vehicle

Abstract

To provide a vehicle that appropriately detects an electric leakage when a plurality of electric leakage detection devices is mounted.SOLUTION: An ECU executes: a step (S100) of obtaining resistance values of insulation resistance of battery packs and of a vehicle body; a step (S106) of determining that electric leakage occurs in the battery pack when the resistance value of the insulation resistance of any of the battery packs is equal to or less than a threshold α (NO in S102); a step (S114) of determining that electric leakage occurs in the vehicle body when the resistance values of the insulation resistance of all of the battery packs are greater than the threshold (YES in S102) and when the resistance value of the insulation resistance of the vehicle body is equal to or less than the threshold; and a step (S112) of turning on each SMR, when the resistance values of the insulation resistance of all of the battery packs and of the vehicle body are greater that the threshold (YES in S102 and YES in S104).SELECTED DRAWING: Figure 4

Description

[[Technical Field]]

[0001] The present disclosure relates to a vehicle including replaceable batteries. [[Background Art]]

[0002] For example, Japanese Patent Laid-Open No. 2015-082350 (Patent Document 1) discloses a configuration where a battery management device provided in a battery pack is communicably connected to various electronic control devices on the vehicle side via a CAN (Controller Area Network) communication network, and transmits information indicating a leakage detection result and the like. [[Prior Art Documents]] [[Patent Documents]]

[0003] [[Patent Document 1]] Japanese Patent Laid-Open No. 2015-082350 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0004] However, for example, in a vehicle equipped with replaceable batteries, a plurality of leakage detection devices for detecting leakage may be mounted on both the battery side and the vehicle side. Therefore, when leakage detection is performed in parallel by each leakage detection device, they may interfere with each other and cannot appropriately detect leakage.

[0005] The present disclosure has been made to solve the above-described problem, and an object thereof is to provide a vehicle that appropriately detects leakage when a plurality of leakage detection devices are mounted. [[Means for Solving the Problem]]

[0006] A vehicle relating to a certain aspect of this disclosure comprises a vehicle body, a battery detachable from the vehicle body, a first detection device provided on the battery for detecting the presence or absence of a ground fault, and a second detection device provided on the vehicle body for detecting the presence or absence of a ground fault. Each of the first and second detection devices detects the presence or absence of a ground fault when the battery and the electrical equipment of the vehicle body are electrically disconnected, which is a first state. The second detection device detects the presence or absence of a ground fault when the battery and the electrical equipment are electrically connected, which is a second state.

[0007] In this configuration, in the first state, the first and second detection devices detect the presence or absence of leakage current between the battery and the vehicle's electrical equipment, respectively, and in the second state, the second detection device detects the presence or absence of leakage current between the battery and the vehicle's electrical equipment. Therefore, leakage current detection is performed according to the battery's installation / removal state, making it possible to identify the location of leakage current while avoiding interference. Consequently, leakage current can be appropriately detected even when multiple leakage current detection devices are installed.

[0008] In one embodiment, the second detection device detects the presence or absence of a ground fault while the detection of the presence or absence of a ground fault using the first detection device is stopped in the second state.

[0009] In this way, interference from other detection devices can be avoided, and leakage current can be detected using the second detection device.

[0010] In one further embodiment, the vehicle is further equipped with a control device that acquires information about the detection results of whether or not there is a ground fault from the first detection device and the second detection device. When the second state is reached, the control device acquires the execution status of ground fault detection and uses the acquired execution status to make either a request for ground fault detection by the first detection device or a request for stopping ground fault detection.

[0011] In this way, interference between leakage current detection by the first detection device and leakage current detection by the second detection device can be avoided, allowing for highly accurate leakage current detection. [Effects of the Invention]

[0012] According to this disclosure, it is possible to provide a vehicle that can properly detect electrical leakage when multiple leakage detection devices are installed. [Brief explanation of the drawing]

[0013] [Figure 1] This figure shows an example of the configuration of a vehicle according to this embodiment. [Figure 2] This figure shows an example of the configuration of a battery replacement system for replacing battery packs. [Figure 3] This is a flowchart illustrating an example of how to replace a battery pack. [Figure 4] Figure 3 is a flowchart showing an example of the leakage current detection process. [Figure 5] This flowchart shows an example of the leakage detection process when Ready-Off. [Figure 6] This flowchart shows an example of the process for setting the state of leakage current detection. [Modes for carrying out the invention]

[0014] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated.

