Vehicle, battery pack

Abstract

To smoothly move air in the internal space of a battery pack.SOLUTION: A vehicle according to the present invention includes a battery pack having a battery module, a battery case, and a plasma actuator, the battery module has a plurality of lithium ion battery cells, the battery case has the battery module disposed in an internal space, and the plasma actuator is disposed in the internal space and generates an airflow in the internal space by applying electric power.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a vehicle equipped with a battery pack and to the technical field of the battery pack. [Background technology]

[0002] For example, in electric vehicles, such as hybrid vehicles and electric automobiles, which are configured so that the wheels can be driven by the power of an electric motor, a battery (secondary battery) is mounted for supplying power to the electric motor. Generally, the discharge characteristics of a battery change depending on the temperature, and when the temperature of the battery is high, the battery needs to be cooled.

[0003] As a method for cooling batteries, for example, a method is known in which a fan is connected via a duct to a battery pack containing batteries, and air is sent into the battery pack (see Patent Document 1 below). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-166976 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, with such a blower, it is difficult to move all of the air inside the battery pack smoothly, and some of the air may become stagnant in corners of the battery pack, making it difficult to efficiently cool the batteries.

[0006] The present invention has been made in view of the above circumstances, and has an object to allow air to move smoothly within the internal space of a battery pack. [Means for solving the problem]

[0007] A vehicle according to one embodiment of the present invention comprises a battery pack having a battery module, a battery case, and a plasma actuator, the battery module having a plurality of lithium ion battery cells, the battery case having the battery module disposed in an interior space, and the plasma actuator being disposed in the interior space and generating an airflow in the interior space upon application of electric power. The ionic wind generated by the plasma actuator becomes an air current in the internal space and flows near the outer surface of the battery module. Effect of the Invention

[0008] According to the present invention, air can be moved smoothly within the internal space of the battery pack. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a vehicle. [Diagram 2] FIG. 2 is a diagram illustrating an example of a battery pack configuration. [Diagram 3] FIG. 2 is a diagram illustrating a schematic configuration example of a battery module. [Figure 4] 1 is a diagram illustrating an example of the configuration of a plasma actuator. [Diagram 5] 10 is a flowchart illustrating an example of a process executed by a control unit. [Figure 6] FIG. 13 is a diagram illustrating an example of the configuration of a battery pack according to a first modified example. [Figure 7] FIG. 13 is a diagram illustrating an example of the configuration of a battery pack according to a second modified example. [Figure 8] FIG. 13 is a diagram illustrating an example of the configuration of a battery pack according to a third modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <1. Vehicle and battery pack configuration> An example of the configuration of a vehicle 1 and a battery pack 2 mounted on the vehicle 1 will be described with reference to FIG. The vehicle 1 includes a battery pack 2, a PCU (Power Control Unit) 3, a motor 4, a control unit 5, and an auxiliary battery 6.

[0011] The battery pack 2 is a high-voltage vehicle-mounted battery, and is disposed, for example, in the space between the luggage compartment board and the vehicle body floor. The battery pack 2 supplies power used to drive the wheels and various electronic devices of the vehicle 1. Fig. 1 shows the power supply from the battery pack 2 to drive the wheels, and does not show the power supply used to drive the other parts.

[0012] The battery pack 2 is charged based on a DC voltage supplied from a rectifier circuit (not shown).

[0013] The battery pack 2 supplies the PCU 3 with a power supply voltage for driving the motor 4 .

[0014] The PCU 3 is configured to include an inverter for driving the motor 4, a DC / DC converter, and the like. The PCU 3 generates an AC current for driving the motor 4 based on the above-mentioned power supply voltage, and supplies the AC current to the motor 4. The PCU 3 controls the torque of the motor 4 by controlling the AC current. The PCU 3 may also be provided with a regenerative braking function to optimize energy efficiency by utilizing regenerative energy.

[0015] The motor 4 is configured as a motor generator having a power generating function, and drives the wheels based on the supplied alternating current.

[0016] The control unit 5 is configured with a CPU (Central Processing Unit), a memory, etc., and performs overall control of the vehicle 1. The control unit 5 may be provided as a single unit, or may be configured with multiple ECUs (Electronic Control Units). The multiple ECUs may include various types of ECUs, such as a battery control ECU that performs charging control of the battery pack 2, a display control ECU that performs display control of a display device (including meters, etc.) provided in the vehicle 1, an airbag control ECU, and an air conditioning control ECU.

