Vehicle power supply

Abstract

To make power supply from a battery to a power supply object difficult to stop.SOLUTION: A vehicular power supply device 10 includes: a first positive electrode side relay 51; a second positive electrode side relay 52; and a positive electrode side switch section 53. The first positive electrode side relay 51 is provided in a first positive electrode side branch passage 31 between a battery 20 and a first power supply object 21. The second positive electrode side relay 52 is provided in a second positive electrode side branch passage 32 between the battery 20 and a second power supply object 22. The positive electrode side switch section 53 is provided between a first positive electrode side conductive passage 33 to be a passage on the first power supply object 21 side of the first positive electrode side relay 51 in the first positive electrode side branch passage 31 and a second positive electrode side conductive passage 34 to be a passage on the second power supply object 22 side of the second positive electrode side relay 52 in the second positive electrode side branch passage 32.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a power supply device using an electric vehicle. This 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 high-voltage line for rapid charging. 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.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In this type of technology, when the first line is cut, power cannot be supplied to the first power supply target, and when the second line is cut, power cannot be supplied to the second power supply target.

[0005] An object of the present disclosure is to provide a technology in which power supply from a battery to a power supply target is hardly interrupted.

Means for Solving the Problems

[0006] The vehicle power supply device of the present disclosure is A vehicle power supply device used in an in-vehicle power supply system comprising: a battery; a common positive terminal connected to the positive terminal of the battery; a first positive branch path branching from the common positive terminal; a first power supply target connected to the first positive branch path; a second positive branch path branching from the common positive terminal; and a second power supply target connected to the second positive branch path, wherein Between the battery and the first power supply target, a first positive-side relay is provided in the first positive-side branch circuit, Between the battery and the second power supply target, a second positive-side relay is provided in the second positive-side branch circuit, The system includes a positive-side switch section provided between a first positive-side conductive path, which is a path on the first power supply target side of the first positive-side branch path that is closer to the first power supply target than the first positive-side relay, and a second positive-side conductive path, which is a path on the second power supply target side of the second positive-side branch path that is closer to the second power supply target than the second positive-side relay. [Effects of the Invention]

[0007] The technology disclosed herein ensures that the power supply from the battery to the power source is less likely to be interrupted. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic circuit diagram showing a vehicle power supply system equipped with a vehicle power supply device according to the first embodiment. [Figure 2] Figure 2 is an explanatory diagram illustrating the operation when the vehicle power supply unit performs the first control when the relay to be switched is the first positive-side relay. [Figure 3] Figure 3 is an explanatory diagram illustrating the operation when the vehicle power supply unit performs the first control when the relay to be switched is the second positive side relay. [Figure 4] Figure 4 is an explanatory diagram illustrating the operation when the vehicle power supply unit performs the first control when the relay to be switched is the first negative-side relay. [Figure 5]Figure 5 is an explanatory diagram illustrating the operation when the vehicle power supply unit performs the first control when the relay to be switched is the second negative-side relay. [Figure 6] Figure 6 is a schematic circuit diagram showing a vehicle power supply system equipped with a vehicle power supply device according to the second embodiment. [Modes for carrying out the invention]

[0009] The embodiments of this disclosure are listed and illustrated below.

[0010] [1] A vehicle power supply device used in an in-vehicle power supply system comprising: a battery; a common positive terminal connected to the positive terminal of the battery; a first positive branch path branching from the common positive terminal; a first power supply target connected to the first positive branch path; a second positive branch path branching from the common positive terminal; and a second power supply target connected to the second positive branch path, Between the battery and the first power supply target, a first positive-side relay is provided in the first positive-side branch circuit, Between the battery and the second power supply target, a second positive-side relay is provided in the second positive-side branch circuit, The system comprises a positive-side switch section provided between a first positive-side conductive path, which is a path on the first power supply target side of the first positive-side branch path that is closer to the first power supply target than the first positive-side relay, and a second positive-side conductive path, which is a path on the second power supply target side of the second positive-side branch path that is closer to the second power supply target than the second positive-side relay, among the first positive-side branch paths. Vehicle power supply unit.

[0011] The above-described vehicle power supply unit can supply power from the battery to a first power supply target via a common positive-side path and a first positive-side branch path, and to a second power supply target via a common positive-side path and a second positive-side branch path. Moreover, even if the first positive-side branch path is disconnected on the battery side of the positive-side switch unit, the vehicle power supply unit can supply power to the first power supply target via the second positive-side branch path by switching the positive-side switch unit to the ON state. Furthermore, even if the second positive-side branch path is disconnected on the battery side of the positive-side switch unit, the vehicle power supply unit can supply power to the second power supply target via the first positive-side branch path by switching the positive-side switch unit to the ON state. In other words, the above-described vehicle power supply unit is less likely to experience interruptions in the power supply from the battery to the first and second power supply targets.

[0012] [2] The in-vehicle power supply system comprises a first capacitor connected to the first positive electrode conductive path and a second capacitor connected to the second positive electrode conductive path, Furthermore, the system includes a circuit that performs a pre-charge operation, supplying power to at least one of the first capacitor and the second capacitor when the first positive relay and the second positive relay are in the off state. The vehicle power supply device described in [1].

[0013] The above-mentioned vehicle power supply unit can perform a pre-charge operation by using the circuit section to charge at least one of the first and second capacitors before switching the first positive-side relay or the second positive-side relay to the ON state. By taking this measure, the above-mentioned vehicle power supply unit can suppress the inrush current flowing through the relay that is switched to the ON state among the first and second positive-side relays, and consequently suppress the deterioration of the relay.

[0014] 〔3〕The in-vehicle power supply system includes a negative-side common path connected to the terminal on the negative electrode side of the battery, a first negative-side branch path branched from the negative-side common path and connected to the first power supply target, and a second negative-side branch path branched from the negative-side common path and connected to the second power supply target. Furthermore, 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 battery and the negative-side switch unit. A second negative-side relay provided in the second negative-side branch path between the battery and the negative-side switch unit. A parallel circuit configured by connecting a parallel relay and a resistance unit in series. The parallel circuit is provided in parallel to each of the first negative-side relay and the second negative-side relay. The vehicle power supply device according to 〔2〕.

[0015] Although the deterioration of the relay can be suppressed by switching the first positive-side relay or the second positive-side relay to the on state after the pre-charge operation, deterioration can still occur. 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, the vehicle power supply device can perform a pre-charge operation to charge the first capacitor and the second capacitor. Then, after this pre-charge operation, the vehicle power supply device switches the first negative-side relay or the second negative-side relay provided in parallel with the parallel relay to the on state, so that power from the battery can be supplied to the first power supply target and the second power supply target without passing through the resistance unit. By performing such an operation, the deterioration of the first positive-side relay and the second positive-side relay can be more effectively suppressed.

[0016] 〔4〕The circuit unit has the parallel circuit provided in parallel to each of the first positive-side relay and the second positive-side relay. Furthermore, the system includes a first positive-side relay, a second positive-side relay, a first negative-side relay, a second negative-side relay, and a control unit for controlling the parallel relays. The control unit, When the start condition for starting the charging and discharging of the battery is met, a first control is executed to turn on the parallel relay of the parallel circuit which is provided in parallel with the relay 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. If the switching condition is met during the execution of the first control, the second control is executed to switch the relay to the ON state. The vehicle power supply device described in [3].

