Vehicle power supply device

Abstract

A vehicle power supply device (10) is provided with a first positive-electrode-side relay (51), a second positive-electrode-side relay (52), and a positive-electrode-side switch unit (53). A first positive-electrode-side relay (51) is provided in a first positive-electrode-side branch path (31) between a battery (20) and a first power supply object (21). A second positive-electrode-side relay (52) is provided in a second positive-electrode-side branch path (32) between the battery (20) and a second power supply object (22). A positive-electrode-side switch unit (53) is provided between a first positive-electrode-side conduction path (33), which is a path in the first positive-electrode-side branch path (31) closer to the first power supply target (21) than the first positive-electrode-side relay (51), and a second positive-electrode-side conduction path (34), which is a path in the first positive-electrode-side branch path (31) closer to the first power supply target (21) than the first positive-electrode-side relay (51). The second positive-electrode-side conductive path (34) is a path in the second positive-electrode-side branch path (32) closer to the second power supply target (22) than the second positive-electrode-side relay (52).

Description

Technical Field

[0001] The present disclosure relates to a power supply device for a vehicle. Background Art

[0002] A power supply device for an electric vehicle is disclosed in Patent Document 1. The power supply device includes a driving battery. The driving battery is connected to an MCU inverter via a high-voltage line and is connected to a V2X device via a fast-charging high-voltage line. That is, the driving battery of Patent Document 1 is connected to a first power supply target via a first line and is connected to a second power supply target via a second line.

[0003] Prior Art Documents Patent Documents Patent Document 1: International Publication No. 2014 / 103707 Summary of the Invention

[0004] Problems to be Solved by the Invention

[0005] In such a technique, when the first line is cut off, power cannot be supplied to the first power supply target, and when the second line is cut off, power cannot be supplied to the second power supply target.

[0006] An object of the present disclosure is to provide a technique in which power supply from a battery to a power supply target is hardly interrupted.

[0007] Technical Means for Solving the Problems

[0008] The vehicle power supply device of the present disclosure is used in an in-vehicle power supply system including: a battery; a positive-side common path connected to a positive-side terminal of the battery; a first positive-side branch path branching from the positive-side common path; a first power supply target connected to the first positive-side branch path; a second positive-side branch path branching from the positive-side common path; and a second power supply target connected to the second positive-side branch path, wherein the vehicle power supply device includes: a first positive-side relay provided in the first positive-side branch path between the battery and the first power supply target; a second positive-side relay provided in the second positive-side branch path between the battery and the second power supply target; and The positive electrode side switch unit is disposed between the first positive electrode side conduction path and the second positive electrode side conduction path. The first positive electrode side conduction path is the path in the first positive electrode side branch path that is closer to the first power supply object side than the first positive electrode side relay, and the second positive electrode side conduction path is the path in the second positive electrode side branch path that is closer to the second power supply object side than the second positive electrode side relay.

[0009] Advantages of the Invention

[0010] The technology related to the present disclosure makes it difficult to interrupt the power supply from the storage battery to the power supply object. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a circuit diagram schematically showing a vehicle power supply system including a vehicle power supply device having a first embodiment. Figure 2 It is an explanatory diagram for explaining the operation when the vehicle power supply device executes the first control in the case where the relay to be switched is the first positive electrode side relay. Figure 3 It is an explanatory diagram for explaining the operation when the vehicle power supply device executes the first control in the case where the relay to be switched is the second positive electrode side relay. Figure 4 It is an explanatory diagram for explaining the operation when the vehicle power supply device executes the first control in the case where the relay to be switched is the first negative electrode side relay. Figure 5 It is an explanatory diagram for explaining the operation when the vehicle power supply device executes the first control in the case where the relay to be switched is the second negative electrode side relay. Figure 6 It is a circuit diagram schematically showing a vehicle power supply system including a vehicle power supply device having a second embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0012] Hereinafter, embodiments of the present disclosure will be listed and exemplified.

[0013] 〔1〕A vehicle power supply device, which is used in a vehicle power supply device. The vehicle power supply device includes: a storage battery; a positive electrode side common path connected to a positive electrode side terminal of the storage battery; a first positive electrode side branch path branched from the positive electrode side common path; a first power supply object connected to the first positive electrode side branch path; a second positive electrode side branch path branched from the positive electrode side common path; and a second power supply object connected to the second positive electrode side branch path. Among them, The vehicle power supply device includes: The first positive electrode side relay is disposed in the first positive electrode side branch path between the storage battery and the first power supply object; The second positive electrode side relay is disposed in the second positive electrode side branch path between the storage battery and the second power supply object; and The positive electrode side switch unit is disposed between the first positive electrode side conduction path and the second positive electrode side conduction path. The first positive electrode side conduction path is the path on the side of the first power supply object closer to the first positive electrode side relay in the first positive electrode side branch path, and the second positive electrode side conduction path is the path on the side of the second power supply object closer to the second positive electrode side relay in the second positive electrode side branch path.

[0014] The above vehicle power supply device can supply the power based on the storage battery to the first power supply object via the positive electrode side common path and the first positive electrode side branch path, and can supply the power to the second power supply object via the positive electrode side common path and the second positive electrode side branch path. Moreover, even when the first positive electrode side branch path is cut off on the side closer to the storage battery than the positive electrode side switch unit, the above vehicle power supply device can supply power to the first power supply object via the second positive electrode side branch path by switching the positive electrode side switch unit to the on state. In addition, even when the second positive electrode side branch path is cut off on the side closer to the storage battery than the positive electrode side switch unit, the above vehicle power supply device can supply power to the second power supply object via the first positive electrode side branch path by switching the positive electrode side switch unit to the on state. That is, it is difficult for the above vehicle power supply device to interrupt the power supply from the storage battery to the first power supply object and the second power supply object.

[0015] 〔2〕In the vehicle power supply device described in 〔1〕, the in-vehicle power supply system includes: a first capacitor connected to the first positive electrode side conduction path; and a second capacitor connected to the second positive electrode side conduction path, The vehicle power supply device further includes a circuit unit that performs a pre-charging operation in a state where the first positive electrode side relay and the second positive electrode side relay are in an off state, and the pre-charging operation supplies power to at least one of the first capacitor and the second capacitor.

[0016] The above vehicle power supply device can perform a pre-charging operation of charging at least one of the first capacitor and the second capacitor by using the circuit unit before switching the first positive electrode side relay or the second positive electrode side relay to the on state. By taking such measures, the above vehicle power supply device can suppress the inrush current flowing into the relay that is switched to the on state among the first positive electrode side relay and the second positive electrode side relay, and further can suppress the deterioration of the relay.

[0017] 〔3〕In the vehicle power supply device described in 〔2〕, the in-vehicle power supply system includes: a negative-side common path connected to the negative-side terminal of the storage battery; a first negative-side branch path branched from the negative-side common path and connected to the first power supply object; and a second negative-side branch path branched from the negative-side common path and connected to the second power supply object. The vehicle power supply device further includes: a negative-side switch unit provided between the first negative-side branch path and the second negative-side branch path; a first negative-side relay provided in the first negative-side branch path between the storage battery and the negative-side switch unit; a second negative-side relay provided in the second negative-side branch path between the storage battery and the negative-side switch unit; and a parallel circuit formed by connecting a resistor unit and a parallel relay in series. The parallel circuit is provided in parallel with each of the first negative-side relay and the second negative-side relay.

[0018] Although deterioration of the relay is suppressed by switching the first positive-side relay or the second positive-side relay to the on state after the pre-charge operation, deterioration may still occur. The above vehicle power supply device can perform a pre-charge operation for charging the first capacitor and the second capacitor when the parallel relay, the positive-side switch unit, and the negative-side switch unit are in the on state and the first positive-side relay or the second positive-side relay is in the on state. Moreover, the above vehicle power supply device can supply power from the storage battery to the first power supply object and the second power supply object without passing through the resistor unit by switching the first negative-side relay or the second negative-side relay provided in parallel with the parallel relay to the on state after this pre-charge operation. By performing such an operation, deterioration of the first positive-side relay and the second positive-side relay can be more effectively suppressed.

