Battery system

Abstract

To provide a battery system that can continue the reasonable use of a battery for a while even when the airtightness of its housing is destroyed.SOLUTION: A battery system that is installed in an electric vehicle to supply power for driving includes: a battery 41 having an airtight housing 413 and a plurality of battery modules 411 housed in the housing; and a cooler capable of cooling the lower part of the housing more strongly than the upper and middle parts of the housing. A reservoir 414 is provided on the lower inner part of the housing to collect condensation.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Patent Document 1 describes a vehicle battery bag having a structure for draining condensation formed inside the case or rainwater that has infiltrated into the case from the outside to the outside. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-133819 A Summary of the Invention [Problem to be solved by the invention]

[0004] By making the battery housing airtight, it is possible to prevent condensation from forming inside the battery. On the other hand, if a part of the housing is damaged and the airtightness is broken, it is convenient to be able to continue using the battery reasonably to the extent that the vehicle can be driven to a repair shop or dealer.

[0005] An object of the present invention is to provide a battery system that allows the battery to continue to be used reasonably for a while even if the airtightness of the casing is destroyed. [Means for solving the problem]

[0006] A battery system according to one aspect of the present invention includes: A battery system mounted on an electric vehicle to supply power for driving the vehicle, A battery having an airtight housing and a plurality of battery modules housed in the housing; a cooler capable of cooling a lower portion of the housing more strongly than an upper portion and a middle portion of the housing; Equipped with A reservoir for collecting condensation is provided at the lower inner portion of the housing. Effect of the Invention

[0007] According to the present invention, even if the airtightness of the casing is destroyed, it is possible to continue using the battery for a while without strain. [Brief description of the drawings]

[0008] [Figure 1] 1 is a block diagram showing an electric vehicle equipped with a battery system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing a configuration of a battery. [Diagram 3] 13 is a flowchart showing a failure avoidance process executed by a controller. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0010] Fig. 1 is a block diagram showing an electric vehicle equipped with a battery system according to the present embodiment, and Fig. 2 is a diagram showing the configuration of the battery.

[0011] The electric vehicle 1 includes drive wheels 2, a driving motor 3 that drives the drive wheels 2, a battery system 40 of this embodiment, an inverter 5 that converts power between a battery 41 of the battery system 40 and the driving motor 3, a driving operation unit 6 that allows driving operations, a display unit 8 arranged in the driver's cab, a vehicle controller 9 that controls driving, electric equipment 10 that operates with power from the battery 41, and a temperature regulator 11 that adjusts the temperature of the battery 41. The driving operation unit 6 includes a steering operation unit 6a such as a steering wheel, an accelerator operation unit 6b such as an accelerator pedal, and a brake operation unit 6c such as a brake pedal. The driving motor 3 is an electric motor.

[0012] The temperature adjustment device 11 is configured to be capable of cooling and heating the battery 41. The temperature adjustment device 11 includes a flow path 111 through which a temperature adjustment medium passes, which is located around and inside the battery 41, a temperature adjustment unit 112 such as a heater, a heat pump, or a heat exchanger capable of heating and cooling the medium, and a drive unit 113 such as a pump or a fan that circulates the medium.

[0013] The vehicle controller 9 is an ECU (Electronic Control Unit) and operates according to a control program stored in the memory unit 9a. The vehicle controller 9 receives an operation signal from the driving operation unit 6, and drives the driving motor 3 by controlling the inverter 5 according to the operation signal. The above control provides driving force or regenerative braking force according to the driving operation. The vehicle controller 9 further controls the driving of the electric device 10 based on commands from the passenger or environmental conditions, and also controls the user interface, such as displaying a warning on the display unit 8.

[0014] The electrical equipment 10 includes a pump and a fan of an air conditioner in the vehicle, and lights. The electrical equipment 10 consumes power from the battery 41 directly or indirectly.

[0015] The battery system 40 is a system that supplies electric power for driving. The battery system 40 includes a battery 41 that stores electric power for driving, a controller 42 that performs control processing, and a cooler 43 that can cool the battery 41.