[0017] The above-mentioned vehicle power supply unit can perform a pre-charge operation on a parallel circuit connected in parallel to the relay to be switched by executing a first control. Then, the vehicle power supply unit switches the relay to be switched to the ON state by executing a second control. In other words, the vehicle power supply unit can select from four relays to be switched to the ON state after the pre-charge operation: the first positive-side relay, the second positive-side relay, the first negative-side relay, and the second negative-side relay.

[0018] [5] The control unit compares the degree of deterioration of the first positive relay, the second positive relay, the first negative relay, and the second negative relay, and selects the relay to be switched based on the comparison result. The vehicle power supply device described in [4].

[0019] The above-mentioned vehicle power supply unit can reflect the degree of relay degradation when selecting the relay to be switched.

[0020] [6] The control unit selects the relay with the least degree of degradation as the relay to be switched. The vehicle power supply device described in [5].

[0021] The above-mentioned vehicle power supply unit tends to cause each relay to deteriorate evenly, making it easier to extend the lifespan of the device, including the relays.

[0022] [7] The parallel circuit provided in parallel with the first negative-side relay has a configuration in which the negative-side resistor as the resistor and the 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 has a configuration in which the negative-side resistor and the second negative-side parallel relay, which is the parallel relay, are connected in series. A vehicle power supply device as described in any one of [3] to [6].

[0023] The above-mentioned vehicle power supply device can share the negative electrode resistor section between a parallel circuit provided in parallel with the first negative electrode relay and a parallel circuit provided in parallel with the second negative electrode relay.

[0024] [8] The in-vehicle power supply system comprises a negative-side common path connected to the negative terminal of the battery, a first negative-side branch path branching from the negative-side common path and connected to the first power supply target, and a second negative-side branch path branching from the negative-side common path and connected to the second power supply target, Furthermore, it includes a negative electrode side switch section provided between the first negative electrode side branch path and the second negative electrode side branch path. A vehicle power supply device as described in any one of [1] through [7].

[0025] Even if the first negative-side branch circuit is disconnected on the battery side of the negative-side switch unit, the vehicle power supply unit can still electrically connect the first power supply target to the battery's negative terminal via the second negative-side branch circuit by switching the negative-side switch unit to the ON state. Furthermore, even if the second negative-side branch circuit is disconnected on the battery side of the negative-side switch unit, the vehicle power supply unit can still electrically connect the second power supply target to the battery's negative terminal via the first negative-side branch circuit by switching the negative-side switch unit to the ON state. In other words, the vehicle power supply unit is less likely to experience interruptions in the power supply from the battery to the power supply target.

[0026] [9] Equipped with a thermal fuse that melts when the melting temperature is exceeded, The thermal fuse is provided in at least one of the following paths: the path on the battery side of the positive electrode switch in the first positive electrode branch path; the path on the battery side of the positive electrode switch in the second positive electrode branch path; the path on the battery side of the negative electrode switch in the first negative electrode branch path; and the path on the battery side of the negative electrode switch in the second negative electrode branch path. The vehicle power supply device described in [8].

[0027] The above-mentioned vehicle power supply unit can cut off the circuit through which the thermal fuse is installed if the thermal fuse exceeds its melting temperature. Furthermore, even if the above-mentioned circuit is cut off, the above-mentioned vehicle power supply unit can bypass the cut-off circuit and continue supplying power to the first or second power supply target.

[0028]

[10] The system comprises the first positive relay, the second positive relay, and a control unit that controls the circuit section, When the start condition for starting the charging and discharging of the battery is met, the control unit causes the circuit unit to perform the pre-charge operation, and then executes control to switch the relay to be switched on among the first positive side relay and the second positive side relay to the ON state. Furthermore, the control unit compares the degree 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. The vehicle power supply device described in [2].

[0029] The above-mentioned vehicle power supply unit can reflect the degree of relay degradation when selecting the relay to be switched.

[0030] <First Embodiment> 1. Configuration of the vehicle power supply system 100 Figure 1 shows a vehicle power supply system 100 equipped with a vehicle power supply unit 10. The vehicle power supply system 100 is used in a vehicle not shown. The vehicle may be an electric vehicle, a gasoline-powered vehicle, or a hybrid vehicle. In addition to the vehicle power supply unit 10, the vehicle power supply system 100 includes a battery 20, a first power supply target 21, and a second power supply target 22.

[0031] Battery 20 may be a lithium-ion battery, a lead-acid battery, or any other type of battery. The negative terminal of battery 20 is electrically connected to ground. In this specification, voltage refers to the voltage relative to ground potential unless otherwise specified.

[0032] The first power supply target 21 is supplied with power based on the battery 20. The first power supply target 21 is, for example, an in-vehicle electrical device. In this embodiment, the first power supply target 21 is configured as a drive unit that drives the wheels of a vehicle. The first power supply target 21 includes an inverter 23 and a motor 24. The inverter 23 generates an alternating current voltage (e.g., three-phase alternating current) from a direct current voltage based on the voltage supplied from the battery 20 and supplies it to the motor 24. The motor 24 is, for example, a main engine motor. The motor 24 is a device that rotates based on the power supplied from the battery 20 and provides rotational force to the wheels of a vehicle.

[0033] 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 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 external electrical device. More specifically, the second power supply target 22 may be an in-vehicle charger (e.g., an onboard charger) or an external charger (e.g., an offboard charger). If the second power supply target 22 is an in-vehicle electrical device, the entire vehicle power supply system 100 is installed in the vehicle. If the second power supply target 22 is an external electrical device, the components of the vehicle power supply system 100 other than the second power supply target 22 are installed in the vehicle.

[0034] The vehicle power supply system 100 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.

[0035] The positive terminal common path 30 is electrically connected to the positive terminal of the battery 20. The first positive terminal branch path 31 and the second positive terminal branch path 32 each branch off from the positive terminal common path 30. The negative terminal common path 40 is electrically connected to the negative terminal of the battery 20. The first negative terminal branch path 41 and the second negative terminal branch path 42 each branch off from the negative terminal common path 40. The first power supply target 21 is electrically connected to the first positive terminal branch path 31 and the first negative terminal branch path 41. The second power supply target 22 is electrically connected to the second positive terminal branch path 32 and the second negative terminal branch path 42.

[0036] The first positive-side branch 31 has a first positive-side conductive path 33 which is a path within the first positive-side branch 31 that is closer to the first power supply target 21 than the first positive-side relay 51 which will be described later. The second positive-side branch 32 has a second positive-side conductive path 34 which is a path within the second positive-side branch 32 that is closer to the second power supply target 22 than the second positive-side relay 52 which will be described later. The first negative-side branch 41 has a first negative-side conductive path 43 which is a path within the first negative-side branch 41 that is closer to the first power supply target 21 than the first negative-side relay 61 which will be described later. The second negative-side branch 42 has a second negative-side conductive path 44 which is a path within the second negative-side branch 42 that is closer to the second power supply target 22 than the second negative-side relay 62 which will be described later.

[0037] The vehicle power supply system 100 includes a first capacitor 54 and a second capacitor 64.