[0017] Although not shown in FIG. 1, the battery pack 2 may be capable of being charged via a connector portion provided on the vehicle 1.

[0018] The control unit 5 calculates and manages the SOC (State Of Charge) of the battery pack 2 using measured values ​​such as the output current value and the output voltage value of the battery pack 2. Note that the PCU 3 may manage the SOC information, and the control unit 5 may be able to acquire the SOC from the PCU 3. The control unit 5 is capable of performing control according to the SOC.

[0019] The control unit 5 performs cooling control to adjust the internal temperature of the battery pack 2. This will be described in detail later.

[0020] The auxiliary battery 6 is a lead battery having a smaller capacity than the battery pack 2 and outputting a direct current voltage of 12V.

[0021] The auxiliary battery 6 supplies a power supply voltage for cooling the battery pack 2 to a predetermined portion of the battery pack 2.

[0022] An example of the configuration of the battery pack 2 will be described with reference to FIG.

[0023] The battery pack 2 includes a battery case 7, a battery module 8, a blower 9, a plasma actuator 10, and a temperature sensor 11.

[0024] The battery case 7 is formed in a rectangular box shape, and an internal space 12 is provided therein.

[0025] As shown in FIG. 3, the battery module 8 is configured by arranging a plurality of lithium ion battery cells 13 formed in a flat rectangular shape in the thickness direction, and is configured as a battery pack connected in parallel or in series.

[0026] Each of the lithium ion battery cells 13 is provided with a positive terminal 13a and a negative terminal 13b.

[0027] A plurality of battery modules 8 are arranged at a distance from each other in the internal space 12 of the battery case 7. The spaces between the battery modules 8 and the space between the battery modules 8 and the battery case 7 are each formed as a flow path P through which air flows.

[0028] The flow path P has a portion where the air flows linearly and a portion where the air flows bent due to an obstacle, etc. In Fig. 2, the portion in the flow path P where the air flows bent is mainly indicated by an arrow.

[0029] The blower 9 takes in air from within the vehicle cabin via a first duct 14 connected to the vehicle cabin, for example, and sends the air into the interior space 12 via a second duct 15.

[0030] The air sent into the interior space 12 by the blower 9 passes through one of the flow paths P and then returns to the vehicle interior via the third duct 16.

[0031] The blower 9 is supplied with a driving voltage from the battery module 8 or the auxiliary battery 6 .

[0032] The plasma actuator 10 is attached to the outer surface of the battery module 8, for example, in the vicinity of a bent portion of the flow path P.

[0033] As shown in FIG. 4, the plasma actuator 10 comprises a dielectric 17 formed, for example, in the shape of a thin film or plate, a first electrode 18 provided on one surface of the dielectric 17 in the thickness direction, and a second electrode 19 provided on the other surface of the dielectric 17 in the thickness direction.

[0034] The first electrode 18 and the second electrode 19 are disposed so that their positions are at least partially offset when viewed in the thickness direction. An AC voltage source 20 that applies an AC voltage is inserted between the first electrode 18 and the second electrode 19. The AC voltage source 20 is realized by a voltage supply from the auxiliary battery 6.

[0035] When a predetermined voltage V is applied to the first electrode 18 and the second electrode 19 by the AC voltage source 20, an ion wind Wi is generated on the side of the dielectric 17 where the first electrode 18 is provided, as shown in Fig. 4. The ion wind Wi flows from the first electrode 18 toward the second electrode 19.

[0036] The strength (wind force) of the ion wind Wi increases in proportion to the AC voltage supplied from the AC voltage source 20.

[0037] The temperature sensor 11 is disposed, for example, downstream of the flow path P in the internal space 12.

[0038] The temperature detected by the temperature sensor 11 is used for control by the control unit 5. For example, when the temperature detected by the temperature sensor 11 is higher than a predetermined value, the control unit 5 controls the blower 9 to increase the airflow, thereby enhancing the cooling effect on the battery module 8.