[0015] Figure 1 shows an example of the configuration of a vehicle 100 according to this embodiment. Referring to Figure 1, the vehicle 100 comprises a vehicle body 10 and battery packs 20A and 20B. The vehicle body 10 is the part of the vehicle 100 other than the battery packs 20A and 20B. The vehicle body 10 is equipped with a vehicle drive system that serves as a drive source. The vehicle drive system includes an MG (Motor Generator) 11a and an inverter 11b. The vehicle drive system is configured to drive the vehicle 100 using the power output from each of the battery packs 20A and 20B. The battery packs 20A and 20B are configured to be connected in parallel to the inverter 11b. The vehicle 100 is, for example, an electric vehicle without an internal combustion engine. However, it is not limited to this, and the vehicle 100 may be a plug-in hybrid vehicle equipped with an internal combustion engine, or another electric vehicle. In this embodiment, since the battery packs 20A and 20B have the same configuration, they will be referred to as "battery pack 20" below unless otherwise distinguished.

[0016] The vehicle body 10 includes circuits CR11 and CR12. The battery pack 20 includes circuits CR21 and CR22. Circuit CR12 includes an auxiliary battery 17. Circuit CR21 includes a battery 21. The battery 21 is a secondary battery, such as a lithium-ion battery, nickel-metal hydride battery, or sodium-ion battery. The type of secondary battery may be a liquid-type secondary battery or an all-solid-state secondary battery. Multiple secondary batteries may form a battery pack. The auxiliary battery 17 corresponds to a low-voltage power supply that outputs power at a voltage lower than the voltage of the battery 21. A DC / DC converter 16 is provided between circuits CR11 and CR12.

[0017] Circuit CR11 within the vehicle body 10 includes an MG11a, an inverter 11b, a DC charging relay 14a, a DC inlet 14b, an AC charger 15a, and an AC inlet 15b. Circuit CR11 is also equipped with a leakage current detector 12. Circuit CR21 within the battery pack 20 is equipped with a BMS (Battery Management System) 22a and a leakage current detector 22b.

[0018] The vehicle body 10 further includes a terminal T11A to / from which the battery pack 20A can be attached / detached, a terminal T11B to / from which the battery pack 20B can be attached / detached, a parallel circuit CR13 connecting the terminal T11A and the terminal T11B in parallel, and an SMR (System Main Relay) 13 disposed between the parallel circuit CR13 and a vehicle drive device (inverter 11b). The circuit CR11 is connected to each of the terminals T11A and T11B via the SMR 13 and the parallel circuit CR13. Each of the battery packs 20A and 20B includes a terminal T21 to / from which the vehicle body 10 can be attached / detached, and an SMR 23 disposed between the terminal T21 and the circuit CR21. The circuit CR21 is connected to the terminal T21 via the SMR 23.

[0019] The terminal T21 of the battery pack 20A is connected to the terminal T11A of the vehicle body 10. The SMR 23 of the battery pack 20A is disposed between the terminal T21 and the battery cell 21 in the battery pack 20A. The terminal T21 of the battery pack 20B is connected to the terminal T11B of the vehicle body 10. The SMR 23 of the battery pack 20B is disposed between the terminal T21 and the battery cell 21 in the battery pack 20B. Each relay enables easy and appropriate switching between connection and disconnection between the inverter 11b and each of the battery packs 20A and 20B.

[0020] The vehicle body 10 further includes a terminal T12A to / from which the battery pack 20A can be attached / detached, and a terminal T12B to / from which the battery pack 20B can be attached / detached. The circuit CR12 in the vehicle body 10 is connected to each of the terminals T12A and T12B via the parallel circuit CR13. The parallel circuit CR13 connects the terminal T12A and the terminal T12B in parallel. A communication line CL1 (broken line in FIG. 1) in the vehicle body 10 is also connected to each of the terminals T12A and T12B. Each of the battery packs 20A and 20B further includes a terminal T22. In each of the battery packs 20A and 20B, the circuit CR22 and a communication line CL2 (broken line in FIG. 1) are connected to the terminal T22.