[0038] The first capacitor 54 is provided between the first positive-side branch circuit 31 (more specifically, the first positive-side conductive circuit 33) and the first negative-side branch circuit 41 (more specifically, the first negative-side conductive circuit 43). One end of the first capacitor 54 is electrically connected to the first positive-side branch circuit 31 (more specifically, the first positive-side conductive circuit 33). The other end of the first capacitor 54 is electrically connected to the first negative-side branch circuit 41 (more specifically, the first negative-side conductive circuit 43). The first capacitor 54 is provided between the battery 20 and the first power supply target 21. The first capacitor 54 functions as a smoothing capacitor that smooths the voltage applied to the first positive-side branch circuit 31 (more specifically, the first positive-side conductive circuit 33).

[0039] The second capacitor 64 is provided between the second positive electrode branch circuit 32 (more specifically, the second positive electrode conductive circuit 34) and the second negative electrode branch circuit 42 (more specifically, the second negative electrode conductive circuit 44). One end of the second capacitor 64 is electrically connected to the second positive electrode branch circuit 32 (more specifically, the second positive electrode conductive circuit 34). The other end of the second capacitor 64 is electrically connected to the second negative electrode branch circuit 42 (more specifically, the second negative electrode conductive circuit 44). The second capacitor 64 is provided between the battery 20 and the second power supply target 22. The second capacitor 64 functions as a smoothing capacitor that smooths the voltage applied to the second positive electrode branch circuit 32 (more specifically, the second positive electrode conductive circuit 34).

[0040] 2. Configuration of the vehicle power supply unit 10 The vehicle power supply unit 10 is used in the vehicle power supply system 100. The vehicle power supply unit 10 supplies power supplied from the battery 20 to the first power supply target 21 and the second power supply target 22.

[0041] The vehicle power supply unit 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 to include mechanical switches having contacts.

[0042] The first positive-side relay 51 is provided in the first positive-side branch circuit 31 between the battery 20 and the first power supply target 21. One end of the first positive-side relay 51 is electrically connected to the positive terminal of the battery 20 in a short-circuit configuration. The other end of the first positive-side relay 51 is electrically connected to one end of the first capacitor 54 and one end of the first power supply target 21 in a short-circuit configuration. When the first positive-side relay 51 is ON, it electrically connects the positive terminal of the battery 20 to one end of the first capacitor 54 and one end of the first power supply target 21. When the first positive-side relay 51 is OFF, it disconnects the electrical connection between the positive terminal of the battery 20 and one end of the first capacitor 54 and one end of the first power supply target 21 via the first positive-side relay 51.

[0043] The second positive-side relay 52 is provided in the second positive-side branch circuit 32 between the battery 20 and the second power supply target 22. One end of the second positive-side relay 52 is electrically connected to the positive terminal of the battery 20 in a short-circuit configuration. The other end of the second positive-side relay 52 is electrically connected to one end of the second capacitor 64 and one end of the second power supply target 22 in a short-circuit configuration. When the second positive-side relay 52 is ON, it electrically connects the positive terminal of the battery 20 to one end of the second capacitor 64 and one end of the second power supply target 22. When the second positive-side relay 52 is OFF, it disconnects the electrical connection between the positive terminal of the battery 20 and one end of the second capacitor 64 and one end of the second power supply target 22 via the second positive-side relay 52.

[0044] The first negative-side relay 61 is provided in the first negative-side branch circuit 41 between the battery 20 and the first power supply target 21. One end of the first negative-side relay 61 is electrically connected to the negative-side terminal of the battery 20 in a short-circuit configuration. 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 target 21 in a short-circuit configuration. When the first negative-side relay 61 is ON, it electrically connects the negative-side terminal of the battery 20 to the other end of the first capacitor 54 and the other end of the first power supply target 21. When the first negative-side relay 61 is in the off state, it disconnects the electrical connection between the negative terminal of the battery 20, the other end of the first capacitor 54, and the other end of the first power supply target 21 via the first negative-side relay 61.

[0045] The second negative-side relay 62 is provided in the second negative-side branch circuit 42 between the battery 20 and the second power supply target 22. One end of the second negative-side relay 62 is electrically connected to the negative-side terminal of the battery 20 in a short-circuit configuration. 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 target 22 in a short-circuit configuration. When the second negative-side relay 62 is ON, it electrically connects the negative-side terminal of the battery 20 to the other end of the second capacitor 64 and the other end of the second power supply target 22. When the second negative-side relay 62 is in the off state, it disconnects the electrical connection between the negative terminal of the battery 20, the other end of the second capacitor 64, and the other end of the second power supply target 22 via the second negative-side relay 62.

[0046] The vehicle power supply unit 10 comprises a positive-side switch section 53 and a negative-side switch section 63. The positive-side switch section 53 and the negative-side switch section 63 may include a mechanical switch having contacts, or they may include a semiconductor switching element such as an FET (Field Effect Transistor).

[0047] The positive electrode side switch section 53 is provided between the first positive electrode side conductive path 33 and the second positive electrode side conductive path 34. One end of the positive electrode side switch section 53 is electrically connected to the first positive electrode side conductive path 33 in a configuration that is short-circuited to the first positive electrode side conductive path 33. One end of the positive electrode side switch section 53 is electrically connected to the other end of the first positive electrode side relay 51, one end of the first capacitor 54, and one end of the first power supply target 21 in a configuration that is short-circuited to the other end of the first positive electrode side relay 51, one end of the first capacitor 54, and one end of the first power supply target 21. The other end of the positive electrode side switch section 53 is electrically connected to the second positive electrode side conductive path 34 in a configuration that is short-circuited to the second positive electrode side conductive path 34. The other end of the positive-side switch unit 53 is short-circuited 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 target 22, thereby electrically connecting 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 target 22. When the positive-side switch unit 53 is in the ON state, the first positive-side conductive path 33 and the second positive-side conductive path 34 are short-circuited, thereby electrically connecting the first positive-side conductive path 33 and the second positive-side conductive path 34. When the positive-side switch unit 53 is in the OFF state, the bidirectional flow of current through the positive-side switch unit 53 is interrupted.

[0048] The negative electrode side switch section 63 is provided between the first negative electrode side conductive path 43 and the second negative electrode side conductive path 44. One end of the negative electrode side switch section 63 is electrically connected to the first negative electrode side conductive path 43 in a configuration that is short-circuited to the first negative electrode side conductive path 43. The other end of the negative electrode side switch section 63 is electrically connected to the other end of the first negative electrode side relay 61, the other end of the first capacitor 54, and the other end of the first power supply target 21 in a configuration that is short-circuited to the other end of the first negative electrode side relay 61, the other end of the first capacitor 54, and the other end of the first power supply target 21. The other end of the negative electrode side switch section 63 is electrically connected to the second negative electrode side conductive path 44 in a configuration that is short-circuited to the second negative electrode side conductive path 44. The other end of the negative-side switch unit 63 is short-circuited 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 target 22, thereby electrically connecting them. When the negative-side switch unit 63 is ON, the first negative-side conductive path 43 and the second negative-side conductive path 44 are short-circuited, thereby electrically connecting the first negative-side conductive path 43 and the second negative-side conductive path 44. When the negative-side switch unit 63 is OFF, the bidirectional flow of current through the negative-side switch unit 63 is interrupted.

