CN113386693B

CN113386693B - Power supply device for vehicle

Info

Publication number: CN113386693B
Application number: CN202110195167.8A
Authority: CN
Inventors: 松尾雄平
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2020-03-11
Filing date: 2021-02-20
Publication date: 2024-09-27
Anticipated expiration: 2041-02-20
Also published as: JP7010989B2; JP2021142824A; CN113386693A

Abstract

A power supply device for a vehicle, which, even when an abnormality occurs in a power supply system, continues the supply of electric power to an important load, is provided with: a first power supply; a first load that is connected to the first power supply through a first connection point and that assumes an important function related to running or stopping of the vehicle; a second power supply connected in parallel with the first power supply; a second load that is connected to the second power supply through a second connection point and that assumes an important function related to running or stopping of the vehicle; and a third power supply that is connected to the first power supply via a third connection point and is capable of outputting a voltage higher than a voltage of the first power supply, the vehicle power supply device including: a first switch disposed between the first connection point and the third connection point; a second switch disposed between the second connection point and the third connection point; and a control device that controls the first switch and the second switch.

Description

Power supply device for vehicle

Technical Field

The present invention relates to a power supply device for a vehicle.

Background

Conventionally, in a power supply control technique for a vehicle, a technique is known in which, when an abnormality occurs in a main power supply, power is supplied from a sub-power supply to a specific important load, thereby continuing supply of power to the specific important load (for example, japanese patent application laid-open No. 2017-218013).

Disclosure of Invention

Problems to be solved by the invention

However, in the above-described power supply control technique for a vehicle, when an abnormality such as a voltage drop due to ground occurs in the power supply system, the voltage of the power supply system may not rise even if electric power is supplied from the secondary power supply, and the load may not be driven. That is, the conventional method has the following problems: depending on the type of abnormality generated in the power supply system, the supply of electric power to a specific important load may not be continued.

The present invention has been made in view of such a situation, and an object thereof is to continue supply of electric power to an important load even when an abnormality occurs in a power supply system.

Means for solving the problems

The power supply device for a vehicle of the present invention adopts the following configuration.

(1) A power supply device for a vehicle according to an aspect of the present invention includes: a first power supply; a first load that is connected to the first power supply through a first connection point and that assumes an important function related to running or stopping of the vehicle; a second power supply connected in parallel with the first power supply; a second load that is connected to the second power supply through a second connection point and that assumes an important function related to running or stopping of the vehicle; and a third power supply that is connected to the first power supply via a third connection point and is capable of outputting a voltage higher than a voltage of the first power supply, wherein the vehicle power supply device includes: a first switch disposed between the first connection point and the third connection point; a second switch disposed between the second connection point and the third connection point; and a control device that controls the first switch and the second switch.

(2) The vehicle power supply device according to (1) above, wherein the control device controls the first switch and the second switch to be in a disconnected state when an abnormality occurs on the third power supply side with respect to the third connection point.

(3) The vehicle power supply device according to (1) or (2) above, wherein the control device controls the first switch and the second switch to a disconnected state when an abnormality occurs on the first load side or the second load side of the first switch.

(4) The vehicle power supply device according to any one of (1) to (3) above, wherein the control device controls the first switch and the second switch to be in a non-connected state when an abnormality occurs on the first load side or on the second load side than the first switch, controls the first switch to be in a connected state when a potential difference between the first connection point and the third connection point is smaller than a predetermined potential difference when the first switch is controlled to be in a non-connected state, and controls the first switch to be in a connected state when a potential difference between the second connection point and the third connection point is smaller than a predetermined potential difference when the second switch is controlled to be in a non-connected state.

(5) The vehicle power supply device according to any one of (1) to (4) above, further comprising a third load connected to the third connection point and serving as a normal load, the normal load being a function other than an important function related to running or stopping of the vehicle, wherein the control device supplies electric power to the third load from the first power supply or the second power supply, or from both the first power supply and the second power supply, when output from the third power supply is stopped.