[0021] The auxiliary battery 17 supplies electric power for driving auxiliary devices mounted on the vehicle 100. The auxiliary battery 17 outputs DC power to the circuit CR12. The circuit CR12 further includes ECUs 18a, 18b, 18c, 18d in addition to the auxiliary battery 17. The circuit CR22 further includes ECUs 28a, 28b. The auxiliary battery 17 supplies electric power to each of ECUs 18a to 18d, 28a, 28b connected to a low-voltage power supply line, for example.

[0022] The ECU 18a corresponds to a control device (EV-ECU) that supervises various types of control related to the vehicle 100. The ECU 18b corresponds to a control device (Plg-ECU) that detects respective states of a DC inlet 14b and an AC inlet 15b. The ECU 18c corresponds to a control device (Bat-C-ECU) that controls a DC charging relay 14a and an AC charger 15a. The ECU 18d corresponds to a control device (first leakage ECU) that monitors an electric leakage state of the circuit CR11. The ECU 28a corresponds to a control device (Bat-ECU) that monitors a state of a battery 21 and controls an SMR 23. The ECU 28b corresponds to a control device (second leakage ECU) that monitors an electric leakage state of the circuit CR21.

[0023] Each ECU includes a processor and a storage device. The storage device is configured to be capable of storing stored information. In addition to programs, various types of information used in the programs are stored in the storage device. In the present embodiment, various types of control are executed by the processor executing programs stored in the storage device. However, these processes may be executed only by hardware (an electronic circuit) without using software.

[0024] In the vehicle 100, the respective ECUs are communicatively connected to each other via an in-vehicle network (CAN, for example). The ECU 18a acquires information from other ECUs, controls an inverter 11b, a DC / DC converter 16, and SMRs 13, 23, and transmits control commands to the ECU 18c and the ECU 28a.

[0025] The leakage current detector 12 detects the leakage current state of circuit CR11 (for example, insulation resistance) and outputs the detection result to ECU18d. The BMS22a detects the state of battery 21 (current, voltage, temperature, etc.) and outputs the detection result to ECU28a. The leakage current detector 22b detects the leakage current state of circuit CR21 and outputs the detection result to ECU28b. ECU18a acquires information indicating the battery state and leakage current state from ECU18d, 28a, and 28b.

[0026] The DC / DC converter 16 transforms the DC power between circuits CR11 and CR12. Specifically, the DC / DC converter 16 steps down the DC power from battery 21 and outputs it to the auxiliary battery 17 and other auxiliary devices connected to circuit CR12. The capacity of battery 21 is greater than the capacity of auxiliary battery 17.

[0027] The battery pack 20A and / or battery pack 20B are mounted on the vehicle body 10 by connecting terminals T21 and T22 of the battery pack 20A to terminals T11A and T12A, or by connecting terminals T21 and T22 of the battery pack 20B to terminals T11B and T12B, thereby completing the vehicle 100. In the vehicle 100, the communication line CL1 of the vehicle body 10 is connected to the communication line CL2 of the battery pack 20A and the communication line CL2 of the battery pack 20B. These communication lines constitute the in-vehicle network of the vehicle 100.

[0028] Each of the DC inlet 14b and AC inlet 15b has a terminal for detecting whether the charging cable (plug) is connected or not, and outputs a signal to ECU 18b indicating whether the charging cable is connected or not. ECU 18a obtains information indicating the inlet status from ECU 18b and sends a control command to ECU 18c. The AC charger 15a performs AC / DC conversion. Plug-in charging of the battery 21 is performed through the cooperation of ECUs 18a to 18c.

[0029] The vehicle body 10 further includes an HMI (Human Machine Interface) 19a and a communication device 19b. The HMI 19a and the communication device 19b are also powered by an auxiliary battery 17. The HMI 19a includes an input device and a display device installed in the vehicle cabin. The HMI 19a may also include a touch panel display. The input device outputs a signal to the ECU 18a in response to user input. The communication device 19b is configured to communicate wirelessly with the server 380 (Figure 2), which will be described later. The vehicle body 10 is also equipped with various sensors (typically referred to as on-board sensors 19c), which are not shown. The ECU 18a is configured to acquire detection results from these sensors directly or via other ECUs.