[0049] The vehicle power supply unit 10 includes positive-side parallel circuits 55A and 55B. The positive-side parallel circuits 55A and 55B are examples of parallel circuits and examples of circuit sections. The positive-side parallel circuits 55A and 55B perform a pre-charge operation by supplying power to at least one of the first capacitor 54 and the second capacitor 64 when the first positive-side relay 51 and the second positive-side relay 52 are in the off state.

[0050] The positive-side parallel circuit 55A is provided in parallel with the first positive-side relay 51. The positive-side parallel circuit 55A has a configuration in which the positive-side resistor 56 and the first positive-side parallel relay 57 are connected in series. One end of the positive-side parallel circuit 55A is short-circuited to the path between one end of the first positive-side relay 51 and the positive terminal of the battery 20, and is electrically connected to the path between one end of the first positive-side relay 51 and the positive terminal of the battery 20. One end of the positive-side parallel circuit 55A is short-circuited to the positive terminal of the battery 20, one end of the first positive-side relay 51, and one end of the second positive-side relay 52, and is electrically connected to the positive terminal of the battery 20, one end of the first positive-side relay 51, and one end of the second positive-side relay 52. The other end of the positive-side parallel circuit 55A is short-circuited to the first positive-side conductive path 33, and is electrically connected to the first positive-side conductive path 33. The other end of the positive-side parallel circuit 55A is short-circuited 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 unit 53, and 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 unit 53.

[0051] The positive-side parallel circuit 55B is provided in parallel with the second positive-side relay 52. ​​The positive-side parallel circuit 55B has a configuration in which the positive-side resistor 56 and the second positive-side parallel relay 58 are connected in series. One end of the positive-side parallel circuit 55B is short-circuited to the path between one end of the second positive-side relay 52 and the positive terminal of the battery 20, and is electrically connected to the path between one end of the second positive-side relay 52 and the positive terminal of the battery 20. One end of the positive-side parallel circuit 55B is short-circuited to the positive terminal of the battery 20, one end of the first positive-side relay 51, and one end of the second positive-side relay 52, and is electrically connected to the positive terminal of the battery 20, one end of the first positive-side relay 51, and one end of the second positive-side relay 52. The other end of the positive-side parallel circuit 55B is short-circuited to the second positive-side conductive path 34, and is electrically connected to the second positive-side conductive path 34. The other end of the positive-side parallel circuit 55B is 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 target 21, and the other end of the positive-side switch unit 53, and 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 target 21, and the other end of the positive-side switch unit 53.

[0052] One end of the positive-side resistor 56 is short-circuited to the path between one end of the first positive-side relay 51, one end of the second positive-side relay 52, and the positive terminal of the battery 20, and is electrically connected to the path between one end of the first positive-side relay 51, one end of the second positive-side relay 52, and the positive terminal of the battery 20. The other end of the positive-side resistor 56 is short-circuited to one end of the first positive-side parallel relay 57 and one end of the second positive-side parallel relay 58, and is electrically connected to one end of the first positive-side parallel relay 57 and one end of the second positive-side parallel relay 58.

[0053] The other end of the first positive-side parallel relay 57 is short-circuited to the first positive-side conductive path 33 and is electrically connected to the first positive-side conductive path 33. The other end of the first positive-side parallel relay 57 is short-circuited 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 and 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.

[0054] The other end of the second positive-side parallel relay 58 is short-circuited to the second positive-side conductive path 34, and is electrically connected to the second positive-side conductive path 34. The other end of the second positive-side relay 52, one end of the second capacitor 64, one end of the first power supply target 21, and the other end of the positive-side switch unit 53 are short-circuited, and are 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 target 21, and the other end of the positive-side switch unit 53.

[0055] The positive electrode side resistor 56 is composed of, for example, a known resistor. The first positive electrode side parallel relay 57 and the second positive electrode side parallel relay 58 may be configured to include a mechanical switch having contacts, or they may be configured to include a semiconductor switching element such as an FET (Field Effect Transistor). When the first positive electrode side parallel relay 57 is ON, it allows the flow of current from the battery 20 to the first power supply target 21 via the first positive electrode side parallel relay 57, and when it is OFF, it blocks the flow of current from the battery 20 to the first power supply target 21 via the first positive electrode side parallel relay 57. When the second positive electrode side parallel relay 58 is ON, it allows the flow of current from the battery 20 to the second power supply target 22 via the second positive electrode side parallel relay 58, and when it is OFF, it blocks the flow of current from the battery 20 to the second power supply target 22 via the second positive electrode side parallel relay 58.

[0056] The positive-side parallel circuit 55A performs a pre-charge operation to supply power to the first positive-side conductive path 33 when the first positive-side relay 51 is off and the first positive-side parallel relay 57 is on. The positive-side parallel circuit 55B performs a pre-charge operation to supply power to the second positive-side conductive path 34 when the second positive-side relay 52 is off and the second positive-side parallel relay 58 is on.

[0057] The vehicle power supply unit 10 includes negative-side parallel circuits 65A and 65B. The negative-side parallel circuits 65A and 65B are examples of parallel circuits.

[0058] The negative-side parallel circuit 65A is provided in parallel with the first negative-side relay 61. The negative-side parallel circuit 65A has a configuration in which the negative-side resistor 66 and the first negative-side parallel relay 67 are connected in series. One end of the negative-side parallel circuit 65A is short-circuited to the path between one end of the first negative-side relay 61 and the negative terminal of the battery 20, and is electrically connected to the path between one end of the first negative-side relay 61 and the negative terminal of the battery 20. One end of the negative-side parallel circuit 65A is short-circuited to the positive terminal of the battery 20, one end of the first negative-side relay 61, and one end of the second negative-side relay 62, and is electrically connected to the positive terminal of the battery 20, one end of the first negative-side relay 61, and one end of the second negative-side relay 62. The other end of the negative-side parallel circuit 65A is short-circuited to the first negative-side conductive path 43, and is electrically connected to the first negative-side conductive path 43. The other end of the negative-side parallel circuit 65A is short-circuited 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 target 21, and one end of the negative-side switch unit 63, and 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 target 21, and one end of the negative-side switch unit 63.

[0059] The negative-side parallel circuit 65B is provided in parallel with the second negative-side relay 62. The negative-side parallel circuit 65B has a configuration in which the negative-side resistor 66 and the second negative-side parallel relay 68 are connected in series. One end of the negative-side parallel circuit 65B is short-circuited to the path between one end of the second negative-side relay 62 and the negative terminal of the battery 20, and is electrically connected to the path between one end of the second negative-side relay 62 and the negative terminal of the battery 20. One end of the negative-side parallel circuit 65B is short-circuited to the positive terminal of the battery 20, one end of the first negative-side relay 61, and one end of the second negative-side relay 62, and is electrically connected to the positive terminal of the battery 20, one end of the first negative-side relay 61, and one end of the second negative-side relay 62. The other end of the negative-side parallel circuit 65B is short-circuited to the second negative-side conductive path 44, and is electrically connected to the second negative-side conductive path 44. The other end of the negative-side parallel circuit 65B is short-circuited 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 target 22, and the other end of the negative-side switch unit 63, and 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 target 22, and the other end of the negative-side switch unit 63.

