Vehicle battery system
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- PRIME PLANET ENERGY & SOLUTIONS INC
- Filing Date
- 2024-12-09
- Publication Date
- 2026-06-19
Smart Images
Figure 2026100335000001_ABST
Abstract
Description
[Technical Field]
[0001] The technology disclosed herein relates to an in-vehicle battery system. [Background technology]
[0002] Onboard batteries used in electric vehicles and the like are used in the form of power modules, in which various components are attached to a power source (such as a secondary battery). From the standpoint of ensuring safety, leakage current detection technology is sometimes employed in these power modules (see Japanese Patent Publication Nos. 2023-081521 and 2023-081523, etc.). Furthermore, Japanese Patent Publication No. 2005-057965 discloses a power conversion device that can detect whether or not there is an abnormality in the leakage current detection means, and if it is in a normal state, can continue to supply power without interrupting the power supply. [Prior art documents] [Patent Documents]
[0003] [Patent Document 1] Japanese Patent Publication No. 2023-081521 [Patent Document 2] Japanese Patent Publication No. 2023-081523 [Patent Document 3] Japanese Patent Publication No. 2005-057965 [Overview of the project] [Problems that the invention aims to solve]
[0004] In recent years, in response to the increasing demand for safety in power modules, there has been a need to develop systems that can further reduce the risks associated with electrical leakage. The automotive battery system disclosed herein was developed in response to these demands. [Means for solving the problem]
[0005] The in-vehicle battery system disclosed herein comprises 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 degree of degradation of the power module based on its usage status, a detection unit that detects whether or not there is a leakage current in the power module, a determination unit that determines whether or not the degree of degradation exceeds a predetermined assumed lifespan when a leakage current is detected by the detection unit, and a stop-use unit that stops the use of power from the power module to the power load when the determination unit determines that the degree of degradation exceeds the assumed lifespan.
[0006] The inventors, after diligently studying how to reduce the risks associated with electrical leakage in automotive batteries, have arrived at the following conclusions. First, since drivers do not directly contact the power module while the vehicle is in motion, the likelihood of being exposed to electric shock even if electrical leakage occurs is low. On the other hand, suddenly cutting off power to a moving vehicle carries the risk of accidents due to sudden braking or the need for towing by a tow truck. From these perspectives, it is considered better not to immediately cut off the power supply to the vehicle even if electrical leakage is detected while the vehicle is in motion. However, each component of the power module has a limited lifespan. If electrical leakage occurs when these components have reached the end of their lifespan, there is a risk of high-risk malfunctions such as smoke or fire from the power supply. In the event of electrical leakage when components have reached the end of their lifespan, power use should be stopped even if the vehicle is brought to a sudden stop.
[0007] The in-vehicle battery system disclosed herein is made based on the above findings. When the determination unit of this in-vehicle battery system detects leakage, it determines whether the degree of deterioration progress of the power module exceeds the assumed life. And when it is determined that the degree of deterioration progress exceeds the assumed life, the use stop unit stops the power use from the power module to the power load. Thereby, since power use can be stopped when leakage occurs in a state where the life has expired and other parts have failed, high-risk abnormalities such as smoking and ignition can be prevented. Further, when the life of the power module has not expired, this in-vehicle battery system does not stop the power use of the vehicle just by detecting leakage. Thereby, the risk due to sudden stop of the vehicle can be reduced. As described above, according to the in-vehicle battery system disclosed herein, the risk associated with leakage of the power module can be suitably reduced.
Brief Description of Drawings
[0008] [Figure 1] Figure 1 is a diagram schematically showing an in-vehicle battery system according to the first embodiment. [Figure 2] Figure 2 is a circuit diagram showing a leakage detection circuit of the in-vehicle battery system according to the first embodiment. [Figure 3] Figure 3 is a cross-sectional view showing a waterproof case of the in-vehicle battery system according to the first embodiment. [Figure 4] Figure 4 is a flowchart for explaining the control during traveling of the in-vehicle battery system according to the first embodiment. [Figure 5] Figure 5 is a flowchart for explaining the control at the start of traveling of the in-vehicle battery system according to the first embodiment.
Embodiments for Carrying Out the Invention
[0009] Embodiments of the technology disclosed herein will be described below. Matters other than those specifically mentioned herein that are necessary for carrying out the technology disclosed herein can be understood as design matters for those skilled in the art based on the prior art in the relevant field. The technology disclosed herein can be carried out based on the contents disclosed herein and the common technical knowledge in the relevant field. In this specification, the notation "A to B" indicating a range shall mean A or greater and B or less, as well as "preferably greater than A" and "preferably less than B".
[0010] <First Embodiment> Hereinafter, an embodiment of the in-vehicle battery system disclosed herein will be described with reference to Figures 1 to 3. Figure 1 is a schematic diagram showing the in-vehicle battery system according to the first embodiment. Figure 2 is a circuit diagram showing the leakage current detection circuit of the in-vehicle battery system according to the first embodiment. Figure 3 is a cross-sectional view showing the waterproof case of the in-vehicle battery system according to the first embodiment.
[0011] A. Configuration of the in-vehicle battery system As shown in Figure 1, the in-vehicle battery system 1 according to this embodiment includes a power module 10 and a control device 100. The following describes each of these components.