[0030] In this embodiment, the HMI 19a includes a start switch. Generally, a start switch is referred to as a "power switch" or "ignition switch." By operating the start switch, the user of the vehicle 100 can start or stop the control system of the vehicle 100 (including each ECU), or put the vehicle 100 into a Ready-ON state or a Ready-OFF state.

[0031] The Ready-ON state is when the voltage from at least one of the batteries 21 of the battery packs 20A and 20B connected to the vehicle body 10 is applied to the CR11 circuit of the vehicle body 10. In the Ready-ON state, the SMR13 is closed, and at least one of the SMR23 of the battery packs 20A and 20B is also closed, and power is supplied to the vehicle drive system (MG11a and inverter 11b) from the battery 21 corresponding to the closed SMR23. The Ready-OFF state is when the voltage from the batteries 21 is not applied to the CR11 circuit. In the Ready-OFF state, the SMR13 is open, and no power is supplied to the vehicle drive system from either of the batteries 21 of the battery packs 20A and 20B.

[0032] The battery packs 20A and 20B installed in vehicle 100 are replaceable with other battery packs. Figure 2 shows an example of the configuration of a battery exchange system for exchanging battery packs. The battery exchange system 300 shown in Figure 2 is implemented, for example, in a battery exchange station.

[0033] Referring to Figure 2, the battery replacement system 300 is configured to remove a battery pack mounted on the vehicle 100 from the vehicle body 10 and install another battery pack on the vehicle body 10. Below, an example is described in which two battery packs (battery packs 20A and 20B) are removed from the vehicle 100 simultaneously and two replacement battery packs are installed on the vehicle 100 simultaneously. However, this is not limited to this, and battery packs 20A and 20B may be replaced one at a time. Furthermore, the battery pack replacement includes the case in which only one battery pack is installed in either the mounting position of battery pack 20A or battery pack 20B after both battery packs have been removed.

[0034] Hereinafter, the two battery packs recovered from vehicle 100 will be referred to as "battery packs B11 and B12," and the two battery packs installed in vehicle 100 in place of battery packs B11 and B12 will be referred to as "battery packs B21 and B22." Each of battery packs B11, B12, B21, and B22 has the battery pack configuration shown in Figure 1. Battery packs B21 and B22 function as battery packs 20A and 20B (Figure 1) in vehicle 100.

[0035] More specifically, the battery exchange system 300 comprises a first storage device 310, a second storage device 320, a recovery device 330, a filling device 340, an exchange device 350, a server 380, and a display device 390. The first storage device 310 stores multiple battery packs to be supplied to vehicles. In addition to a pack storage section (e.g., a storage compartment), the first storage device 310 includes a charger and a supply device. The second storage device 320 stores multiple battery packs recovered from multiple vehicles. In addition to a pack storage section, the second storage device 320 includes an inspection device and a sorting device. The server 380 comprises a processor, a memory device, and a communication device, and functions as a control device. The memory device stores information about each battery pack present in the battery exchange system 300 (e.g., specification information), distinguished by battery pack identification information (pack ID). The display device 390 displays information according to instructions from the server 380.

[0036] The battery replacement method will be described below using Figures 1 to 4. Figure 3 is a flowchart showing an example of a battery pack replacement method. Figure 4 is a flowchart showing an example of the leakage current detection process in Figure 3. After the vehicle 100 is parked in a predetermined area within the battery replacement station, the ECU 18a starts the processing flow S11 to S14 shown in Figure 3. This processing flow may also be started in response to a request from the user terminal of the vehicle 100 or from an input device within the vehicle 100. The ECU 18a and the server 380 are configured to enable wireless communication.

[0037] In step 10 (hereinafter referred to as step S), the ECU 18a sends a signal to the server 380 requesting the replacement of the battery pack (hereinafter referred to as the "replacement request signal"). The replacement request signal includes the identification information of the vehicle 100 (vehicle ID) and the specification information of each battery pack (battery packs B11, B12) installed in the vehicle 100. The replacement request signal may also include the specification information of the vehicle body 10 in place of or in addition to the specification information of battery packs B11, B12.