[0060] One end of the negative electrode side resistor 66 is short-circuited to the path between one end of the first negative electrode side relay 61 and one end of the second negative electrode side relay 62 and the negative terminal of the battery 20, and is electrically connected to the path between one end of the first negative electrode side relay 61 and one end of the second negative electrode side relay 62 and the negative terminal of the battery 20. The other end of the negative electrode side resistor 66 is short-circuited to one end of the first negative electrode side parallel relay 67 and one end of the second negative electrode side parallel relay 68, and is electrically connected to one end of the first negative electrode side parallel relay 67 and one end of the second negative electrode side parallel relay 68.

[0061] The other end of the first negative-side parallel relay 67 is short-circuited to the first negative-side conductive path 43 and is electrically connected to the first negative-side conductive path 43. The other end of the first negative-side parallel relay 67 is short-circuited 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 target 21, and one end of the negative-side switch section 63 and 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 target 21, and one end of the negative-side switch section 63.

[0062] The other end of the second negative-side parallel relay 68 is short-circuited to the second negative-side conductive path 44, and is electrically connected to the second negative-side conductive path 44. The other end of the second negative-side parallel relay 68 is short-circuited 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 target 22, and the other end of the negative-side switch unit 63, and 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 target 22, and the other end of the negative-side switch unit 63.

[0063] The negative electrode side resistor 66 is composed of, for example, a known resistor. The first negative electrode side parallel relay 67 and the second negative electrode side parallel relay 68 may be configured to include a mechanical switch having contacts, or they may be configured to include a semiconductor switching element such as an FET (Field Effect Transistor). When the first negative electrode side parallel relay 67 is ON, it allows the flow of current from the first power supply target 21 to the battery 20 via the first negative electrode side parallel relay 67, and when it is OFF, it blocks the flow of current from the first power supply target 21 to the battery 20 via the first negative electrode side parallel relay 67. When the second negative electrode side parallel relay 68 is ON, it allows the flow of current from the second power supply target 22 to the battery 20 via the second negative electrode side parallel relay 68, and when it is OFF, it blocks the flow of current from the second power supply target 22 to the battery 20 via the second negative electrode side parallel relay 68.

[0064] The vehicle power supply unit 10 is equipped with a thermal fuse 59. The thermal fuse 59 blows when its temperature exceeds its melting point. The thermal fuse 59 is installed in the first negative side branch circuit 41 (more specifically, the path of the first negative side branch circuit 41 that is closer to the battery 20 than the first negative side relay 61).

[0065] The vehicle power supply unit 10 comprises voltage detection units 70, 71, 72, 73, 74, 75, current detection unit 76, temperature detection units 77, 78, 79, 80, and control unit 81.

[0066] Voltage detection unit 70 detects the potential difference across the first positive relay 51. Voltage detection unit 71 detects the potential difference across the second positive relay 52. ​​Voltage detection unit 72 detects the potential difference across the first negative relay 61. Voltage detection unit 73 detects the potential difference across the second negative relay 62. Voltage detection unit 74 detects the voltage of the first capacitor 54 (more specifically, the potential difference across the first capacitor 54). Voltage detection unit 75 detects the voltage of the second capacitor 64 (more specifically, the potential difference across the second capacitor 64). Voltage detection units 70, 71, 72, 73, 74, and 75 are configured, for example, as known voltage detection circuits. Voltage detection units 70, 71, 72, 73, 74, and 75 output a signal that allows for the identification of the detected value. The control unit 81 determines the potential difference across each of the first positive relay 51, the second positive relay 52, the first negative relay 61, and the second negative relay 62 based on the signals output from the voltage detection units 70, 71, 72, and 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.

[0067] The current detection unit 76 detects the value of the current flowing through the negative electrode common path 40. The current detection unit 76 is configured, for example, as a known current sensor. The current detection unit 76 outputs a signal that allows for the identification of the detected value. The control unit 81 detects the value of the current flowing through the negative electrode common path 40 based on the signal output from the current detection unit 76.

[0068] The temperature detection unit 77 detects the temperature of the first positive-side relay 51 when it is ON (more specifically, the temperature of the contacts of the first positive-side relay 51). The temperature detection unit 78 detects the temperature of the second positive-side relay 52 when it is ON (more specifically, the temperature of the contacts of the second positive-side relay 52). The temperature detection unit 79 detects the temperature of the first negative-side relay 61 when it is ON (more specifically, the temperature of the contacts of the first negative-side relay 61). The temperature detection unit 80 detects the temperature of the second negative-side relay 62 when it is ON (more specifically, the temperature of the contacts of the second negative-side relay 62). The temperature detection units 77, 78, 79, and 80 are configured, for example, as known temperature sensors. The temperature detection units 77, 78, 79, and 80 output a signal that allows for the identification of the detected value. The control unit 81 determines the temperature 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.

[0069] 3. Configuration of the control unit 81 The control unit 81 is comprised of an integrated circuit, such as an MCU (Micro Controller Unit). The control unit 81 includes an information processing unit such as a CPU, and a storage unit such as ROM or RAM.

[0070] 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.

[0071] When the start condition for starting the charging and discharging of the battery 20 is met, the control unit 81 executes a first control to turn on the parallel relays of the parallel circuit provided in parallel with the relay to be switched, which are 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. If the switching condition is met while the first control is being executed, the control unit 81 executes a second control to switch the relay to be switched on.

[0072] The starting condition is, for example, that the vehicle has switched to the starting state. The starting state of the vehicle is, for example, that the starting switch (e.g., ignition switch, power switch, etc.) has been switched to the ON state. The control unit 81 determines the ON / OFF state of the starting switch by, for example, obtaining an ON / OFF signal indicating the ON / OFF state of the starting switch directly or via another control device.

[0073] 3-1. Example of operation when the relay to be switched is the first positive side relay 51 If 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, which is provided in parallel with the first positive-side relay 51, to the ON state. In addition to this control, the control unit 81 performs different controls in the first control depending on the target to which power is supplied, as follows.

[0074] When the target to which power is supplied is the first power supply target 21, the control unit 81 controls, for example, the first negative side relay 61 to the ON state. As a result, current flows through the paths RA1 and RA2 shown in Figure 2, and power from the battery 20 is supplied to the first capacitor 54. In other words, a pre-charge operation is performed to charge the first capacitor 54.

[0075] When the target to which power is supplied is the second power supply target 22, the control unit 81 controls, for example, the positive-side switch unit 53 and the second negative-side relay 62 to be in the ON state. As a result, current flows through the paths RA1 and RA3 shown in Figure 2, and power from the battery 20 is supplied to the second capacitor 64. In other words, a pre-charge operation is performed to charge the second capacitor 64.

[0076] If the target to be supplied with power is both the first power supply target 21 and the second power supply target 22, the control unit 81 controls, for example, the positive-side switch unit 53, the first negative-side relay 61, and the second negative-side relay 62 to be in the ON state. As a result, current flows through the paths RA1, RA2, and RA3 shown in Figure 2, and power from the battery 20 is supplied to the first capacitor 54 and the second capacitor 64. In other words, a pre-charge operation is performed to charge the first capacitor 54 and the second capacitor 64.

