Vehicle-mounted battery system

Abstract

A battery system for a vehicle is provided. A control device (100) of a battery system (1) for a vehicle includes: an acquisition unit (110) that acquires a deterioration progress D of a power module (10) based on a usage state of the power module (10); a detection unit (120) that detects whether or not there is a leakage in the power module (10); a determination unit (130) that determines whether or not the deterioration progress D exceeds a presumed life L when the detection unit (120) detects the leakage; and a use stop unit (140) that stops power use from the power module (10) to a power load (200) when it is determined that the deterioration progress D exceeds the presumed life L. With the thus configured battery system (1) for a vehicle, it is possible to appropriately reduce the risk of leakage of the power module (10).

Description

Technical Field

[0001] The technology disclosed here relates to automotive battery systems. Background Technology

[0002] Vehicle batteries used in electric vehicles and the like are typically power modules with various components integrated into the power source (such as a secondary battery). From a safety perspective, these power modules may employ leakage detection technology (see Japanese Patent Application Publication Nos. 2023-081521 and 2023-081523, etc.). Furthermore, Japanese Patent Application Publication No. 2005-057965 discloses a power conversion device capable of detecting any abnormalities in a leakage detection unit, and under normal conditions, continuously supplying power without interruption.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2023-081521

[0004] Patent Document 2: Japanese Patent Application Publication No. 2023-081523

[0005] Patent Document 3: Japanese Patent Application Publication No. 2005-057965

[0006] In recent years, in order to meet the increasing safety requirements of power supply modules, efforts have been made to develop systems that can further reduce the risk of leakage. Summary of the Invention

[0007] The on-board battery system disclosed here is based on the above requirements.

[0008] The vehicle battery system disclosed herein includes: a power module connected to the vehicle's power load; and a control device that controls the charging and discharging of the power module. The control device includes: an acquisition unit that acquires the degradation progress of the power module based on its usage status; a detection unit that detects whether there is leakage in the power module; a determination unit that, when leakage is detected by the detection unit, determines whether the degradation progress exceeds a predetermined assumed lifespan; and a usage stop unit that, when the determination unit determines that the degradation progress exceeds the assumed lifespan, stops the use of power from the power module to the power load.

[0009] The inventors, through in-depth research aimed at reducing the risk of leakage associated with automotive batteries, have arrived at the following insights. First, since the driver does not directly contact the power module while the vehicle is in motion, the risk of electric shock is low even if a leakage occurs. On the other hand, suddenly cutting off the vehicle's power supply while driving could lead to an abrupt stop, causing an accident, or requiring towing. Based on these considerations, even if a leakage is detected while the vehicle is in motion, it is not advisable to immediately stop the power supply. However, the components of the power module each have a limited lifespan. If a leakage occurs at the end of this lifespan, it could lead to dangerous anomalies such as smoke or fire. When a leakage occurs at the end of this lifespan, the vehicle should be brought to an immediate stop and all power should be discontinued.

[0010] The vehicle battery system disclosed herein is based on the above-mentioned insights. When a leakage is detected, the determination unit of this vehicle battery system determines whether the degradation rate of the power module exceeds its assumed lifespan. Furthermore, if it is determined that the degradation rate exceeds the assumed lifespan, a stop unit stops the power supply from the power module to the power load. Therefore, in the event of a leakage due to the exhaustion of the power module's lifespan and other component failures, power supply can be stopped, thus preventing high-risk anomalies such as smoke and fire. Furthermore, if the power module's lifespan has not expired, the vehicle battery system will not stop supplying power to the vehicle only when a leakage is detected. This reduces the risk caused by sudden vehicle stops. As described above, the vehicle battery system disclosed herein appropriately reduces the risk of leakage associated with the power module. Attached Figure Description

[0011] Figure 1 This is a schematic diagram illustrating the vehicle-mounted battery system of the first embodiment.

[0012] Figure 2 This is a circuit diagram showing the leakage detection circuit of the vehicle battery system according to the first embodiment.

[0013] Figure 3 This is a cross-sectional view showing the waterproof casing of the vehicle-mounted battery system according to the first embodiment.

[0014] Figure 4 This is a flowchart illustrating the control of the vehicle-mounted battery system during driving according to the first embodiment.

[0015] Figure 5 This is a flowchart illustrating the control process of the vehicle-mounted battery system at the start of driving according to the first embodiment.

[0016] Explanation of reference numerals in the attached figures

[0017] 1…On-board battery system; 10…Power module; 20…Power supply; 30…Conductive path; 40…Contactor; 50…Waterproof housing; 100…Control device; 110…Acquisition unit; 120…Detection unit; 130…Judgment unit; 140…Use stop unit; 150…Communication unit; 200…Power load; 300…ECU; 400…Notification unit. Detailed Implementation

[0018] The following describes implementations of the technology disclosed herein. Furthermore, except for matters specifically mentioned in this specification, other matters necessary for implementing the technology disclosed herein can be grasped by those skilled in the art based on prior art in this field. The technology disclosed herein can be implemented based on the content disclosed in this specification and common technical knowledge in this field. Furthermore, the expression "A to B" indicating a range in this specification includes not only the meaning of A or more and B or less, but also the meaning of "preferably larger than A" and "preferably smaller than B".

[0019] <First Implementation>

[0020] The following is for reference Figures 1-3 One embodiment of the on-board battery system disclosed herein will be described. Figure 1 This is a schematic diagram illustrating the vehicle-mounted battery system of the first embodiment. Figure 2 This is a circuit diagram showing the leakage detection circuit of the vehicle battery system according to the first embodiment. Figure 3 This is a cross-sectional view showing the waterproof casing of the vehicle-mounted battery system according to the first embodiment.

