Gas leakage detection system and gas leakage detection method

Abstract

The present invention comprises a first gas leakage determination unit that determines whether leakage of gas from a battery pack has occurred, and a second gas leakage determination unit that determines whether leakage of gas from the battery pack has occurred while the battery pack is being used. The first gas leakage determination unit determines leakage of a prescribed gas included in the battery pack on the basis of the amount of increase from detection data used in the previous determination. The second gas leakage determination unit determines leakage of the prescribed gas on the basis of the amount of increase from the detection data used in the determination performed by the first gas leakage determination unit at the start of use.

Description

Gas leak detection system and gas leak detection method

[0001] The present invention relates to a gas leakage detection system and a gas leakage detection method for a battery pack.

[0002] In recent years, with the advancement of electrification, batteries are being used as a power source for various devices. For example, electric vehicles powered by on-board battery packs are becoming popular. Such battery packs can be reused by being installed in other devices, not just the same device.

[0003] However, repeated use of a battery pack can cause deterioration in battery performance due to changes over time, etc. Such performance deterioration not only makes the operation of the device using the battery pack unstable, but also makes it necessary to detect changes in the state as early as possible from the perspective of safety.

[0004] Known methods for checking the deterioration of battery pack performance due to aging include, for example, measuring capacity or detecting an increase in internal resistance. Patent Document 1, for example, discloses a configuration for detecting leakage of constituent materials of a lithium-ion battery using an odor sensor.

[0005] Japanese Patent Application Publication No. 11-172618

[0006] In addition to detecting abnormalities such as battery smoking or battery fire, there is a need to detect events such as minute changes in the state of a battery pack that occur during continued use. The above-mentioned known methods are not capable of detecting minute events that occur during continued use of a battery pack.

[0007] Furthermore, in recent years, development of sealed battery packs, such as CTP (Cell To Pack), has progressed, which do not require airtightness or component replacement in the event of an internal abnormality. This configuration makes it difficult to check the internal state of the battery pack after assembly at production. In the case of battery packs intended for reuse, minute deterioration that cannot be tracked by existing battery performance monitoring (e.g., voltage and temperature) cannot be detected. As a result, it may not be possible to prevent malfunctions caused by the battery pack. In particular, for battery packs that constitute in-vehicle batteries, it is desirable to detect changes in the state of the battery pack early, not only when replacing the battery pack, but also while driving.

[0008] The present invention has been devised in view of the above-mentioned problems, and aims to provide a method capable of detecting minute changes in events in a battery pack. However, other objects of the present invention are not limited to this purpose, but also to achieve effects that cannot be obtained by conventional techniques, which are derived from the configurations shown in the following detailed description of the preferred embodiments of the present invention.

[0009] A gas leakage detection system for a battery pack according to one embodiment of the present invention has the following configuration: That is, the gas leakage detection system for a battery pack includes: a first gas leakage determination unit that determines whether or not gas leakage is occurring from the battery pack using detection data detected by a gas sensor when use of the battery pack is started, and a second gas leakage determination unit that determines whether or not gas leakage is occurring from the battery pack using detection data detected by the gas sensor while the battery pack is being used, wherein the first gas leakage determination unit determines leakage of a predetermined gas contained in the battery pack based on an increase in detection data from detection data used in a previous determination by the first gas leakage determination unit or the second gas leakage determination unit, and the second gas leakage determination unit determines leakage of the predetermined gas based on an increase in detection data from detection data used in the determination by the first gas leakage determination unit at the start of use.

[0010] A gas leakage detection method for a battery pack according to another embodiment of the present invention has the following configuration: That is, the gas leakage detection method for a battery pack includes: a first gas leakage determination step of determining whether or not gas leakage is occurring from the battery pack using detection data detected by a gas sensor at the start of use of the battery pack, and a second gas leakage determination step of determining whether or not gas leakage is occurring from the battery pack using detection data detected by the gas sensor while the battery pack is in use, wherein the first gas leakage determination step determines leakage of a predetermined gas contained in the battery pack based on an increase in detection data from detection data used in a previous determination by the first gas leakage determination step or the second gas leakage determination step, and the second gas leakage determination step determines leakage of the predetermined gas based on an increase in detection data from detection data used in the determination by the first gas leakage determination step at the start of use.

[0011] The present invention makes it possible to detect minute changes in events in a battery pack.

[0012] Fig. 1 is a schematic diagram showing an example of the configuration of a vehicle according to an embodiment of the present invention. Fig. 2 is an external perspective view showing an example of the configuration of a battery pack according to an embodiment of the present invention. Fig. 3 is a block diagram showing an example of the configuration of a gas leak detection system according to an embodiment of the present invention. Fig. 4 is a flowchart of a gas leak detection process according to an embodiment of the present invention.