(6) The power supply device for a vehicle according to any one of (1) to (5) above, wherein the first power supply and the second power supply include power supplies that can be charged and discharged.

(7) The vehicle power supply device according to any one of (1) to (6) above, wherein the control device acquires information indicating a voltage of the first connection point when the first switch is controlled to be in a disconnected state and a voltage of the second connection point when the second switch is controlled to be in a disconnected state, and the control device controls the first switch to be in a connected state if the voltage of the first connection point is within a predetermined range, and controls the second switch to be in a connected state if the voltage of the second connection point is within a predetermined range.

(8) The vehicle power supply device according to any one of (1) to (7) above, wherein the control device determines that the first switch is in a stuck-at-connected state when a potential difference between the first connection point and the third connection point is smaller than a predetermined potential difference when the first switch is controlled to be in a connected state, and determines that the second switch is in a stuck-at-connected state when a potential difference between the second connection point and the third connection point is smaller than a predetermined potential difference when the second switch is controlled to be in a connected state.

(9) The vehicle power supply device according to any one of (1) to (8) above, further comprising a voltage control device that controls an output voltage of the third power supply, wherein the control device obtains information indicating a voltage of the first connection point when the first switch is controlled to be in a disconnected state and a voltage of the second connection point when the second switch is controlled to be in a disconnected state, and wherein the voltage control device controls the output voltage of the third power supply to be higher than the voltages of the first connection point and the second connection point.

(10) The vehicle power supply device according to (9) above, wherein the voltage control device controls the output voltage of the third power supply to a voltage higher than the voltages of the first connection point and the second connection point, and the control device determines that the first switch is in a stuck-open state when a potential difference between the first connection point and the third connection point in a case where the first switch is controlled to be in a connected state is larger than a predetermined value, and determines that the second switch is in a stuck-open state when a potential difference between the second connection point and the third connection point in a case where the second switch is controlled to be in a connected state is larger than a predetermined value.

(11) The vehicle power supply device according to (9) or (10) above, wherein the control device acquires information indicating a voltage of the first connection point when the first switch is in the disconnected state and a voltage of the second connection point when the second switch is in the disconnected state, and wherein the voltage control device controls the first switch to the connected state in a state in which the output voltage of the third power supply is controlled to a voltage obtained based on the voltage of the first connection point when the first switch is in the disconnected state, and controls the second switch to the connected state in a state in which the output voltage of the third power supply is controlled to a voltage obtained based on the voltage of the second connection point when the second switch is in the disconnected state.

(12) The power supply device for a vehicle according to any one of (1) to (11) above, further comprising a third switch arranged in parallel with the first switch between the first connection point and the third connection point, wherein the first switch is in a non-connected state when not controlled, and the third switch is in a connected state when not controlled.

(13) The vehicle power supply device according to the above (12), wherein the control device determines that the third switch is in a stuck-at fault in a disconnected state when the output from the third power supply is stopped, and the first switch and the second switch are controlled to be in a disconnected state and the third switch is controlled to be in a connected state, when a potential difference between the first connection point and the third connection point is greater than a predetermined value.

(14) The vehicle power supply device according to (12) or (13) pertaining to (9) to (11), wherein the control device determines that the third switch is in a stuck-at failure in a connected state when a potential difference between the first connection point and the third connection point in a state where the first switch, the second switch, and the third switch are controlled to be in a disconnected state and an output voltage of the third power supply is controlled to be a voltage higher than an output voltage of the first power supply is smaller than a predetermined potential difference.

(15) The power supply device for a vehicle according to any one of (1) to (14) above, wherein the first load and the second load each include at least one of an auxiliary load for braking of the vehicle, an auxiliary load for steering, and an auxiliary load for driving assistance or automatic driving of the vehicle.

(16) In the power supply device for a vehicle according to any one of (1) to (15) above, the second power supply includes a lithium ion secondary battery.

Effects of the invention

According to the present invention, it is possible to provide a power supply device for a vehicle in which the supply of electric power to an important load is not interrupted even when an abnormality occurs in the power supply system.