[0021] A. Composition of on-board battery systems

[0022] like Figure 1 As shown, the vehicle-mounted battery system 1 of this embodiment includes a power module 10 and a control device 100. The components will be described below.

[0023] 1. Power supply module 10

[0024] like Figure 1 As shown, the power module 10 is connected to the power load 200 of the vehicle (not shown). Furthermore, the power load 200 is a mechanism that converts the electricity supplied from the power module 10 into power, thereby enabling the vehicle to move. The specific structure of the power load 200 is not particularly limited, and conventionally known devices (motors, etc.) can be appropriately selected.

[0025] Furthermore, while not limiting the technology disclosed herein, the power module 10 may include, for example, a power supply 20, a conductive path 30, a contactor 40, and a waterproof housing 50. The constituent components of the power module 10 will be described below.

[0026] (1) Power supply 20

[0027] Power source 20 is the power supply for the vehicle. In this embodiment, power source 20 is a battery pack comprising multiple (N) battery cells 21A to 21N (see reference). Figure 2 In this power supply (battery pack) 20, multiple battery cells 21A to 21N are arranged adjacent to each other along a predetermined arrangement direction. Adjacent battery cells are electrically connected via a connecting member. Furthermore, the positive terminal of the first battery cell 21A located at one end of the power supply 20 is not connected to any other battery cells. This first battery cell 21A's positive terminal becomes the overall positive terminal 22, which can be connected to the power load 200. On the other hand, the negative terminal of the nth battery cell 21N located at the other end of the power supply 20 is also not connected to any other battery cells. This nth battery cell 21N's negative terminal becomes the overall negative terminal 24, which can be connected to the power load 200.

[0028] Furthermore, the term "battery cell" here refers to a device capable of charging and discharging. Examples of such battery cells include secondary batteries such as lithium-ion batteries, nickel-metal hydride batteries, and nickel-cadmium batteries; primary batteries such as manganese dry batteries and alkaline dry batteries; capacitors such as double-layer capacitors; and power generation components such as fuel cells and solar cells. The number of battery cells constituting the power supply 20 is not particularly limited and can be appropriately varied depending on the performance requirements (output voltage, installation space, etc.) of the power module 10. For example, the power supply 20 may be composed of a single battery cell. However, considering the performance of the power module 10, it is preferable that the number of battery cells constituting the power supply 20 is 50 or more, more preferably 75 or more, further preferably 90 or more, and particularly preferably 100 or more. The upper limit for the number of battery cells is not particularly limited and can be 200 or less, or 150 or less.

[0029] (2) Conductive path 30

[0030] like Figure 1 As shown, conductive path 30 connects power supply 20 to power load 200. In this embodiment, conductive path 30 includes a positive conductive path 32 connecting the positive terminal of power supply 20 to power load 200, and a negative conductive path 34 connecting the negative terminal of power supply 20 to power load 200. Specifically, as... Figure 2 As shown, the positive electrode conductive path 32 is connected to the total positive terminal 22 of the first battery cell 21A. On the other hand, the negative electrode conductive path 34 is connected to the total negative terminal 24 of the nth battery cell 21N.

[0031] (3) Contactor 40

[0032] Contactor 40 is disposed in conductive path 30 for switching the connection between power supply 20 and power load 200 on / off. Furthermore, the power module 10 in this embodiment has a pair of contactors 40 on the positive and negative sides. Specifically, the positive-side contactor 42 is installed in the positive conductive path 32. On the other hand, the negative-side contactor 44 is installed in the negative conductive path 34. Furthermore, the structure of the contactors 40 is not particularly limited, and contactors suitable for constructing this circuit can be used without particular restriction. Although details will be described later, the positive-side contactor 42 and the negative-side contactor 44 are connected to the use stop unit 140 of the control device 100. Moreover, the positive-side contactor 42 and the negative-side contactor 44 are configured to switch on / off based on a signal from the use stop unit 140. For example, the positive-side contactor 42 and the negative-side contactor 44 can be normally closed contactors that connect the power supply 20 to the power load 200 when no stop signal is input from the stop unit 140, and disconnect the connection when a stop signal is input. Other examples of the contactor 40 could include normally open contactors that disconnect the power supply 20 from the power load 200 when no connection signal is input, and connect the power supply 20 to the power load 200 when a connection signal is input.

[0033] (4) Waterproof outer casing 50

[0034] like Figure 1 As shown, the power module 10 in this embodiment includes a waterproof housing 50 that houses the power supply 20, the conductive path 30, and the contactor 40. This prevents large-scale leakage caused by water immersion in the conductive components (power supply 20, conductive path 30, contactor 40) within the power module 10.