[0013] A battery pack gas leak detection system and a gas leak detection method will be described as embodiments with reference to the drawings. The embodiments described below are merely examples, and are not intended to exclude various modifications or applications of techniques not explicitly described in the following embodiments. The configurations of the present embodiments can be implemented in various modifications without departing from the spirit thereof. Furthermore, they can be selected or combined as needed. In addition, the same reference numerals are used to indicate correspondence between the same components in each drawing.

[0014] First Embodiment In this embodiment, attention is focused on gas leakage as a state change in a battery pack. Furthermore, an in-vehicle battery pack will be used as an example of a gas leakage detection target. In particular, a pouch-type battery pack will be used for the description. Furthermore, in this embodiment, the gas leakage detection system is realized by an information processing device (for example, an ECU, which will be described later) mounted on the vehicle.

[0015] [Overall Configuration] A vehicle 100 equipped with a battery pack according to this embodiment and capable of using the battery pack as a power source will be described. The vehicle 100 is a hybrid vehicle equipped with an engine 101 as a drive source, a motor 107 (rotating electric machine) for driving, and a generator 102 for generating electricity. Therefore, the vehicle 100 according to this embodiment may be a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV) capable of external charging or external power supply. In this embodiment, the vehicle 100 is described as a front-wheel drive vehicle, but is not limited thereto. Rear-wheel drive, four-wheel drive, and the like may also be used. Note that the connections and arrangement of the components within the vehicle 100 shown in FIG. 1 are merely examples, and some connections may be omitted or simplified.

[0016] The generator 102 is connected to the engine 101 and can operate independently of the operation of the motor 107. The engine 101 is connected to a drive shaft 104 via an engine clutch 103. When the engine clutch 103 is engaged, power generated by the engine 101 is transmitted to the drive shaft 104. The motor 107 is connected to the drive shaft 104 via a motor clutch 106. When the motor clutch 106 is engaged, power generated by the motor 107 is transmitted to the drive shaft 104. Drive wheels 105 (front wheels) are mounted on the drive shaft 104. Driven wheels 116 (rear wheels) are mounted on an axle 117.

[0017] The vehicle 100 is also provided with an ECU (Electronic Control Unit) 108, which corresponds to the control device according to this embodiment. The ECU 108 is, for example, an electronic control device configured as an LSI (Large-Scale Integration) device or an embedded electronic device that integrates a microprocessor, a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The ECU 108 acquires signals detected by various sensors provided in the vehicle 100 and controls the vehicle 100. In this embodiment, the ECU 108 realizes the function of a battery pack gas leakage detection system 108a, which will be described later. In addition to the function of the gas leakage detection system 108a, the ECU 108 also provides various functions, such as driving assistance control for the vehicle 100. The ECU 108 may be configured with a plurality of ECUs according to the functions to provide various functions.

[0018] The sensors provided in the vehicle 100 include an acceleration sensor 109, a speed sensor 110, a temperature sensor 111, an image sensor 112, a voltage sensor 113, and a gas sensor 114. The acceleration sensor 109 detects the acceleration of the vehicle 100. The speed sensor 110 detects the speed of the vehicle 100. The temperature sensor 111 detects the temperature at a predetermined position within the vehicle 100. The image sensor 112 is, for example, a camera, and acquires images of the surroundings of the vehicle 100. The voltage sensor 113 detects the voltage of the battery 115. The gas sensor 114 detects gas within the vehicle 100, particularly around the battery 115. Note that the sensors are not limited to these, and may also include an accelerator position sensor, a brake sensor, an engine rotation sensor, a battery remaining capacity sensor, a position sensor, and the like. Furthermore, the installation locations of the sensors and the number of each type of sensor to be installed are not particularly limited. For example, depending on the functions provided by an ADAS (Advanced Driving Assistant System), the detection values ​​of various sensors may be commonly used, or a separate sensor may be provided for each function.

[0019] The engine 101 is an internal combustion engine (gasoline engine or diesel engine) that uses gasoline or diesel as fuel. The operating state of the engine 101 may be controlled by the ECU 108, or may be controlled by an electronic control device (not shown) separate from the ECU 108. The generator 102 and the motor 107 according to this embodiment are motor-generators that function as both an electric motor and a generator. The motor 107 is a drive source that exchanges electric power with the battery 115, and functions mainly as an electric motor to drive the vehicle 100 and as a generator during regeneration.