Drawings

Fig. 1 is a diagram showing an example of a functional configuration of a vehicle power supply device according to an embodiment of the present invention.

Fig. 2 is a diagram showing an example of a correspondence relationship between the state of a switch and the state of charge and discharge in the embodiment of the present invention.

Fig. 3 is a diagram showing an example of the timing of the switching operation of the switch when an abnormality occurs in the third power supply system in the embodiment of the present invention.

Fig. 4 is a diagram showing an example of the timing of the switching operation of the switch when an abnormality occurs in the first power supply system in the embodiment of the present invention.

Fig. 5 is a diagram showing an example of the timing of the switching operation of the switch when an abnormality occurs in the second power supply system in the embodiment of the present invention.

Fig. 6 is a diagram showing an example of the timing of the switching operation of the switch at the time of switching the ignition power supply in the embodiment of the present invention.

Fig. 7 is a diagram showing an example of timing of an ECU rewriting operation when the ignition is turned off in the embodiment of the present invention.

Fig. 8 is a diagram showing an example of the reverse connection confirmation operation of the battery in the embodiment of the present invention.

Fig. 9 is a diagram showing an example of timing of the inter-battery current suppressing operation when the ignition power is turned on in the embodiment of the present invention.

Fig. 10 is a diagram showing an example of a series of operations for detecting adhesion failure of the first switch, the second switch, and the third switch in the embodiment of the present invention.

Fig. 11 is a diagram showing an example of timing of a reconnection operation after occurrence of an abnormality in the embodiment of the present invention.

Fig. 12 is a diagram showing an example of a series of operations of reconnecting after occurrence of an abnormality in the embodiment of the present invention.

Reference numerals illustrate:

100 … power supply device for vehicle,

10 … A first power supply system,

20 … A second power supply system,

30 … Third power supply system,

11 … A first power supply,

12 … A first load,

21 … A second power supply,

22 … A second load,

31 … A third power supply,

32 … A third load,

13 … Starter motor,

40 … Connecting part,

41. 42, 43, 49 … Switches,

90 … Control means,

91 … Potential measuring part,

92 … Voltage control device,

V1 … first power supply system potential,

V2 … potential of the second power supply system,

V3 … third power supply system potential,

The connection point of P1, P2 and P3 …,

L1, L11, L12, L13, L2, L21, L22, L23, L3, L31, L32 … connecting lines,

F11, F12, F21, F22, F32 … fuses.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals are used for members having the same functions, and the description thereof may be omitted.

The power supply device 100 for a vehicle according to the embodiment of the present invention is mounted on an electric vehicle. Electric vehicles include various vehicles such as electric vehicles, hybrid electric vehicles (HEV; hybrid ELECTRICAL VEHICLE), and Fuel cell vehicles (FCV; fuel CELL VEHICLE). The electric motor vehicle is driven by using a storage battery as a power source. The hybrid electric vehicle is driven by using a battery and an internal combustion engine as power sources. The fuel cell motor vehicle is driven by using a fuel cell as a driving source. In the following description, these types of vehicles are collectively referred to as electric vehicles without distinction.

[ Functional Structure of Power supply device 100 for vehicle ]

Fig. 1 is a diagram showing an example of a functional configuration of a vehicle power supply device 100 according to an embodiment of the present invention.

The vehicle power supply device 100 includes a first power supply system 10, a second power supply system 20, a third power supply system 30, a connection unit 40, a switch 42, and a control device 90.

[ Connection portion 40]

The connection unit 40 is disposed between the first power supply system 10 and the third power supply system 30, and is configured to switch a connection state between the first power supply system 10 and the third power supply system 30. As an example, the connection unit 40 includes a switch 41. The switch 41 is constituted by, for example, an electromagnetic on-off device, a semiconductor switch, or the like, and performs an opening and closing operation based on the control of the control device 90. The switch 41 is also referred to as a first switch.

The point at which the connection unit 40 is connected to the first power supply system 10 is referred to as a connection point P1, and is also referred to as a first connection point. The point at which the connection unit 40 is connected to the third power supply system 30 is referred to as a connection point P3, and is also referred to as a third connection point. The switch 41 is disposed between the connection point P1 and the connection point P3.

