Electric leakage detection device for vehicle

Abstract

To appropriately detect leakage of a high-voltage DC circuit in which a plurality of standardized battery packs are connected in series.SOLUTION: A leakage detection device for a vehicle is applied to a vehicle including a high-voltage DC circuit in which a plurality of battery packs are connected in series, and an insulation resistance part that insulates the high-voltage DC circuit from a ground on the vehicle. The leakage detection device includes a leakage detection circuit, a control unit, and a calculation unit. The electric leakage detection circuit is included in each of the plurality of battery packs and is a circuit for detecting voltage information including a voltage of the insulation resistance part. The control unit is included in each of the plurality of battery packs and controls the leakage detection circuit. The operation unit is mounted on the vehicle outside the plurality of battery packs and communicates with each of the plurality of battery packs. The operation unit determines whether or not there is electrical leakage in the high voltage DC circuit based on the voltage information received from the plurality of battery packs.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a leakage detection device for a vehicle equipped with a plurality of battery packs connected in series. [Background technology]

[0002] Patent Document 1 discloses a leakage detection device for detecting leakage in a battery. This leakage detection device estimates the voltage applied to the detection resistor after a transient response period based on the transient voltage applied to the detection resistor, and determines the presence or absence of leakage based on the estimated voltage.

[0003] Furthermore, Patent Document 2 discloses a battery management system for multiple battery packs. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-174326 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-015094 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, it is conceivable to include the leakage detection device described in Patent Document 1 together with a battery in a single battery pack. This allows batteries to be replaced individually, and results in a standardized battery pack having common hardware that enables a single battery pack to provide all necessary functions, including leakage detection. Furthermore, such standardized battery packs may be installed in a vehicle as multiple battery packs connected in series, depending on the vehicle's required performance. Therefore, it is desirable to be able to appropriately detect leakage in a high-voltage DC circuit in which multiple battery packs are connected in series. [Means for solving the problem]

[0006] A vehicle leakage detection device according to the present disclosure is applied to a vehicle including a high-voltage DC circuit in which multiple battery packs are connected in series and an insulation resistance unit that insulates the high-voltage DC circuit from a ground on the vehicle. The leakage detection device includes a leakage detection circuit, a control unit, and a calculation unit. The leakage detection circuit is included in each of the multiple battery packs and is a circuit for detecting voltage information including the voltage of the insulation resistance unit. The control unit is included in each of the multiple battery packs and controls the leakage detection circuit. The calculation unit is mounted on the vehicle outside the multiple battery packs and communicates with each of the multiple battery packs. The calculation unit determines the presence or absence of a leakage in the high-voltage DC circuit based on voltage information received from the multiple battery packs. [Effects of the Invention]

[0007] According to the present disclosure, a calculation unit installed in a vehicle outside of the battery packs determines whether or not there is a leakage current in a high-voltage DC circuit based on voltage information acquired using a leakage detection circuit included in each battery pack, thereby enabling appropriate detection of a leakage current even in a high-voltage DC circuit in which multiple standardized battery packs are connected in series. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing a functional configuration of a vehicle to which an electric leakage detection device according to an embodiment is applied; [Figure 2] 2 is a circuit diagram showing an example of the configuration of a leakage detection circuit included in each battery pack shown in FIG. 1. [Figure 3] 4 is a diagram for explaining a method for acquiring a positive detection voltage VRp and a negative detection voltage VRn. FIG. [Figure 4] 4 is a flowchart illustrating a leakage determination process according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0010] 1. Configuration of earth leakage detection device 1 is a block diagram showing the functional configuration of a vehicle 1 to which a leakage detection device according to this embodiment is applied. The vehicle 1 is an electrically powered vehicle such as a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), or a fuel cell electric vehicle (FCEV). The vehicle 1 includes a high-voltage DC circuit 2 and an insulation resistance unit 3.

[0011] The high-voltage DC circuit 2 is configured by connecting a plurality of battery packs 10 (10_1 to 10_N: N is an integer of 2 or more) in series. In the example shown in Fig. 1, the high-voltage DC circuit 2 has two battery packs 10_1 and 10_2. More specifically, the battery packs 10_1 and 10_2 are connected in series in this order from the high-potential side.

[0012] The high-voltage DC circuit 2 is insulated from the ground GND (e.g., the vehicle body) on the vehicle 1 via an insulation resistance unit 3. The insulation resistance unit 3 includes a positive electrode side insulation resistor Rp and a negative electrode side insulation resistor Rn (see FIG. 2).