[0012] 1. Power module 10 As shown in Figure 1, the power module 10 is connected to the power load 200 of the vehicle (not shown). The power load 200 is a mechanism that converts the electricity supplied from the power module 10 into power. This allows the vehicle to move. The specific structure of the power load 200 is not particularly limited and can be appropriately selected from conventionally known equipment (motors, etc.).
[0013] Furthermore, although not limited to the technologies disclosed herein, the power module 10 includes, for example, a power supply 20, a conductive path 30, a contactor 40, and a waterproof case 50. The components of the power module 10 will be described below.
[0014] (1) Power supply 20 The power supply 20 is the power source for the vehicle. In this embodiment, the power supply 20 is a battery pack comprising a plurality (N) of battery cells 21A to 21N (see Figure 2). In this power supply (battery pack) 20, each of the plurality of battery cells 21A to 21N is arranged adjacent to each other along a predetermined arrangement direction. Two adjacent battery cells are electrically connected by a connecting member. 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 cell. This positive terminal of the first battery cell 21A becomes a total positive terminal 22 that is open to connect 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 cell. This negative terminal of the nth battery cell 21N becomes a total negative terminal 24 that is open to connect to the power load 200.
[0015] Here, "battery cell" refers to a device capable of charging and discharging. Examples of such battery cells include secondary batteries such as lithium-ion secondary batteries, nickel-metal hydride batteries, and nickel-cadmium batteries; primary batteries such as manganese dry cells and alkaline dry cells; capacitors such as electric double-layer capacitors; and power generation elements such as fuel cells and solar cells. Furthermore, the number of battery cells constituting the power supply 20 is not particularly limited and can be appropriately changed according to the performance required of the power supply module 10 (output voltage, installation space, etc.). For example, the power supply 20 may consist of one battery cell. However, considering the performance of the power supply module 10, the number of battery cells constituting the power supply 20 is preferably 50 or more, more preferably 75 or more, even more preferably 90 or more, and particularly preferably 100 or more. Furthermore, the upper limit of the number of battery cells is not particularly limited and may be 200 or less, or 150 or less.
[0016] (2) Conductive path 30 As shown in Figure 1, the conductive path 30 connects the power supply 20 and the power load 200. In this embodiment, the conductive path 30 includes a positive conductive path 32 that connects the positive electrode of the power supply 20 to the power load 200, and a negative conductive path 34 that connects the negative electrode of the power supply 20 to the power load 200. Specifically, as shown in Figure 2, the positive conductive path 32 is connected to the total positive terminal 22 of the first battery cell 21A. On the other hand, the negative conductive path 34 is connected to the total negative terminal 24 of the nth battery cell 21N.
[0017] (3) Contactor 40 The contactor 40 is provided in the conductive path 30 and switches the connection between the power supply 20 and the power load 200 ON / OFF. In this embodiment, the power module 10 has a pair of contactors 40, one on the positive side and one on the negative side. Specifically, the positive side contactor 42 is attached to the positive conductive path 32. On the other hand, the negative side contactor 44 is attached to the negative conductive path 34. The structure of the contactor 40 is not particularly limited, and any contactor that can be used to construct this type of electrical circuit can be used without any particular restriction. As will be described in detail later, the positive side contactor 42 and the negative side contactor 44 are connected to the deactivation unit 140 of the control device 100. The positive side contactor 42 and the negative side contactor 44 are configured to be switched ON / OFF by a signal from the deactivation unit 140. For example, normally closed contactors can be used for the positive contactor 42 and the negative contactor 44, which connect the power supply 20 and 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. Another example of the contactor 40 is a normally open contactor, which disconnects the power supply 20 and the power load 200 when no connection signal is input, and connects the power supply 20 and the power load 200 when a connection signal is input.
[0018] (4) Waterproof case 50 As shown in Figure 1, the power module 10 in this embodiment includes a waterproof case 50 that houses the power supply 20, the conductive path 30, and the contactor 40. This prevents large-scale electrical leakage caused by water ingress into the conductive components (power supply 20, conductive path 30, contactor 40) inside the power module 10.
[0019] As shown in Figure 3, the waterproof case 50 in this embodiment comprises a case body 52, a lid 54, fixing bolts 56, and a gasket 58. The case body 52 is a box-shaped member with an open top. A flange portion 52a extending outward from the upper end of the case body 52 is provided. This flange portion 52a is formed around the entire circumference of the upper end of the case body 52. The lid 54 is a plate-shaped member that closes the opening on the top surface of the case body 52. The outer peripheral edge portion 54a of the lid 54 is positioned to face the flange portion 52a of the case body 52. The fixing bolts 56 pass through the outer peripheral edge portion 54a of the lid 54 and the flange portion 52a of the case body 52. This allows the case body 52 and the lid 54 to be fixed together. It is preferable that multiple fixing bolts 56 (for example, four or more) are attached in the circumferential direction of the case body 52. Furthermore, from the viewpoint of suppressing electrical leakage into the waterproof case 50, it is preferable that the case body 52 and the lid 54 are made of an insulating resin material (PP, PE, ABS resin, etc.). In addition, the gasket 58 is an annular elastic member (SBR, IIR, etc.). This gasket 58 is placed around the entire circumference between the outer peripheral edge 54a of the lid 54 and the flange portion 52a of the case body 52. This seals the inside of the waterproof case 50. Also, the waterproof case 50 shown in Figure 3 is equipped with multiple waterproof connectors 59. A typical power module 10 is provided with multiple outlets A for drawing conductive cables (conductive paths 30) and communication cables from the inside of the waterproof case 50 to the outside. By providing waterproof connectors 59 on these outlets A, the intrusion of moisture into the inside of the waterproof case 50 can be more effectively prevented.