[0020] The generator 102 functions as an electric motor (starter) when starting the engine 101, and is driven by engine power to generate electricity when the engine 101 is running. Furthermore, the generator 102 transmits driving force to the drive shaft 104 of the vehicle 100 in a powered state. An inverter (not shown) that converts direct current and alternating current is provided around (or inside) each of the motor 107 and the generator 102. The rotation speeds and operating states (powered operation, regenerative / powered operation) of the motor 107 and the generator 102 are controlled by controlling the inverter (not shown).

[0021] The vehicle 100 can run in a plurality of driving modes, such as EV mode, series mode, and parallel mode. These driving modes are selected by the ECU 108 in accordance with the vehicle state, driving state, the driving force required by the driver, and the like. Furthermore, the operations of the engine 101, generator 102, and motor 107 are controlled and used differently depending on the driving mode. The load on each part (e.g., power source) of the vehicle 100 differs depending on the driving mode.

[0022] An electric power steering (EPS) 120 is connected to the drive wheels 105 (front wheels in this case) to assist steering by a driver via a steering wheel (not shown). The engine 101 and a motor 107 are connected in parallel to the drive wheels 105 via a transaxle (not shown) incorporating multiple gears and clutches. The engine 101 is also connected to a generator 102 via the transaxle (not shown), and power from the engine 101 is also transmitted to the generator 102. The transaxle is a power transmission device that integrates a final drive (final reduction gear) including a differential and a transmission (reduction gear), and incorporates multiple mechanisms that transmit power between a drive source and a driven device.

[0023] The engine clutch 103 is, for example, a wet multi-plate clutch or a dog clutch. Power on the upstream side of the power transmission path (the engine 101 and generator 102 side) of the engine clutch 103 is transmitted to the drive shaft 104 when the engine clutch 103 is engaged (connected), and is cut off when the engine clutch 103 is disengaged (released).

[0024] The motor clutch 106 is, for example, a wet multi-plate clutch or a dog clutch. Power on the upstream side of the power transmission path from the motor clutch 106 (i.e., the driving force of the motor 107) is transmitted to the drive shaft 104 when the motor clutch 106 is engaged, and is blocked when the motor clutch 106 is disengaged.

[0025] The EPS 120 assists the driver in steering under the control of the ECU 108 .

[0026] [Battery Pack] Fig. 2 is an external perspective view of a battery pack 200 according to this embodiment. In this embodiment, a plurality of battery packs 200 are provided inside the battery 115 shown in Fig. 1. In this embodiment, the battery pack 200 will be described taking as an example a pouch-type lithium ion battery configuration. However, this is not limited thereto, and any battery pack may have a cylindrical or rectangular configuration as long as it is applicable to the gas leakage detection method described below.

[0027] In FIG. 2A, the battery pack 200 includes a main body 201, a positive electrode tab 202, and a negative electrode tab 203. The internal structure of the main body 201 may be a known structure, and a detailed description thereof will be omitted here. The positive electrode tab 202 and the negative electrode tab 203 are each connected to a bus bar (not shown) that is an electrical conductor. The positive electrode tab 202 may be made of, for example, aluminum (Al). The negative electrode tab 203 may be made of, for example, copper (Cu). The bus bar connected to the tabs may be made of copper (Cu). As shown in FIG. 2B, an edge 210 of the main body 201 is welded by heat sealing or the like.

[0028] During production or use of the battery pack 200, the three edges of the edge 210, excluding the tab portion, may be folded back. The strength of the areas subjected to such loads may be reduced. Furthermore, areas such as the ends 211a to 211d are prone to deterioration due to the structural differences that may occur.

[0029] In this embodiment, the temperature sensor 111 measures the temperature at a tab portion or a bus bar connected to the tab portion. However, the temperature measurement location is not limited to this and may be at another location. In the case of an in-vehicle battery pack 200, a plurality of battery packs 200 may be combined into a single module. In such a module, the temperature may be measured at a conductor connected to the tab portion of the battery pack 200.

[0030] Furthermore, in this embodiment, the measurement location of the gas sensor 114 may be near a connection point (interface) where the battery pack 200 or a module including multiple battery packs 200 is connected to the outside. In this case, the measurement location of the gas sensor 114 may be specified according to the characteristics of the gas to be detected. For example, when measuring lithium (Li) or sulfur (S) filled in the battery pack 200, these gases are lighter than air and therefore will accumulate above the air if they leak. Taking such characteristics into consideration, the measurement location of the gas sensor 114 may be located, for example, above the connection point of the module.