[0016] The battery 41 is, for example, a lithium ion secondary battery, a nickel-hydrogen secondary battery, or the like, but is not particularly limited in type. As shown in Fig. 2, the battery 41 includes a plurality of battery modules 411, a housing 413 that houses the plurality of battery modules 411, and a sensor 415 that detects a break in the airtightness of the housing 413.

[0017] The battery module 411 is configured by modularizing a plurality of battery cells. The plurality of battery modules 411 are arranged so as to be lined up in the horizontal direction. The plurality of battery modules 411 have electrodes on the upper part, and the electrodes of the plurality of battery modules 411 are connected at the upper part by a bus bar 412. Note that the bus bar 412 is not limited to being located on the upper surface of the battery module 411, but may be located in the upper part of the battery module 411 divided vertically in half. A part of the anode bus bar 412 and a part of the cathode bus bar 412 are led out to the outside of the housing 413 to input and output electric power.

[0018] The housing 413 is airtight. A reservoir 414 capable of storing condensation when condensation occurs inside the housing 413 is provided at the lower inner part of the housing 413. The reservoir 414 may be a space (groove, recess, etc.) provided at a position lower than the lower end of the battery module 411 (the inner bottom surface supporting the battery module 411). When the reservoir 414 is a groove, recess, etc., the housing 413 may have a plurality of reservoirs 414 at the lower inner part, and the condensation may be smoothly moved to the reservoir 414 along the side of each battery module 411. For example, the inner bottom surface of the housing 413 may be provided with a flow path (fine groove, etc.) that guides the condensation from the lower end of each of the plurality of battery modules 411 to the reservoir 414. The reservoir 414 is not limited to the above configuration, and may be a liquid-absorbing mat or liquid absorber provided below the battery modules 411 or below the gap between adjacent battery modules 411.

[0019] The sensor 415 detects a break in the airtightness of the housing 413. The sensor 415 may have any configuration as long as it can detect a break in the airtightness of the housing 413. For example, the sensor 415 may have a configuration including a conductor wire stretched along the entire inner surface of the housing 413 on the wall surface or within the wall of the housing 413, and an electric circuit that conducts electricity through the conductor wire and monitors the electricity state. With such a sensor 415, when a force is applied to the housing 413 and a break occurs in a part of the housing 413 that breaks the airtightness, the break cuts the conductor wire. Then, the breakage of the conductor wire changes the electricity state of the electric circuit, and the change can be output as a sensor signal indicating that the airtightness has been broken. Also, when a part of the housing 413 is broken, the capacitance of the part changes. Therefore, the sensor 415 may be a plurality of capacitance type sensors provided on the wall surface of the housing 413 or in each part within the wall. Such sensor 415 can detect any damage that breaks the airtightness of housing 413. Also, by keeping the inside of housing 413 at a pressure different from atmospheric pressure, sensor 415 can detect the break in airtightness based on a change in pressure inside housing 413.

[0020] The cooler 43 is configured to be able to cool the lower part of the battery 41 more strongly than the upper and middle parts. The upper part, middle part, and lower part respectively refer to the upper, middle, and lower ranges of each battery module 411 housed in the housing 413 divided into three parts at equal intervals in the vertical direction. Specifically, the cooler 43 includes a flow path 431 for flowing a cooling medium in the lower part of the battery 41, a cooling unit 432 such as a heat pump or a heat exchanger for cooling the cooling medium, and a driving unit (such as a pump or a fan) 433 for flowing the cooling medium in the flow path 431 (see FIGS. 1 and 2). The flow path 431 may be provided in the bottom wall of the housing 413, or may be disposed near the bottom surface of the housing 413.

[0021] The cooler 43 is not limited to the above example, and may have any configuration as long as it can cool the lower part of the battery 41 more strongly than the upper and middle parts. For example, the cooler may be a Peltier element or a cooling fan attached to the bottom surface of the housing of the battery 41.

[0022] The cooler 43 may be configured to use a part of the temperature adjustment device 11 (see FIG. 1). That is, when the temperature adjustment device 11 is configured to have flow paths 111, 431 for passing a liquid around and inside the battery 41, a configuration for flowing a low-temperature medium through the flow path 431 in the lower part of the battery 41 may be adopted as the cooler 43. The cooler 43 may be configured to stop the flow of the medium flowing through the flow path 111 in the upper part and inside of the battery 41, or may be configured to set the temperature of the medium high.