[0020] 2. Control device 100 The control device 100 is a device that controls the charging and discharging of the power module 10. As shown in FIG. 1, the control device 100 includes an acquisition unit 110, a detection unit 120, a determination unit 130, and a use stop unit 140. In addition, the control device 100 in the present embodiment further includes a communication means 150. Hereinafter, the configuration of the control device 100 will be described.
[0021] (1) Acquisition unit 110 The acquisition unit 110 acquires the degree of deterioration progress D of the power module 10 based on the usage status of the power module 10. Then, the degree of deterioration progress D acquired by the acquisition unit 110 is transmitted to the determination unit 130. Note that the "degree of deterioration progress D" in this specification is a numerical value obtained by quantifying the deterioration state of the components of the power module 10 based on the usage status of the power module 10. For example, the degree of deterioration progress D is the total operation time T T of the in-vehicle battery system 1, the total driving distance T of the vehicle D , and preferably calculated based on the total charge-discharge current integrated value T E of the power module 10 (typically the power supply 20), etc.
[0022] For example, the total operation time T T of the in-vehicle battery system 1 can be measured by a timer mounted on the control device 100. Specifically, the acquisition unit 110 measures the integrated value of the time when the contact 40 is ON (the time when power is supplied from the power supply 20 to the power load 200) as the total operation time T T . When this total operation time T T is adopted as the degree of deterioration progress D, the "time (h)" corresponding to the total operation time T T is set for the assumed life L described later. Note that when the total operation time T T is adopted as the degree of deterioration progress D, the acquisition unit 110 may measure the standby time T1 when the contact 40 is OFF. Then, the corrected total operation time T T by this standby time T1 can also be used as the degree of deterioration progress D. Thereby, the comprehensive degree of deterioration considering the standby time T1 can be evaluated.
[0023] Next, the total mileage of the vehicle T D This is measured in the ECU (Engine control unit) 300. Therefore, by connecting the acquisition unit 110 and the ECU 300 via the communication means 150, the acquisition unit 110 can determine the total mileage T D You can obtain this. Total distance T D If we adopt the degree of deterioration D, the assumed lifespan L will be the total mileage T. D The corresponding "distance (km)" is set. D This can also be corrected by the waiting time T1. This allows us to evaluate the overall degree of degradation, taking the waiting time T1 into consideration.
[0024] The acquisition unit 110 shown in Figure 1 is connected to the power supply 20 via a voltage detection line 112 and a current detection line 114. This allows the power supply module 10 to acquire the cumulative charge / discharge current integrated value T. E This allows you to obtain the cumulative charge / discharge current integrated value T. E If the degradation progression D is adopted, a specific "integrated current value (Ah)" is set for the assumed lifespan L. Also, the cumulative charge / discharge current integrated value T E Total distance traveled T D It can also be converted to this. In this case, the expected lifespan L can also be set to "distance (km)".
[0025] Furthermore, the acquisition unit 110 in this embodiment is connected to the power supply 20 via the temperature detection line 116. This allows the temperature profile of the power supply 20 to be acquired. The total operating time T mentioned above T Total distance traveled T D and the cumulative charge / discharge current integrated value T E The degradation progression D can also be adopted as the value corrected using the temperature profile of power supply 20. This allows for accurate reflection of the degree of degradation associated with the temperature environment.
[0026] Furthermore, the acquisition unit 110 in this embodiment may be connected to the contactor 40 (not shown). This allows the number of operations of the contactor 40 (number of ON / OFF switching cycles) to be acquired. The number of operations of the contactor 40 affects the deterioration of the contactor 40. For this reason, the cumulative operating time T mentioned above... T Total distance traveled T D and the cumulative charge / discharge current integrated value T E The degradation progression D can also be adopted as the degradation rate D, which is corrected using the temperature profile of the power supply 20. This makes it possible to estimate the degradation rate of the power supply module 10 based on the degradation rate of the contactor 40.
[0027] The power module 10 is composed of multiple components (power supply 20, conductive path 30, contactor 40, waterproof case 50, etc.). In this case, the user of the system can freely set which component's deterioration progress is considered to be "power module 10 deterioration progress D". For example, the acquisition unit 110 is configured to select any component from the components of the power module 10 and set the deterioration progress of the selected component as "power module 10 deterioration progress D". As a preferred example, the acquisition unit 110 is preferably configured to consider the deterioration progress of the waterproof case 50 as "power module 10 deterioration progress D". As described above, the power module 10 in this embodiment prevents leakage due to water ingress by housing conductive members such as the power supply 20, conductive path 30, and contactor 40 inside the waterproof case 50. However, when the lifespan of the waterproof case 50 is reached, large-scale leakage may occur in the conductive members, potentially leading to high-risk abnormalities such as smoke and fire. In contrast, by considering the degree of deterioration of the waterproof case 50 as "degree D of deterioration of the power module 10," the occurrence of high-risk abnormalities can be more effectively prevented.