[0031] The gas sensor 114 according to this embodiment is configured to adsorb a surrounding gas and detect a change in the Fermi level due to the adsorption phenomenon. The detected change in the Fermi level is converted into an electrical signal and provided to the ECU 108. Note that information regarding the type of gas to be measured is assumed to be specified and stored in advance.

[0032] Furthermore, the measurement positions of the sensors may be configured to be provided around areas that are likely to deteriorate due to the structure of the battery pack 200, as shown in FIG. 2(b).

[0033] The battery pack 200 is charged and discharged during driving, etc. Furthermore, by connecting the vehicle 100 to an external facility such as a charging station (not shown), external quick charging, external power supply, etc. are performed. In this embodiment, the number of charge / discharge cycles in such cases is managed appropriately. For example, the ECU 108 may manage the number of cycles for the on-board battery pack 200 (or the battery 115).

[0034] Furthermore, assuming that the battery pack 200 is mounted on a vehicle, the degree of consumption of the battery pack 200 may vary depending on the driving mode of the vehicle 100. In this embodiment, it is assumed that information relating to the operating status of the driving mode of the vehicle 100 is managed appropriately. For example, history information on switching of the driving mode may be managed by the ECU 108.

[0035] Furthermore, the shape of the pouch-type battery pack 200 may change due to aging or other factors. For example, the thickness of the main body 201 or edge 210 of the battery pack 200 may change. Therefore, such shape changes may be monitored as one indicator of aging or other factors.

[0036] 3 is a block diagram showing an example of the functional configuration of the gas leak detection system 108a of the battery pack 200 according to this embodiment. As described above, the gas leak detection system 108a according to this embodiment is realized as part of the ECU 108 provided in the vehicle 100. When the gas leak detection system is used as a configuration other than an on-board configuration, it may be configured so that the functions of the gas leak detection method described below are provided by an information processing device capable of acquiring information from various sensors.

[0037] The gas leak detection system 108a includes a data acquisition unit 301, a voltage determination unit 302, a gas determination unit 303, a temperature determination unit 304, a state determination unit 305, and a state notification unit 306. Each unit may be realized, for example, by a processing unit (not shown) included in the ECU 108 reading and executing various data and programs stored in a storage unit (not shown). The units shown as blocks here are merely examples, and one block may be further divided into multiple blocks, or multiple blocks may be combined into one block.

[0038] The data acquisition unit 301 acquires and manages data detected by various sensors. The voltage determination unit 302 acquires voltage data detected by the voltage sensor 113 via the data acquisition unit 301. The voltage determination unit 302 then determines whether or not there is an abnormality in the battery pack 200 based on the voltage data. An example of the determination will be described later in conjunction with the flowchart of FIG. 4.

[0039] The gas determination unit 303 acquires detection data detected by the gas sensor 114 via the data acquisition unit 301. Then, the gas determination unit 303 determines whether or not there is an abnormality in the battery pack 200 based on the detection data. An example of the determination will be described later in conjunction with the flowchart of FIG. 4. The temperature determination unit 304 acquires temperature data detected by the temperature sensor 111 via the data acquisition unit 301. Then, the temperature determination unit 304 determines whether or not there is an abnormality in the battery pack 200 based on the temperature data. An example of the determination will be described later in conjunction with the flowchart of FIG. 4.

[0040] The state determination unit 305 determines the state of the vehicle based on the determination results of the voltage determination unit 302, the gas determination unit 303, the temperature determination unit 304, etc. In particular, it determines whether a state change that would affect the operation of the vehicle 100 has occurred based on each determination result. The state notification unit 306 notifies a linked component of the state determination result by the state determination unit 305. For example, the state notification unit 306 may perform control to notify the driver of the vehicle 100 that an abnormality has been detected. This notification may be, for example, visually via a display (not shown) or audibly via a speaker (not shown). Furthermore, the state notification unit 306 may switch driving control of the vehicle 100 by notifying another function provided by the ECU 108. In this embodiment, an example will be described in which driving restrictions on the vehicle 100 are implemented depending on the abnormality determination result.

[0041] In this embodiment, gas leakage determination is performed in two stages. For convenience, these stages are referred to as "gas leakage determination process A" and "gas leakage determination process B." Details of each gas leakage determination process will be described later in conjunction with the flowchart of FIG. 4.

[0042] [Processing Flow] Figure 4 is a flowchart of a control process for the vehicle 100 based on the detection results obtained by the gas leak detection method according to this embodiment. This processing flow is realized by a processing unit (not shown) of the ECU 108 reading and executing various data and programs stored in a memory unit (not shown). Furthermore, detection data detected by various sensors provided in the vehicle 100 is used when executing this processing flow. Here, for ease of explanation, the processing entity will be collectively described as the ECU 108.