[0077] If the switching condition is met during the execution of this first control, the control unit 81 executes 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 target.

[0078] 3-2. Example of operation when the relay to be switched is the second positive side relay 52 If the relay to be switched is the second positive-side relay 52, the control unit 81 performs the 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, which is provided in parallel with the second positive-side relay 52, to the ON state. In addition to this control, the control unit 81 performs different controls in the first control depending on the target to which power is supplied, as follows.

[0079] When the target to which power is supplied is the first power supply target 21, the control unit 81 controls, for example, the positive-side switch unit 53 and the first negative-side relay 61 to the ON state. As a result, current flows through the paths RB1 and RB2 shown in Figure 3, and power from the battery 20 is supplied to the first capacitor 54. In other words, a pre-charge operation is performed to charge the first capacitor 54.

[0080] When the target to which power is supplied is the second power supply target 22, the control unit 81 controls, for example, the second negative side relay 62 to the ON state. As a result, current flows through the paths RB1 and RB3 shown in Figure 3, and power from the battery 20 is supplied to the second capacitor 64. In other words, a pre-charge operation is performed to charge the second capacitor 64.

[0081] If the target to be supplied with power is both the first power supply target 21 and the second power supply target 22, the control unit 81 controls, for example, the positive-side switch unit 53, the first negative-side relay 61, and the second negative-side relay 62 to be in the ON state. As a result, current flows through the paths RB1, RB2, and RB3 shown in Figure 3, and power from the battery 20 is supplied to the first capacitor 54 and the second capacitor 64. In other words, a pre-charge operation is performed to charge the first capacitor 54 and the second capacitor 64.

[0082] If the switching condition is met during the execution of this first control, the control unit 81 executes the 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, a larger amount of power is supplied to the target.

[0083] 3-3. Example of operation when the relay to be switched is the first negative side relay 61 If the relay to be switched is the first negative-side relay 61, the control unit 81 performs the 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, which is provided in parallel with the first negative-side relay 61, to the ON state. In addition to this control, the control unit 81 performs different controls in the first control depending on the target to which power is supplied, as follows.

[0084] When the target to which power is supplied is the first power supply target 21, the control unit 81 controls, for example, the first positive side relay 51 to the ON state. As a result, current flows through the paths RC1 and RC3 shown in Figure 4, and power from the battery 20 is supplied to the first capacitor 54. In other words, a pre-charge operation is performed to charge the first capacitor 54.

[0085] When the target to which power is supplied is the second power supply target 22, the control unit 81 controls, for example, the second positive-side relay 52 and the negative-side switch unit 63 to the ON state. As a result, current flows through the paths RC2 and RC3 shown in Figure 4, and power from the battery 20 is supplied to the second capacitor 64. In other words, a pre-charge operation is performed to charge the second capacitor 64.

[0086] If the target to be supplied with power is both the first power supply target 21 and the second power supply target 22, the control unit 81 controls, for example, the first positive-side relay 51, the second positive-side relay 52, and the negative-side switch unit 63 to the ON state. As a result, current flows through the paths RC1, RC2, and RC3 shown in Figure 4, and power from the battery 20 is supplied to the first capacitor 54 and the second capacitor 64. In other words, a pre-charge operation is performed to charge the first capacitor 54 and the second capacitor 64.

[0087] If a switching condition is met during the execution of this first control, the control unit 81 executes the 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, a larger amount of power is supplied to the target.

[0088] 3-4. Example of operation when the relay to be switched is the second negative side relay 62 If 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, which is provided in parallel with the second negative-side relay 62, to the ON state. In addition to this control, the control unit 81 performs different controls in the first control depending on the target to which power is supplied, as follows.

[0089] When the target to which power is supplied is the first power supply target 21, the control unit 81 controls, for example, the first positive-side relay 51 and the negative-side switch unit 63 to the ON state. As a result, current flows through the paths RD1 and RD3 shown in Figure 5, and power from the battery 20 is supplied to the first capacitor 54. In other words, a pre-charge operation is performed to charge the first capacitor 54.

[0090] When the target to which power is supplied is the second power supply target 22, the control unit 81 controls, for example, the second positive side relay 52 to the ON state. As a result, current flows through the paths RD2 and RD3 shown in Figure 5, and power from the battery 20 is supplied to the second capacitor 64. In other words, a pre-charge operation is performed to charge the second capacitor 64.

[0091] If the target to be supplied with power is both the first power supply target 21 and the second power supply target 22, the control unit 81 controls, for example, the first positive-side relay 51, the second positive-side relay 52, and the negative-side switch unit 63 to the ON state. As a result, current flows through the paths RD1, RD2, and RD3 shown in Figure 5, and power from the battery 20 is supplied to the first capacitor 54 and the second capacitor 64. In other words, a pre-charge operation is performed to charge the first capacitor 54 and the second capacitor 64.

[0092] If the switching condition is met during the execution of this first control, the control unit 81 executes 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 target.

[0093] The above-mentioned switching conditions may also be that the potential difference across the relay to be switched falls below a predetermined value. The switching conditions may also be that the value of the current flowing through the parallel relays (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) of the parallel circuit (in this embodiment, the positive-side parallel circuit 55A, 55B, or the negative-side parallel circuit 65A, 65B) provided in parallel with the relay to be switched falls below a predetermined value. The switching conditions may also be that a predetermined time has elapsed since the start of the first control. If the power supply target is the first power supply target 21, the switching conditions may also be that the voltage of the first capacitor 54 exceeds a predetermined value. If the power supply target is the second power supply target 22, the switching conditions may also be that the voltage of the second capacitor 64 exceeds a predetermined value. The switching conditions may also be other conditions.

[0094] 3-5. Selecting the target for switching The control unit 81 compares the degree of degradation 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 the relay to be switched based on the comparison result. More specifically, the control unit 81 selects the relay with the least degree of degradation as the relay to be switched.

[0095] The degree of relay degradation is determined based on factors such as the potential difference across the relay when it is ON, the current flowing through the relay, the resistance when the relay is ON, the number of relay operations, the temperature when the relay is ON (more specifically, the temperature of the relay contacts), and combinations of these factors. The degree of relay degradation may be these values ​​themselves, or it may be a value obtained by substituting these values ​​into a calculation formula.

[0096] The degree of relay degradation is greater the greater the potential difference across the relay. The degree of relay degradation is greater the smaller the current flowing through the relay. The degree of relay degradation is greater the greater the resistance when the relay is ON. The degree of relay degradation is greater the greater the number of relay operations. Assuming a constant current flowing through the relay, the degree of relay degradation is greater the greater the temperature when the relay is ON.

[0097] The control unit 81, as a method for determining the potential difference across the relay, for example, determines the potential difference across the relay that has been switched to the ON state by the first control or the second control.

[0098] The control unit 81 determines the value of the current flowing through a relay, for example, by determining the value of the current flowing through a relay that has been switched to the ON state by the first control or the second control.

[0099] The control unit 81 determines the resistance value of the relay when it is in the ON state by, for example, the method described above, determining the potential difference across the relay and the value of the current flowing through the relay. Then, the control unit 81 determines the resistance value of the relay based on the determined potential difference and current values.