[0028] Furthermore, the degradation progression D of the power module 10 is not limited to the degradation progression of a specific component. Specifically, the acquisition unit 110 may acquire the degradation progression of each component of the power module 10 (power supply 20, conductive path 30, contactor 40, waterproof case 50, etc.). In this case, it is preferable for the acquisition unit 110 to consider the degradation progression of the component that is most degraded as the "degradation progression D of the power module 10". This makes it possible to more effectively reduce the risks associated with continuing to use components that have reached the end of their lifespan.
[0029] Furthermore, as will be described in more detail later, the detection unit 120 of the control device 100 can also be configured to identify the component where the electrical leakage occurred. In this case, the acquisition unit 110 may select a degree of deterioration to be considered as the "degree of deterioration D of the power module 10" based on the component where the electrical leakage was detected.
[0030] (2) Detection unit 120 The detection unit 120 is a circuit that detects the presence or absence of leakage current in the power supply module 10. The detection unit 120 only needs to be able to detect leakage current in at least a portion of the conductive members (power supply 20, conductive path 30, contactor 40) within the power supply module 10, and conventionally known leakage current detection devices can be used without any particular limitations.
[0031] For example, in this embodiment, the detection unit 120 is connected between the positive electrode conductive path 32 and the negative electrode conductive path 34. This detection unit 120 is connected to ground at an intermediate point 121. That is, the intermediate point 121 of the detection unit 120 is configured to conduct to the location of the leakage current via ground when a leakage current occurs in the power supply module 10.
[0032] Furthermore, the detection unit 120 detects the first ground voltage V, which is the potential difference between the positive electrode conductive path 32 via the ground and the leakage point. g(t1) The second ground voltage V is the potential difference between the negative electrode conductive path 34 via the ground and the leakage point. g(t2)It is configured to detect the following. 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.
[0033] The first switch 122 is a switching element connected to the positive electrode conductive path 32 side of the midpoint 121. On the other hand, the second switch 123 is a switching element connected to the negative electrode conductive path 34 side of the midpoint 121. The structure of these switching elements is not particularly limited, and 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 such that when the first switch 122 is turned ON, the second switch 123 is turned OFF, and when the second switch 123 is turned ON, the first switch 122 is turned OFF.
[0034] Next, the four resistors provided in the detection unit 120 will be described. The first voltage detection resistor 124 is a resistor provided between the first switch 122 and the midpoint 121. The second voltage detection resistor 125 is a resistor provided between the second switch 123 and the midpoint 121. Furthermore, the first voltage divider resistor 126 is a resistor provided between the positive electrode conductive path 32 and the first switch 122. The second voltage divider resistor 127 is a resistor provided between the negative electrode 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 electrical resistance Ra. Also, the first voltage divider resistor 126 and the second voltage divider resistor 127 are set to the same electrical resistance Rb. However, each of the above resistors may have different electrical resistances.
[0035] Next, the detection unit 120 includes a voltage detection unit 129. This voltage detection unit 129 is connected to a first connection point 129a provided between the first switch 122 and the first voltage detection resistor 124, and to a second connection point 129b provided between the second switch 123 and the second voltage detection resistor 125. Furthermore, a differential arithmetic circuit 129c is arranged between the aforementioned first connection point 129a (second connection point 129b) and the voltage detection unit 129. In this embodiment, the voltage detection unit 129 detects the first ground voltage V based on the input voltage. g(t1) And the second ground voltage V g(t2) And the third ground voltage V g(t3) And the fourth ground voltage V g(t4) Four types of ground voltage V consisting of these g Detect these ground voltages V g The detection procedure is disclosed in Japanese Patent Publication No. 2023-081523, so redundant explanations will be omitted.
[0036] 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 electrode conductive path 32 and the negative electrode conductive path 34, and the reference potential difference V is the potential difference between the positive electrode conductive path 32 and the negative electrode conductive path 34. S The detection unit 120 detects the reference potential difference V detected by the reference potential difference detection unit 128. S The voltage detection unit 129 acquires four types of ground voltages V g Based on this, the leakage current source within the power module 10 can be identified. The procedure for identifying this source is also disclosed in Japanese Patent Application Publication No. 2023-081523, so a redundant explanation will be omitted.
[0037] (3) Determination unit 130 When a leakage current is detected by the detection unit 120, the determination unit 130 determines whether the degree of deterioration D exceeds a predetermined assumed lifespan L. Specifically, the determination unit 130 is connected to the acquisition unit 110. Therefore, the degree of deterioration D acquired by the acquisition unit 110 is transmitted to the determination unit 130. The determination unit 130 is also connected to the detection unit 120. As a result, the leakage current information acquired by the detection unit 120 is also transmitted to the determination unit 130. This information is stored in the memory area of the determination unit 130.