[0035] like Figure 3As shown, the waterproof housing 50 in this embodiment includes a housing body 52, a cover 54, fixing bolts 56, and washers 58. The housing body 52 is a box-shaped component with an opening on its upper surface. A flange portion 52a extending outward from the upper end of the housing body 52 is provided. This flange portion 52a is formed on the entire circumference of the upper end of the housing body 52. ​​On the other hand, the cover 54 is a plate-shaped component that seals the opening on the upper surface of the housing body 52. ​​Moreover, the outer peripheral edge portion 54a of the cover 54 is configured to face the flange portion 52a of the housing body 52. ​​Furthermore, the fixing bolts 56 pass through the outer peripheral edge portion 54a of the cover 54 and the flange portion 52a of the housing body 52. ​​Thus, the housing body 52 and the cover 54 can be fixed. In addition, it is preferable to install a plurality (e.g., more than four) of fixing bolts 56 in the circumferential direction of the housing body 52. Furthermore, from the viewpoint of suppressing leakage current to the waterproof housing 50, it is preferable that the housing body 52 and the cover 54 be made of an insulating resin material (PP, PE, ABS resin, etc.). Also, the gasket 58 is an annular elastic component (SBR, IIR, etc.). This gasket 58 is disposed around the entire circumference between the outer peripheral edge 54a of the cover 54 and the flange 52a of the housing body 52. ​​This seals the interior of the waterproof housing 50. Additionally, Figure 3 The waterproof housing 50 shown has multiple waterproof connectors 59. The typical power module 10 has multiple outlets A for conductive cables (conductive paths 30) and communication cables extending from the inside of the waterproof housing 50 to the outside. By providing waterproof connectors 59 at these outlets A, the intrusion of moisture into the interior of the waterproof housing 50 can be more effectively prevented.

[0036] 2. Control device 100

[0037] The control device 100 is a device for controlling the charging and discharging of the power module 10. For example... Figure 1 As shown, the control device 100 includes an acquisition unit 110, a detection unit 120, a determination unit 130, and a usage stop unit 140. Furthermore, the control device 100 in this embodiment also includes a communication unit 150. The configuration of the control device 100 will be described below.

[0038] (1) Acquisition Department 110

[0039] The acquisition unit 110 acquires the degradation progress D of the power module 10 based on its usage status. Furthermore, the degradation progress D acquired by the acquisition unit 110 is sent to the determination unit 130. In this specification, "degradation progress D" is a value obtained by numerically representing the degradation state of the components of the power module 10 based on its usage status. For example, it is preferably based on the total operating time T of the vehicle battery system 1. T Total distance traveled by the vehicle T DThe total cumulative charging and discharging current T of power module 10 (typically power supply 20) E Calculate the degradation progress D.

[0040] For example, the total operating time T of the vehicle battery system 1 can be measured by a timer installed on the control device 100. T Specifically, the acquisition unit 110 measures the cumulative value of the time when the contactor 40 is in the ON state (the time when power is supplied from the power source 20 to the power load 200) as the total operating time T. T The total operating time T was used. T Assuming a degradation rate D, the assumed lifespan L (described later) is set with respect to the total operating time T. T The corresponding "time (h)". Furthermore, when using the total operating time T... T In the case of degradation progress D, the acquisition unit 110 can also measure the standby time T1 during which the contactor 40 is disconnected. Furthermore, it can also calculate the total operating time T based on this standby time T1. T The corrected time was used as the degradation progress D. Therefore, the overall degradation level, taking into account the standby time T1, can be evaluated.

[0041] Next, the total distance T traveled by the vehicle is measured in the ECU (Engine Control Unit) 300. D Therefore, by connecting the acquisition unit 110 to the ECU 300 via the communication unit 150, the acquisition unit 110 is able to acquire the total driving distance T. D Using the total driving distance T D Assuming a degradation rate D, the total travel distance T is set relative to the assumed lifespan L. D The corresponding "distance (km)". Furthermore, the total travel distance T can be adjusted based on the standby time T1. D Therefore, it is possible to evaluate the overall degree of degradation considering the standby time T1.

[0042] Figure 1 The acquisition unit 110 shown is connected to the power supply 20 via voltage detection line 112 and current detection line 114. Therefore, the total cumulative charge / discharge current T of the power supply module 10 can be acquired. E The total cumulative charge / discharge current T was used. E Assuming a degradation rate D, a specific "current accumulation value (Ah)" is set for the assumed lifetime L. Additionally, the total cumulative charge / discharge current T... E It can also be converted into the total driving distance T D In this case, it is also possible to set "distance (km)" as the assumed lifespan L.

[0043] Furthermore, in this embodiment, the acquisition unit 110 is connected to the power supply 20 via a temperature detection line 116. This allows the acquisition of the temperature change curve of the power supply 20. The total operating time T can also be calculated based on the temperature change curve of the power supply 20. T Total driving distance T D and the total cumulative value of charging and discharging current T E The corrected value is taken as the degradation progress D. Therefore, it can accurately reflect the degree of degradation associated with the temperature environment.

[0044] Alternatively, the acquisition unit 110 in this embodiment can also be connected to the contactor 40 (not shown). This allows the acquisition of the number of operations of the contactor 40 (the number of times it switches on / off). The number of operations of the contactor 40 affects its degradation. Therefore, the total operating time T mentioned above can also be calculated based on the temperature change curve of the power supply 20. T Total driving distance T D and the total cumulative value of charging and discharging current T E The corrected value is taken as the degradation progress D. Therefore, the degradation level of the power module 10 can be estimated based on the degradation level of the contactor 40.