[0013] Each of the battery packs 10_1 and 10_2 (hereinafter also simply referred to as each battery pack 10) is standardized as follows, for example. That is, each battery pack 10 includes, as common hardware, a battery 11, a relay 12, and a battery ECU (Electronic Control Unit) 13. The battery packs 10 standardized in this way are suitable for use in which each battery pack 10 is replaced individually.

[0014] The battery 11 is a high-voltage DC power source, and is, for example, a stack of multiple battery cells. In the high-voltage DC circuit 2, the battery 11 of each battery pack 10 is connected to a high-voltage unit 4. Examples of the high-voltage unit 4 include an electric motor for vehicle operation, a DC / DC converter, an air-conditioning inverter, a water heater, an AC charger, and a solar charger.

[0015] The relay 12 connects / disconnects a positive line PLb and a negative line NLb in the battery pack 10 accommodating the relay 12. More specifically, the relay 12 of the battery pack 10_1 includes a positive-side relay 12_1p and a negative-side relay 12_1n, and the relay 12 of the battery pack 10_2 includes a positive-side relay 12_2p and a negative-side relay 12_2n. One end of the positive line PLb is connected to the positive electrode of the battery 11, and one end of the negative line NLb is connected to the negative electrode of the battery 11. Each relay 12 is controlled by a host ECU 20, which will be described later.

[0016] More specifically, the positive electrode line PLb of the battery pack 10_1 arranged on the high potential side is connected to the high voltage unit 4 via a positive electrode line PL0 outside each battery pack 10. The negative electrode line NLb of the battery pack 10_1 is connected to the positive electrode line PLb of the battery pack 10_2 arranged on the low potential side via a connection line CL outside each battery pack 10. The negative electrode line NLb of the battery pack 10_2 is connected to the high voltage unit 4 via a negative electrode line NL0 outside each battery pack 10. The insulation resistance unit 3 is connected between a node NP on the positive electrode line PL0 and a node NN on the negative electrode line NL0.

[0017] The battery ECU 13 includes a leakage detection circuit 14 and a control unit 15. The leakage detection circuit 14 is a circuit for detecting "voltage information VI" including "the voltage of the insulation resistance unit 3." An example of the leakage detection circuit 14 will be described later with reference to FIG. 2. The control unit 15 controls the leakage detection circuit 14 included in the same battery pack 10. For example, the control unit 15 is a microcomputer including a processor and a memory. The processor executes a control program to realize the functions of the control unit 15. The control program may be recorded on a computer-readable recording medium.

[0018] The vehicle 1 further includes a host ECU 20. The host ECU 20 is mounted on the vehicle 1 outside the plurality of battery packs 10 and performs overall control of the drive system of the vehicle 1. The host ECU 20 communicates with the battery ECU 13 of each battery pack 10. The host ECU 20 includes a calculation unit 21. For example, the calculation unit 21 is a microcomputer including a processor and a memory. The processor executes a control program to realize the functions of the control unit 15. The control program may be recorded on a computer-readable recording medium.

[0019] The "earth leakage detection device" according to this embodiment is a device for detecting an earth leakage in a high voltage DC circuit 2 mounted on a vehicle 1. In the example of vehicle 1 shown in Fig. 1, the earth leakage detection device includes, as components, an earth leakage detection circuit 14 and a control unit 15 included in each battery pack 10, and an arithmetic unit 21.

[0020] FIG. 2 is a circuit diagram showing an example of the configuration of the leakage detection circuit 14 included in each battery pack 10 shown in FIG.

[0021] The leakage detection circuit 14_1 of the battery pack 10_1 includes a first limiting resistor Ra1, a first detection resistor Rb1, a first switch SW1, a first voltage detection circuit 16, a second limiting resistor Ra2, a second detection resistor Rb2, a second switch SW2, and a second voltage detection circuit 17. This is the same as the leakage detection circuit 14_2 of the battery pack 10_2.

[0022] The first detection resistor Rb1 is connected between the first node N1 and ground GND. The first node N1 is connected to a node NP1 (node ​​NP2 in the leakage detection circuit 14_2) via a first switch SW1 and a first limiting resistor Ra1. That is, the first detection resistor Rb1 is connected to the positive electrode of the battery 11_1 (battery 11_2 in the leakage detection circuit 14_2) via the first switch SW1 and the first limiting resistor Ra1. The first voltage detection circuit 16 detects the voltage between the first node N1 and ground GND, i.e., the voltage applied to the first detection resistor Rb1. An example of the first voltage detection circuit 16 is one that uses a differential amplifier circuit. The voltage detected by the first voltage detection circuit 16 will be referred to as a "first detection voltage Vb1" hereinafter.