[0039] Furthermore, when the temperature detected by the temperature sensor 11 is higher than a predetermined value, the control unit 5 controls the voltage applied to the plasma actuator 10 to be increased, thereby strengthening the ion wind Wi and enhancing the cooling effect on the battery module 8.

[0040] Furthermore, when the temperature detected by the temperature sensor 11 becomes abnormally high and higher than the threshold value, the control unit 5 increases the amount of ozone generated by the plasma actuator 10 by maximizing the voltage applied to the plasma actuator 10.

[0041] An example of a case where the internal space 12 of the battery case 7 becomes abnormally hot is a case where a part of the battery module 8 catches fire. The battery module 8 generates harmful substances when it catches fire. At this time, the generated harmful substances are detoxified by the oxidizing action of the ozone generated by the plasma actuator 10.

[0042] This makes it possible to reduce the amount of harmful substances contained in the air flowing from the interior space 12 into the vehicle compartment via the third duct 16, thereby improving the safety of passengers.

[0043] <2. Processing by the control unit> 5 shows an example of the processing executed by the control unit 5. Note that the series of processing by the control unit 5 may be realized by an arithmetic processing unit executing a program, or may be realized by hardware using a logic circuit or the like.

[0044] In step S101 of FIG. 5, the control unit 5 acquires a sensing result as temperature information from the temperature sensor 11.

[0045] In step S102, the control unit 5 determines whether or not the temperature acquired from the temperature sensor 11 is equal to or higher than a threshold value.

[0046] If it is determined that the temperature is less than the threshold value (step S102: No), the control unit 5 performs cooling control according to the temperature in step S103. As a result, the control unit 5 appropriately controls the voltages applied to the blower 9 and the plasma actuator 10, and cools the battery module 8.

[0047] On the other hand, if it is determined that the temperature is equal to or higher than the threshold value (step S102: Yes), control unit 5 stops blower 9 in step S104.

[0048] Next, in step S105, the control unit 5 sets the voltage applied to the plasma actuator 10 to the maximum. This makes it possible to maximize the amount of ozone generated in the plasma actuator 10.

[0049] The temperature detected by temperature sensor 11 may differ depending on the number of battery modules 8 in which an abnormality has occurred or the number of lithium ion battery cells 13 in which an abnormality has occurred. In such a case, after control unit 5 stops blower 9 in step S104, in step S105, it may control the voltage applied to plasma actuator 10 so that plasma actuator 10 generates an appropriate amount of ozone that is just enough to detoxify harmful substances.

[0050] For example, threshold values ​​are set based on the detected temperature by the temperature sensor 11 when an abnormality occurs in one of the four battery modules 8 shown in Figure 2, the detected temperature by the temperature sensor 11 when an abnormality occurs in two battery modules 8, the detected temperature by the temperature sensor 11 when an abnormality occurs in three battery modules 8, and the detected temperature by the temperature sensor 11 when an abnormality occurs in all four battery modules 8.

[0051] Then, by comparing the detected temperature with each threshold value, it is estimated how many battery modules 8 have experienced an abnormality, and the voltage applied to the plasma actuator 10 is controlled accordingly to adjust the amount of ozone generated.

[0052] Specifically, the control unit 5 increases the voltage applied to the plasma actuator 10 as the number of battery modules 8 in which abnormalities have occurred increases.

[0053] <3. Modifications> Some modified examples will be described with reference to the accompanying drawings.

[0054] In the first modified example, the number of locations where the plasma actuator 10 is arranged is increased. Specifically, as shown in FIG. 6, in the internal space 12 of the battery pack 2A, the plasma actuators 10 are disposed near each corner where neither the first duct 14 nor the third duct 16 is provided.

[0055] This makes it possible to further prevent air from stagnating in the internal space 12, and the cooling efficiency for the battery module 8 can be improved.

[0056] It should be noted that the battery pack 2A in this modified example is not provided with the blower 9. For the battery module 8 arranged inside the battery pack 2A, if the cooling effect of the ion wind Wi generated in the plasma actuator 10 is sufficient, it is possible to omit the blower 9 as shown in Figure 6 of this example.

[0057] This makes it possible to reduce the weight and size of the battery pack 2A.