[0100] The control unit 81 determines the number of relay operations by, for example, counting the number of times each relay is switched to the ON state by the second control.

[0101] The control unit 81 determines the temperature of a relay when it is in the ON state, for example, by determining the temperature of a relay that has been switched to the ON state by the first control or the second control.

[0102] 4. Examples of effects The vehicle power supply unit 10 can supply power from the battery 20 to the first power supply target 21 via the positive-side common path 30 and the first positive-side branch path 31, and to the second power supply target 22 via the positive-side common path 30 and the second positive-side branch path 32. Moreover, even if the first positive-side branch path 31 is disconnected on the battery 20 side of the positive-side switch unit 53, the vehicle power supply unit 10 can supply power to the first power supply target 21 via the second positive-side branch path 32 by switching the positive-side switch unit 53 to the ON state. Furthermore, even if the second positive-side branch path 32 is disconnected on the battery 20 side of the positive-side switch unit 53, the vehicle power supply unit 10 can supply power to the second power supply target 22 via the first positive-side branch path 31 by switching the positive-side switch unit 53 to the ON state. In other words, the vehicle power supply unit 10 is less likely to experience interruptions in the power supply from the battery 20 to the first power supply target 21 and the second power supply target 22.

[0103] The vehicle power supply unit 10 can perform a pre-charge operation by using the positive-side parallel circuits 55A and 55B to charge the first capacitor 54 and the second capacitor 64 before switching the first positive-side relay 51 or the second positive-side relay 52 to the ON state. By taking this measure, the vehicle power supply unit 10 can suppress the inrush current flowing through the relay that is switched to the ON state among the first positive-side relay 51 and the second positive-side relay 52, and consequently suppress the deterioration of the relay.

[0104] After the pre-charge operation, the first positive-side relay 51 or the second positive-side relay 52 switches to the ON state, which suppresses relay degradation, but degradation can still occur. The vehicle power supply unit 10 can perform a pre-charge operation to charge the first capacitor 54 and the second capacitor 64 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 unit 53, and the negative-side switch unit 63 are ON, and the first positive-side relay 51 or the second positive-side relay 52 is ON. Then, after this pre-charge operation, the vehicle power supply unit 10 switches the first negative-side relay 61 or the second negative-side relay 62, which is installed in parallel with the negative-side parallel relay (more specifically, the first negative-side parallel relay 67 or the second negative-side parallel relay 68) that is ON, to the ON state. This allows power from the battery 20 to be supplied to the first power supply target 21 and the second power supply target 22 without going through the negative-side resistor 66. By performing this operation, the deterioration of the first positive-side relay 51 and the second positive-side relay 52 is more effectively suppressed.

[0105] The vehicle power supply unit 10 can perform a pre-charge operation on the parallel circuits (in this embodiment, the positive-side parallel circuits 55A, 55B and the negative-side parallel circuits 65A, 65B) that are connected in parallel to the relay to be switched by executing a first control. Then, the vehicle power supply unit 10 switches the relay to be switched to the ON state by executing a second control. In other words, the vehicle power supply unit 10 can select the relay to be switched to the ON state after the pre-charge operation from four relays: 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.

[0106] The vehicle power supply unit 10 can reflect the degree of relay degradation in the selection of the relay to be switched from 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. Furthermore, the vehicle power supply unit 10 selects the relay with the least degree of degradation as the relay to be switched. As a result, the vehicle power supply unit 10 makes it easier to degrade each relay evenly, thus extending the lifespan of the device including the relays.

[0107] The vehicle power supply unit 10 can share the negative electrode resistor 66 between the negative electrode parallel circuit 65A, which is provided in parallel with the first negative electrode relay 61, and the negative electrode parallel circuit 65B, which is provided in parallel with the second negative electrode relay 62.

[0108] Even if the first negative-side branch circuit 41 is disconnected on the battery 20 side of the negative-side switch unit 63, the vehicle power supply unit 10 can electrically connect the first power supply target 21 to the negative terminal of the battery 20 via the second negative-side branch circuit 42 by switching the negative-side switch unit 63 to the ON state. Similarly, even if the second negative-side branch circuit 42 is disconnected on the battery 20 side of the negative-side switch unit 63, the vehicle power supply unit 10 can electrically connect the second power supply target 22 to the negative terminal of the battery 20 via the first negative-side branch circuit 41 by switching the negative-side switch unit 63 to the ON state. In other words, the vehicle power supply unit 10 is less likely to experience interruptions in the power supply from the battery 20 to the first power supply target 21 and the second power supply target 22.

[0109] The thermal fuse 59 is located in the path on the battery 20 side of the negative electrode side switch section 63 in the first negative electrode side branch circuit 41. The vehicle power supply unit 10 can blow the path in which the thermal fuse 59 is located if the thermal fuse 59 exceeds its blowing temperature. Moreover, even if the above path is blown, the vehicle power supply unit 10 can bypass the blown path from the second negative electrode side branch circuit 42 and continue supplying power to the first power supply target 21 or the second power supply target 22.

[0110] <Second Embodiment> The vehicle power supply unit 210 of the second embodiment has a configuration that mainly omits the negative-side parallel circuits 65A, 65B and the negative-side switch unit 63 from the vehicle power supply unit 10 of the first embodiment. In the second embodiment, the same reference numerals are used for components that are the same as in the first embodiment, and detailed explanations are omitted.

[0111] As shown in Figure 6, the vehicle power supply system 200, which includes the vehicle power supply device 210 of the second embodiment, comprises a battery 20, a first power supply target 21, a second power supply target 22, a first capacitor 54, and a second capacitor 64.

[0112] 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.

[0113] The vehicle power supply unit 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 and 55B, and a thermal fuse 59.

[0114] The vehicle power supply unit 210 includes voltage detection units 70, 71, 74, 75, current detection unit 76, temperature detection units 77, 78, and control unit 81.

[0115] When the start conditions for starting the charging and discharging of the battery 20 are met, the control unit 81 causes a parallel circuit (in this embodiment, the positive-side parallel circuit 55A or the positive-side parallel circuit 55B) connected in parallel with the relay to be switched to perform a pre-charge operation. In this embodiment, the first positive-side relay 51 and the second positive-side relay 52 can be the relays to be switched. After causing the pre-charge operation, the control unit 81 executes control to switch the relay to be switched to the ON state.

[0116] The control unit 81 compares the degree of degradation of the first positive-side relay 51 and the second positive-side relay 52, and selects the relay to be switched based on the comparison result. The control unit 81 selects the relay with the least degree of degradation as the relay to be switched.

[0117] In the vehicle power supply device 210 of the second embodiment, a pre-charge operation can be performed to charge the first capacitor 54 and the second capacitor 64 using the positive side parallel circuits 55A and 55B, and then the first positive side relay 51 or the second positive side relay 52 can be switched to the ON state. By taking the above measures, the vehicle power supply device 210 can suppress the inrush current flowing through the relay that is switched to the ON state among the first positive side relay 51 and the second positive side relay 52, and consequently, can suppress the deterioration of the relay.