[0023] The second detection resistor Rb2 is connected between the second node N2 and ground GND. The second node N2 is connected to node NN1 (node ​​NN2 in the leakage detection circuit 14_2) via the second switch SW2 and the second limiting resistor Ra2. That is, the second detection resistor Rb2 is connected to the negative electrode of the battery 11_1 (battery 11_2 in the leakage detection circuit 14_2) via the second switch SW2 and the second limiting resistor Ra2. The second voltage detection circuit 17 detects the voltage between the second node N2 and ground GND, i.e., the voltage applied to the second detection resistor Rb2. An example of the second voltage detection circuit 17 is one that uses a differential amplifier circuit. The voltage detected by the second voltage detection circuit 17 will be referred to as the "second detection voltage Vb2" hereinafter.

[0024] The control unit 15 controls the ON / OFF of the first switch SW1 and the second switch SW2, and obtains information (including voltage information VI) on the first detected voltage Vb1 and the second detected voltage Vb2.

[0025] As shown in Fig. 2, the positive electrode side insulation resistor Rp is arranged between the node NP and ground GND. Here, the battery pack 10 located at the end on the high potential side among the plurality of battery packs 10 is referred to as the "first specific battery pack." The positive electrode side insulation resistor Rp is arranged between the positive electrode of the battery pack 10_1 (first specific battery pack) located at the end on the high potential side among two battery packs 10_1 and 10_2 (plurality of battery packs) and ground GND. More specifically, the positive electrode is the positive electrode of the cell located at the end on the high potential side among the plurality of cells included in the battery pack 10_1.

[0026] 2, the negative electrode side insulation resistor Rn is arranged between the node NN and the ground GND. Here, the battery pack 10 located at the end on the low potential side among the plurality of battery packs 10 is referred to as the "second specific battery pack." The negative electrode side insulation resistor Rn is arranged between the negative electrode of the battery pack 10_2 (second specific battery pack) located at the end on the low potential side among the two battery packs 10_1 and 10_2 (plurality of battery packs) and the ground GND. More specifically, the negative electrode is the negative electrode of the cell located at the end on the low potential side among the plurality of cells included in the battery pack 10_2.

[0027] Between the node NP and the ground GND, there exists a common mode capacitance Cp together with a positive side insulation resistance Rp, and between the node NN and the ground GND, there exists a common mode capacitance Cn together with a negative side insulation resistance Rn.

[0028] 2.Electric leakage detection process In the above-described high-voltage DC circuit 2, a plurality of standardized battery packs 10, each having a leakage detection circuit 14 and a control unit 15, are connected in series. In a high-voltage DC circuit 2 having such a configuration, both the positive-side detection voltage VRp and the negative-side detection voltage VRn, which are required to determine whether or not there is a leakage in the high-voltage DC circuit 2, cannot be detected by the leakage detection circuit 14 and the control unit 15 included in one battery pack 10 alone. Therefore, the leakage detection device according to this embodiment executes the following "leakage determination process" to appropriately detect a leakage in the high-voltage DC circuit 2.

[0029] The leakage current determination process is executed by cooperation between the calculation unit 21 and the control units 15 of the multiple battery packs 10. That is, the control unit 15 controls the leakage current detection circuit 14 to obtain voltage information VI including at least the "voltage of the insulation resistance unit 3" and transmits it to the calculation unit 21. The calculation unit 21 determines the presence or absence of leakage current in the high-voltage DC circuit 2 based on the received voltage information VI.

[0030] 1, the battery pack 10_1 corresponds to the first specified battery pack, and the battery pack 10_2 corresponds to the second specified battery pack. More specifically, the "voltage of the insulation resistance unit 3" included in the voltage information VI includes a positive electrode side detected voltage VRp as voltage information transmitted from the battery pack 10_1 (first specified battery pack) to the calculation unit 21, and a negative electrode side detected voltage VRn as voltage information transmitted from the battery pack 10_2 (second specified battery pack) to the calculation unit 21.

[0031] FIG. 3 is a diagram for explaining a method for acquiring the positive electrode side detected voltage VRp and the negative electrode side detected voltage VRn. For simplicity, the following explanation assumes that Ra1=Ra2=Ra and Rb1=Rb2=Rb. In this embodiment, the leakage detection process is performed using a DC voltage division method as described below. During the leakage detection process, the relay 12 of each battery pack 10 is turned on.