[0058] In the second modified example, a temperature sensor 11 is provided for each battery module 8. Specifically, as shown in FIG. 7, in a battery pack 2B, a temperature sensor 11 is provided for each of a plurality of battery modules 8 arranged in an internal space 12 of a battery case .

[0059] Moreover, the temperature sensor 11 is disposed so as to be as far away as possible from the plasma actuator 10 attached to the same battery module 8.

[0060] Of the various parts of the battery module 8, the part where the plasma actuator 10 is arranged tends to have a lower temperature than the other parts. Therefore, by attaching the temperature sensor 11 at a position away from the portion of the surface of the battery module 8 where the plasma actuator 10 is attached, it is possible to prevent the temperature of the battery module 8 from being measured as low, which would weaken the cooling control by the control unit 5.

[0061] Furthermore, by providing a temperature sensor 11 for each battery module 8, it is possible to accurately identify the battery module 8 in which an abnormality has occurred. Therefore, the amount of harmful substances generated by the battery module 8 and the amount of ozone to be generated by the plasma actuator 10 can be estimated more accurately, and the voltage applied to the plasma actuator 10 can be optimized.

[0062] The third modified example is an example in which a hazardous substance detection sensor 21 is provided to detect the hazardous substance itself that is generated when the battery module 8 is abnormal.

[0063] In the battery pack 2C, as shown in FIG. 8, a temperature sensor 11 is provided for each battery module 8, and a harmful substance detection sensor 21 is provided near the most downstream side of the flow path P, specifically, near the connection portion with the third duct 16 in the battery case 7 or within the third duct 16.

[0064] This makes it possible to accurately grasp the amount of harmful substances that are not detoxified by ozone and flow into the vehicle cabin. Therefore, the control unit 5 can more accurately set the power to be applied to the plasma actuator 10. Also, it becomes possible to control the voltage applied to the plasma actuator 10 so as to increase until harmful substances are no longer detected by the harmful substance detection sensor 21, thereby further improving the safety of the occupants.

[0065] The fourth modification relates to the control of the control unit 5. In the processing example shown in FIG. 5, the control unit 5 returns to step S101 after the processing in step S105. Without being limited to this, after completing the processing of step S105, the control unit 5 may appropriately perform processing such as notifying the occupants that an abnormality has occurred in the battery module 8 or control to safely stop the vehicle 1, and then end the series of processing shown in Figure 5 without returning to the processing of step S101.

[0066] <4. Summary> As described in each of the above examples, the vehicle 1 of the present invention comprises a battery pack 2 (2A, 2B, 2C) having a battery module 8, a battery case 7, and a plasma actuator 10, the battery module 8 having a plurality of lithium ion battery cells 13, the battery case 7 having the battery module 8 disposed in an internal space 12, and the plasma actuator 10 being disposed in the internal space 12 and generating an airflow in the internal space 12 by application of electric power. The ion wind Wi generated by the plasma actuator 10 becomes an air current in the internal space 12 and flows near the outer surface of the battery module 8. This makes it possible to lower the temperature of the battery module 8, and prevents the performance of the lithium ion battery cells 13 from deteriorating. Furthermore, if the temperature of the battery module 8 can be sufficiently lowered by the ionic wind Wi generated by the plasma actuator 10, it will be possible to omit the blower 9 that is normally provided to blow air to the battery module 8. Therefore, it is possible to reduce the weight of the vehicle 1 and improve fuel efficiency, and further to reduce the size of the battery pack 2 (2A, 2B, 2C) and improve the degree of freedom in arranging other components. Furthermore, ozone is generated when an ion wind Wi is generated by applying a voltage to the plasma actuator 10. If a failure occurs in the lithium-ion battery cell 13, harmful substances such as carbon monoxide, methane, and hydrogen may be generated from the battery cell, but the oxidizing effect of the ozone generated by the plasma actuator 10 can detoxify these harmful substances. Therefore, it is possible to reduce the size of the exhaust duct for discharging harmful substances outside the vehicle when an abnormality occurs in the battery module 8, or even to omit the exhaust duct, thereby making it possible to reduce the weight of the vehicle 1 and improve fuel efficiency. Furthermore, by positioning the plasma actuator 10 near a branching point, confluence point, or curve point of the air flow path P in the internal space 12 of the battery case 7, specifically, near a point where a curved flow path P exists, it is possible to eliminate air stagnation in the internal space 12 and provide an environment in which air can flow efficiently. Furthermore, by installing the plasma actuator 10 on the surface of the battery module 8 rather than on the inner wall of the battery case 7, the ion wind Wi can be generated at a position closer to the battery module 8, thereby improving the cooling effect on the battery module 8.