[0038] In S12, ECU18a determines whether or not the battery pack has been replaced. If the battery pack replacement is not completed (NO in S12), the determination in S12 is repeated.

[0039] When server 380 receives the above exchange request signal, it starts the processing flow S31 to S33 in Figure 3.

[0040] In S31, the server 380 selects a battery pack from the battery packs (inventory) held by the first storage device 310 that matches the specifications of the vehicle 100 indicated by the replacement request signal. If it is determined that there is no battery pack in inventory that matches the specifications of the vehicle 100, the server 380 may display a predetermined message on the display device 390 and abort the battery replacement process. If a battery pack is selected in S31, the process moves to S32.

[0041] In S32, the server 380 controls the replacement device 350 to remove the battery packs B11 and B12 from the vehicle body 10. This separates the vehicle body 10 from the battery packs B11 and B12. The process then moves to S33.

[0042] In S33, the server 380 controls the charger of the first storage device 310 so that the battery pack B21 or B22 selected in S31 is charged. However, the charging timing can be changed as appropriate. Charged battery packs may also be filled into the first storage device 310. When charging is complete, the server 380 controls the supply device of the first storage device 310 so that the battery pack B21 or B22 is transported (supplied) from the first storage device 310 to the exchange device 350. Subsequently, the server 380 controls the exchange device 350 so that the battery pack B21 or B22 is installed on the vehicle body 10. At this time, the SMR23 of the installed battery pack B21 or B22 is in the open state. After that, the server 380 sends a signal to the ECU 18a indicating that the battery pack installation is complete (hereinafter referred to as the "exchange completion signal").

[0043] Figure 2 shows an example where the battery pack is removed and installed at different locations. The vehicle position may be adjusted before the battery pack is removed, before the battery pack is installed, or both. A transport device (e.g., a conveyor-type transport device) or transport robot, not shown, may move the vehicle. The battery pack may be removed and installed at the same location. The battery pack may be replaced (removed and installed) while the vehicle is stationary. The transport methods for the recovery device 330, supply device, and filling device 340 are also arbitrary. These transport methods may be conveyor-type or utilize a transport robot. In addition, the battery pack (energy storage device) may be replaced manually by the user without communication between the battery replacement system (station) and the vehicle.

[0044] For example, when battery packs B21 and B22 are attached to the vehicle body 10, terminals T21 and T22 of battery pack B21 are connected to terminals T11A and T12A of the vehicle body 10, respectively, and terminals T21 and T22 of battery pack B22 are connected to terminals T11B and T12B of the vehicle body 10, respectively, resulting in the connection state shown in Figure 1. When battery packs B21 and B22 are attached to the vehicle body 10, circuits CR12 and CR22 and communication lines CL1 and CL2 are connected between the vehicle body 10 and battery packs B21 and B22, respectively. Then, the processing flow S21 to S24 shown in Figure 3 is started in each of the battery packs B21 and B22.

[0045] In S21, the ECU28a is started by power supplied from the power source (auxiliary battery 17) inside the vehicle body 10. The process then moves to S22.

[0046] In S22, ECU28a transmits information indicating the state of the battery pack (hereinafter referred to as "state information") to ECU18a. The state information includes, for example, information about the current voltage of battery 21 detected by BMS22a. The state information may also include information about the leakage detection result (leakage state) detected by the leakage detector 22b and leakage ECU28b. The voltage of battery 21 may fluctuate according to the State of Charge (SOC) of battery 21. SOC is, for example, the ratio of the current amount of charge to the amount of charge in a fully charged state, expressed as 0 to 100%. The process then moves to S23.

[0047] In S23, ECU28a determines whether or not it has received an SMR ON command from the vehicle body 10. ECU28a keeps SMR23 in the open state and waits for an SMR ON command from the vehicle body 10 in S23. When ECU28a receives an SMR ON command (YES in S23), processing moves to S24.

[0048] At S24, ECU28a switches SMR23 from the open state (disconnected state) to the closed state (connected state).

[0049] Meanwhile, when the battery packs B21 and B22 are installed on the vehicle body 10, the ECU 18a receives a replacement completion signal (S33) from the server 380. As a result, it is determined to be YES in S12, and the process proceeds to S13.