[0019] 〔4〕In the vehicle power supply device described in 〔3〕, the circuit unit has the parallel circuit provided in parallel with each of the first positive-side relay and the second positive-side relay. The vehicle power supply device further includes a control unit that controls the first positive-side relay, the second positive-side relay, the first negative-side relay, the second negative-side relay, and the parallel relay. When a start condition for starting charge and discharge of the storage battery is satisfied, the control unit executes first control that controls a parallel relay of a parallel circuit, which is provided in parallel with a relay to be switched among a first positive-side relay, a second positive-side relay, a first negative-side relay, and a second negative-side relay, to an on state. When a switching condition is satisfied during execution of the first control, the control unit executes second control that switches the relay to be switched to an on state.

[0020] By executing the first control, the vehicle power supply device can perform a pre-charge operation on a parallel circuit provided in parallel with a relay to be switched. Further, by executing the second control, the vehicle power supply device switches the relay to be switched to an on state. That is, the vehicle power supply device can select, from among the four relays of the first positive-side relay, the second positive-side relay, the first negative-side relay, and the second negative-side relay, a relay to be switched that is switched to an on state after the pre-charge operation.

[0021] 〔5〕In the vehicle power supply device described in 〔4〕, the control unit compares the degrees of deterioration of the first positive-side relay, the second positive-side relay, the first negative-side relay, and the second negative-side relay, and selects the relay to be switched based on the comparison result.

[0022] The vehicle power supply device can reflect the degree of deterioration of the relay in the selection of the relay to be switched.

[0023] 〔6〕In the vehicle power supply device described in 〔5〕, the control unit selects the relay with the lowest degree of deterioration as the relay to be switched.

[0024] In the vehicle power supply device, each relay is likely to deteriorate evenly, so that it is easy to achieve a long service life of a device including the relay.

[0025] 〔7〕In the vehicle power supply device according to any one of 〔3〕 to 〔6〕, a parallel circuit provided in parallel with the first negative-side relay has a structure in which a negative-side resistor portion serving as the resistor portion and a first negative-side parallel relay serving as the parallel relay are connected in series. A parallel circuit provided in parallel with the second negative-side relay has a structure in which the negative-side resistor portion and a second negative-side parallel relay serving as the parallel relay are connected in series.

[0026] The above-described vehicle power supply device can share a negative-side resistor portion in a parallel circuit provided in parallel with the first negative-side relay and a parallel circuit provided in parallel with the second negative-side relay.

[0027] 〔8〕In the vehicle power supply device according to any one of 〔1〕 to 〔7〕, the in-vehicle power supply system includes: a negative-side common path connected to a negative-side terminal of the storage battery; a first negative-side branch path branched from the negative-side common path and connected to the first power supply object; and a second negative-side branch path branched from the negative-side common path and connected to the second power supply object. The vehicle power supply device further includes a negative-side switch portion provided between the first negative-side branch path and the second negative-side branch path.

[0028] Even when the first negative-side branch path is cut off on the storage battery side with respect to the negative-side switch portion, the above-described vehicle power supply device can switch the negative-side switch portion to the on state and electrically connect the first power supply object to the negative-side terminal of the storage battery via the second negative-side branch path. In addition, even when the second negative-side branch path is cut off on the storage battery side with respect to the negative-side switch portion, the above-described vehicle power supply device can switch the negative-side switch portion to the on state and electrically connect the second power supply object to the negative-side terminal of the storage battery via the first negative-side branch path. That is, it is more difficult for the above-described vehicle power supply device to interrupt the power supply from the storage battery to the power supply object.

[0029] 〔9〕In the vehicle power supply device according to 〔8〕, the vehicle power supply device includes a thermal fuse that melts when the melting temperature is exceeded. The thermal fuse is provided in at least any one of the following paths: a path on the storage battery side with respect to the positive-side switch portion in the first positive-side branch path, a path on the storage battery side with respect to the positive-side switch portion in the second positive-side branch path, a path on the storage battery side with respect to the negative-side switch portion in the first negative-side branch path, and a path on the storage battery side with respect to the negative-side switch portion in the second negative-side branch path.

[0030] When the thermal fuse exceeds the melting temperature, the above-described vehicle power supply device can melt the path in which the thermal fuse is provided. Moreover, even when the above path is melted, the above-described vehicle power supply device can continue to supply power to the first power supply object or the second power supply object by bypassing the melted path.

[0031] 〔10〕In the vehicle power supply device described in 〔2〕, the vehicle power supply device includes a control unit that controls the first positive-side relay, the second positive-side relay, and the circuit unit. When the start condition for starting the charge and discharge of the storage battery is satisfied, the control unit performs control to switch the relay to be switched among the first positive-side relay and the second positive-side relay to the on state after causing the circuit unit to perform the pre-charge operation. In addition, the control unit compares the degradation degrees of the first positive-side relay and the second positive-side relay, and selects the relay to be switched based on the comparison result.

[0032] The above vehicle power supply device can reflect the degradation degree of the relay in the selection of the relay to be switched.

[0033] <First Embodiment>

[0034] 1. Structure of Vehicle Power Supply System 100

[0035] In Figure 1 , a vehicle power supply system 100 including a vehicle power supply device 10 is shown. The vehicle power supply system 100 is used in a vehicle (not shown). The vehicle can be an electric vehicle, an engine vehicle, or a hybrid vehicle. In addition to the vehicle power supply device 10, the vehicle power supply system 100 further includes a storage battery 20, a first power supply target 21, and a second power supply target 22.

[0036] The storage battery 20 can be a lithium-ion storage battery, a lead storage battery, or other storage batteries. The negative terminal of the storage battery 20 is electrically connected to the ground. In this specification, unless otherwise specified, the voltage refers to the voltage with respect to the ground potential.

[0037] Electric power based on the storage battery 20 is supplied to the first power supply target 21. The first power supply target 21 is, for example, an in-vehicle electrical device. In the present embodiment, the first power supply target 21 is configured as a drive unit that drives the wheels of the vehicle. The first power supply target 21 includes an inverter 23 and a motor 24. The inverter 23 generates an alternating voltage (for example, a three-phase alternating current) from the direct current voltage based on the voltage supplied from the storage battery 20, and supplies it to the motor 24. The motor 24 is, for example, a main system motor. The motor 24 rotates based on the electric power supplied from the storage battery 20, and applies a rotational force to the wheels of the vehicle.

[0038] The second power supply target 22 is supplied with power based on the battery 20. The second power supply target 22 is an electrical device. The second power supply target 22 may also be, for example, an electrical device that utilizes V2X (Vehicle to everything) communication. The second power supply target 22 may be an in-vehicle electrical device or an out-of-vehicle electrical device. More specifically, the second power supply target 22 may be an in-vehicle charger (such as an in-vehicle charger) or an out-of-vehicle charger (such as a non-vehicle charger). When the second power supply target 22 is an in-vehicle electrical device, the entire vehicle power supply system 100 is mounted on the vehicle. When the second power supply target 22 is an out-of-vehicle electrical device, the structure of the vehicle power supply system 100 other than the second power supply target 22 is mounted on the vehicle.

[0039] The vehicle power supply system 100 includes a positive electrode side common path 30, a first positive electrode side branch path 31, a second positive electrode side branch path 32, a negative electrode side common path 40, a first negative electrode side branch path 41, and a second negative electrode side branch path 42.

[0040] The positive electrode side common path 30 is electrically connected to the positive electrode side terminal of the battery 20. The first positive electrode side branch path 31 and the second positive electrode side branch path 32 branch from the positive electrode side common path 30 respectively. The negative electrode side common path 40 is electrically connected to the negative electrode side terminal of the battery 20. The first negative electrode side branch path 41 and the second negative electrode side branch path 42 branch from the negative electrode side common path 40 respectively. The first power supply target 21 is electrically connected to the first positive electrode side branch path 31 and the first negative electrode side branch path 41. The second power supply target 22 is electrically connected to the second positive electrode side branch path 32 and the second negative electrode side branch path 42.