[0118] The vehicle power supply unit 210 can reflect the degree of relay degradation in the selection of the relay to be switched between the first positive-side relay 51 and the second positive-side relay 52. ​​Furthermore, the vehicle power supply unit 210 selects the relay with the least degree of degradation as the relay to be switched. As a result, the vehicle power supply unit 210 makes it easier to degrade each relay evenly, thus extending the lifespan of the device including the relays.

[0119] <Other Embodiments> This disclosure is not limited to the embodiments described above and in the drawings. For example, any combination of the features of the embodiments described above or below is possible as long as it does not contradict each other. Furthermore, any feature of the embodiments described above or below may be omitted unless explicitly stated as essential. In addition, the embodiments described above may be modified as follows.

[0120] In the above embodiment, the thermal fuse 59 was provided in the first negative electrode side branch 41, but the thermal fuse 59 may be provided in a different path. For example, the thermal fuse 59 may be provided in the first positive electrode side branch 31, the second positive electrode side branch 32, or the second negative electrode side branch 42. The thermal fuse 59 may be provided in multiple paths.

[0121] In the above embodiment, the circuit section was a positive-side parallel circuit 55A, 55B, but other configurations are also possible. For example, the circuit section may be a DC-DC converter.

[0122] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is not limited to the embodiments disclosed herein, and is intended to include all modifications within the scope set forth in the claims or within the scope equivalent to the claims. [Explanation of symbols]

[0123] 10... Vehicle power supply unit 20… Battery 21…First electricity supply target 22…Second power supply target 23…Inverter 24…motor 30… Common path on the positive side 31...First positive pole side branch 32...Second positive pole side branch 33…First positive electrode side conductive path 34…Second positive electrode side conductive path 40... Common path on the negative side 41...First negative pole side branch 42...Second negative pole side branch 43...First negative electrode conductive path 44…Second negative electrode conductive 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 electrode side resistance section 57…First positive side parallel relay 58…Second positive side parallel relay 59… Thermal fuse 61…First negative side relay 62...Second negative side relay 63... Negative side switch section 64...Second capacitor 65A…Negative side parallel circuit (parallel circuit) 65B…Negative side parallel circuit (parallel circuit) 66... ​​Negative electrode side resistance section 67…First negative side parallel relay 68...Second negative side parallel relay 70...Voltage detection unit 71...Voltage detection unit 72...Voltage detection unit 73...Voltage detection unit 74...Voltage detection unit 75...Voltage detection unit 76...Current detection unit 77...Temperature detection unit 78...Temperature detection unit 79...Temperature detection unit 80...Temperature detection unit 81... Control Unit 100... Vehicle power supply system 200... Vehicle power supply system 210... Vehicle power supply unit RA1…Route RA2…Route RA3…Route RB1…Route RB2…Route RB3… Route RC1…Route RC2… Route RC3… Route RD1…Route RD2… Route RD3… Route

Claims

1. A vehicle power supply device used in an in-vehicle power supply system comprising: a battery; a common positive terminal connected to the positive terminal of the battery; a first positive branch path branching from the common positive terminal; a first power supply target connected to the first positive branch path; a second positive branch path branching from the common positive terminal; and a second power supply target connected to the second positive branch path, wherein Between the battery and the first power supply target, a first positive-side relay is provided in the first positive-side branch circuit, Between the battery and the second power supply target, a second positive-side relay is provided in the second positive-side branch circuit, The system comprises a positive-side switch section provided between a first positive-side conductive path, which is a path on the first power supply target side of the first positive-side branch path that is closer to the first power supply target than the first positive-side relay, and a second positive-side conductive path, which is a path on the second power supply target side of the second positive-side branch path that is closer to the second power supply target than the second positive-side relay, The in-vehicle power supply system comprises a first capacitor connected to the first positive electrode conductive path and a second capacitor connected to the second positive electrode conductive path. Furthermore, the system includes a circuit that performs a pre-charge operation, supplying power to at least one of the first capacitor and the second capacitor when the first positive relay and the second positive relay are in the off state. The in-vehicle power supply system comprises a negative-side common path connected to the negative terminal of the battery, a first negative-side branch path branching from the negative-side common path and connected to the first power supply target, and a second negative-side branch path branching from the negative-side common path and connected to the second power supply target. Furthermore, a negative electrode side switch section is provided between the first negative electrode side branch path and the second negative electrode side branch path, Between the battery and the negative electrode side switch section, a first negative electrode side relay is provided in the first negative electrode side branch path, Between the battery and the negative electrode side switch section, a second negative electrode side relay is provided in the second negative electrode side branch circuit, It comprises a parallel circuit having a resistor and a parallel relay connected in series, The parallel circuit is provided in parallel with each of the first negative-side relay and the second negative-side relay. Vehicle power supply unit.

2. The circuit section has the parallel circuit provided in parallel with each of the first positive-side relay and the second positive-side relay, Furthermore, the system 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 relays. The control unit, When the start condition for starting the charging and discharging of the battery is met, a first control is executed to turn on the parallel relay of the parallel circuit which is provided in parallel with the relay to be switched, among the first positive relay, the second positive relay, the first negative relay, and the second negative relay. If the switching condition is met during the execution of the first control, the second control is executed to switch the relay to the ON state. The vehicle power supply device according to claim 1.

3. The control unit compares the degree of deterioration of the first positive relay, the second positive relay, the first negative relay, and the second negative relay, and selects the relay to be switched based on the comparison result. The vehicle power supply device according to claim 2.

4. The control unit selects the relay with the least degree of degradation as the relay to be switched. The vehicle power supply device according to claim 3.

5. The parallel circuit provided in parallel with the first negative-side relay has a configuration in which the negative-side resistor as the resistor and the 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 has a configuration in which the negative-side resistor and the second negative-side parallel relay, which is the parallel relay, are connected in series. A vehicle power supply device according to any one of claims 1 to 4.

6. A vehicle power supply device used in an in-vehicle power supply system comprising: a battery; a common positive terminal connected to the positive terminal of the battery; a first positive branch path branching from the common positive terminal; a first power supply target connected to the first positive branch path; a second positive branch path branching from the common positive terminal; and a second power supply target connected to the second positive branch path, wherein Between the battery and the first power supply target, a first positive-side relay is provided in the first positive-side branch circuit, Between the battery and the second power supply target, a second positive-side relay is provided in the second positive-side branch circuit, The system comprises a positive-side switch section provided between a first positive-side conductive path, which is a path on the first power supply target side of the first positive-side branch path that is closer to the first power supply target than the first positive-side relay, and a second positive-side conductive path, which is a path on the second power supply target side of the second positive-side branch path that is closer to the second power supply target than the second positive-side relay, The in-vehicle power supply system comprises a first capacitor connected to the first positive electrode conductive path and a second capacitor connected to the second positive electrode conductive path. Furthermore, the circuit unit performs a pre-charge operation that supplies power to at least one of the first capacitor and the second capacitor when the first positive relay and the second positive relay are in the off state, The system comprises the first positive-side relay, the second positive-side relay, and a control unit that controls the circuit section, When the start condition for starting the charging and discharging of the battery is met, the control unit causes the circuit unit to perform the pre-charge operation, and then executes control to switch the relay to be switched on among the first positive side relay and the second positive side relay to the ON state. Furthermore, the control unit compares the degree 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. Vehicle power supply unit.

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