[0032] The positive electrode detection voltage VRp is the voltage between the positive electrode of the battery pack 10_1 (first specific battery pack) (more specifically, the positive electrode of the cell located at the end on the high potential side among the multiple cells included in the battery pack 10_1) and ground GND. In other words, the positive electrode detection voltage VRp is the voltage between the positive electrodes of the multiple battery packs 10 mounted on the vehicle 1 as a whole and ground GND. The positive electrode detection voltage VRp is detected by the leakage detection circuit 14_1 of the battery pack 10_1. When detecting the positive electrode detection voltage VRp, the control unit 15 of the battery pack 10_1 turns off the first switch SW1 and turns on the second switch SW2. The second detection voltage Vb2 indicates the positive electrode detection voltage VRp. That is, the control unit 15 can acquire the positive electrode detection voltage VRp. At this time, the relationship expressed by the following equation (1) is established.

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[0033] The negative electrode detection voltage VRn is the voltage between the negative electrode of the battery pack 10_2 (second specific battery pack) (more specifically, the negative electrode of the cell located at the end on the low potential side among the multiple cells included in the battery pack 10_2) and ground GND. In other words, the negative electrode detection voltage VRn is the voltage between the negative electrodes of the multiple battery packs 10 mounted on the vehicle 1 as a whole and ground GND. The negative electrode detection voltage VRn is detected by the leakage detection circuit 14_2 of the battery pack 10_2. When detecting the negative electrode detection voltage VRn, the control unit 15 of the battery pack 10_2 turns on the first switch SW1 and turns off the second switch SW2. The first detection voltage Vb1 indicates the negative electrode detection voltage VRn. That is, the control unit 15 can acquire the negative electrode detection voltage VRn. At this time, the relationship expressed by the following equation (2) is established.

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[0034] In order to prevent the operations of the leakage detection circuits 14_1 and 14_2 for acquiring the voltages VRp and VRn from interfering with each other, the ON timing of the second switch SW2 of the leakage detection circuit 14_1 when acquiring the positive side detection voltage VRp and the ON timing of the first switch SW1 of the leakage detection circuit 14_2 when acquiring the negative side detection voltage VRn are set so as not to overlap with each other.

[0035] Furthermore, in order to acquire the total voltage VB (more specifically, VBi (e.g., VB1 and VB2; see FIG. 3)) of each battery pack 10 (10_1, 10_2), the control unit 15 of each battery pack 10 turns on both the first switch SW1 and the second switch SW2 of its own leakage detection circuit 14. The total voltage VBi is the output voltage of the battery 11. The first detection voltage Vb1 and the second detection voltage Vb2 are both the detection voltage Vb. At this time, the relationship expressed by the following equation (3) holds. Note that the total voltage VBi of each battery pack 10 may be acquired using a circuit different from the leakage detection circuit 14 (e.g., a circuit that detects the sum of the cell voltages of the battery 11).

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[0036] 4 is a flowchart showing the leakage determination process according to the present embodiment. The process of this flowchart is executed by the calculation unit 21 and the control unit 15 of each battery pack 10 in cooperation with each other.

[0037] The process of step S100 is executed to determine the arrangement order of the battery packs 10. The process of step S100 is executed only when the battery pack 10 is assembled into the vehicle 1 (including replacement of the battery pack 10). In other words, when not being assembled, the process of step S100 is omitted.

[0038] Specifically, in step S100, the control unit 15 of each battery pack 10 determines whether its own battery pack 10 is located at the highest or lowest potential (i.e., at the end on the high potential side or the end on the low potential side) among the multiple battery packs 10 installed in the vehicle 1. This determination can be made, for example, by using a detection circuit that detects the potential of the positive electrode or negative electrode of a predetermined cell included in the battery pack 10 relative to ground GND. When the processing of step S100 for all battery packs 10 has been completed, the processing proceeds to step S102.

[0039] In step S102, the control unit 15 of the battery pack 10 (e.g., battery pack 10_1 in FIG. 3) corresponding to the battery pack with the highest potential (i.e., the first specific battery pack) controls the leakage detection circuit 14 to sequentially detect the positive electrode side detected voltage VRp and the total voltage VB1. Specifically, the control unit 15 turns off the first switch SW1 and turns on the second switch SW2 (see FIG. 3), and acquires the positive electrode side detected voltage VRp based on equation (1). Next, the control unit 15 turns on both the first switch SW1 and the second switch SW2, and acquires the total voltage VB1 based on equation (3). Thereafter, the process proceeds to step S104.