[0045] Furthermore, the power module 10 is composed of multiple components (power supply 20, conductive path 30, contactor 40, waterproof housing 50, etc.). At this time, the user of the system can freely set which component's degradation progress is considered "the degradation progress D of the power module 10". For example, the acquisition unit 110 can be configured to select any component from the constituent components of the power module 10 and set the degradation progress of that selected component as "the degradation progress D of the power module 10". For example, it is preferable that the acquisition unit 110 is configured to consider the degradation progress of the waterproof housing 50 as "the degradation progress D of the power module 10". As described above, the power module 10 in this embodiment prevents leakage caused by water immersion by housing conductive components such as the power supply 20, conductive path 30, and contactor 40 within the waterproof housing 50. However, if the waterproof housing 50 reaches the end of its lifespan, large-scale leakage may easily occur in the conductive components, leading to high-risk abnormalities such as smoke and fire. In contrast, by considering the degradation progress of the waterproof housing 50 as the "degradation progress D of the power module 10", it is possible to more effectively prevent the occurrence of high-risk anomalies.

[0046] Furthermore, the degradation progress D of the power module 10 is not limited to the degradation progress of a specific component. Specifically, the acquisition unit 110 can also acquire the degradation progress of each component of the power module 10 (power supply 20, conductive path 30, contactor 40, waterproof housing 50, etc.). In this case, it is preferable that the acquisition unit 110 considers the degradation progress of the most severely degraded component as the "degradation progress D of the power module 10". This allows for a more appropriate reduction of the risks caused by components whose continued service life has been exhausted.

[0047] Furthermore, although details will be described later, the detection unit 120 of the control device 100 may also be configured to identify a component that has experienced leakage. In this case, the acquisition unit 110 may also select a degradation level considered as "degradation level D of the power module 10" based on the detected leakage component.

[0048] (2) Testing Department 120

[0049] The detection unit 120 is a circuit that detects whether there is leakage in the power module 10. The detection unit 120 only needs to be able to detect leakage in at least a portion of the conductive components (power supply 20, conductive path 30, contactor 40) in the power module 10, and conventionally known leakage detection devices can be used without particular limitations.

[0050] For example, in this embodiment, the detection unit 120 is connected between the positive conductive path 32 and the negative conductive path 34. The detection unit 120 is connected to the ground wire at the midpoint 121. That is, the midpoint 121 of the detection unit 120 is configured such that, in the event of leakage in the power module 10, it is connected to the leakage point via the ground wire.

[0051] In addition, the detection unit 120 is configured to detect the potential difference between the positive conductive path 32 of the ground wire and the leakage point, i.e., the first grounding voltage V. g（t1） The potential difference between the negative conductive path 34 of the ground wire and the leakage point, i.e., the second grounding voltage V, is also known as the second grounding voltage. g（t2） Specifically, the detection unit 120 is provided with two switching elements consisting of a first switch 122 and a second switch 123, and four resistors consisting of a first voltage detection resistor 124, a second voltage detection resistor 125, a first voltage divider resistor 126, and a second voltage divider resistor 127.

[0052] The first switch 122 is a switching element connected to the positive conductive path 32 side relative to the midpoint 121. On the other hand, the second switch 123 is a switching element connected to the negative conductive path 34 side relative to the midpoint 121. The structure of these switching elements is not particularly limited; semiconductor switching elements such as transistors and FETs, or mechanical switches such as relays, can be used. Furthermore, the detection unit 120 controls the operation of each switching element so that the second switch 123 is off when the first switch 122 is on, and the first switch 122 is off when the second switch 123 is on.

[0053] Next, the four resistors provided in the detection unit 120 will be described. The first voltage detection resistor 124 is provided between the first switch 122 and the intermediate point 121. The second voltage detection resistor 125 is provided between the second switch 123 and the intermediate point 121. The first voltage divider resistor 126 is provided between the positive conductive path 32 and the first switch 122. The second voltage divider resistor 127 is provided between the negative conductive path 34 and the second switch 123. In this embodiment, the first voltage detection resistor 124 and the second voltage detection resistor 125 are set to the same resistance value Ra. The first voltage divider resistor 126 and the second voltage divider resistor 127 are set to the same resistance value Rb. However, the resistors described above may have different resistance values.

[0054] Next, the detection unit 120 includes a voltage detection unit 129. This voltage detection unit 129 is connected to a first connection point 129a between the first switch 122 and the first voltage detection resistor 124, and a second connection point 129b between the second switch 123 and the second voltage detection resistor 125. Furthermore, a differential operation circuit 129c is disposed between the first connection point 129a (second connection point 129b) and the voltage detection unit 129. Moreover, in this embodiment, the voltage detection unit 129 detects the voltage V based on the input voltage. g（t1） Second grounding voltage V g（t2） Third grounding voltage V g（t3） and the fourth grounding voltage V g（t4） The four types of grounding voltages V constitute g These grounding voltages V g The testing sequence has been disclosed in Japanese Patent Application Publication No. 2023-081523, so repeated descriptions are omitted.

[0055] Furthermore, the detection unit 120 in this embodiment includes a reference potential difference detection unit 128. The reference potential difference detection unit 128 is connected between the positive conductive path 32 and the negative conductive path 34, and detects the potential difference between the positive conductive path 32 and the negative conductive path 34, i.e., the reference potential difference V.S Furthermore, the specific structure of the reference potential difference detection unit 128 is not particularly limited, and conventionally known voltage detection units can be used without particular restriction. Moreover, the detection unit 120 can detect the reference potential difference V detected by the reference potential difference detection unit 128. S The four grounding voltages V obtained by the voltage detection unit 129 are: g This is to determine the leakage current generation part within the power module 10. The determination order at this time is also disclosed in Japanese Patent Application Publication No. 2023-081523, so repeated explanations are omitted.