[0038] Furthermore, the memory area of the determination unit 130 also stores the assumed lifespan L, which is a threshold value for the degradation progression D. As will be described in detail later, this assumed lifespan L serves as a criterion for deciding whether or not to stop power consumption from the power module 10 when leakage information is transmitted from the detection unit 120. This assumed lifespan L can be set as appropriate by the user of this system according to their purpose. For example, it is preferable to set either the design lifespan or the guaranteed 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. If this design lifespan is set as the assumed lifespan L, the power module 10 can be used until the service life of the components, thus contributing to a reduction in the operating costs of the in-vehicle battery system 1. On the other hand, the guaranteed lifespan is set to a shorter period than the design lifespan as the period for which the safety of the power module 10 is guaranteed. If this guaranteed lifespan is set as the assumed lifespan L, an in-vehicle battery system 1 with superior safety can be constructed.
[0039] (4) Discontinued use part 140 The power outage unit 140 stops the power supply from the power module 10 to the power load 200 when the determination unit 130 determines that the degradation progression D exceeds the expected lifespan L (D>L). In this embodiment, the power outage unit 140 is configured to control the contactor 40 to turn off the connection between the power supply 20 and the power load 200 when D>L is determined. Specifically, the power outage unit 140 is connected to the determination unit 130 and the contactor 40. The power outage unit 140 can also generate a stop signal to turn off the contactor 40. When the determination unit 130 receives the lifespan termination determination result (D>L), the power outage unit 140 transmits the stop signal to the contactor 40. This cuts off the power supply from the power supply 20 to the power load 200. As a result, it is possible to prevent a situation where the power module 10 continues to be used even though a leakage current is occurring and the lifespan has reached its limit.
[0040] Furthermore, it is preferable that the deactivation unit 140 is configured to stop power supply from the power module 10 to the power load 200 after a predetermined evacuation time has elapsed when the determination unit 130 determines that the deterioration progression D exceeds the expected lifespan L. Specifically, the deactivation unit 140 in this embodiment is set to a predetermined evacuation time (approximately 30 to 60 seconds). When the determination unit 130 receives a determination result of the end of lifespan (D>L), the deactivation unit 140 transmits a stop signal to the contactor 40 after the aforementioned evacuation time has elapsed. This prevents accidents caused by sudden braking of the vehicle. In addition, this configuration also ensures that the driver has time to evacuate from the vehicle.
[0041] (5) Communication means 150 The communication means 150 is a device for exchanging various data between external devices of the in-vehicle battery system 1 and the control device 100. For example, in the in-vehicle battery system 1 shown in Figure 1, the control device 100, the ECU 300, and the notification unit 400 are connected via the communication means 150. This allows each device to exchange data with each other. The communication means 150 can use any conventionally known communication device without any particular restrictions; for example, the communication means 150 may be a wired communication means or a wireless communication means. The communication means 150 can receive the determination result from the determination unit 130 and notify the vehicle control side that it will perform a forced stop by stopping power use after a predetermined evacuation time. This allows the driver to be informed that the vehicle should enter an evacuation state.
[0042] The acquisition unit 110, the determination unit 130, the deactivation unit 140, and the communication means 150 may be composed of, for example, a single microcomputer. This microcomputer includes a central processing unit (CPU) that executes a control program, a read-only memory (ROM) that stores the program executed by the CPU, a random access memory (RAM) used as a working area for expanding the program, and a storage device such as memory that stores the program and various data. Alternatively, the determination unit 130, the deactivation unit 140, and the communication means 150 may be constructed by the cooperation of multiple devices.
[0043] Furthermore, in the in-vehicle battery system 1 shown in Figure 1, the control device 100 is also housed inside the waterproof case 50. This prevents water from entering the control device 100. In addition, it is preferable to position the control device 100 at the highest position within the waterproof case 50. It is also preferable that the surface of the control device 100 is waterproofed. These measures make it possible to more reliably prevent water from entering the control device 100. However, the installation position of the control device 100 can be appropriately changed depending on the vehicle configuration, etc., and is not limited to the technology disclosed herein. For example, the acquisition unit 110, the determination unit 130, the use-stop unit 140, and the communication means 150 may be incorporated into the vehicle-side control device (e.g., ECU 300).
[0044] 3.Notification section 400 Furthermore, the in-vehicle battery system 1 according to this embodiment includes a notification unit 400 that notifies the user of a leakage current when a leakage current is detected by the detection unit 120. This further improves the safety of the in-vehicle battery system 1. Specifically, by notifying the user in advance of the occurrence of a leakage current, the likelihood of avoiding accidents caused by sudden braking increases. Also, in the in-vehicle battery system 1 according to this embodiment, if the lifespan of the power module 10 has not expired, the use of power to the power load 200 will not be stopped even if a leakage current occurs. In this case, if the user is notified of the occurrence of a leakage current, it can be encouraged to perform inspections or repairs voluntarily. Note that the notification unit 400 only needs to be able to notify the user of the detection of a leakage current, and its specific configuration is not particularly limited. For example, the notification unit 400 may be an image display device or an audio notification device.
[0045] B. Control during vehicle operation The configuration of the in-vehicle battery system 1 according to this embodiment has been described above. Next, the operation of this in-vehicle battery system 1 while driving will be described. Figure 4 is a flowchart illustrating the control of the in-vehicle battery system during driving according to the first embodiment.