[0043] In step S401, ECU 108 starts the operation of vehicle 100. The start-up here may be when a start instruction (such as turning on the ignition) from the driver is received, or when an instruction to switch to a mode that allows driving is received.

[0044] In step S402, the ECU 108 acquires detection data from various sensors equipped in the vehicle 100. The detection data here may be detection data at the time when the vehicle 100 is started, or may be detection data recorded going back a certain period from the time of start-up. Note that the detection data may be held and managed by the ECU 108 or the like for a predetermined period after being detected by the various sensors.

[0045] In step S403, ECU 108 determines whether or not a voltage abnormality has occurred based on the voltage data acquired in step S402. The voltage abnormality here may be, for example, when the detected value is equal to or lower than a threshold value, or when the target voltage data cannot be detected. If it is determined that a voltage abnormality has occurred (YES in step S403), the processing by ECU 108 proceeds to step S415. On the other hand, if it is determined that no voltage abnormality has occurred (NO in step S403), the processing by ECU 108 proceeds to step S404.

[0046] In step S404, the ECU 108 determines whether a predetermined time has elapsed since the previous determination. The predetermined time here is assumed to be specified in advance. The previous determination refers to the most recently performed gas leakage determination process, which may be gas leakage determination process A in step S406 or gas leakage determination process B in step S411. The predetermined time may be, for example, 24 hours. If the predetermined time has elapsed (YES in step S404), the process of the ECU 108 proceeds to step S406. On the other hand, if the predetermined time has not elapsed (NO in step S404), the process of the ECU 108 proceeds to step S405.

[0047] In step S405, ECU 108 determines whether the battery temperature has exceeded a certain temperature within a predetermined period based on the temperature data acquired in step S402. The certain temperature here is assumed to be predetermined. The certain temperature may be, for example, 40°C. For example, when external quick charging or external power supply is performed on battery pack 200, a temperature rise may occur depending on the amount of current. In such a case, this determination may be made assuming that a temperature change has occurred due to an increase in the load on battery pack 200. If the certain temperature has been exceeded (YES in step S405), the processing by ECU 108 proceeds to step S406. On the other hand, if the certain temperature has not been exceeded (NO in step S405), the processing by ECU 108 proceeds to step S408.

[0048] In step S406, the ECU 108 performs a gas leakage determination process A for determining whether a gas leak has occurred, based on the detection data acquired in step S402. Specifically, the ECU 108 identifies a detection value corresponding to a predetermined gas in the detection data detected by the gas sensor 114. Then, the process of the ECU 108 proceeds to step S407.

[0049] As described above, the gas sensor 114 detects the surrounding gas based on the Fermi level and provides the detection data to the gas leak detection system 108a. The acquired data is then recorded as appropriate. In the gas leak determination process A, the degree of change in the predetermined gas component to be detected is determined. Here, time information when the determination process is performed is recorded. This time information is referenced in step S404.

[0050] In step S407, ECU 108 determines whether the determination result of step S406 exceeds a predetermined value. The predetermined value here is assumed to be predefined. For example, the predetermined value may be set to a 10% increase rate from the previous determination for the target gas component. Note that different values ​​may be used for the case where the process proceeds from step S404 to step S406 and the case where the process proceeds from step S405 to step S406. The increase amount in the predetermined value may be set as an increase rate (proportion) relative to the detection data in the previous determination, or may be set by adding a fixed value to the detection data in the previous determination. If the determination result of gas leakage determination process A exceeds the predetermined value (YES in step S407), the process by ECU 108 proceeds to step S415. On the other hand, if the determination result of gas leakage determination process A does not exceed the predetermined value (NO in step S407), the process by ECU 108 proceeds to step S408.

[0051] In step S408, ECU 108 starts driving vehicle 100. This start may be based on accelerator operation or brake operation, or on shifting the shift lever. Then, the processing of ECU 108 proceeds to step S409. The subsequent processing is performed in parallel with the driving of vehicle 100. That is, steps S409 to S413 are performed while battery pack 200 is being used to drive vehicle 100.

[0052] In step S409, ECU 108 acquires the current outside air temperature and battery temperature via temperature sensor 111. The outside air temperature may be acquired using a temperature sensor installed in a position different from that of temperature sensor 111 that acquires the battery temperature.

