to a heat transfer plate (e.g., heat transfer plate 101) of the heat transfer switching mechanism 15 has been described as an example, but the present invention is not limited to this. A heat insulating member does not have to be attached to the heat transfer plate.

In the above description, the heat transfer switching mechanism 15 has a heat transfer plate, a heat insulating member, and a drive unit (for example, the heat transfer plate 101, the heat insulating member 102, and the drive unit 110), but is not limited to this. For example, the heat transfer switching mechanism 15 may be capable of switching the state of two members that are to change the state of heat transfer between a "first state in which the two members are in contact" and a "second state in which the two members are separated without contacting". Specifically, the heat transfer switching mechanism 15 may have a drive unit that does not have a heat transfer plate and a heat insulating member and switches between the first state and the second state by moving at least one of the two members. Such a drive unit may be an electromagnetic solenoid or another actuator.

In addition, in the above description, other devices (e.g., devices of the electric drive system) mounted on the vehicle may be connected to the coolant circuit (one example of a heat exchange medium circuit) formed by the radiator 2 and the heat exchange section 12 of the battery unit 10 to be cooled.

In addition, in the SOC control shown in FIG. 9, the processing of steps S25 and S26 (parallel connection step) may be omitted. In addition, in the SOC control shown in FIG. 9, the processing of step S27 (power source switching step) may be omitted.

The above embodiments and modifications may be combined as appropriate. The above embodiments and modifications are essentially preferred examples and are not intended to limit the scope of the technology disclosed herein, its applications, or its uses.

As explained above, the technology disclosed herein is useful as a vehicle battery unit.

Reference Signs List 1 Vehicle power supply system 2 Radiator 3 First flow path 4 Second flow path 5 Pump 6 Fan 10 Vehicle battery unit 11 Battery module 12 Heat exchanger 13 Peltier module 14 Heat transfer member 15 Heat transfer switching mechanism 21 Temperature sensor 22 SOC sensor 30 Control device 31 Memory unit 32 Control unit 41 First output terminal 42 Second output terminal 43 Ground terminal 45 Battery circuit 50 Power supply line 60 Relay 70 Peltier circuit

Claims (5)

A plurality of battery modules for a vehicle;
A heat exchange section;
a plurality of Peltier modules provided between the plurality of battery modules and the heat exchange unit, the Peltier modules promoting heat transfer by energization;
a first output terminal for outputting a first electric power to be supplied to the vehicle;
A ground terminal;
a battery circuit capable of switching a connection state of the plurality of battery modules between a state in which a battery module serving as a first power source that outputs the first power among the plurality of battery modules is connected between the first output terminal and the ground terminal, and a state in which the plurality of battery modules are connected in parallel;
a Peltier circuit capable of switching a connection state of the plurality of Peltier modules to a state in which the plurality of Peltier modules are connected in parallel between the first output terminal and the ground terminal ,
A control unit is provided,
The control unit is
an SOC detection process for detecting an SOC of each of the plurality of battery modules when a battery module serving as the first power source among the plurality of battery modules is connected between the first output terminal and the ground terminal;
When the variation in SOC of the plurality of battery modules detected by the SOC detection process exceeds a threshold value, a parallel connection process is performed to control the battery circuit so that the plurality of battery modules are connected in parallel.
A control device for a vehicle battery unit. A plurality of battery modules for a vehicle;
A heat exchange section;
a plurality of Peltier modules provided between the plurality of battery modules and the heat exchange unit, the Peltier modules promoting heat transfer by energization;
a first output terminal for outputting a first electric power to be supplied to the vehicle;
A ground terminal;
a battery circuit capable of switching a connection state of the plurality of battery modules to a state in which a battery module serving as a first power source that outputs the first power among the plurality of battery modules is connected between the first output terminal and the ground terminal, and capable of switching the battery module serving as the first power source among the plurality of battery modules;
a Peltier circuit capable of switching a connection state of the plurality of Peltier modules to a state in which the plurality of Peltier modules are connected in parallel between the first output terminal and the ground terminal ,
A control unit is provided,
The control unit is
an SOC detection process for detecting an SOC of each of the plurality of battery modules when a battery module serving as the first power source among the plurality of battery modules is connected between the first output terminal and the ground terminal;
When the variation in SOC of the plurality of battery modules detected by the SOC detection process exceeds a threshold value, a power supply switching process is performed to control the battery circuit so that a battery module serving as the first power supply is switched among the plurality of battery modules.
A control device for a vehicle battery unit. The vehicle battery unit control device according to claim 1 or 2 ,
the vehicle battery unit includes a second output terminal for outputting a second power that is supplied to the vehicle and is higher than the first power;
a control device for a vehicle battery unit, characterized in that the battery circuit is capable of switching a connection state of the plurality of battery modules to a state in which a battery module serving as the first power source among the plurality of battery modules is connected between the first output terminal and the ground terminal, and at least two of the plurality of battery modules are connected in series between the second output terminal and the ground terminal . The control device for a vehicle battery unit according to any one of claims 1 to 3 ,
the vehicle battery unit is characterized in that it comprises a heat transfer switching mechanism that can switch a state of heat transfer between the plurality of battery modules and the heat exchange unit via the plurality of Peltier modules between a heat transfer permissive state, in which the heat transfer is permitted, and a heat transfer inhibited state , in which the heat transfer is inhibited. The vehicle battery unit control device according to claim 4 ,
The control unit is
A Peltier control process for controlling energization and de-energization of each of the plurality of Peltier modules;
a heat transfer control process for controlling the heat transfer switching mechanism so that the state of the heat transfer is the heat transfer permitted state when at least one of the plurality of Peltier modules is energized, and for controlling the heat transfer switching mechanism so that the state of the heat transfer is the heat transfer inhibited state when the plurality of Peltier modules is not energized.
A control device for a vehicle battery unit.

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