[0023] The battery 41 does not normally require cooling if it is at an appropriate temperature (e.g., 20°C to 40°C). Therefore, when the temperature adjustment device 11 also functions as the cooler 43, the temperature adjustment device 11 (cooler 43) is normally controlled to perform a cooling operation when the battery 41 exceeds a threshold temperature (e.g., 40°C) and to stop or weaken the cooling operation when the battery 41 is below the threshold temperature.

[0024] The controller 42 is an ECU and operates according to a control program stored in the storage unit 42a. The controller 42 monitors the airtightness of the housing 413 of the battery 41 and performs processing to deal with the break when the airtightness is broken. The output of the sensor 415 is sent to the controller 42, and the controller 42 can control the operation of the cooler 43. Furthermore, the controller 42 can communicate with the vehicle controller 9 to notify the vehicle controller 9 that the airtightness of the housing 413 has been broken, and can also send a drive request for the electric device 10 to the vehicle controller 9.

[0025] The controller 42 may be integrated into the vehicle controller 9, and the control processing of the controller 42 may be executed by the vehicle controller 9.

[0026] <Obstacle avoidance processing> 3 is a flowchart showing a failure avoidance process executed by the controller 410. The failure avoidance process is a control process that allows the battery 41 to continue to be used reasonably for a while if the airtightness of the casing 413 is broken.

[0027] The battery 41 is disposed, for example, in the abdomen of the electric vehicle 1. The airtightness of the housing 413 of the battery 41 may be broken if the abdomen of the electric vehicle 1 rubs against a curb or rock, causing a part of the housing 413 to be damaged. Even in such a case, by allowing the battery 41 to continue to be used reasonably for a while, the driver can continue to drive the electric vehicle 1 during that time and move the electric vehicle 1 to a repair shop, a dealer, or a safe place where traffic congestion or an accident can be avoided.

[0028] The obstacle avoidance process is started based on the start of the electric vehicle 1. In the obstacle avoidance process, first, the controller 42 monitors the output of the sensor 415 and determines whether or not there is a possibility that the airtightness of the housing 413 has been broken (step S1). Then, the controller 42 repeats the process of step S1 until it is determined as YES in step S1.

[0029] If the determination result in step S1 is YES, the controller 42 notifies the vehicle controller 9 of the determination result (step S2). In response to the notification, the vehicle controller 9 outputs a warning to the display unit 8 and recommends the driver to move the electric vehicle 1 for repair in response to the warning.

[0030] Next, the controller 42 operates the cooler 43 to cool the lower portion of the battery 41 more strongly than the upper and middle portions (step S3). If the temperature adjustment device 11 has cooled the upper and middle portions of the battery 41, in step S3, the controller 42 may stop or weaken the cooling of the upper and middle portions of the battery 41 by sending a request to the vehicle controller 9. By such control, the lower portion of the battery 41 can be cooled more strongly than the upper and middle portions.

[0031] Furthermore, when the temperature adjustment device 11 also functions as the cooler 43, the temperature adjustment device 11 (cooler 43) normally performs a cooling operation when the battery 41 exceeds a threshold temperature (e.g., 40°C) and stops or weakens the cooling operation when the battery 41 is below the threshold temperature. On the other hand, in step S3, even if the battery 41 is below the threshold temperature, the controller 42 causes the temperature adjustment device 11 (cooler 43) to perform a cooling operation to cool the lower part of the battery 41 more strongly than the upper and middle parts.

[0032] Even if the airtightness is broken and humid air enters the housing 413 due to the process of step S3, the lower part of the battery 41 is cooled more strongly than the upper and middle parts, so that condensation occurs in the lower part of the battery module 411. The condensation then flows downward along the battery module 411 and accumulates in the reservoir 414. Therefore, condensation is prevented from accumulating near the electrodes or busbar 412 of the battery module 411, and the battery 41 can be used without strain for a while even if the airtightness of the housing 413 is broken.