[0050] In S13, ECU18a determines whether or not it has received the above status information from ECU28a of battery pack B21 or B22. If ECU18a receives the above status information from the battery pack (YES in S13), the process moves to S14.

[0051] In S14, ECU18a performs a ground fault detection process. The ground fault detection process is explained below using the flowchart in Figure 4.

[0052] In S100, ECU18a obtains the insulation resistance values ​​of each battery pack 20A, 20B and the vehicle body 10. ECU18a may obtain the insulation resistance values ​​from the status information received from ECU28a of battery packs 20A and 20B, or it may obtain the insulation resistance values ​​from ECU28b. Furthermore, ECU18a obtains the insulation resistance value of the vehicle body 10 from ECU18d. The process then moves to S102.

[0053] In S102, ECU18a determines whether the insulation resistance values ​​of each battery pack 20A and 20B are greater than the threshold value α. The threshold value α is a predetermined value used to determine the presence or absence of leakage current, and is determined through experiments, etc. If it is determined that both are greater than the threshold value α (YES in S102), the process moves to S104.

[0054] In S104, ECU18a determines whether the insulation resistance of the vehicle body 10 is greater than threshold α. As the threshold α is as described above, a detailed explanation will not be repeated. Note that the threshold used in the process of S102 and the threshold used in the process of S104 may be different values. If it is determined that the value is greater than threshold α (YES in S104), the process moves to S110. Note that if at least one of the insulation resistance values ​​of battery packs B21 and B22 is less than or equal to threshold α (NO in S102), the process moves to S106.

[0055] In S106, ECU18a determines that there is a leakage current in the battery packs 20A and 20B whose insulation resistance value is below the threshold α. ECU18a sets a flag associated with the pack ID of the battery pack whose insulation resistance value is below the threshold α to the ON state, for example. The process then moves to S108.

[0056] At S108, ECU18a executes a first fail-safe process. The first fail-safe process may include at least one of the following: a process to control the SMR23 of the battery pack with the pack ID corresponding to the ON state flag to the OFF state; a process to prevent the SMR23 from switching to the ON state; a process to control the SMR13 to the OFF state; and a process to prevent the SMR13 from switching to the ON state. The process is then terminated.

[0057] In S110, ECU18a sets the leakage detection for battery packs 20A and 20B to the off state. Specifically, ECU18a switches off the circuit (leakage detector 22b) that detects the resistance value of the insulation resistance of each battery pack 20A and 20B, making it impossible to detect leakage current (detection stopped state). The process then moves to S112.

[0058] In S112, ECU18a sets each SMR to the ON state. ECU18a sends an SMR ON command to SMR13 and SMR23 of battery packs 20A and 20B. After that, processing ends. If it is determined that the insulation resistance value of the vehicle body 10 is below the threshold α (NO in S104), processing moves to S114.

[0059] In S114, ECU18a determines that there is a ground fault on the vehicle body 10 side. ECU18a sets a flag to the ON state, for example, to indicate that there is a ground fault on the vehicle body 10 side. The process then moves to S116.

[0060] At S116, ECU18a executes a second fail-safe process. The second fail-safe process may include processes to control SMR13 to the off state, processes to prevent SMR13 from switching to the on state, and processes to prevent SMR23 of battery packs 20A and 20B from switching to the on state. The process is then terminated.

[0061] Furthermore, ECU18a may perform leakage current detection when Ready-OFF in each battery pack.

[0062] The following explains the leakage detection process when the device is in Ready-OFF mode, referring to Figure 5. Figure 5 is a flowchart showing an example of the leakage detection process when the device is in Ready-OFF mode.

[0063] In S200, ECU18a determines whether it is in Ready-OFF mode. ECU18a may determine it is in Ready-OFF mode if it has received an operation (off operation) on the start switch in Ready-ON mode, and has not received any further operation (on operation) on the start switch. If it is determined to be in Ready-OFF mode (YES in S200), the process moves to S202.

[0064] In S202, ECU18a turns off SMR13 and SMR23 of battery packs 20A and 20B. The process then moves to S204.