[0053] In step S410, ECU 108 determines whether the outside air temperature is higher than the battery temperature. If the outside air temperature is higher than the battery temperature (YES in step S410), the process by ECU 108 proceeds to step S414. On the other hand, if the outside air temperature is not higher than the battery temperature (NO in step S410), the process by ECU 108 proceeds to step S411. In other words, if the battery temperature is higher than the outside air temperature, it is determined that the load on battery pack 200 is high, and gas leakage determination process B is executed.

[0054] In step S411, the ECU 108 acquires new detection data from the gas sensor 114 and performs gas leakage determination process B based on the data. The process content of gas leakage determination process B may be the same as that of gas leakage determination process A in step S406. Here, time information when the determination process was performed is also recorded. Then, the process of the ECU 108 proceeds to step S412. The time information here is referenced in step S404.

[0055] In step S412, the ECU 108 determines whether the determination result of step S411 exceeds a predetermined value. It is assumed that the predetermined value here is predefined. For example, the predetermined value may be set to the difference between the value of the gas component of interest in gas leakage determination process A at startup (step S406) and the value of gas leakage determination process B during driving (step S411). The predetermined value for the difference here may be defined as a percentage (%) (detection result of gas leakage determination process A × α (%)) or a fixed value (detection result of gas leakage determination process A + β). If the determination result of gas leakage determination process B exceeds the predetermined value (YES in step S412), the process by the ECU 108 proceeds to step S413. On the other hand, if the determination result of gas leakage determination process B does not exceed the predetermined value (NO in step S412), the process by the ECU 108 proceeds to step S414.

[0056] In step S413, ECU 108 notifies that a gas leak has been detected. This notification may be made, for example, using a display (not shown) provided on vehicle 100. Then, the process of ECU 108 proceeds to step S414.

[0057] In step S414, ECU 108 determines whether or not an instruction to stop vehicle 100 has been received. The instruction to stop here may be based on, for example, a brake operation or a shift lever operation. If an instruction to stop the vehicle has been received (YES in step S414), this processing flow ends. On the other hand, if an instruction to stop the vehicle has not been received (NO in step S414), the processing of ECU 108 returns to step S409 and the processing is repeated.

[0058] In step S415, the ECU 108 restricts the vehicle's running based on the detection of the power supply abnormality or gas leakage. For example, the ECU 108 may restrict the vehicle from starting to run. Alternatively, the ECU 108 may control the vehicle to remain stopped.

[0059] In step S416, the ECU 108 notifies the vehicle of the detection result and notifies the vehicle that it is not possible to drive, and then ends this processing flow.

[0060] In the example of FIG. 4 , whether or not to perform the gas leakage determination process B is switched based on the outside air temperature (steps S409 and S410), but this is not limiting. For example, whether or not to perform the gas leakage determination process B may be switched based on the SOC (State of Charge) of the battery pack 200 (battery 115). In this case, control may be performed so that the gas leakage determination process B is performed when the SOC is equal to or greater than a predetermined threshold value (e.g., 80%). Furthermore, whether or not to perform the gas leakage determination process B may be switched based on a combination of the above-mentioned multiple criteria.

[0061] 4, when a gas leak is detected while the vehicle is running, only a notification is given to the driver, and the running control itself depends on the driver's operation to control (stop) the vehicle (steps S412 and S413). However, the present invention is not limited to this, and the system may be configured to prevent switching to a predetermined running mode or to perform safer running control depending on the level of gas leakage.

[0062] Furthermore, the shape (e.g., thickness) of the pouch-type battery pack 200 may change depending on the number of cycles, etc. Therefore, a detection value for this change in the outer shape may be used to determine whether or not to execute the gas leakage determination process A (step S406) or the gas leakage determination process B (step S411).

[0063] Furthermore, the load on the battery pack 200 may vary depending on the driving mode of the vehicle 100. In other words, the frequency of charging and power supply changes. Therefore, it may be determined whether to execute the gas leakage determination process A (step S406) or the gas leakage determination process B (step S411) based on history information such as the duration of the driving mode and the number of times the driving mode is switched. For example, if the number of cycles exceeds a predetermined threshold, the value of the predetermined time used in step S404 may be controlled to be reduced. In other words, for a battery pack that is assumed to have deteriorated due to an increase in the number of charging and discharging cycles, the gas leakage determination process A may be controlled to be executed more frequently.

[0064] Furthermore, external quick charging or external power feeding is performed by connecting the vehicle 100 to an external facility (not shown). In such cases, a load is generated on the battery pack 200. Therefore, whether or not to execute the gas leakage determination process B (step S411) may be controlled based on the number of times external quick charging or external power feeding has been performed on the vehicle 100 or a change in the amount of current. For example, when the vehicle 100 performs external quick charging or external power feeding and an amount of current equal to or greater than a predetermined threshold is detected in the battery pack 200, the gas leakage determination process B may be controlled to be executed immediately thereafter.