[0041] The first positive electrode side branch path 31 has a first positive electrode side conductive path 33, which is the path on the first power supply target 21 side of the first positive electrode side branch path 31 closer to the first positive electrode side relay 51 described later. The second positive electrode side branch path 32 has a second positive electrode side conductive path 34, which is the path on the second power supply target 22 side of the second positive electrode side branch path 32 closer to the second positive electrode side relay 52 described later. The first negative electrode side branch path 41 has a first negative electrode side conductive path 43, which is the path on the first power supply target 21 side of the first negative electrode side branch path 41 closer to the first negative electrode side relay 61 described later. The second negative electrode side branch path 42 has a second negative electrode side conductive path 44, which is the path on the second power supply target 22 side of the second negative electrode side branch path 42 closer to the second negative electrode side relay 62 described later.

[0042] The vehicle power supply system 100 includes a first capacitor 54 and a second capacitor 64.

[0043] The first capacitor 54 is disposed between the first positive-side branch path 31 (more specifically, the first positive-side conduction path 33) and the first negative-side branch path 41 (more specifically, the first negative-side conduction path 43). One end of the first capacitor 54 is electrically connected to the first positive-side branch path 31 (more specifically, the first positive-side conduction path 33). The other end of the first capacitor 54 is electrically connected to the first negative-side branch path 41 (more specifically, the first negative-side conduction path 43). The first capacitor 54 is disposed between the storage battery 20 and the first power supply object 21. The first capacitor 54 functions as a smoothing capacitor for smoothing the voltage applied to the first positive-side branch path 31 (more specifically, the first positive-side conduction path 33).

[0044] The second capacitor 64 is disposed between the second positive-side branch path 32 (more specifically, the second positive-side conduction path 34) and the second negative-side branch path 42 (more specifically, the second negative-side conduction path 44). One end of the second capacitor 64 is electrically connected to the second positive-side branch path 32 (more specifically, the second positive-side conduction path 34). The other end of the second capacitor 64 is electrically connected to the second negative-side branch path 42 (more specifically, the second negative-side conduction path 44). The second capacitor 64 is disposed between the storage battery 20 and the second power supply object 22. The second capacitor 64 functions as a smoothing capacitor for smoothing the voltage applied to the second positive-side branch path 32 (more specifically, the second positive-side conduction path 34).

[0045] 2. Structure of the vehicle power supply device 10

[0046] The vehicle power supply device 10 is used in the vehicle power supply system 100. The vehicle power supply device 10 supplies the power supplied from the storage battery 20 side to the first power supply object 21 and the second power supply object 22.

[0047] The vehicle power supply device 10 includes a first positive-side relay 51, a second positive-side relay 52, a first negative-side relay 61, and a second negative-side relay 62. The first positive-side relay 51, the second positive-side relay 52, the first negative-side relay 61, and the second negative-side relay 62 are configured as mechanical switches including contacts.

[0048] The first positive electrode side relay 51 is disposed in the first positive electrode side branch path 31 between the storage battery 20 and the first power supply object 21. One end of the first positive electrode side relay 51 is electrically connected to the positive electrode side terminal of the storage battery 20 in a structure short-circuited to the positive electrode side terminal of the storage battery 20. The other end of the first positive electrode side relay 51 is electrically connected to one end of the first capacitor 54 and one end of the first power supply object 21 in a structure short-circuited to one end of the first capacitor 54 and one end of the first power supply object 21. When the first positive electrode side relay 51 is in the on state, the positive electrode side terminal of the storage battery 20 is electrically connected to one end of the first capacitor 54 and one end of the first power supply object 21 via the first positive electrode side relay 51. When the first positive electrode side relay 51 is in the off state, the electrical connection between the positive electrode side terminal of the storage battery 20 and one end of the first capacitor 54 and one end of the first power supply object 21 via the first positive electrode side relay 51 is cut off.

[0049] The second positive electrode side relay 52 is disposed in the second positive electrode side branch path 32 between the storage battery 20 and the second power supply object 22. One end of the second positive electrode side relay 52 is electrically connected to the positive electrode side terminal of the storage battery 20 in a structure short-circuited to the positive electrode side terminal of the storage battery 20. The other end of the second positive electrode side relay 52 is electrically connected to one end of the second capacitor 64 and one end of the second power supply object 22 in a structure short-circuited to one end of the second capacitor 64 and one end of the second power supply object 22. When the second positive electrode side relay 52 is in the on state, the positive electrode side terminal of the storage battery 20 is electrically connected to one end of the second capacitor 64 and one end of the second power supply object 22 via the second positive electrode side relay 52. When the second positive electrode side relay 52 is in the off state, the electrical connection between the positive electrode side terminal of the storage battery 20 and one end of the second capacitor 64 and one end of the second power supply object 22 via the second positive electrode side relay 52 is cut off.

[0050] The first negative-side relay 61 is disposed in the first negative-side branch path 41 between the storage battery 20 and the first power supply object 21. One end of the first negative-side relay 61 is electrically connected to the negative-side terminal of the storage battery 20 in a structure short-circuited with the negative-side terminal of the storage battery 20. The other end of the first negative-side relay 61 is electrically connected to the other end of the first capacitor 54 and the other end of the first power supply object 21 in a structure short-circuited with the other end of the first capacitor 54 and the other end of the first power supply object 21. When the first negative-side relay 61 is in the on state, the negative-side terminal of the storage battery 20 is electrically connected to the other end of the first capacitor 54 and the other end of the first power supply object 21 via the first negative-side relay 61. When the first negative-side relay 61 is in the off state, the electrical connection between the negative-side terminal of the storage battery 20 and the other end of the first capacitor 54 and the other end of the first power supply object 21 via the first negative-side relay 61 is cut off.

[0051] The second negative-side relay 62 is disposed in the second negative-side branch path 42 between the storage battery 20 and the second power supply object 22. One end of the second negative-side relay 62 is electrically connected to the negative-side terminal of the storage battery 20 in a structure short-circuited with the negative-side terminal of the storage battery 20. The other end of the second negative-side relay 62 is electrically connected to the other end of the second capacitor 64 and the other end of the second power supply object 22 in a structure short-circuited with the other end of the second capacitor 64 and the other end of the second power supply object 22. When the second negative-side relay 62 is in the on state, the negative-side terminal of the storage battery 20 is electrically connected to the other end of the second capacitor 64 and the other end of the second power supply object 22 via the second negative-side relay 62. When the second negative-side relay 62 is in the off state, the electrical connection between the negative-side terminal of the storage battery 20 and the other end of the second capacitor 64 and the other end of the second power supply object 22 via the second negative-side relay 62 is cut off.

[0052] The vehicle power supply device 10 includes a positive-side switch unit 53 and a negative-side switch unit 63. The positive-side switch unit 53 and the negative-side switch unit 63 may be configured to include a mechanical switch having contacts, or may be configured to include a semiconductor switching element such as an FET (Field Effect Transistor).

[0053] The positive-side switch unit 53 is provided between the first positive-side conduction circuit 33 and the second positive-side conduction circuit 34. One end of the positive-side switch unit 53 is electrically connected to the first positive-side conduction circuit 33 in a structure short-circuited with the first positive-side conduction circuit 33. One end of the positive-side switch unit 53 is electrically connected to the other end of the first positive-side relay 51, one end of the first capacitor 54, and one end of the first power supply object 21 in a structure short-circuited with the other end of the first positive-side relay 51, one end of the first capacitor 54, and one end of the first power supply object 21. The other end of the positive-side switch unit 53 is electrically connected to the second positive-side conduction circuit 34 in a structure short-circuited with the second positive-side conduction circuit 34. The other end of the positive-side switch unit 53 is electrically connected to the other end of the second positive-side relay 52, one end of the second capacitor 64, and one end of the second power supply object 22 in a structure short-circuited with the other end of the second positive-side relay 52, one end of the second capacitor 64, and one end of the second power supply object 22. When the positive-side switch unit 53 is in the on state, the first positive-side conduction circuit 33 and the second positive-side conduction circuit 34 are electrically connected in a structure where the first positive-side conduction circuit 33 is short-circuited with the second positive-side conduction circuit 34. When the positive-side switch unit 53 is in the off state, the bidirectional current flow via the positive-side switch unit 53 is cut off.