[0046] As shown in Figure 4, the control method for this vehicle 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 described below.
[0047] (1) Leakage current detection process S1 In the leakage detection process S1, the detection unit 120 detects leakage current in the power module 10. If leakage current is detected on the power module 10 side, the detection unit 120 switches the switching elements 122 and 123 as appropriate to detect four types of ground voltage V g(t1) ~V g(t4) Next, the detection unit 120 detects the reference potential difference V in the reference potential difference detection unit 128. S The detection unit 120 then obtains four types of ground voltage V g(t1) ~V g(t4) and reference potential difference V S Based on this, leakage current detection of the power module 10 is performed. Note that detailed procedures and calculations for identifying the leakage current location are disclosed in Japanese Patent Publication No. 2023-081523, so a detailed explanation is omitted here.
[0048] (2) Earth leakage determination process S2 In the leakage current determination step S2, the determination unit 130 determines whether or not it has received leakage current information from the detection unit 120. If it has not received leakage current information from the detection unit 120, the determination unit 130 notifies that there is "no leakage current" (see S8) and terminates the diagnostic operation (No in S2). If it is determined that there is "no leakage current", it is preferable for the on-board battery system 1 to perform the diagnostic operation again after a predetermined period of time has elapsed. On the other hand, if it has received leakage current information from the detection unit 120, the determination unit 130 stores the leakage current information in the non-volatile memory of the storage area and proceeds to the leakage current notification step S3 (see Yes in S2). As will be described in more detail later, the leakage current information stored in the non-volatile memory remains until the processing to address the leakage current (inspection, repair, etc.) is completed.
[0049] (3) Earth leakage notification process S3 Next, in the leakage current notification process S3, the notification unit 400 notifies the user of the leakage current information. Specifically, the determination unit 130 transmits the leakage current information to the notification unit 400 via the communication means 150. The notification unit 400 then notifies the user of the leakage current information through voice and image display. This encourages the user to voluntarily stop and evacuate, thereby more effectively reducing the risks associated with the leakage current. Furthermore, by notifying the user of the leakage current information in advance, it is also possible to encourage inspection and repair of the power module 10.
[0050] (4) Acquisition process S4 Next, in acquisition step S4, the acquisition unit 110 acquires the degradation progress D of the power module 10 based on the usage status of the power module 10. As mentioned above, the method for acquiring the degradation progress D can be set in advance by the user. For example, "Degradation progress D of the power module 10" may be the degradation progress of a pre-set component, the degradation progress of the component with the most advanced degradation, or the degradation progress of the component in which leakage current was detected.
[0051] (5) Lifespan determination process S5 In the lifespan determination process S5, the degradation progression D of the power module 10 is compared with a pre-set assumed lifespan L. If the degradation progression D is less than or equal to the assumed lifespan L (D ≤ L), it is determined that the lifespan of the power module 10 has not yet expired, and the vehicle can continue to run. In this case, the determination unit 130 terminates the diagnostic operation (No. in S5). If it is determined that "there is a leakage current, but the lifespan has not yet expired," it is preferable for the on-board battery system 1 to perform the diagnostic operation again after a predetermined period has elapsed. This prevents the power module 10 from expiring and causing a high-risk malfunction between the time a leakage current occurs and the time the vehicle is taken to a repair shop.
[0052] On the other hand, if the degradation progression D exceeds the expected lifespan L in the lifespan determination process S5 (D>L), the power module 10 has reached the end of its lifespan and is experiencing electrical leakage. In this case, it is determined that it is difficult to continue driving the vehicle because there is a risk of high-risk abnormalities such as smoke or fire due to the intrusion of moisture from the outside. In this case, the determination unit 130 transmits the lifespan termination determination result (D>L) to the notification unit 400 and the stop-use unit 140, and proceeds to the stop preparation process S6 (see Yes in S5).
[0053] (6) Stop preparation process S6 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 evacuation time and informs them that the emergency stop will be implemented after the evacuation time has elapsed. This allows the user to voluntarily stop and evacuate before the emergency stop, thereby preventing accidents caused by the emergency stop.
[0054] (7) Stopping process S7 In the shutdown process S7, the power supply from the power module 10 to the power load 200 is stopped. Specifically, the shutdown unit 140 transmits a shutdown signal to the contactor 40 after the elapsed time. Upon receiving the shutdown signal, the contactor 40 is forcibly turned OFF. This cuts off the power supply from the power source 20 to the power load 200.
[0055] As described above, the in-vehicle battery system 1 according to this embodiment is configured to stop power supply to the vehicle when a power leakage is detected and the power module 10 has reached the end of its lifespan. This prevents high-risk abnormalities such as smoke and fire. Furthermore, if the power module 10 has not reached the end of its lifespan, the in-vehicle battery system 1 does not stop power supply to the vehicle simply by detecting a power leakage. This reduces the risk of sudden vehicle braking. As described above, the in-vehicle battery system 1 according to this embodiment can suitably reduce the risks associated with power leakage in the power module 10.
[0056] C. Control operation during restart Furthermore, it is preferable that the on-board battery system 1 is configured to limit the power supply to the power load 200 if a short circuit is detected during the previous run. This prevents high-risk malfunctions from occurring after driving resumes, thus enabling the construction of an on-board battery system 1 with superior safety. A detailed explanation follows below.