[0033] Furthermore, the controller 42 transmits a request to the vehicle controller 9 to drive the electric devices 10 other than the driving motor 3 extra, and increases the discharge current of the battery 41 by the extra drive (step S4). In step S4, the controller 42 may omit the extra drive when the remaining capacity of the battery 41 is equal to or lower than a threshold (e.g., very low) based on the remaining capacity and the temperature of the battery 41. Similarly, when the temperature of the upper part of the battery module 411 is a temperature at which condensation cannot occur, the controller 42 may omit the extra drive. The extra drive means a drive that is not included in the drive request of the driver and the drive request based on the normal vehicle state. As the extra drive, the pump and fan of the in-vehicle air conditioner and the drive of the lights may be adopted.

[0034] The process of step S4 increases the discharge current of battery 41, and this increase in current increases the temperature near the electrodes of battery module 411 and bus bar 412. Therefore, the temperature inside casing 413 can be made lower at the bottom and higher at the top, and condensation can be further prevented from occurring at the top of battery module 411. Therefore, even if the airtightness of casing 413 is broken, battery 41 can continue to be used reasonably for a while.

[0035] Thereafter, the controller 42 checks whether or not a cancellation operation for the obstacle avoidance process, which can be performed by a dealer or the like, has been performed (step S5). If the result is NO, the controller 42 returns the process to step S3 and continues to execute the processes of steps S3 and S4. By repeating the processes of steps S3 and S4, the cooling intensity of step S3 may be adjusted according to the temperatures of the upper, middle and lower parts of the battery 41. Furthermore, the amount of extra drive may be adjusted according to the remaining capacity of the battery 41 and the temperature of the upper part of the battery 41.

[0036] On the other hand, if the decision result in the step S5 is YES, the controller 42 ends the obstacle avoidance process.

[0037] The above-mentioned program for the failure avoidance processing is stored in a non-transient storage medium (non-transient computer readable medium) such as the storage unit 42a of the controller 42. The controller 42 may be configured to read the program stored in the portable non-transient storage medium and execute the program. The above-mentioned portable non-transient storage medium may store the above-mentioned program for the failure avoidance processing.

[0038] As described above, the battery system 40 of the present embodiment includes the battery 41 having the airtight housing 413, the battery 41 having the plurality of battery modules 411 housed in the housing 413, and the cooler 43 capable of cooling the lower part of the housing 413 more strongly than the upper and middle parts. Furthermore, a reservoir 414 for accumulating condensation is provided in the lower part of the inside of the housing 413. Therefore, when the airtightness of the housing 413 is broken, the cooler 43 operates to cause condensation to occur in the lower part of the battery module 411, and the condensation can be accumulated in the reservoir 414. Therefore, it is possible to prevent condensation from occurring in the upper part of the battery module 411 and condensation from accumulating in the upper part. Therefore, even if the airtightness of the housing 413 is broken, the battery 41 can be used without strain for at least a while.

[0039] Furthermore, according to the battery system 40 of the present embodiment, the storage section 414 is provided at a position lower than the lower ends of the multiple battery modules 411. This configuration allows condensation to be stored in the storage section 414 away from the battery modules 411. This reduces the risk of condensation accumulating between adjacent battery modules 411 below the battery modules 411. In the battery module 411, potential is generated in areas other than the electrode portions. This reduces the risk of the above-mentioned problems, allowing the battery 41 to be used continuously with less strain.

[0040] Furthermore, the battery system 40 of this embodiment includes a sensor 415 that detects a break in the airtightness of the housing 413, and a controller 42 that controls the cooler 43. When the sensor 415 detects a break in the airtightness, the controller 42 causes the cooler 43 to cool the lower part of the housing 413 more strongly than the upper and middle parts. Therefore, during the normal period when the airtightness of the housing 413 is not broken, the above-mentioned action of the cooler 43 (the action of strongly cooling the lower part) can be canceled, and efficiency can be improved.