[0054] The negative-side switch unit 63 is provided between the first negative-side conduction circuit 43 and the second negative-side conduction circuit 44. One end of the negative-side switch unit 63 is electrically connected to the first negative-side conduction circuit 43 in a structure short-circuited with the first negative-side conduction circuit 43. One end of the negative-side switch unit 63 is electrically connected to the other end of the first negative-side relay 61, the other end of the first capacitor 54, and the other end of the first power supply object 21 in a structure short-circuited with the other end of the first negative-side relay 61, the other end of the first capacitor 54, and the other end of the first power supply object 21. The other end of the negative-side switch unit 63 is electrically connected to the second negative-side conduction circuit 44 in a structure short-circuited with the second negative-side conduction circuit 44. The other end of the negative-side switch unit 63 is electrically connected to the other end of the second negative-side relay 62, the other end of the second capacitor 64, and the other end of the second power supply object 22 in a structure short-circuited with the other end of the second negative-side relay 62, the other end of the second capacitor 64, and the other end of the second power supply object 22. When the negative-side switch unit 63 is in the on state, the first negative-side conduction circuit 43 and the second negative-side conduction circuit 44 are electrically connected in a structure where the first negative-side conduction circuit 43 is short-circuited with the second negative-side conduction circuit 44. When the negative-side switch unit 63 is in the off state, the bidirectional current flow via the negative-side switch unit 63 is cut off.

[0055] The vehicle power supply device 10 includes positive-side parallel circuits 55A and 55B. The positive-side parallel circuits 55A and 55B are an example of a parallel circuit and an example of a circuit section. The positive-side parallel circuits 55A and 55B perform a pre-charging operation in a state where the first positive-side relay 51 and the second positive-side relay 52 are open, and the pre-charging operation supplies power to at least one of the first capacitor 54 and the second capacitor 64.

[0056] The positive-side parallel circuit 55A is provided in parallel with the first positive-side relay 51. The positive-side parallel circuit 55A forms a structure in which the positive-side resistance section 56 and the first positive-side parallel relay 57 are connected in series. One end of the positive-side parallel circuit 55A is electrically connected to the path between one end of the first positive-side relay 51 and the positive-side terminal of the battery 20 in a structure short-circuiting the path. One end of the positive-side parallel circuit 55A is electrically connected to the positive-side terminal of the battery 20, one end of the first positive-side relay 51, and one end of the second positive-side relay 52 in a structure short-circuiting them. The other end of the positive-side parallel circuit 55A is electrically connected to the first positive-side conductive path 33 in a structure short-circuiting them. The other end of the positive-side parallel circuit 55A is electrically connected to the other end of the first positive-side relay 51, one end of the first capacitor 54, one end of the first power supply target 21, and one end of the positive-side switch section 53 in a structure short-circuiting them.

[0057] The positive electrode side parallel circuit 55B is provided in parallel with respect to the second positive electrode side relay 52. The positive electrode side parallel circuit 55B is configured to form a structure in which the positive electrode side resistance portion 56 and the second positive electrode side parallel relay 58 are connected in series. One end of the positive electrode side parallel circuit 55B is electrically connected to the path between one end of the second positive electrode side relay 52 and the positive electrode side terminal of the storage battery 20 in a structure short-circuiting the path therebetween. One end of the positive electrode side parallel circuit 55B is electrically connected to the positive electrode side terminal of the storage battery 20, one end of the first positive electrode side relay 51, and one end of the second positive electrode side relay 52 in a structure short-circuiting them. The other end of the positive electrode side parallel circuit 55B is electrically connected to the second positive electrode side conductive circuit 34 in a structure short-circuiting them. The other end of the positive electrode side parallel circuit 55B is electrically connected to the other end of the second positive electrode side relay 52, one end of the second capacitor 64, one end of the first power supply object 21, and the other end of the positive electrode side switch portion 53 in a structure short-circuiting them.

[0058] One end of the positive electrode side resistance portion 56 is electrically connected to the path between one end of the first positive electrode side relay 51 and one end of the second positive electrode side relay 52 and the positive electrode side terminal of the storage battery 20 in a structure short-circuiting the path therebetween. The other end of the positive electrode side resistance portion 56 is electrically connected to one end of the first positive electrode side parallel relay 57 and one end of the second positive electrode side parallel relay 58 in a structure short-circuiting them.

[0059] The other end of the first positive electrode side parallel relay 57 is electrically connected to the first positive electrode side conductive circuit 33 in a structure short-circuiting them. The other end of the first positive electrode side parallel relay 57 is electrically connected to the other end of the first positive electrode side relay 51, one end of the first capacitor 54, one end of the first power supply object 21, and the other end of the positive electrode side switch portion 53 in a structure short-circuiting them.

[0060] The other end of the second positive-side parallel relay 58 is electrically connected to the second positive-side conduction path 34 in a structure short-circuited to the second positive-side conduction path 34. In a structure short-circuited to the other end of the second positive-side relay 52, one end of the second capacitor 64, one end of the first power supply object 21, and the other end of the positive-side switch section 53, it is electrically connected to the other end of the second positive-side relay 52, one end of the second capacitor 64, one end of the first power supply object 21, and the other end of the positive-side switch section 53.

[0061] The positive-side resistance section 56 is constituted by, for example, a known resistor. The first positive-side parallel relay 57 and the second positive-side parallel relay 58 may be configured as a mechanical switch including a contact, or may be configured as a semiconductor switch element such as an FET (Field Effect Transistor). When the first positive-side parallel relay 57 is in the on state, it allows the flow of current from the battery 20 side to the first power supply object 21 side via the first positive-side parallel relay 57, and when in the off state, it cuts off the flow of current from the battery 20 side to the first power supply object 21 side via the first positive-side parallel relay 57. When the second positive-side parallel relay 58 is in the on state, it allows the flow of current from the battery 20 side to the second power supply object 22 side via the second positive-side parallel relay 58, and when in the off state, it cuts off the flow of current from the battery 20 side to the second power supply object 22 side via the second positive-side parallel relay 58.

[0062] When the first positive-side relay 51 is in the off state and the first positive-side parallel relay 57 is in the on state, the positive-side parallel circuit 55A performs a pre-charging operation for supplying power to the first positive-side conduction path 33. When the second positive-side relay 52 is in the off state and the second positive-side parallel relay 58 is in the on state, the positive-side parallel circuit 55B performs a pre-charging operation for supplying power to the second positive-side conduction path 34.

[0063] The vehicle power supply device 10 includes negative-side parallel circuits 65A and 65B. The negative-side parallel circuits 65A and 65B correspond to an example of a parallel circuit.

[0064] The negative-side parallel circuit 65A is provided in parallel with respect to the first negative-side relay 61. The negative-side parallel circuit 65A is configured to form a structure in which the negative-side resistance portion 66 and the first negative-side parallel relay 67 are connected in series. One end of the negative-side parallel circuit 65A is electrically connected to the path between one end of the first negative-side relay 61 and the negative-side terminal of the storage battery 20 in a structure that short-circuits the path. One end of the negative-side parallel circuit 65A is electrically connected to the positive-side terminal of the storage battery 20, one end of the first negative-side relay 61, and one end of the second negative-side relay 62 in a structure that short-circuits them. The other end of the negative-side parallel circuit 65A is electrically connected to the first negative-side conductive path 43 in a structure that short-circuits them. The other end of the negative-side parallel circuit 65A is electrically connected to the other end of the first negative-side relay 61, the other end of the first capacitor 54, the other end of the first power supply object 21, and one end of the negative-side switch portion 63 in a structure that short-circuits them.

[0065] The negative-side parallel circuit 65B is provided in parallel with respect to the second negative-side relay 62. The negative-side parallel circuit 65B is configured to form a structure in which the negative-side resistance portion 66 and the second negative-side parallel relay 68 are connected in series. One end of the negative-side parallel circuit 65B is electrically connected to the path between one end of the second negative-side relay 62 and the negative-side terminal of the storage battery 20 in a structure that short-circuits the path. One end of the negative-side parallel circuit 65B is electrically connected to the positive-side terminal of the storage battery 20, one end of the first negative-side relay 61, and one end of the second negative-side relay 62 in a structure that short-circuits them. The other end of the negative-side parallel circuit 65B is electrically connected to the second negative-side conductive path 44 in a structure that short-circuits them. The other end of the negative-side parallel circuit 65B is electrically connected to the other end of the second negative-side relay 62, the other end of the second capacitor 64, the other end of the second power supply object 22, and the other end of the negative-side switch portion 63 in a structure that short-circuits them.