[0067] In addition, the vehicle 1 may be equipped with a control unit 5 that controls the battery module 8, and the control unit 5 may perform control to increase the voltage applied to the plasma actuator 10 when an abnormality occurs in the battery module 8. This makes it possible to increase the amount of ozone generated from the plasma actuator 10. Therefore, it becomes possible to detoxify many of the harmful substances generated due to an abnormality in the battery module 8, thereby improving the safety of passengers. In addition, if a blower 9 is provided to send air into the internal space 12 of the battery pack 2 (2A, 2B, 2C), the control unit 5 may control the blower 9 to stop blowing air when an abnormality occurs. This makes it possible to prevent harmful substances from flowing into the vehicle interior before they have been detoxified.

[0068] The vehicle 1 may be provided with a temperature sensor 11 arranged in the interior space 12 to measure the temperature of the battery module 8, and the control unit 5 may determine whether or not an abnormality has occurred in the battery module 8 based on the temperature detected by the temperature sensor 11. This makes it possible to detect, with a simple configuration, the occurrence of an abnormality in the battery module 8. Therefore, it is possible to prevent the configuration of the battery module 8 from becoming complicated and to simplify the control. Furthermore, by using the temperature sensor 11 for abnormality detection, it is possible to preferably detect ignitions and the like that would produce harmful substances, and therefore it is possible to preferably control the voltage applied to the plasma actuator 10, and it is possible to preferably detoxify harmful substances. It should be noted that by adopting a configuration in which a detection sensor (harmful substance detection sensor 21) that directly detects the generation of harmful substances is separately provided, the voltage applied to the plasma actuator 10 can be controlled more appropriately.

[0069] The vehicle 1 includes an auxiliary battery 6 disposed outside the battery pack 2 (2A, 2B, 2C), and the plasma actuator 10 may be supplied with power from the auxiliary battery 6. As a result, even if an abnormality occurs in the battery module 8 arranged in the battery pack 2 (2A, 2B, 2C), the application of voltage to the plasma actuator 10 is not stopped, making it possible to continue detoxifying harmful substances.

[0070] The battery pack 2 (2A, 2B, 2C) of the present invention comprises a battery module 8 having lithium ion battery cells 13, a battery case 7 in which the battery module 8 is arranged in an internal space 12, and a plasma actuator 10 arranged in the internal space 12 and generating an airflow in the internal space 12 by applying electric power. This battery pack 2 (2A, 2B, 2C) can also provide the various functions and effects described above.

[0071] The various examples described above can be combined as appropriate. [Explanation of symbols]

[0072] 1 vehicle 2, 2A, 2B, 2C Battery Pack 5. Control section 6 Auxiliary battery 7 Battery case 8 Battery Module 10 Plasma Actuator 11 Temperature Sensor 12 Interior Space 13 Lithium-ion battery cells

Claims

1. The battery pack includes a battery module, a battery case, and a plasma actuator. the battery module includes a plurality of lithium ion battery cells; The battery case has an internal space in which the battery module is disposed, The plasma actuator is disposed in the internal space and generates an airflow in the internal space by applying electric power thereto. vehicle.

2. A control unit that controls the battery module, The control unit performs control to increase a voltage applied to the plasma actuator when an abnormality occurs in the battery module.

2. The vehicle of claim 1.

3. a temperature sensor disposed in the internal space and configured to measure a temperature of the battery module; The control unit determines whether or not the abnormality has occurred in the battery module based on the temperature detected by the temperature sensor.

3. A vehicle as claimed in claim 2.

4. an auxiliary battery disposed outside the battery pack; The plasma actuator is supplied with power from the auxiliary battery. A vehicle according to any one of claims 1 to 3.

5. a battery module having lithium ion battery cells; a battery case having an internal space in which the battery module is disposed; A plasma actuator that is disposed in the internal space and generates an airflow in the internal space by applying electric power. Battery pack.

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