[0056] (3) Judgment Unit 130

[0057] When the detection unit 120 detects a leakage current, the determination unit 130 determines whether the degradation progress D exceeds a predetermined assumed lifespan L. Specifically, the determination unit 130 is connected to the acquisition unit 110. Therefore, the degradation progress D acquired by the acquisition unit 110 is sent to the determination unit 130. Furthermore, the determination unit 130 is also connected to the detection unit 120. Thus, the leakage current information acquired by the detection unit 120 is also sent to the determination unit 130. This information is stored in a storage area within the determination unit 130.

[0058] Furthermore, the storage area of ​​the determination unit 130 also stores an assumed lifespan L, which serves as a threshold for the degradation progress D. Although details will be described later, this assumed lifespan L serves as the criterion for determining whether to stop the use of power from the power module 10 when leakage information is sent from the detection unit 120. The assumed lifespan L can be appropriately set by the user of this system according to the purpose. For example, it is preferable to set either the design lifespan or the warranty lifespan as the assumed lifespan L. The design lifespan is the limit of use calculated based on the service life of the components of the power module 10. When the design lifespan is set as the assumed lifespan L, the service life of the power module 10 and its components can be used, which helps to reduce the operating cost of the vehicle battery system 1. On the other hand, the warranty lifespan is set to a period shorter than the design lifespan as the period for ensuring the safety of the power module 10. When the warranty lifespan is set as the assumed lifespan L, a vehicle battery system 1 with superior safety can be constructed.

[0059] (4) Use stop unit 140

[0060] When the determination unit 130 determines that the degradation rate D exceeds the assumed lifespan L (D > L), the use stop unit 140 stops the power supply from the power module 10 to the power load 200. In this embodiment, the use stop unit 140 is configured to control the contactor 40 to disconnect the power supply 20 from the power load 200 when D > L is determined. Specifically, the use stop unit 140 is connected to the determination unit 130 and the contactor 40. In addition, the use stop unit 140 can generate a stop signal that disconnects the contactor 40. Moreover, when the determination unit 130 receives a lifespan end determination result (D > L), the use stop unit 140 sends a stop signal to the contactor 40. As a result, the power supply from the power supply 20 to the power load 200 is cut off. As a result, it is possible to prevent the power module 10 from continuing to exhaust its lifespan despite leakage.

[0061] Furthermore, the stop unit 140 is preferably configured such that when the determination unit 130 determines that the degradation rate D exceeds the assumed lifespan L, the power supply from the power module 10 to the power load 200 is stopped after a predetermined buffer time. Specifically, in this embodiment, the stop unit 140 is set with a predetermined buffer time (approximately 30 to 60 seconds). Moreover, when the determination unit 130 receives a lifespan end determination result (D > L), the stop unit 140 sends a stop signal to the contactor 40 after the aforementioned buffer time. This prevents accidents caused by sudden vehicle stops. In addition, this configuration also ensures sufficient time for the driver to evacuate the vehicle.

[0062] (5) Communication unit 150

[0063] The communication unit 150 is a device used to exchange various data between external devices and the control device 100 of the vehicle-mounted battery system 1. For example, in Figure 1 In the vehicle battery system 1 shown, the control device 100, ECU 300, and notification unit 400 are connected via a communication unit 150. This allows for data exchange with each device. Furthermore, the communication unit 150 can use conventionally known communication devices without particular restriction; for example, it can be either a wired or wireless communication unit. The communication unit 150 receives the determination result from the determination unit 130 and can notify the vehicle control side to perform a forced stop based on power depletion after a predetermined buffer time. This allows the driver to be notified that the vehicle should enter a hazard-avoidance driving state.

[0064] Alternatively, for example, the acquisition unit 110, determination unit 130, usage stop unit 140, and communication unit 150 can be configured using a single microcomputer. This microcomputer includes a central processing unit (CPU) that executes control programs, a ROM (read-only memory) that stores the programs executed by the CPU, RAM (random access memory) that serves as the working area for program execution, and a memory that stores the aforementioned programs and various data. Furthermore, the determination unit 130, usage stop unit 140, and communication unit 150 can be constructed through the cooperation of multiple devices.

[0065] In addition, Figure 1 In the vehicle-mounted battery system 1 shown, a control device 100 is also housed inside the waterproof housing 50. This prevents the control device 100 from being submerged in water. Furthermore, it is preferable that the control device 100 is positioned at the highest point within the waterproof housing 50. Additionally, the control device 100 is preferably treated with a waterproof coating on its surface. These measures provide more reliable protection against water immersion in the control device 100. However, the location of the control device 100 can be appropriately varied depending on the vehicle configuration, and the technology disclosed herein is not limited. For example, the acquisition unit 110, determination unit 130, usage stop unit 140, and communication unit 150 may also be provided within a vehicle-side control device (e.g., ECU 300).

[0066] 3. Notification Department 400

[0067] Furthermore, the vehicle battery system 1 of this embodiment includes a notification unit 400 that notifies the user of a leakage when the detection unit 120 detects a leakage. This further improves the safety of the vehicle battery system 1. Specifically, by notifying the user in advance of the occurrence of a leakage, the likelihood of accidents caused by sudden stopping can be reduced. Additionally, the vehicle battery system 1 of this embodiment does not stop supplying power to the power load 200 even if a leakage occurs, provided that the lifespan of the power module 10 has not been exhausted. Notifying the user of the occurrence of a leakage at this time encourages the user to proactively inspect and repair the device. Moreover, the notification unit 400 is not particularly limited in its specific configuration, as long as it can notify the user of the leakage detection. For example, the notification unit 400 can be either an image display device or an audio notification device.