[0066] One end of the negative-side resistor portion 66 is electrically connected to the path between one end of the first negative-side relay 61, one end of the second negative-side relay 62, and the negative-side terminal of the storage battery 20 in a structure short-circuiting the path. The other end of the negative-side resistor portion 66 is electrically connected to one end of the first negative-side parallel relay 67 and one end of the second negative-side parallel relay 68 in a structure short-circuiting them.

[0067] The other end of the first negative-side parallel relay 67 is electrically connected to the first negative-side conduction path 43 in a structure short-circuiting them. The other end of the first negative-side parallel relay 67 is electrically connected to the other end of the first negative-side relay 61, the other end of the first capacitor 54, the other end of the first power supply object 21, and one end of the negative-side switch portion 63 in a structure short-circuiting them.

[0068] The other end of the second negative-side parallel relay 68 is electrically connected to the second negative-side conduction path 44 in a structure short-circuiting them. The other end of the second negative-side parallel relay 68 is electrically connected to the other end of the second negative-side relay 62, the other end of the second capacitor 64, the other end of the second power supply object 22, and the other end of the negative-side switch portion 63 in a structure short-circuiting them.

[0069] The negative-side resistor portion 66 is constituted by, for example, a known resistor. The first negative-side parallel relay 67 and the second negative-side parallel relay 68 may be of a structure including a mechanical switch having contacts or may be of a structure including a semiconductor switching element such as an FET (Field Effect Transistor). When the first negative-side parallel relay 67 is in the ON state, it allows the current to flow from the first power supply object 21 side to the storage battery 20 side via the first negative-side parallel relay 67, and when in the OFF state, it cuts off the current flowing from the first power supply object 21 side to the storage battery 20 side via the first negative-side parallel relay 67. When the second negative-side parallel relay 68 is in the ON state, it allows the current to flow from the second power supply object 22 side to the storage battery 20 side via the second negative-side parallel relay 68, and when in the OFF state, it cuts off the current flowing from the second power supply object 22 side to the storage battery 20 side via the second negative-side parallel relay 68.

[0070] The vehicle power supply device 10 is provided with a thermal fuse 59. The thermal fuse 59 melts when its own temperature exceeds the melting temperature. The thermal fuse 59 is provided in the first negative-side branch path 41 (more specifically, the path on the battery 20 side of the first negative-side relay 61 in the first negative-side branch path 41).

[0071] The vehicle power supply device 10 is provided with voltage detection units 70, 71, 72, 73, 74, 75, a current detection unit 76, temperature detection units 77, 78, 79, 80, and a control unit 81.

[0072] The voltage detection unit 70 detects the potential difference across the first positive-side relay 51. The voltage detection unit 71 detects the potential difference across the second positive-side relay 52. The voltage detection unit 72 detects the potential difference across the first negative-side relay 61. The voltage detection unit 73 detects the potential difference across the second negative-side relay 62. The voltage detection unit 74 detects the voltage of the first capacitor 54 (more specifically, the potential difference across the first capacitor 54). The voltage detection unit 75 detects the voltage of the second capacitor 64 (more specifically, the potential difference across the second capacitor 64). The voltage detection units 70, 71, 72, 73, 74, 75 are configured as, for example, well-known voltage detection circuits. The voltage detection units 70, 71, 72, 73, 74, 75 output signals capable of determining the detected values. The control unit 81 determines the potential differences across the first positive-side relay 51, the second positive-side relay 52, the first negative-side relay 61, and the second negative-side relay 62 based on the signals output from the voltage detection units 70, 71, 72, 73. The control unit 81 determines the voltage of the first capacitor 54 based on the signal output from the voltage detection unit 74. The control unit 81 determines the voltage of the second capacitor 64 based on the signal output from the voltage detection unit 75.

[0073] The current detection unit 76 detects the value of the current flowing through the negative-side common path 40. The current detection unit 76 is configured as, for example, a well-known current sensor. The current detection unit 76 outputs a signal capable of determining the detected value. The control unit 81 detects the value of the current flowing through the negative-side common path 40 based on the signal output from the current detection unit 76.

[0074] The temperature detection unit 77 detects the temperature of the first positive-side relay 51 in the on state (more specifically, the temperature of the contact of the first positive-side relay 51). The temperature detection unit 78 detects the temperature of the second positive-side relay 52 in the on state (more specifically, the temperature of the contact of the second positive-side relay 52). The temperature detection unit 79 detects the temperature of the first negative-side relay 61 in the on state (more specifically, the temperature of the contact of the first negative-side relay 61). The temperature detection unit 80 detects the temperature of the second negative-side relay 62 in the on state (more specifically, the temperature of the contact of the second negative-side relay 62). The temperature detection units 77, 78, 79, and 80 are configured as, for example, known temperature sensors. The temperature detection units 77, 78, 79, and 80 output signals capable of determining the detection values. The control unit 81 determines the temperatures of the first positive-side relay 51, the second positive-side relay 52, the first negative-side relay 61, and the second negative-side relay 62 based on the signals output from the temperature detection units 77, 78, 79, and 80.

[0075] 3. Structure of the control unit 81

[0076] The control unit 81 is configured to include, for example, an integrated circuit such as an MCU (Micro Controller Unit). The control unit 81 includes an information processing unit such as a CPU and storage units such as a ROM and a RAM.

[0077] The control unit 81 controls the first positive-side relay 51, the second positive-side relay 52, the first negative-side relay 61, the second negative-side relay 62, the first positive-side parallel relay 57, the second positive-side parallel relay 58, the first negative-side parallel relay 67, the second negative-side parallel relay 68, the positive-side switch unit 53, and the negative-side switch unit 63.

[0078] When the start condition for starting the charge and discharge of the storage battery 20 is satisfied, the control unit 81 executes a first control that controls the parallel relays of the parallel circuits connected in parallel to the relays to be switched among the first positive-side relay 51, the second positive-side relay 52, the first negative-side relay 61, and the second negative-side relay 62 to the on state. When the switching condition is satisfied during the execution of the first control, the control unit 81 executes a second control that switches the relay to be switched to the on state.

[0079] The start condition is, for example, that the vehicle is switched to the start state. The start state of the vehicle is, for example, that the start switch (e.g., ignition switch, power switch, etc.) is switched to the on state. The control unit 81 determines the on / off state of the start switch, for example, by directly obtaining or obtaining via another control device an on / off signal indicating the on / off state of the start switch.

[0080] Operation example when the relay to be switched is the first positive-side relay 51

[0081] When the relay to be switched is the first positive-side relay 51, the control unit 81 performs the first control as follows, for example. The control unit 81 controls the first positive-side parallel relay 57 of the positive-side parallel circuit 55A provided in parallel with the first positive-side relay 51 to the ON state. In addition to this control, in the first control, the control unit 81 performs different controls according to the power supply target as follows.

[0082] When the power supply target is the first power supply target 21, the control unit 81 controls the first negative-side relay 61 to the ON state, for example. As a result, current flows through Figure 2 the paths RA1 and RA2 shown, and the power from the storage battery 20 is supplied to the first capacitor 54. That is, a pre-charge operation for charging the first capacitor 54 is performed.

[0083] When the power supply target is the second power supply target 22, the control unit 81 controls the positive-side switch unit 53 and the second negative-side relay 62 to the ON state, for example. As a result, current flows through Figure 2 the paths RA1 and RA3 shown, and the power from the storage battery 20 is supplied to the second capacitor 64. That is, a pre-charge operation for charging the second capacitor 64 is performed.

[0084] When the power supply target is both the first power supply target 21 and the second power supply target 22, the control unit 81 controls the positive-side switch unit 53, the first negative-side relay 61, and the second negative-side relay 62 to the ON state, for example. As a result, current flows through Figure 2 the paths RA1, RA2, and RA3 shown, and the power from the storage battery 20 is supplied to the first capacitor 54 and the second capacitor 64. That is, a pre-charge operation for charging the first capacitor 54 and the second capacitor 64 is performed.