[0057] Figure 5 is a flowchart illustrating the control of the in-vehicle battery system 1 at the start of driving according to the first embodiment. As shown in Figure 5, this control method at the start of driving includes a record reference step S11, a leakage current detection step S12, a start / stop step S13, and a start-up step S14.
[0058] (1) Record reference process S11 In the record 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 transmitted from the detection unit 120 is stored as non-volatile memory in the storage area of the determination unit 130. The determination unit 130 reads this non-volatile memory when the vehicle starts running.
[0059] (2) Earth leakage determination step S12 In the leakage detection process S12, the determination unit 130 determines whether or not a leakage current was detected by the detection unit 120 during the previous run when the vehicle is started. If leakage current information is confirmed in the non-volatile memory, the determination unit 130 proceeds to the start / stop process S13 (see Yes in S2). On the other hand, if no leakage current information is confirmed, the control process proceeds to the start-up process S14 (see No in S2).
[0060] (3) Start / stop process S13 In the start-up / shutdown process S13, the deactivation unit 140 stops the use of power from the power module 10 to the power load 200. In this embodiment, the deactivation unit 140 is configured to control the contactor 40 to turn off the connection between the power supply 20 and the power load 200. As described above, the leakage information in the non-volatile memory remains until action is taken to address the leakage (inspection, repair, etc.). Therefore, if leakage information is confirmed in the leakage detection process S12, it is determined that a leakage was detected during the previous run and that no action has been taken to address the leakage. In this case, the deactivation unit 140 stops the use of power to the power load 200 and interrupts the restart of the vehicle. This prevents high-risk malfunctions from occurring after the vehicle resumes operation.
[0061] (4) Start-up process S14 In the startup process S14, the deactivation unit 140 starts supplying power from the power module 10 to the power load 200. If no leakage information is detected in the leakage detection process S12, it is determined that no leakage was detected during the previous run, or that appropriate measures were taken to address the leakage. In this case, since the possibility of a high-risk abnormality occurring after restarting the run is low, the deactivation unit 140 turns on the contactor 40 and starts restarting the vehicle. After this, the vehicle can be driven according to the normal procedure.
[0062] <Other Embodiments> The first embodiment of the leakage current detection method disclosed herein has been described above. It should be noted that the above-described embodiment is not intended to limit the leakage current detection method disclosed herein, and various aspects can be modified.
[0063] For example, the detection unit 120 in the first embodiment employs the configuration described in Japanese Patent Application Publication No. 2023-081523 so that a specific location of electrical leakage can be identified. However, the detection unit 120 is not limited to the above configuration and only needs to be able to detect whether or not there is electrical leakage in the power supply module 10. For example, the in-vehicle battery system 1 may start determining whether the degradation progression D exceeds the expected lifespan L when electrical leakage is detected anywhere in the conductive path 30 from the power supply module 10 to the power load 200. Even in such a case, the risks associated with electrical leakage in the power supply module 10 can be appropriately reduced.
[0064] Furthermore, the power module 10 in the first embodiment includes a waterproof case 50 that houses the power supply 20, the conductive path 30, and the contactor 40. However, the waterproof case 50 is not an essential component in the technology disclosed herein. For example, if each component of the power module 10 (power supply 20, conductive path 30, contactor 40) is individually waterproofed, there is no need to provide the waterproof case 50. In this case, the expiration date of the waterproofing treatment for each component may be defined as the "expected lifespan L of the battery module."
[0065] Furthermore, in the first embodiment, the deactivation unit 140 transmits a stop signal to the contactor 40 after a time has elapsed following the determination of the end of life from the determination unit 130. However, this configuration is not an essential requirement of the technology disclosed herein. For example, when the deactivation unit 140 receives the determination of the end of life from the determination unit 130, it may transmit a stop signal to the contactor 40 with a time delay, such as "turning off the contactor 40 after the time has elapsed." Even if such a configuration is adopted, time can be secured for the user to evacuate from the vehicle. Alternatively, when the deactivation unit 140 receives the determination of the end of life from the determination unit 130, it may stop power use without providing a time for evacuation. Even after power use is stopped, the vehicle will continue to travel a certain distance by inertia, so accidents due to sudden stops can be sufficiently suppressed.
[0066] Furthermore, in the in-vehicle battery system 1 according to the first embodiment, the power supply from the power module 10 to the power load 200 is cut off by turning off 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, control of the contactor 40 is not essential in the technology disclosed herein. For example, when a leakage current is detected by the detection unit 120 and the determination unit 130 determines that the degradation progression D exceeds the expected lifespan L, the deactivation unit 120 may transmit an emergency stop signal to the vehicle's control unit (ECU 300). Even with such a configuration, the use of power from the power module 10 to the power load 200 can be stopped, and the vehicle can be stopped from running.
[0067] The technologies disclosed herein have been described in detail above with reference to specific embodiments, but these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the embodiments described above. In other words, the technologies disclosed herein encompass the forms described in items 1 to 7 below.