[0041] In the above embodiment, the controller 42 causes the cooler 43 to perform the above-mentioned function based on the output of the sensor 415 that detects the breakage of the airtightness. However, even if it is unclear whether the housing 413 of the battery 41 has been broken, the controller 42 may preventively control the cooler 43 to perform the above-mentioned function based on the running condition such as the detection of a collision or impact of the electric vehicle 1. In addition, in the above embodiment, the controller 42 causes the cooler 43 to perform the above-mentioned function based on the output of the sensor 415. However, the cooler 43 may perform the above-mentioned function all the time or in an environmental condition where condensation is likely to occur. Even with such control, if the airtightness of the housing 413 is broken due to some event, condensation is caused to occur in the lower part of the battery module 411 and stored in the storage part 414, so that condensation can be prevented from occurring in the upper part of the battery module 411.

[0042] Furthermore, according to the battery system 40 of the present embodiment, when the sensor 415 detects a break in the airtightness of the housing 413, the controller 42 further drives the electric device 10 so as to increase the current of the battery 41 (see step S4 in FIG. 3). This control makes it possible to increase the temperature of the upper part of the battery module 411, and further suppresses the occurrence of condensation on the upper part of the battery module 411.

[0043] Furthermore, according to the battery system 40 of the present embodiment, when the temperature adjustment device 11 also functions as the cooler 43, the temperature adjustment device 11 (cooler 43) normally performs a cooling operation when the temperature of the battery 41 exceeds a threshold temperature (e.g., 40°C), and stops or weakens the cooling operation when the temperature is below the threshold temperature. On the other hand, when the sensor 415 detects a break in the airtightness of the housing 413, the temperature adjustment device 11 (cooler 43) performs a cooling operation and cools the lower part of the battery 41 more strongly than the upper and middle parts, even if the temperature of the battery 41 is below the threshold temperature. With this configuration, even if the temperature of the battery 41 is at an appropriate temperature for the operation of the battery 41, by cooling the lower part of the battery 41, it is possible to prevent condensation from occurring and accumulating on the upper part of the battery module 411.

[0044] The above describes the embodiments of the present invention. However, the present invention is not limited to the above embodiments. For example, the above embodiments show an example in which the temperature regulator 11 is provided to regulate the temperature of the upper part and inside of the battery 41, but the temperature regulator 11 may be omitted. Also, the above embodiments show an example in which the configuration according to the present invention is applied to an electric vehicle that does not have an internal combustion engine. However, the configuration according to the present invention may be applied to an electric vehicle that has an internal combustion engine. Other details shown in the embodiments may be modified as appropriate without departing from the spirit of the invention. [Explanation of symbols]

[0045] 1 Electric vehicles 2 Drive wheels 3. Traction motor 5. Inverter 8 Display 9 Vehicle Controller 10 Electrical Equipment 11 Temperature control device 111 Flow Path 112 Temperature control section 113 Drive unit 40 Battery System 41 Battery 42 Controller 411 Battery Module 412 Busbar 413 Case 414 Storage section 415 Sensors 43 Cooler 431 Flow Path 432 Cooling section 433 Drive unit

Claims

1. A battery system mounted on an electric vehicle to supply power for driving the vehicle, A battery having an airtight housing and a plurality of battery modules housed in the housing; a cooler capable of cooling a lower portion of the housing more strongly than an upper portion and a middle portion of the housing; Equipped with A battery system characterized in that a reservoir for collecting condensation is provided at the lower inside portion of the housing.

2. The storage section is provided at a position lower than lower ends of the plurality of battery modules. The battery system of claim 1 .

3. a sensor for detecting a break in the airtightness of the housing; A controller for controlling the cooling device; Further comprising:

2. The battery system according to claim 1, wherein the controller controls the cooler to cool the lower portion of the housing more strongly than the upper and middle portions when the sensor detects a break in airtightness.

4. The electric vehicle is provided with a driving motor driven by power from the battery and an electric device separate from the driving motor, 4. The battery system according to claim 3, wherein the controller further controls the electric device so as to increase a current of the battery when the sensor detects a break in airtightness.

5. When the sensor does not detect a break in the airtightness, the cooler performs a cooling operation when the battery exceeds a threshold temperature, and stops or weakens the cooling operation when the battery is equal to or lower than the threshold temperature.

4. The battery system according to claim 3, wherein when the sensor detects a break in airtightness, the cooler performs the cooling operation even when the battery temperature is equal to or lower than the threshold temperature.

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