[0085] When the switching condition is satisfied during the execution of such first control, the control unit 81 performs the second control. In the second control, the control unit 81 switches the first positive-side relay 51 to the ON state and switches the first positive-side parallel relay 57 to the OFF state. As a result, a larger amount of power is supplied to the supply target.

[0086] 3-2. Operation example when the relay to be switched is the second positive-side relay 52

[0087] When the relay to be switched is the second positive-side relay 52, the control unit 81 executes first control as follows, for example. The control unit 81 controls the second positive-side parallel relay 58 of the positive-side parallel circuit 55B provided in parallel with the second positive-side relay 52 to the ON state. In addition to this control, in the first control, the control unit 81 executes different controls according to the power supply target as follows.

[0088] When the power supply target is the first power supply target 21, the control unit 81 controls the positive-side switch unit 53 and the first negative-side relay 61 to the ON state, for example. As a result, current flows through Figure 3 the paths RB1 and RB2 shown, and the power from the storage battery 20 is supplied to the first capacitor 54. That is, a pre-charge operation for charging the first capacitor 54 is performed.

[0089] When the power supply target is the second power supply target 22, the control unit 81 controls the second negative-side relay 62 to the ON state, for example. As a result, current flows through Figure 3 the paths RB1 and RB3 shown, and the power from the storage battery 20 is supplied to the second capacitor 64. That is, a pre-charge operation for charging the second capacitor 64 is performed.

[0090] When the power supply target is both the first power supply target 21 and the second power supply target 22, the control unit 81 controls the positive-side switch unit 53, the first negative-side relay 61, and the second negative-side relay 62 to the ON state, for example. As a result, current flows through Figure 3 the paths RB1, RB2, and RB3 shown, and the power from the storage battery 20 is supplied to the first capacitor 54 and the second capacitor 64. That is, a pre-charge operation for charging the first capacitor 54 and the second capacitor 64 is performed.

[0091] When the switching condition is satisfied during the execution of such first control, the control unit 81 executes second control. In the second control, the control unit 81 switches the second positive-side relay 52 to the ON state and switches the second positive-side parallel relay 58 to the OFF state. As a result, greater power is supplied to the supply target.

[0092] 3-3. Operation example when the relay to be switched is the first negative-side relay 61

[0093] When the relay to be switched is the first negative-side relay 61, the control unit 81 performs first control as follows, for example. The control unit 81 controls the first negative-side parallel relay 67 of the negative-side parallel circuit 65A provided in parallel with the first negative-side relay 61 to the ON state. In addition to this control, in the first control, the control unit 81 performs different controls as follows according to the object to which power is supplied.

[0094] When the object to which power is supplied is the first power supply object 21, the control unit 81 controls the first positive-side relay 51 to the ON state, for example. As a result, current flows through Figure 4 the paths RC1 and RC3 shown, and the power from the storage battery 20 is supplied to the first capacitor 54. That is, a pre-charge operation for charging the first capacitor 54 is performed.

[0095] When the object to which power is supplied is the second power supply object 22, the control unit 81 controls the second positive-side relay 52 and the negative-side switch unit 63 to the ON state, for example. As a result, current flows through Figure 4 the paths RC2 and RC3 shown, and the power from the storage battery 20 is supplied to the second capacitor 64. That is, a pre-charge operation for charging the second capacitor 64 is performed.

[0096] When the objects to which power is supplied are both the first power supply object 21 and the second power supply object 22, the control unit 81 controls the first positive-side relay 51, the second positive-side relay 52, and the negative-side switch unit 63 to the ON state, for example. As a result, current flows through Figure 4 the paths RC1, RC2, and RC3 shown, and the power from the storage battery 20 is supplied to the first capacitor 54 and the second capacitor 64. That is, a pre-charge operation for charging the first capacitor 54 and the second capacitor 64 is performed.

[0097] When the switching condition is satisfied during the execution of such first control, the control unit 81 performs second control. In the second control, the control unit 81 switches the first negative-side relay 61 to the ON state and switches the first negative-side parallel relay 67 to the OFF state. As a result, greater power is supplied to the supply object.

[0098] 3-4. Example of operation when the relay to be switched is the second negative-side relay 62

[0099] When the relay to be switched is the second negative-side relay 62, the control unit 81 performs the first control as follows, for example. The control unit 81 controls the second negative-side parallel relay 68 of the negative-side parallel circuit 65B provided in parallel with the second negative-side relay 62 to the on state. In addition to this control, in the first control, the control unit 81 performs different controls according to the power supply target as follows.

[0100] When the power supply target is the first power supply target 21, the control unit 81 controls the first positive-side relay 51 and the negative-side switch unit 63 to the on state, for example. As a result, current flows through Figure 5 the paths RD1 and RD3 shown, and the power from the storage battery 20 is supplied to the first capacitor 54. That is, a pre-charge operation for charging the first capacitor 54 is performed.

[0101] When the power supply target is the second power supply target 22, the control unit 81 controls the second positive-side relay 52 to the on state, for example. As a result, current flows through Figure 5 the paths RD2 and RD3 shown, and the power from the storage battery 20 is supplied to the second capacitor 64. That is, a pre-charge operation for charging the second capacitor 64 is performed.

[0102] When the power supply targets are both the first power supply target 21 and the second power supply target 22, the control unit 81 controls the first positive-side relay 51, the second positive-side relay 52, and the negative-side switch unit 63 to the on state, for example. As a result, current flows through Figure 5 the paths RD1, RD2, and RD3 shown, and the power from the storage battery 20 is supplied to the first capacitor 54 and the second capacitor 64. That is, a pre-charge operation for charging the first capacitor 54 and the second capacitor 64 is performed.

[0103] When the switching condition is satisfied during the execution of such first control, the control unit 81 performs the second control. In the second control, the control unit 81 switches the second negative-side relay 62 to the on state and switches the second negative-side parallel relay 68 to the off state. As a result, a larger amount of power is supplied to the supply target.

[0104] The above switching condition may also be that the potential difference across the relay to be switched becomes equal to or less than a specified value. The switching condition may also be that the value of the current flowing through a parallel circuit (in this embodiment, the positive-side parallel circuits 55A, 55B or the negative-side parallel circuits 65A, 65B) provided in parallel with the relay to be switched (in this embodiment, the first positive-side parallel relay 57, the second positive-side parallel relay 58, the first negative-side parallel relay 67 or the second negative-side parallel relay 68) becomes equal to or less than a specified value. The switching condition may also be that a specified time has elapsed since the start of the first control. When the power supply object is the first power supply object 21, the switching condition may also be that the voltage of the first capacitor 54 becomes equal to or higher than a specified value. When the power supply object is the second power supply object 22, the switching condition may also be that the voltage of the second capacitor 64 becomes equal to or higher than a specified value. The switching condition may also be other conditions.

[0105] 3-5. Selection of the Object to be Switched

[0106] The control unit 81 compares the degrees of deterioration of the first positive-side relay 51, the second positive-side relay 52, the first negative-side relay 61, and the second negative-side relay 62, and selects a relay to be switched based on the comparison result. More specifically, the control unit 81 selects the relay with the lowest degree of deterioration as the relay to be switched.

[0107] The degree of deterioration of the relay is determined, for example, based on the potential difference across the relay when the relay is in the ON state, the value of the current flowing through the relay, the resistance value of the relay when it is in the ON state, the number of operations of the relay, the temperature of the relay when it is in the ON state (more specifically, the temperature of the relay contacts), and multiple combinations thereof. The degree of deterioration of the relay may be these values themselves, or may be a value obtained by substituting these values into an arithmetic expression.

[0108] The greater the potential difference across the relay, the greater the degree of deterioration of the relay. The smaller the value of the current flowing through the relay, the greater the degree of deterioration of the relay. The greater the resistance value of the relay when it is in the ON state, the greater the degree of deterioration of the relay. The more the number of operations of the relay, the greater the degree of deterioration of the relay. Assuming that the value of the current flowing through the relay is constant, the greater the temperature of the relay when it is in the ON state, the greater the degree of deterioration of the relay.

[0109] As a method for determining the potential difference across the relay, the control unit 81 determines, for example, the potential difference across the relay that has been switched to the ON state by the first control or the second control.

[0110] As a method for determining the value of the current flowing through the relay, the control unit 81 determines, for example, the value of the current flowing through the relay that is switched to the on state by the first control or the second control.