[0065] As described above, this embodiment makes it possible to detect minute changes in events in the battery pack. In particular, it is possible to perform gas leakage detection at appropriate timing depending on the usage status of the battery pack, thereby reducing the time and power costs associated with excessive gas leakage detection.

[0066] As described above, the method for detecting gas leakage from a battery pack according to the present invention is not limited to a battery pack mounted in a vehicle, but can also be applied to other devices. In addition, the method may be configured as a system capable of detecting gas leakage from a battery pack alone.

[0067] Furthermore, in the present invention, a program or application for realizing the functions of one or more of the above-described embodiments can be supplied to a system or device using a network or a storage medium, etc., and one or more processors in the computer of the system or device can read and execute the program.

[0068] As such, the present invention is not limited to the above-described embodiments, and the present invention also contemplates the mutual combination of the various components of the embodiments, as well as modifications and applications by those skilled in the art based on the description in the specification and well-known techniques, and these modifications and applications are included in the scope of protection sought.

[0069] As described above, the present specification discloses the following: (1) A gas leakage detection system (e.g., 108, 108a) for a battery pack (e.g., 200), comprising: a first gas leakage determination unit (e.g., 303, 305) that determines whether or not gas leakage is occurring from the battery pack using detection data detected using a gas sensor (e.g., 114) when the battery pack is first used; and a second gas leakage determination unit (e.g., 303, 305) that determines whether or not gas leakage is occurring from the battery pack using detection data detected using the gas sensor while the battery pack is in use, wherein the first gas leakage determination unit determines leakage of a predetermined gas contained in the battery pack based on an increase in detection data from detection data used in a previous determination by the first gas leakage determination unit or the second gas leakage determination unit, and the second gas leakage determination unit determines leakage of the predetermined gas based on an increase in detection data from detection data used in a determination by the first gas leakage determination unit at the start of use. This configuration makes it possible to detect minute changes in the battery pack, and in particular to perform gas leakage detection at appropriate times depending on the usage status of the battery pack, thereby reducing the time and power costs associated with excessive gas leakage detection.

[0070] (2) The gas leak detection system according to (1), wherein the first gas leak determination unit executes the determination process when a predetermined time has elapsed since the previous determination by the first gas leak determination unit or the second gas leak determination unit. This configuration makes it possible to execute the gas leak determination process based on the elapsed time since the previous determination.

[0071] (3) The gas leak detection system according to (2), wherein the first gas leak determination unit changes the predetermined time period according to the number of discharge and charge cycles of the battery pack. With this configuration, it is possible to adjust the timing of executing the gas leak determination process according to the number of discharge and charge cycles of the battery pack.

[0072] (4) The gas leak detection system according to (2), wherein the battery pack is a battery pack mounted on a vehicle (e.g., 100), and the first gas leak determination unit changes the predetermined time based on history information of a driving mode of the vehicle using the battery pack. This configuration makes it possible to adjust the timing of executing the gas leak determination process in accordance with a load on the battery pack caused by a driving mode of the vehicle in which the battery pack is mounted.

[0073] (5) The gas leak detection system according to any one of (1) to (4), wherein the first gas leak determination unit determines whether the battery pack has exceeded a predetermined temperature during a predetermined period of time prior to the start of use of the battery pack based on the temperature information of the battery pack, and executes a determination process if the predetermined temperature has been exceeded. According to this configuration, if the temperature of the battery pack has exceeded the predetermined temperature when the battery pack is not in use, the gas leak determination process is controlled to be executed when the battery pack starts to be used. Therefore, it is possible to determine whether a gas leak has occurred due to a temperature change when the battery pack is not in use.

[0074] (6) The gas leak detection system according to any one of (1) to (5), wherein the second gas leak determination unit executes a determination process when the amount of current of the battery pack exceeds a predetermined threshold. With this configuration, it is possible to control the timing of executing the gas leak determination process in accordance with a change in the amount of current of the battery pack caused by external power supply / external charging, etc.

[0075] (7) The gas leakage detection system according to any one of (1) to (6), wherein the battery pack is a pouch-type battery pack. With this configuration, it is possible to execute a gas leakage determination process for a pouch-type battery pack used as an in-vehicle battery pack, for example.