[0040] In step S104, the control unit 15 of the battery pack 10 (e.g., battery pack 10_2 in FIG. 3) corresponding to the battery pack with the lowest potential (i.e., the second specific battery pack) controls the leakage detection circuit 14 to sequentially detect the negative electrode side detected voltage VRn and the total voltage VB2. Specifically, the control unit 15 turns on the first switch SW1 and turns off the second switch SW2 (see FIG. 3), and acquires the negative electrode side detected voltage VRn based on equation (2). Next, the control unit 15 turns on both the first switch SW1 and the second switch SW2, and acquires the total voltage VB2 based on equation (3). Thereafter, the process proceeds to step S106.

[0041] In step S106, the control unit 15 of the highest battery pack 10 transmits the acquired positive electrode side detected voltage VRp and total voltage VB1 to the upper ECU 20. Next, in step S108, the control unit 15 of the lowest battery pack 10 transmits the acquired negative electrode side detected voltage VRn and total voltage VB2 to the upper ECU 20. In this way, the control unit 15 (battery ECU 13) transmits the voltage values ​​themselves to the upper ECU 20 and does not perform any calculation for leakage detection. Thereafter, the process proceeds to step S110. Additionally, in the example process shown in FIG. 4, the voltage information VI includes the positive electrode side detected voltage VRp, the negative electrode side detected voltage VRn, and the total voltages VB1 and VB2.

[0042] The process of step S110 is executed to determine whether or not there is a leakage current in the high voltage DC circuit 2. Normally, the insulation resistance (Rp / / Rn) is high and the detection voltage (VRp+VRn) is low. Conversely, when a leakage current occurs, the insulation resistance (Rp / / Rn) is low and the detection voltage (VRp+VRn) is high.

[0043] Therefore, the calculation unit 21 compares, for example, the sum (VRp+VRn) of the received positive detection voltage VRp and negative detection voltage VRn with a predetermined threshold Vth. If VRp+VRn is equal to or greater than the threshold Vth (step S110; Yes), the calculation unit 21 determines that a leakage current has occurred in the high-voltage DC circuit 2 (step S112). On the other hand, if VRp+VRn is less than the threshold Vth (step S110; No), the calculation unit 21 determines that a leakage current has not occurred in the high-voltage DC circuit 2 (step S114).

[0044] The process of step S110 may be performed as follows: That is, the calculation unit 21 may determine whether or not there is a leakage current in the high voltage DC circuit 2 by comparing the insulation resistance (Rp / / Rn) with a predetermined threshold value.

[0045] Specifically, the insulation resistance (Rp / / Rn) corresponds to the combined resistance of the positive electrode insulation resistance Rp and the negative electrode insulation resistance Rn. From the above equations (1) and (2), the following equation (4) is obtained. Transforming equation (4) yields the following equation (5).

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[0046] Ra and Rb are circuit constants. Information about Ra and Rb is provided to the calculation unit 21 in advance. The positive electrode side detected voltage VRp, the negative electrode side detected voltage VRn, and the total voltage VB of each battery pack 10 (e.g., VB1 and VB2) are transmitted to the host ECU 20 as voltage information VI. Therefore, the calculation unit 21 can calculate the insulation resistance (Rp / / Rn) based on equation (5). In addition, in an example in which three or more battery packs 10 connected in series are installed in the vehicle 1, the voltage information VI also includes the total voltage VBi of one or more intermediate battery packs 10 other than the top and bottom battery packs 10 in order to calculate the insulation resistance (Rp / / Rn) based on equation (5).

[0047] Then, if the calculated insulation resistance (Rp / / Rn) is equal to or less than the threshold value, the calculation unit 21 may determine that a leakage current has occurred in the high-voltage DC circuit 2. On the other hand, if the insulation resistance (Rp / / Rn) is greater than the threshold value, the calculation unit 21 may determine that a leakage current has not occurred in the high-voltage DC circuit 2.

[0048] Furthermore, in order to shorten the time required for the DC voltage division type leakage current determination process, the "stable detection voltage Vb(∞) after the transient response period" described in Patent Document 1 (JP 2023-174326 A) may be used. More specifically, to determine the presence or absence of leakage current, the calculation unit 21 may calculate the insulation resistance (Rp / / Rn) based on the detection voltage Vb(∞) and the above equation (5), or the calculation unit 21 may calculate (estimate) VRp(∞) and VRn(∞) based on equation (8) described in Patent Document 1, and use the sum (VRp(∞) + VRn(∞)) to determine the presence or absence of leakage current.