[0111] As a method for determining the resistance value when the relay is in the on state, the control unit 81 determines, for example, the potential difference across the relay and the value of the current flowing through the relay by the above method. Then, the control unit 81 determines the resistance value of the relay based on the determined potential difference and current value.

[0112] As a method for determining the number of operations of the relay, the control unit 81 counts, for example, the number of times each relay is switched to the on state by the second control.

[0113] As a method for determining the temperature when the relay is in the on state, the control unit 81 determines, for example, the temperature of the relay that is switched to the on state by the first control or the second control.

[0114] 4. Examples of effects

[0115] The vehicle power supply device 10 can supply the power based on the battery 20 to the first power supply target 21 via the positive electrode side common path 30 and the first positive electrode side branch path 31, and can supply it to the second power supply target 22 via the positive electrode side common path 30 and the second positive electrode side branch path 32. Moreover, even when the first positive electrode side branch path 31 is cut off on the battery 20 side with respect to the positive electrode side switch unit 53, the vehicle power supply device 10 can supply power to the first power supply target 21 via the second positive electrode side branch path 32 by switching the positive electrode side switch unit 53 to the on state. In addition, even when the second positive electrode side branch path 32 is cut off on the battery 20 side with respect to the positive electrode side switch unit 53, the vehicle power supply device 10 can supply power to the second power supply target 22 via the first positive electrode side branch path 31 by switching the positive electrode side switch unit 53 to the on state. That is, it is difficult for the vehicle power supply device 10 to interrupt the power supply from the battery 20 to the first power supply target 21 and the second power supply target 22.

[0116] Before switching the first positive electrode side relay 51 or the second positive electrode side relay 52 to the on state, the vehicle power supply device 10 can perform a pre-charge operation of charging the first capacitor 54 and the second capacitor 64 using the positive electrode side parallel circuits 55A and 55B. By taking such measures, the vehicle power supply device 10 can suppress the inrush current flowing into the relay that is switched to the on state among the first positive electrode side relay 51 and the second positive electrode side relay 52, and further suppress the deterioration of the relay.

[0117] Although deterioration of the relay is suppressed by switching the first positive-side relay 51 or the second positive-side relay 52 to the ON state after the pre-charge operation, deterioration may still occur. When the negative-side parallel relay (more specifically, the first negative-side parallel relay 67 or the second negative-side parallel relay 68), the positive-side switch section 53, and the negative-side switch section 63 are in the ON state and the first positive-side relay 51 or the second positive-side relay 52 is in the ON state, the vehicle power supply device 10 can perform a pre-charge operation for charging the first capacitor 54 and the second capacitor 64. Further, after this pre-charge operation, the vehicle power supply device 10 can supply power from the storage battery 20 to the first power supply target 21 and the second power supply target 22 without passing through the negative-side resistance section 66 by switching the first negative-side relay 61 or the second negative-side relay 62, which is provided in parallel with the ON-state negative-side parallel relay (more specifically, the first negative-side parallel relay 67 or the second negative-side parallel relay 68), to the ON state. By performing such an operation, deterioration of the first positive-side relay 51 and the second positive-side relay 52 can be suppressed more effectively.

[0118] The vehicle power supply device 10 can perform a pre-charge operation on parallel circuits (in this embodiment, the positive-side parallel circuits 55A, 55B and the negative-side parallel circuits 65A, 65B) provided in parallel with the relay to be switched by executing first control. Further, the vehicle power supply device 10 switches the relay to be switched to the ON state by executing second control. That is, the vehicle power supply device 10 can select, from among the four relays, namely the first positive-side relay 51, the second positive-side relay 52, the first negative-side relay 61, and the second negative-side relay 62, the relay to be switched to the ON state after the pre-charge operation as the relay to be switched.

[0119] The vehicle power supply device 10 can reflect the degree of deterioration of the relay in the selection of the relay to be switched among the first positive-side relay 51, the second positive-side relay 52, the first negative-side relay 61, and the second negative-side relay 62. Further, the vehicle power supply device 10 selects the relay with the lowest degree of deterioration as the relay to be switched. Therefore, since it is easy for each relay of the vehicle power supply device 10 to deteriorate evenly, it is easy to achieve a long service life of the device including the relay.

[0120] The vehicle power supply device 10 can share the negative-side resistance section 66 between the negative-side parallel circuit 65A provided in parallel with the first negative-side relay 61 and the negative-side parallel circuit 65B provided in parallel with the second negative-side relay 62.

[0121] Even when the first negative-side branch path 41 is cut off on the battery 20 side with respect to the negative-side switch unit 63, the vehicle power supply device 10 can be switched to the on state by the negative-side switch unit 63 and the first power supply object 21 can be electrically connected to the negative-terminal side of the battery 20 via the second negative-side branch path 42. Further, even when the second negative-side branch path 42 is cut off on the battery 20 side with respect to the negative-side switch unit 63, the vehicle power supply device 10 can be switched to the on state by the negative-side switch unit 63 and the second power supply object 22 can be electrically connected to the negative-terminal side of the battery 20 via the first negative-side branch path 41. That is, it is more difficult for the vehicle power supply device 10 to interrupt the power supply from the battery 20 to the first power supply object 21 and the second power supply object 22.

[0122] The thermal fuse 59 is provided in the path on the battery 20 side with respect to the negative-side switch unit 63 in the first negative-side branch path 41. When the temperature of the thermal fuse 59 exceeds the fusing temperature, the vehicle power supply device 10 can fuse the above-described path in which the thermal fuse 59 is provided. Moreover, even when the above-described path is fused, the vehicle power supply device 10 can continue to supply power to the first power supply object 21 or the second power supply object 22 by bypassing the fused path via the second negative-side branch path 42.

[0123] <Second Embodiment>

[0124] The vehicle power supply device 210 according to the second embodiment is a structure in which the negative-side parallel circuits 65A, 65B and the negative-side switch unit 63 are mainly omitted from the vehicle power supply device 10 according to the first embodiment. In addition, in the second embodiment, the same reference numerals are given to the same structures as those in the first embodiment, and detailed descriptions thereof are omitted.

[0125] As Figure 6 shown, the vehicle power supply system 200 including the vehicle power supply device 210 according to the second embodiment includes a battery 20, a first power supply object 21, a second power supply object 22, a first capacitor 54, and a second capacitor 64.

[0126] The vehicle power supply system 200 includes a positive-side common path 30, a first positive-side branch path 31, a second positive-side branch path 32, a negative-side common path 40, a first negative-side branch path 41, and a second negative-side branch path 42.

[0127] The vehicle power supply device 210 includes a first positive-side relay 51, a second positive-side relay 52, a first negative-side relay 61, a second negative-side relay 62, a positive-side switch unit 53, positive-side parallel circuits 55A, 55B, and a thermal fuse 59.

[0128] The vehicle power supply device 210 includes voltage detection units 70, 71, 74, 75, current detection unit 76, temperature detection units 77, 78, and control unit 81.

[0129] When the start condition for starting the charge and discharge of the storage battery 20 is satisfied, the control unit 81 causes a parallel circuit (in this embodiment, the positive electrode side parallel circuit 55A or the positive electrode side parallel circuit 55B) provided in parallel with the relay to be switched to perform a pre-charge operation. In this embodiment, the first positive electrode side relay 51 and the second positive electrode side relay 52 can be the relays to be switched. After performing the pre-charge operation, the control unit 81 executes control to switch the relay to be switched to the ON state.

[0130] The control unit 81 compares the degradation degrees of the first positive electrode side relay 51 and the second positive electrode side relay 52, and selects the relay to be switched based on the comparison result. The control unit 81 selects the relay with the smallest degradation degree as the relay to be switched.

[0131] In the vehicle power supply device 210 of the second embodiment, it is also possible to take measures to switch the first positive electrode side relay 51 or the second positive electrode side relay 52 to the ON state after performing a pre-charge operation of charging the first capacitor 54 and the second capacitor 64 using the positive electrode side parallel circuits 55A and 55B. By taking the above measures, the vehicle power supply device 210 can suppress the inrush current flowing into the relay switched to the ON state among the first positive electrode side relay 51 and the second positive electrode side relay 52, and further suppress the degradation of the relay.