[0068] B. Vehicle control during operation

[0069] The configuration of the vehicle-mounted battery system 1 according to this embodiment has been described above. Next, the operation of the vehicle-mounted battery system 1 during driving will be described. Figure 4 This is a flowchart illustrating the control of the vehicle-mounted battery system during driving according to the first embodiment.

[0070] like Figure 4 As shown, the vehicle control method includes a leakage detection step S1, a leakage determination step S2, a leakage notification step S3, a lifespan acquisition step S4, a lifespan determination step S5, a stop preparation step S6, and a stop step S7. Each step will be explained below.

[0071] (1) Leakage detection procedure S1

[0072] In the leakage current detection process S1, the detection unit 120 performs leakage current detection on the power module 10. If leakage current is detected on the power module 10 side, the detection unit 120 appropriately switches the switching elements 122 and 123 to obtain four grounding voltages V. g（t1） ~V g（t4） Next, the detection unit 120 acquires the reference potential difference V in the reference potential difference detection unit 128. S Then, the detection unit 120 detects four grounding voltages V. g（t1） ~V g（t4） and reference potential difference V S The power module 10 is subjected to leakage current detection. Furthermore, the detailed sequence and calculations for determining the leakage point are disclosed in Japanese Patent Application Publication No. 2023-081523, therefore detailed descriptions are omitted.

[0073] (2) Leakage current detection process S2

[0074] In the leakage current determination process S2, the determination unit 130 determines whether leakage current information has been received from the detection unit 120. Furthermore, if no leakage current information is received from the detection unit 120, the determination unit 130 notifies "no leakage current state" (see S8) and ends the diagnostic operation (No in S2). Additionally, if the determination is "no leakage current state," it is preferable that the vehicle battery system 1 performs the diagnostic operation again after a predetermined period. On the other hand, if leakage current information is received from the detection unit 120, the determination unit 130 saves the leakage current information in a non-volatile memory in the storage area and initiates the control process to the leakage current notification process S3 (Yes in S2). Although details will be described later, the leakage current information stored in the non-volatile memory is retained until the leakage current response (inspection, repair, etc.) is completed.

[0075] (3) Leakage notification procedure S3

[0076] Next, in the leakage notification process S3, the notification unit 400 notifies the user of the leakage information. Specifically, the determination unit 130 sends the leakage information to the notification unit 400 via the communication unit 150. Then, the notification unit 400 notifies the user of the leakage information through sound or image display. This can urge the user to actively stop the vehicle and take evasive action, thus more effectively reducing the risk associated with leakage. In addition, by notifying the user of the leakage information in advance, it is also possible to urge the inspection and repair of the power module 10.

[0077] (4) Obtaining process S4

[0078] Next, in the acquisition process S4, the acquisition unit 110 acquires the degradation progress D of the power module 10 based on its usage status. Furthermore, as described above, the method for acquiring the degradation progress D can be preset by the user. For example, "the degradation progress D of the power module 10" can be a preset degradation progress of a component, the degradation progress of the most severely degraded component, or the degradation progress of a component where leakage is detected.

[0079] (5) Life determination process S5

[0080] In the lifespan determination process S5, the degradation progress D of the power module 10 is compared with a preset assumed lifespan L. Here, if the degradation progress D is less than or equal to the assumed lifespan L (D≤L), the lifespan of the power module 10 has not been exhausted, so it is determined that the vehicle can continue to operate. In this case, the determination unit 130 ends the diagnostic operation (S5 no). Furthermore, if it is determined that "although there is a leakage condition, the lifespan has not been exhausted," it is preferable that the vehicle battery system 1 performs the diagnostic operation again after a predetermined period has elapsed. This prevents the power module 10 from exhausting its lifespan and causing a high-risk anomaly during the period from the occurrence of leakage to the time of going to the repair shop.

[0081] On the other hand, in the lifespan determination process S5, if the degradation rate D exceeds the assumed lifespan L (D > L), the power module 10 is in a state of lifespan exhaustion and leakage. In this case, high-risk anomalies such as smoke and fire may occur due to external moisture intrusion, so it is determined that the vehicle can hardly continue to operate. In this case, the determination unit 130 sends the lifespan end determination result (D > L) to the notification unit 400 and the use stop unit 140, and causes the control processing to enter the stop preparation process S6 (refer to S5).

[0082] (6) Stop the preparation process S6

[0083] In the stop preparation process S6, the notification unit 400 notifies the user of an emergency stop. Specifically, the notification unit 400 notifies the user of a predetermined buffer time and announces that an emergency stop will be implemented after the buffer time has elapsed. This allows the user to proactively stop and take evasive action before an emergency stop, thus preventing accidents caused by emergency stops.

[0084] (7) Stop process S7

[0085] In the stop process S7, the use of power from the power supply module 10 to the power load 200 is stopped. Specifically, the stop unit 140 sends a stop signal to the contactor 40 after a buffer time. Upon receiving the stop signal, the contactor 40 is forcibly opened. Thus, the power supply from the power supply 20 to the power load 200 can be cut off.

[0086] As described above, the vehicle battery system 1 of this embodiment is configured to stop supplying power to the vehicle when leakage is detected and the lifespan of the power module 10 is exhausted. This prevents high-risk anomalies such as smoke and fire. Furthermore, when the lifespan of the power module 10 is not exhausted, the vehicle battery system 1 does not stop supplying power to the vehicle solely based on the detection of leakage. This reduces the risk caused by sudden vehicle stops. As described above, the vehicle battery system 1 according to this embodiment can appropriately reduce the risk associated with leakage of the power module 10.