[0049] As described above, according to the leakage detection device of this embodiment, the calculation unit 21 of the host ECU 20 mounted on the vehicle 1 outside the plurality of battery packs 10 determines the presence or absence of leakage in the high-voltage DC circuit 2 based on voltage information VI acquired using the leakage detection circuit 14 included in each battery pack 10. This makes it possible to properly detect leakage even in a high-voltage DC circuit 2 in which a plurality of standardized battery packs 10 are connected in series.

[0050] More specifically, according to the leakage detection device of this embodiment, the positive electrode side detected voltage VRp is detected using the leakage detection circuit 14 of the battery pack 10 (first specific battery pack) that is located at the highest potential (high potential end) among the multiple battery packs 10. The negative electrode side detected voltage VRn is detected using the leakage detection circuit 14 of the battery pack 10 (second specific battery pack) that is located at the lowest potential (low potential end) among the multiple battery packs 10. The calculation unit 21 receives voltage information VI that includes at least the positive electrode side detected voltage VRp and the negative electrode side detected voltage VRn thus acquired, and determines whether or not there is a leakage based on the voltage information VI. This makes it possible to appropriately detect a leakage even in the high voltage DC circuit 2. [Explanation of symbols]

[0051] REFERENCE SIGNS LIST 1 vehicle, 2 high voltage DC circuit, 3 insulation resistance section, 10 battery pack, 11 battery, 12 relay, 13 battery ECU, 14 leakage detection circuit, 15 control section, 16 first voltage detection circuit, 17 second voltage detection circuit, 20 upper ECU, 21 calculation section

Claims

1. 1. A leakage detection device applied to a vehicle, the device comprising: a high-voltage DC circuit in which a plurality of battery packs are connected in series; and an insulation resistance unit that insulates the high-voltage DC circuit from a ground on the vehicle, a leakage detection circuit included in each of the plurality of battery packs, for detecting voltage information including a voltage of the insulation resistance section; a control unit included in each of the plurality of battery packs and controlling the leakage detection circuit; a computing unit that is mounted on the vehicle outside the plurality of battery packs and that communicates with each of the plurality of battery packs; Equipped with The calculation unit determines whether or not there is a leakage current in the high-voltage DC circuit based on the voltage information received from the plurality of battery packs. Vehicle leakage current detection device.

2. The electric leakage detection device for a vehicle according to claim 1, The insulation resistance portion is a positive electrode-side insulation resistor disposed between the ground and a positive electrode of a first specific battery pack located at the end of the plurality of battery packs on the high potential side; a negative electrode-side insulation resistor disposed between the ground and a negative electrode of a second specific battery pack located at the end of the plurality of battery packs on the low potential side; Including, The voltage information is a positive electrode side detected voltage as voltage information transmitted from the first specified battery pack to the calculation unit; a negative electrode side detected voltage as voltage information transmitted from the second specified battery pack to the calculation unit; Including, the positive electrode side detected voltage is a voltage between the positive electrode of the first specific battery pack and the ground and is detected by the leakage detection circuit of the first specific battery pack; The negative electrode side detected voltage is a voltage between the negative electrode of the second specific battery pack and the ground and is detected by the leakage detection circuit of the second specific battery pack. Vehicle leakage current detection device.

3. 3. The electric leakage detection device for a vehicle according to claim 2, the control unit of each of the plurality of battery packs determines whether its own battery pack corresponds to either the first or second specified battery pack; the control unit of the battery pack corresponding to the first specific battery pack controls the leakage detection circuit to obtain the positive electrode side detected voltage; The control unit of the battery pack corresponding to the second specific battery pack controls the leakage detection circuit to acquire the negative electrode side detected voltage. Vehicle leakage current detection device.

4. 4. The electric leakage detection device for a vehicle according to claim 2 or 3, The calculation unit determines whether or not there is a leakage current by comparing the sum of the positive electrode side detected voltage and the negative electrode side detected voltage with a threshold value. Vehicle leakage current detection device.

5. 4. The electric leakage detection device for a vehicle according to claim 2 or 3, the voltage information further includes an output voltage of each of the plurality of battery packs; The calculation unit calculating a combined resistance of the positive electrode side insulation resistance and the negative electrode side insulation resistance based on the positive electrode side detected voltage, the negative electrode side detected voltage, and the output voltages of the plurality of battery packs; The combined resistance is compared with a threshold value to determine whether or not the leakage current is present. Vehicle leakage current detection device.

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