[ First Power supply System 10]

The first power supply system 10 includes a first power supply 11 and a first load 12. The first power supply 11 and the first load 12 are connected by a connection line L1.

The first power supply 11 includes a chargeable and dischargeable power supply in this example. The chargeable and dischargeable power supply is a secondary battery such as a lead acid battery. The first power supply 11 is charged with electric power supplied from the third power supply 31.

The first load 12 includes a load that assumes an important function related to running or stopping of the vehicle. For example, the first load 12 may include an auxiliary load for braking of the vehicle, an auxiliary load for steering, and an auxiliary load for driving support or automatic driving of the vehicle. The first load 12 is connected to the first power source 11 at a connection point P1. That is, the first load 12 is connected to the first power supply 11 at the connection point P1, and plays an important role in the running or stopping of the vehicle.

The first power supply system 10 may include a starter motor 13, a fuse F11, and a fuse F12.

The starter motor 13 is a motor that starts an engine (not shown) as an internal combustion engine by applying a starting torque (cranking or the like) to the engine.

The starter motor 13 and the first power supply 11 are connected to the connection line L11. The first load 12 is connected to the connection line L12. The connection portion 40 is connected to the connection line L13.

When the connection lines L11, L12, and L13 are not distinguished, they are also collectively referred to as connection lines L1.

In this example, the fuses F11 and F12 are configured to blow when a large current equal to or greater than the rated current flows.

The fuse F11 is provided between the connection line L11 and the connection line L13, and when an abnormality (for example, grounding) occurs on the connection line L11 side with respect to the fuse F11, the supply of excessive current from the third power supply system 30 side or the second power supply system 20 side is suppressed. When an abnormality (for example, grounding) occurs on the connection line L13 side of the fuse F11 with respect to the fuse F11, the fuse F11 suppresses the supply of excessive current from the first power supply 11.

The fuse F12 is provided between the connection line L12 and the connection line L13, and when an abnormality (for example, grounding) occurs on the connection line L12 side with respect to the fuse F12, the supply of excessive current from the third power supply system 30 side, the second power supply system 20 side, or the first power supply 11 is suppressed.

Third power supply system 30

The third power supply system 30 includes a third power supply 31 and a third load 32. The third power supply 31 and the third load 32 are connected to the connection point P3.

The connection point P3 is connected to the connection point P1 via the connection portion 40. That is, the third power supply 31 is connected to the first power supply 11 at a connection point P3. In the present embodiment, the third power supply 31 can output a voltage higher than the voltage of the first power supply 11.

The third power supply 31 includes an ACG (AC Generator) in this example. The third power supply 31 supplies electric power obtained by converting ac obtained by ACG into dc. As another example, the third power supply 31 may be provided with a device (for example, a DC/DC converter) for converting and supplying power obtained from another DC power supply.

The third load 32 bears a normal load as a function related to the normal operation of the vehicle. Here, the functions related to the normal operation of the vehicle include functions not related to the running or stopping of the vehicle, and unnecessary functions among functions related to the running or stopping of the vehicle. The load that takes on the function related to the running or stopping of the vehicle is also referred to as an important load, and the load that takes on the function related to the normal operation of the vehicle is also referred to as a non-important load. The normal load is a function other than an important function related to running or stopping of the vehicle.

The third load 32 is connected to the connection point P3. That is, the third load 32 is connected to the connection point P3, and functions as a normal load other than the important function related to the running or stopping of the vehicle.

The third power supply 31 is connected to the connection line L31, and the third load 32 is connected to the connection line L32. When the connection line L31 and the connection line L32 are not distinguished, they are also collectively referred to as a connection line L3.

The third power supply system 30 may also include a fuse F32.

In this example, the fuse F32 is configured to blow when a large current equal to or greater than the rated value flows.