[0068] [Item 1] A power module connected to the vehicle's power load, A control device for controlling the charging and discharging of the power module and Equipped with, The control device is An acquisition unit that acquires the degree of deterioration of the power supply module based on the usage status of the power supply module, A detection unit for detecting the presence or absence of leakage current in the power supply module, When a leakage current is detected by the detection unit, a determination unit determines whether the degree of deterioration exceeds a predetermined assumed lifespan, When the determination unit determines that the degree of deterioration exceeds the expected lifespan, the deactivation unit stops the power supply from the power module to the power load. An in-vehicle battery system equipped with [features / equipment].
[0069] [Item 2] The aforementioned power supply module is Power supply and A conductive path connecting the power supply and the power load, A contactor is provided in the aforementioned conductive path and switches the connection between the power supply and the power load ON / OFF. It has at least the following features: The vehicle battery system according to item 1, wherein the stop-use unit controls the contactor to turn off the connection between the power supply and the power load when the determination unit determines that the degree of deterioration has exceeded the expected lifespan.
[0070] [Item 3] The automotive battery system according to item 2, wherein the power module further comprises a waterproof case housing the power supply, the conductive path, and the contactor.
[0071] [Item 4] The vehicle battery system described in item 3, wherein the acquisition unit considers the degree of deterioration of the waterproof case as the degree of deterioration of the power module.
[0072] [Item 5] The vehicle battery system according to any one of items 1 to 4, wherein the acquisition unit acquires the degree of degradation of multiple components among the components of the power module, and considers the degree of degradation of the component with the most advanced degree of degradation as the degree of degradation of the power module.
[0073] [Item 6] An in-vehicle battery system according to any one of items 1 to 5, further comprising a notification unit that notifies the user of a leakage current when a leakage current is detected by the detection unit.
[0074] [Item 7] The vehicle battery system according to any one of items 1 to 6, wherein the degree of degradation is calculated based on at least one selected from the group consisting of the total operating time of the vehicle battery system, the total mileage of the vehicle, and the total charge / discharge current of the power module.
[0075] [Item 8] The vehicle battery system according to any one of items 1 to 7, wherein the deactivation unit, when the determination unit determines that the degree of deterioration exceeds the expected lifespan, stops the use of power from the power module to the power load after a predetermined evacuation period has elapsed.
[0076] [Item 9] The determination unit determines, when the vehicle is started, whether or not a short circuit was detected by the detection unit during the previous run. The vehicle battery system according to any one of items 1 to 8, wherein the deactivation unit stops the use of power from the power module to the power load when the determination unit determines that a short circuit was detected during the previous run. [Explanation of symbols]
[0077] 1. Vehicle-mounted battery system 10 Power Modules 20 Power supply 30 Conductive Path 40 Contactors 50 Waterproof Cases 100 Control device 110 Acquisition Department 120 Detection unit 130 Judgment section 140 Out of use section 150 Communication methods 200 Power load 300 ECU 400 Notification Department
Claims
1. A power module connected to the vehicle's power load, A control device for controlling the charging and discharging of the power module and Equipped with, The control device is An acquisition unit that acquires the degree of deterioration of the power supply module based on the usage status of the power supply module, A detection unit for detecting the presence or absence of leakage current in the power supply module, When a leakage current is detected by the detection unit, a determination unit determines whether the degree of deterioration exceeds a predetermined assumed lifespan, When the determination unit determines that the degree of deterioration exceeds the expected lifespan, the deactivation unit stops the power supply from the power module to the power load. An in-vehicle battery system equipped with [features / equipment].
2. The aforementioned power supply module is Power supply and A conductive path connecting the power supply and the power load, A contactor is provided in the aforementioned conductive path and switches the connection between the power supply and the power load ON / OFF. It has at least the following features: The vehicle battery system according to claim 1, wherein the stop-use unit controls the contactor to turn off the connection between the power supply and the power load when the determination unit determines that the degree of deterioration has exceeded the expected lifespan.
3. The automotive battery system according to claim 2, wherein the power module further comprises a waterproof case housing the power supply, the conductive path, and the contactor.
4. The vehicle battery system according to claim 3, wherein the acquisition unit considers the degree of deterioration of the waterproof case as the degree of deterioration of the power module.
5. The vehicle battery system according to claim 1, wherein the acquisition unit acquires the degree of deterioration of multiple components among the components of the power module, and considers the degree of deterioration of the component with the most advanced degree of deterioration as the degree of deterioration of the power module.
6. The in-vehicle battery system according to claim 1, further comprising a notification unit that notifies the user of a leakage current when a leakage current is detected by the detection unit.
7. The vehicle battery system according to claim 1, wherein the degree of degradation is calculated based on at least one selected from the group consisting of the total operating time of the vehicle battery system, the total mileage of the vehicle, and the cumulative charge-discharge current of the power module.
8. The vehicle battery system according to claim 1, wherein the deactivation unit, when the determination unit determines that the degree of deterioration exceeds the expected lifespan, stops the use of power from the power module to the power load after a predetermined evacuation period has elapsed.
9. The determination unit determines, when the vehicle is started, whether or not a short circuit was detected by the detection unit during the previous run. The vehicle battery system according to any one of claims 1 to 8, wherein the deactivation unit stops the use of power from the power module to the power load when the determination unit determines that a short circuit was detected during the previous run.