[0065] In S204, ECU18a sets the leakage detection for each battery pack 20A and 20B to the ON state. The process then moves to S206.

[0066] In S206, ECU18a obtains the insulation resistance values ​​from each battery pack 20A and 20B. The process then moves to S208.

[0067] In S208, ECU18a determines whether the insulation resistance values ​​of each battery pack 20A and 20B are greater than the threshold α. If it is determined that they are greater than the threshold α (YES in S208), the process moves to S210.

[0068] In S210, ECU18a determines that there is no leakage current in either battery pack 20A or 20B. The process then proceeds to S212.

[0069] In S212, ECU18a sets the leakage detection to the off state. After that, the process ends. If it is determined that the insulation resistance value of at least one of the battery packs 20A and 20B is below the threshold α (NO in S208), the process moves to S214.

[0070] In S214, ECU18a determines that there is a leakage current in battery packs whose insulation resistance value is below the threshold α. ECU18a sets a flag associated with the pack ID of the battery pack whose insulation resistance value is below the threshold α to the ON state, for example. The process then moves to S216.

[0071] At S216, ECU18a executes failsafe processing. Failsafe processing may include at least one of the following: processing to control the SMR23 of the battery pack with the pack ID corresponding to the ON state flag to the OFF state; processing to prevent the SMR23 from switching to the ON state; processing to control the SMR13 to the OFF state; and processing to prevent the SMR13 from switching to the ON state. The processing is then terminated.

[0072] In this way, in vehicle 100, when SMR13 is in an interrupted state during Ready-OFF, the presence or absence of a ground fault can be detected in each battery pack 20A, 20B.

[0073] Various types of information are communicated between the vehicle body 10 and each battery pack. Specifically, the ECU 28a transmits information to the vehicle body 10's ECU 18a regarding whether the leakage detection in each battery pack is on or off, and information regarding the resistance value of the insulation resistance. On the other hand, the ECU 18a transmits to the ECU 28a either a request to set the leakage detection to the on state or a request to set the leakage detection to the off state. The ECU 28a of each battery pack sets the leakage detection to either the on or off state in response to the request from the ECU 18a. Below, with reference to Figure 6, an example of the process by which the ECU 18a (vehicle body ECU) requests the ECU 28a (battery ECU) of each battery pack whether or not to perform leakage detection will be described. Figure 6 is a flowchart of an example of the process of setting the state of leakage detection.

[0074] As shown in Figure 6(A), for example, when the start switch is activated, ECU18a starts up, and as shown in Figure 6(a), ECU28a also starts up.

[0075] As shown in Figure 6(B), ECU 18a sets the leakage detection of the vehicle body 10 to the ON state (leakage detector 12 to the ON state) and starts communicating with ECU 28a. As shown in Figure 6(b), ECU 28a sets the leakage detection of the battery pack 20 to the ON state and transmits an execution status to ECU 18d indicating that the leakage detection is ON, as shown in Figure 6(c).

[0076] As shown in Figure 6(C), when the execution status is received in ECU18a, a request is made to ECU28a to turn off the leakage detection of the battery pack 20, as shown in Figure 6(D).

[0077] As shown in Figure 6(d), the detection request determination process is executed in ECU28a. The detection request determination process includes the steps of determining whether or not there is a request to turn on leakage detection (S300), setting leakage detection to the ON state if there is a request to turn on leakage detection (YES in S300) (S302), determining whether or not there is a request to turn off leakage detection if there is no request to turn on leakage detection (NO in S300) (S304), and setting leakage detection to the OFF state if there is a request to turn off leakage detection (YES in S304) (S306). Therefore, when a request to turn off leakage detection is received from ECU18a, leakage detection is set to the OFF state.

[0078] As shown in Figure 6(e), when the ECU28a transmits an execution status indicating that the leakage detection is in the off state, the ECU18a receives the execution status as shown in Figure 6(E). Subsequently, if the SMR13 is set to the off state during Ready-OFF, the ECU28a is requested to turn on the leakage detection in the battery pack 20, as shown in Figure 6(F).