[0087] C. Control actions during restart

[0088] Furthermore, the preferred on-board battery system 1 is configured such that, if a leakage is detected during the previous driving, the power supply to the power load 200 is limited. This prevents high-risk anomalies from occurring after driving resumes, thus enabling the construction of an on-board battery system 1 with superior safety. This will be explained in detail below.

[0089] Figure 5 This is a flowchart illustrating the control process of the vehicle-mounted battery system 1 according to the first embodiment during the start of driving. For example... Figure 5 As shown, the control method for starting driving includes a recording reference step S11, a leakage current determination step S12, a start / stop step S13, and a start / start step S14.

[0090] (1) Record the reference process S11

[0091] In the recording reference step S11, the determination unit 130 reads the non-volatile memory in the storage area. As explained in the leakage current determination step S2 above, the leakage current information sent from the detection unit 120 is stored as non-volatile storage data in the storage area of ​​the determination unit 130. The determination unit 130 reads this non-volatile memory when the vehicle starts to move.

[0092] (2) Leakage current detection process S12

[0093] In the leakage current determination process S12, the determination unit 130 determines whether a leakage current was detected by the detection unit 120 during the previous driving operation when the vehicle is started. If leakage current information is confirmed in the non-volatile memory, the determination unit 130 causes the control processing to proceed to the start-stop process S13 (referring to S2, yes). On the other hand, if no leakage current information is confirmed, the control processing proceeds to the start-up process S14 (referring to S2, no).

[0094] (3) Start and stop procedures S13

[0095] In the start-stop process S13, the stop unit 140 stops the power supply from the power module 10 to the power load 200. In this embodiment, the stop unit 140 is configured to control the contactor 40 to disconnect the power supply 20 from the power load 200. As described above, leakage information in the non-volatile memory is retained until leakage is addressed (inspection, repair, etc.). Therefore, if leakage information is confirmed in the leakage determination process S12, it is determined that leakage was detected during the last driving and no action was taken to address the leakage. In this case, the stop unit 140 stops the power supply to the power load 200, interrupting the vehicle restart. This prevents high-risk anomalies from occurring after driving resumes.

[0096] (4) Start the start process S14

[0097] In the start-up process S14, the stop unit 140 initiates the power supply from the power module 10 to the power load 200. If no leakage information is confirmed in the leakage detection process S12, it is determined that no leakage was detected during the previous operation, or that appropriate measures have been taken to address the leakage. In this case, the likelihood of a high-risk anomaly occurring after the restart of operation is low, so the stop unit 140 is used to connect the contactor 40, initiating the vehicle restart. Afterward, the vehicle can be driven in the normal sequence.

[0098] <Other Implementation Methods>

[0099] The first embodiment of the leakage current detection method disclosed herein has been described above. Furthermore, the above embodiment is not intended to limit the leakage current detection method disclosed herein, and various modifications can be made.

[0100] For example, the detection unit 120 in the first embodiment adopts the configuration described in Japanese Patent Application Publication No. 2023-081523, which enables the determination of specific leakage locations. However, the detection unit 120 is not limited to the above configuration as long as it can detect whether there is leakage in the power module 10. For example, the vehicle battery system 1 can also start determining whether the degradation rate D exceeds the assumed lifespan L if leakage is detected at any point in the conductive path 30 from the power module 10 to the power load 200. In such cases, the risk of leakage associated with the power module 10 can be appropriately reduced.

[0101] Furthermore, the power module 10 in the first embodiment includes a waterproof housing 50 that houses the power supply 20, the conductive path 30, and the contactor 40. However, the waterproof housing 50 is not an essential component in the technology disclosed herein. For example, if the components of the power module 10 (power supply 20, conductive path 30, and contactor 40) are individually waterproofed, then the waterproof housing 50 is not necessary. In this case, the effective period of the waterproofing treatment for each component can be used as the "assumed lifespan L of the battery module".

[0102] Furthermore, in the first embodiment, the use stop unit 140 sends a stop signal to the contactor 40 after a buffer period has elapsed since receiving the end-of-life determination result from the determination unit 130. However, this configuration is not a necessary component of the technology disclosed herein. For example, the use stop unit 140 may also send a stop signal with a time difference, such as "disconnect the contactor 40 after the buffer period has elapsed," to the contactor 40 upon receiving the end-of-life determination result from the determination unit 130. With such a configuration, time for the user to avoid danger from the vehicle can be ensured. Alternatively, the use stop unit 140 may stop power use without a buffer period upon receiving the end-of-life determination result from the determination unit 130. After power use is stopped, the vehicle will travel a constant distance due to inertia, thus effectively suppressing accidents caused by sudden stopping.

[0103] Furthermore, in the vehicle-mounted battery system 1 of the first embodiment, the power supply from the power module 10 to the power load 200 is cut off by disconnecting the contactor 40 on the conductive path 30. As a result, the use of power from the power module 10 to the power load 200 is stopped. However, the control of the contactor 40 is not necessary in the technology disclosed herein. For example, if leakage is detected by the detection unit 120 and the determination unit 130 determines that the degradation rate D exceeds the assumed lifespan L, the stop unit 120 can also send an emergency stop signal to the vehicle-side control device (ECU 300). With such a configuration, the use of power from the power module 10 to the power load 200 can also be stopped, thereby halting the vehicle's operation.