[0132] The vehicle power supply device 210 can reflect the degradation degree of the relay in the selection of the relay to be switched among the first positive electrode side relay 51 and the second positive electrode side relay 52. In addition, the vehicle power supply device 210 selects the relay with the smallest degradation degree as the relay to be switched. Therefore, the vehicle power supply device 210 easily degrades each relay evenly, so it is easy to achieve the long life of the device including the relay.

[0133] <Other Embodiments>

[0134] The present disclosure is not limited to the embodiments described above with reference to the accompanying drawings. For example, the features of the above or following embodiments can be combined in their entirety within a non-contradictory range. In addition, any feature in the above and following embodiments can be omitted as long as it is not explicitly stated as an essential feature. Also, the above embodiments can be modified as follows.

[0135] In the above-described embodiment, the thermal fuse 59 is provided in the first negative-side branch path 41, but it may also be provided in other paths. For example, the thermal fuse 59 may be provided in the first positive-side branch path 31, may be provided in the second positive-side branch path 32, or may also be provided in the second negative-side branch path 42. The thermal fuse 59 may also be provided in a plurality of paths.

[0136] In the above-described embodiment, the circuit section is the positive-side parallel circuits 55A and 55B, but it may also have other configurations. For example, the circuit section may also be a DCDC converter.

[0137] Furthermore, the embodiments disclosed herein should be considered illustrative in all respects and not restrictive. The scope of the present invention is not limited to the embodiments disclosed herein and is intended to include all modifications within the scope shown by the claims or equivalent to the scope of the claims.

[0138] Reference Numerals 10… Vehicle power supply device 20… Storage battery 21… First power supply target 22… Second power supply target 23… Inverter 24… Electric motor 30… Positive-side common path 31… First positive-side branch path 32… Second positive-side branch path 33… First positive-side conduction path 34… Second positive-side conduction path 40… Negative-side common path 41… First negative-side branch path 42… Second negative-side branch path 43… First negative-side conduction path 44… Second negative-side conduction path 51… First positive-side relay 52… Second positive-side relay 53… Positive-side switch section 54… First capacitor 55A… Positive-side parallel circuit (parallel circuit) 55B… Positive-side parallel circuit (parallel circuit) 56… Positive-side resistance section 57… First positive-side parallel relay 58… Second positive-side parallel relay 59… Thermal fuse 61…First negative electrode side relay 62…Second negative electrode side relay 63…Negative electrode side switch section 64…Second capacitor 65A…Negative electrode side parallel circuit (parallel circuit) 65B…Negative electrode side parallel circuit (parallel circuit) 66…Negative electrode side resistance section 67…First negative electrode side parallel relay 68…Second negative electrode side parallel relay 70…Voltage detection section 71…Voltage detection section 72…Voltage detection section 73…Voltage detection section 74…Voltage detection section 75…Voltage detection section 76…Current detection section 77…Temperature detection section 78…Temperature detection section 79…Temperature detection section 80…Temperature detection section 81…Control section 100…Vehicle power supply system 200…Vehicle power supply system 210…Vehicle power supply device RA1…Path RA2…Path RA3…Path RB1…Path RB2…Path RB3…Path RC1…Path RC2…Path RC3…Path RD1…Path RD2…Path RD3…Path.

Claims

1. A power supply device for a vehicle, which is used in a vehicle-mounted power supply system. The vehicle-mounted power supply system includes: a storage battery; a positive-side common path connected to the positive-side terminal of the storage battery; a first positive-side branch path branched from the positive-side common path; a first power supply object connected to the first positive-side branch path; a second positive-side branch path branched from the positive-side common path; and a second power supply object connected to the second positive-side branch path. Among them, the power supply device for a vehicle includes: a first positive-side relay provided in the first positive-side branch path between the storage battery and the first power supply object; a second positive-side relay provided in the second positive-side branch path between the storage battery and the second power supply object; and a positive-side switch unit provided between a first positive-side conduction path and a second positive-side conduction path. The first positive-side conduction path is the path on the first power supply object side of the first positive-side relay in the first positive-side branch path, and the second positive-side conduction path is the path on the second power supply object side of the second positive-side relay in the second positive-side branch path.

2. The power supply device for a vehicle according to claim 1, wherein the vehicle-mounted power supply system includes: a first capacitor connected to the first positive-side conduction path; and a second capacitor connected to the second positive-side conduction path, the power supply device for a vehicle further includes a circuit unit that performs a pre-charging operation in a state where the first positive-side relay and the second positive-side relay are open, and the pre-charging operation supplies power to at least one of the first capacitor and the second capacitor.

3. The power supply device for a vehicle according to claim 2, wherein the vehicle-mounted power supply system includes: a negative-side common path connected to the negative-side terminal of the storage battery; a first negative-side branch path branched from the negative-side common path and connected to the first power supply object; and a second negative-side branch path branched from the negative-side common path and connected to the second power supply object, the power supply device for a vehicle further includes: a negative-side switch unit provided between the first negative-side branch path and the second negative-side branch path; a first negative-side relay provided in the first negative-side branch path between the storage battery and the negative-side switch unit; a second negative-side relay provided in the second negative-side branch path between the storage battery and the negative-side switch unit; and a parallel circuit formed by connecting a resistor part and a parallel relay in series, the parallel circuit is provided in parallel with each of the first negative-side relay and the second negative-side relay.

4. The power supply device for a vehicle according to claim 3, wherein the circuit unit has the parallel circuit provided in parallel with each of the first positive-side relay and the second positive-side relay, The vehicle power supply device further includes a control unit that controls the first positive-side relay, the second positive-side relay, the first negative-side relay, the second negative-side relay, and the parallel relay. When a start condition for starting charging and discharging of the battery is satisfied, the control unit executes first control, which controls the parallel relay of the parallel circuit provided in parallel with the relays to be switched among the first positive-side relay, the second positive-side relay, the first negative-side relay, and the second negative-side relay to an on state. When a switching condition is satisfied during the execution of the first control, the control unit executes second control, which switches the relay to be switched to an on state.

5. The vehicle power supply device according to claim 4, wherein the control unit compares the degradation degrees of the first positive-side relay, the second positive-side relay, the first negative-side relay, and the second negative-side relay, and selects the relay to be switched based on the comparison result.

6. The vehicle power supply device according to claim 5, wherein the control unit selects the relay with the lowest degradation degree as the relay to be switched.

7. The vehicle power supply device according to any one of claims 3 to 6, wherein the parallel circuit provided in parallel with the first negative-side relay forms a structure in which a negative-side resistor portion as the resistor portion and a first negative-side parallel relay as the parallel relay are connected in series. the parallel circuit provided in parallel with the second negative-side relay forms a structure in which the negative-side resistor portion and a second negative-side parallel relay as the parallel relay are connected in series.

8. The vehicle power supply device according to claim 1, wherein the in-vehicle power supply system includes: a negative-side common path connected to the negative-side terminal of the battery; a first negative-side branch path branched from the negative-side common path and connected to the first power supply object; and a second negative-side branch path branched from the negative-side common path and connected to the second power supply object. The vehicle power supply device further includes a negative-side switch unit provided between the first negative-side branch path and the second negative-side branch path.

9. The vehicle power supply device according to claim 8, wherein the vehicle power supply device includes a thermal fuse that melts when the melting temperature is exceeded. The temperature fuse is disposed in at least any one of the following paths: the path on the battery side of the positive-side switch section in the first positive-side branch path, the path on the battery side of the positive-side switch section in the second positive-side branch path, the path on the battery side of the negative-side switch section in the first negative-side branch path, and the path on the battery side of the negative-side switch section in the second negative-side branch path.

10. The vehicle power supply device according to claim 2, wherein the vehicle power supply device includes a control unit that controls the first positive-side relay, the second positive-side relay, and the circuit unit, when a start condition for starting charging and discharging of the battery is satisfied, the control unit performs control to switch a relay to be switched among the first positive-side relay and the second positive-side relay to an on state after causing the circuit unit to perform the pre-charge operation, in addition, the control unit compares the degrees of deterioration of the first positive-side relay and the second positive-side relay, and selects the relay to be switched based on the comparison result.

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