[0079] As shown in Figures 6(f) and 6(g), the detection request determination process is executed in ECU28a, the leakage detection is set to the ON state, and after leakage detection is performed, ECU28a turns OFF. On the other hand, in ECU18a, the termination sequence is executed as shown in Figures 6(G) and 6(H), and ECU18a turns OFF. By setting the timing for turning on the leakage detection of battery packs 20A and 20B using the execution status, ECU18a can avoid interference between battery packs 20A and 20B and between battery pack 20 and the vehicle body 10 in leakage detection. For example, ECU18a sends the above-described request to ECU28a at the timing for turning on or off the leakage detection in the flowcharts of Figures 3 and 4. ECU18a may also request a change in the leakage detection state of battery packs 20A and 20B using the leakage detection state on the vehicle body 10 side.

[0080] As described above, with the vehicle 100 according to this embodiment, when the battery packs 20A and 20B and the electrical equipment of the vehicle body 10 are electrically disconnected, the presence or absence of leakage current between the battery packs 20A and 20B and the electrical equipment of the vehicle body 10 is detected by the ECU 28b and ECU 18d. Therefore, the presence or absence of leakage current in each of the battery packs 20A and 20B and the vehicle body 10 is detected with high accuracy. Furthermore, when the battery packs 20A and 20B and the electrical equipment of the vehicle body 10 are electrically connected, the presence or absence of leakage current between the battery packs 20A and 20B and the electrical equipment of the vehicle body 10 is detected by the ECU 18d. Since the leakage current detection of the battery packs 20A and 20B is set to the off state, it is possible to detect the presence or absence of leakage current when the battery packs 20A and 20B and the electrical equipment of the vehicle body 10 are connected, while avoiding interference between the leakage current detection using the ECU 28b and the leakage current detection using the ECU 18d of the battery pack 20. In this way, leakage detection is performed according to the attachment / detachment status of battery packs 20A and 20B, making it possible to identify the location of leakage while avoiding interference. Therefore, it is possible to provide a vehicle that can properly detect leakage even when multiple leakage detection devices are installed.

[0081] The following describes variations.

[0082] In the above-described embodiment, the vehicle 100 is shown as an example in which it is equipped with two battery packs 20A and 20B, but the number of battery packs can be one or three or more.

[0083] Furthermore, although the above-described embodiment explained the case where the entity executing the leakage current detection process is ECU18a as an example, the entity executing the leakage current detection process or the entity switching SMR13,23 is not limited to ECU18a, but may be, for example, ECU18d, or other ECUs mounted on the vehicle body 10.

[0084] Furthermore, the vehicle configuration shown in Figure 1 can be modified as appropriate. For example, the SMR13 on the vehicle body 10 may be omitted, or the SMR23 on the battery pack 20 may be omitted. Also, at least one of the DC inlet 14b and AC inlet 15b may be omitted, or they may be replaced with a single AC / DC common inlet. These inlets may be configured to allow bidirectional power transmission. The vehicle body may also perform external power supply (V2X: Vehicle to Everything) using the power output from the attached battery pack.

[0085] Furthermore, the above-mentioned modifications may be implemented by combining all or part of them as appropriate.

[0086] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0087] 10 vehicle bodies, 18a, 28a ECUs, 20A, 20B battery packs, 21 batteries, 23 SMRs, 300 battery replacement systems, 350 replacement devices.

Claims

1. The car body and A battery that can be attached to and detached from the vehicle body, The battery is provided with a first detection device for detecting the presence or absence of electrical leakage, The vehicle body is equipped with a second detection device that detects the presence or absence of electrical leakage, Each of the first detection device and the second detection device detects the presence or absence of a leakage current when the battery and the electrical equipment of the vehicle body are electrically disconnected, The vehicle includes a second detection device that detects the presence or absence of a leakage current when the battery and the electrical equipment are in a second state of being electrically connected.

2. The vehicle according to claim 1, wherein the second detection device detects the presence or absence of a leakage current in the second state and while the detection of the presence or absence of a leakage current using the first detection device is stopped.

3. The vehicle further includes a control device that acquires information regarding the detection results of the presence or absence of leakage current from the first detection device and the second detection device. The vehicle according to claim 1, wherein, when the control device is in the second state, it obtains the execution status of the leakage detection and uses the obtained execution status to make either a request for the first detection device to detect the leakage or a request to stop the leakage detection.

Images