The fuse F32 is provided between the connection line L31 and the connection line L32, and when an abnormality (for example, grounding) occurs on the connection line L32 side with respect to the fuse F32, the supply of excessive current from the first power supply system 10 side, the second power supply system 20 side, or the third power supply 31 is suppressed.

[ Switch 42]

The switch 42 is disposed between the third power supply system 30 and the second power supply system 20, and is used for switching the connection state between the third power supply system 30 and the second power supply system 20. The switch 42 is constituted by, for example, an electromagnetic on-off device, a semiconductor switch, or the like, and is opened and closed by the control of the control device 90. Switch 42 is also referred to as a second switch.

The point at which the switch 42 is connected to the second power supply system 20 is referred to as a connection point P2, and is also referred to as a second connection point. The switch 42 is disposed between the connection point P2 and the connection point P3.

Note that, unless the switch included in the connection unit 40 is distinguished from the switch 42, the switch is collectively referred to as a switch 49.

Second power supply System 20

The second power supply system 20 includes a second power supply 21 and a second load 22. The second power supply 21 and the second load 22 are connected to the connection point P2.

The second load 22 includes a load that takes on an important function related to running or stopping of the vehicle. For example, the second load 22 may include an auxiliary load for braking of the vehicle, an auxiliary load for steering, an auxiliary load for driving support of the vehicle, or automatic driving. The second power supply 21 includes a chargeable and dischargeable power supply in this example. A lithium ion secondary battery is an example of a power source capable of charge and discharge. In this case, the second power supply 21 includes a lithium ion secondary battery.

The connection point P2 is connected to the connection point P3 via the switch 42. The connection point P3 is connected to the connection point P1 via the connection portion 40. That is, the second power supply 21 is connected in parallel with the first power supply 11 at the connection point P2.

The second power supply system 20 may also include a fuse F21 and a fuse F22. The second power supply 21 is connected to the connection line L21. The second load 22 is connected to the connection line L22. The switch 42 is connected to the connection line L23.

When the connection lines L21, L22, and L23 are not distinguished from each other, they are also collectively referred to as connection lines L2.

In this example, the fuses F21 and F22 are configured to blow when a large current equal to or greater than the rated current flows.

The fuse F21 is provided between the connection line L21 and the connection line L23, and when an abnormality (for example, grounding) occurs on the connection line L21 side with respect to the fuse F21, the supply of excessive current from the third power supply system 30 side or the first power supply system 10 side is suppressed. When an abnormality (for example, grounding) occurs on the connection line L23 side of the fuse F21 with respect to the fuse F21, the fuse F21 suppresses the supply of an excessive current from the second power supply 21.

The fuse F22 is provided between the connection line L22 and the connection line L23, and when an abnormality (for example, grounding) occurs on the connection line L22 side with respect to the fuse F22, the supply of excessive current from the third power supply system 30 side, the first power supply system 10 side, or the second power supply 21 is suppressed.

[ Control device 90]

The control device 90 includes a processor CPU (Central Processing Unit) or the like. The control device 90 operates by software stored in ROM (Read Only Memory).

The control device 90 obtains a first power supply system potential V1 as a potential of the connection point P1, a second power supply system potential V2 as a potential of the connection point P2, and a third power supply system potential V3 as a potential of the connection point P3. Specifically, the control device 90 obtains the potential of each power supply system from a potential measuring unit 91, not shown.

In addition, the control device 90 controls the switch 49. Specifically, the control device 90 switches the connection state between the terminals of the switch 49. The control device 90 is physically connected to the switch 49 via a signal line. The control device 90 transmits an operation signal to the switch 49 via a signal line. The operation signal includes a signal to operate the switch 49 in the connected state and the disconnected state.

The control device 90 controls the switch 49 based on the electric potentials of the respective power supply systems acquired from the electric potential measuring unit 91.

The control operation of the control device 90 may be realized by hardware, and the software stored in ROM (Read Only Memory) may be operated after being developed to RAM (Random Access Memory).

[ Operation of Power supply device 100 for vehicle ]

In the vehicle power supply device 100, the control device 90 obtains the first power supply system potential V1, the second power supply system potential V2, and the third power supply system potential V3, and switches the state of the switch 49.