[0104] The above provides a detailed description of the specific embodiments listed herein, but these embodiments are merely illustrative and do not limit the technical solution. The technology described in the technical solution includes various modifications and alterations to the above-described embodiments. That is, the technology disclosed herein includes the methods described in items 1 to 9 below.

[0105] [Project 1]

[0106] A vehicle-mounted battery system, comprising:

[0107] A power module that connects to the vehicle's power load; and

[0108] The control device controls the charging and discharging of the aforementioned power module.

[0109] The aforementioned control device includes:

[0110] The acquisition unit acquires the degradation progress of the power module based on its usage status.

[0111] The testing department checks for leakage in the aforementioned power modules;

[0112] The determination unit, when the aforementioned detection unit detects leakage, determines whether the aforementioned degradation progress exceeds a predetermined assumed lifespan; and

[0113] When the determination unit determines that the degradation rate exceeds the assumed lifespan, the use of the stop unit stops the use of power from the power module to the power load.

[0114] [Project 2]

[0115] According to the vehicle battery system described in Project 1, among which,

[0116] The above power module must have at least the following features:

[0117] power supply;

[0118] A conductive path that connects the aforementioned power source to the aforementioned power load; and

[0119] A contactor, disposed in the aforementioned conductive path, switches the connection between the power supply and the power load.

[0120] When the determination unit determines that the degradation rate exceeds the assumed lifespan, the stop unit controls the contactor to disconnect the power supply from the power load.

[0121] [Project 3]

[0122] According to the vehicle battery system described in Project 2, the power module also includes a waterproof housing that houses the power source, the conductive path, and the contactor.

[0123] [Project 4]

[0124] According to the vehicle battery system described in Project 3, the aforementioned acquisition unit considers the degradation progress of the aforementioned waterproof casing as the degradation progress of the aforementioned power module.

[0125] [Project 5]

[0126] According to any one of items 1 to 4, in the vehicle battery system described above, the acquisition unit acquires the deterioration progress of multiple components among the constituent components of the power module, and regards the deterioration progress of the constituent component with the highest deterioration progress as the deterioration progress of the power module.

[0127] [Project 6]

[0128] The vehicle battery system described in any one of items 1 to 5 further includes a notification unit that notifies the user of leakage when leakage is detected by the aforementioned detection unit.

[0129] [Project 7]

[0130] According to any one of items 1 to 6, the vehicle battery system described therein, wherein the aforementioned degradation rate is calculated based on at least one selected from the group consisting of the total operating time of the vehicle battery system, the total driving distance of the vehicle, and the total cumulative charge and discharge current of the power module.

[0131] [Project 8]

[0132] According to any one of items 1 to 7, in the vehicle battery system, when the determination unit determines that the degradation rate exceeds the assumed lifespan, the use-stopping unit stops the use of power from the power module to the power load after a predetermined buffer time.

[0133] [Project 9]

[0134] According to any one of items 1 to 8, the vehicle battery system described therein,

[0135] When the vehicle is started, the aforementioned determination unit determines whether a leakage was detected by the aforementioned detection unit during the previous driving.

[0136] When the determination unit determines that a leakage was detected during the previous driving, the use stop unit stops the use of power from the power module to the power load.

Claims

1. A vehicle-mounted battery system, characterized in that, have: A power module that connects to the vehicle's power load; and A control device that controls the charging and discharging of the power module. The control device includes: The acquisition unit acquires the degradation progress of the power module based on its usage status. The detection department detects whether there is leakage in the power module; When the detection unit detects leakage, the determination unit determines whether the degradation rate exceeds a predetermined assumed lifespan. as well as When the determination unit determines that the degradation progress exceeds the assumed lifespan, the use of the stop unit stops the use of power from the power module to the power load.

2. The vehicle-mounted battery system according to claim 1, characterized in that, The power module has at least the following features: power supply; A conductive path that connects the power source to the power load; and A contactor, disposed in the conductive path, switches the connection between the power source and the power load. When the determination unit determines that the degradation rate exceeds the assumed lifespan, the use stop unit controls the contactor to disconnect the power supply from the power load.

3. The vehicle-mounted battery system according to claim 2, characterized in that, The power module also includes a waterproof housing that contains the power source, the conductive path, and the contactor.

4. The vehicle-mounted battery system according to claim 3, characterized in that, The acquisition unit considers the degradation progress of the waterproof casing as the degradation progress of the power module.

5. The vehicle-mounted battery system according to claim 1, characterized in that, The acquisition unit acquires the degradation progress of multiple components in the power module, and regards the degradation progress of the component with the highest degradation progress as the degradation progress of the power module.

6. The vehicle-mounted battery system according to claim 1, characterized in that, It also has a notification unit that notifies the user of leakage when the detection unit detects leakage.

7. The vehicle-mounted battery system according to claim 1, characterized in that, The degradation progress is calculated based on at least one selected from the group consisting of the total operating time of the on-board battery system, the total driving distance of the vehicle, and the total cumulative charge and discharge current of the power module.

8. The vehicle-mounted battery system according to claim 1, characterized in that, When the determination unit determines that the degradation progress exceeds the assumed lifespan, the use-stopping unit stops the use of power from the power module to the power load after a predetermined buffer time.

9. The vehicle-mounted battery system according to any one of claims 1 to 8, characterized in that, When the vehicle is started, the determination unit determines whether the detection unit detected a leakage during the previous driving. When the determination unit determines that a leakage was detected during the previous driving, the use stop unit stops the use of power from the power module to the power load.

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