[0076] (8) A gas leakage detection method for a battery pack (e.g., 200), comprising: a first gas leakage determination step (e.g., step S406) of determining whether gas leakage from the battery pack is occurring using detection data detected using a gas sensor (e.g., 114) when the battery pack is first used; and a second gas leakage determination step (e.g., step S411) of determining whether gas leakage from the battery pack is occurring using detection data detected using the gas sensor while the battery pack is in use, wherein the first gas leakage determination step determines leakage of a predetermined gas contained in the battery pack based on an increase in detection data from detection data used in a previous determination by the first gas leakage determination step or the second gas leakage determination step, and the second gas leakage determination step determines leakage of the predetermined gas based on an increase in detection data from detection data used in the determination by the first gas leakage determination step at the start of use. This configuration makes it possible to detect minute changes in the battery pack. In particular, gas leakage detection can be performed at appropriate times depending on the usage status of the battery pack, making it possible to reduce the time and power costs associated with excessive gas leakage detection.

[0077] Although various embodiments have been described above, it goes without saying that the present invention is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any manner as long as they do not deviate from the spirit of the invention.

[0078] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention. Furthermore, the components of the above-described embodiments may be combined in any manner without departing from the spirit of the invention.

[0079] This application is based on a Japanese patent application (Patent Application No. 2024-10389) filed on January 26, 2024, the contents of which are incorporated herein by reference.

[0080] The present invention is applicable to the manufacturing industry of vehicles equipped with driving assistance functions (e.g., electric vehicles, hybrid vehicles, plug-in hybrid vehicles), as well as to the manufacturing industry of control devices installed in vehicles.

[0081] DESCRIPTION OF SYMBOLS 100...Vehicle 101...Engine 102...Generator 103...Engine clutch 104...Drive shaft 105...Drive wheels (front wheels) 106...Motor clutch 107...Motor 108...ECU 108a...Gas leak detection system 109...Acceleration sensor 110...Speed ​​sensor 111...Temperature sensor 112...Image sensor 113...Voltage sensor 114...Gas sensor 115...Battery 116...Driven wheels (rear wheels) 117...Axle 120...EPS 200...Battery pack 201...Main body 202...Positive electrode tab section 203...Negative electrode tab section 301...Data acquisition section 302...Voltage determination section 303...Gas determination section 304...Temperature determination section 305...Status determination section 306...Status notification section

Claims

1. A gas leakage detection system for a battery pack, comprising: a first gas leakage determination unit that determines whether gas leakage has occurred from the battery pack by using detection data detected by a gas sensor at the start of use of the battery pack; and a second gas leakage determination unit that determines whether gas leakage has occurred from the battery pack by using detection data detected by the gas sensor during use of the battery pack. The first gas leakage determination unit determines leakage of a predetermined gas contained in the battery pack based on an increase amount from the detection data used in the previous determination by the first gas leakage determination unit or the second gas leakage determination unit. The second gas leakage determination unit determines leakage of the predetermined gas based on an increase amount from the detection data used in the determination by the first gas leakage determination unit at the start of use.

2. The gas leakage detection system according to claim 1, wherein the first gas leakage determination unit executes a determination process when a predetermined time has elapsed since the previous determination by the first gas leakage determination unit or the second gas leakage determination unit.

3. The gas leakage detection system according to claim 2, wherein the first gas leakage determination unit changes the predetermined time according to the number of charge / discharge cycles related to the battery pack.

4. The battery pack is a battery pack mounted on a vehicle, and the first gas leakage determination unit changes the predetermined time based on history information of a driving mode of the vehicle using the battery pack. The gas leakage detection system according to claim 2.

5. The first gas leakage determination unit determines whether the battery pack has exceeded a predetermined temperature in a predetermined period before the start of use of the battery pack based on temperature information of the battery pack, and when the battery pack has exceeded the predetermined temperature, executes a determination process. The gas leakage detection system according to claim 1.

6. The gas leakage detection system according to claim 1, wherein the second gas leakage determination unit executes a determination process when the current amount of the battery pack exceeds a predetermined threshold value.

7. The battery pack is of a pouch type. The gas leakage detection system according to any one of claims 1 to 6.

8. A method for detecting gas leakage in a battery pack, comprising: a first gas leakage determination step of determining whether gas leakage has occurred from the battery pack using detection data detected by a gas sensor at the start of use of the battery pack; and a second gas leakage determination step of determining whether gas leakage has occurred from the battery pack using detection data detected by the gas sensor during use of the battery pack. The first gas leakage determination step determines leakage of a predetermined gas in the battery pack based on an increase amount from the detection data used in the previous determination by the first gas leakage determination step or the second gas leakage determination step. The second gas leakage determination step determines leakage of the predetermined gas based on an increase amount from the detection data used in the determination by the first gas leakage determination step at the start of use. Gas leakage detection method.

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