The control device 90 switches the state of the switch 49 to switch the charge/discharge states of the first power supply 11 and the second power supply 21.

When detecting an abnormal voltage caused by ground or the like (when an abnormality occurs), the control device 90 can separate the power supply system in which the abnormality has occurred by controlling the switch 49 to the disconnected state.

The switching operation of the switch for switching the charge/discharge operation of each power supply and the operation at the time of occurrence of an abnormality will be described.

[ Switching operation for switching charge/discharge operations ]

In the figure, the horizontal axis shows time variations of the state of the first power supply 11 and the state of the second power supply 21 corresponding to the third power supply system potential V3, the state of the switch 41, and the connection state of the switch 42, with time being taken as the horizontal axis. In the figure, the vertical axis of the third power supply system potential V3 represents the voltage. The state of the switch 41 indicates the connection state of the switch 41. The state of the switch 42 indicates the connection state of the switch 42.

The switch 41 and the switch 42 are turned off before the ignition power is turned on (before time t ₁). The third power supply system potential V3 is also the same as 0V (ground potential) before the ignition power supply is turned on (before time t ₁). Accordingly, the first power supply 11 supplies electric power to the first load 12. That is, the state of the first power supply 11 is a discharge state. In addition, the second power supply 21 supplies electric power to the second load 22. That is, the state of the second power supply 21 is a discharge state.

In one example of the figure, at time t ₁, an ignition power supply is turned on by an ignition switch, not shown.

When the ignition power is turned on, the control device 90 controls the switch 41 and the switch 42 to be turned on. When the switch 41 and the switch 42 are controlled to be turned on and switched to the connected state, the first power supply 11 and the second power supply 21 further supply electric power to the third load 32.

After a predetermined time (time t ₂) has elapsed since the ignition power was turned on (time t ₁), the third power supply system potential V3 rises. In the present embodiment, the third power supply system potential V3 is higher than the output potential of the first power supply 11 and the output potential of the second power supply 21 ("Gr 1,2 battery open end voltage" in fig. 2). Therefore, the first power supply 11 and the second power supply 21 receive power from the third power supply 31. That is, the first power supply 11 and the second power supply 21 are switched to the charged state (time t ₂).

When the control device 90 turns off the switch 41 (time t ₃), the switch 41 is turned off. Accordingly, the supply of electric power from the third power supply 31 to the first power supply 11 is cut off. That is, the first power supply 11 is switched to the discharge state (time t ₃).

When the control device 90 switches the switch 41 to be turned on again (time t ₄), the switch 41 is switched to the connected state. Accordingly, the supply of electric power from the third power supply 31 to the first power supply 11 is restarted. That is, the first power supply 11 is switched to the charged state (time t ₄). When the control device 90 turns off the switch 42 (time t ₅), the switch 42 is turned off. Accordingly, the supply of electric power from the third power supply 31 to the second power supply 21 is cut off. That is, the second power supply 21 is switched to the discharge state (time t ₅).

As described above, in the vehicle power supply device 100, the control device 90 switches the connection state of the switch 49, and thereby the states (the charge state or the discharge state) of the first power supply 11 and the second power supply 21 are switched, respectively.

[ Action at occurrence of abnormality ]

In the vehicle power supply device 100, the control device 90 monitors the potentials of the first power supply system potential V1, the second power supply system potential V2, and the third power supply system potential V3, and switches the state of the switch 49 when an abnormality occurs in the potentials.

The switching operation of the switch 49 by the control device 90 when abnormality occurs in the respective potentials of the first power supply system potential V1, the second power supply system potential V2, and the third power supply system potential V3 will be described. The case where the third power supply system potential V3 is abnormal, the case where the first power supply system potential V1 is abnormal, and the case where the second power supply system potential V2 is abnormal will be described.

[ Action at occurrence of abnormality of third Power supply System potential V3 ]

In the figure, the horizontal axis shows time variations of the third power supply system potential V3, the first power supply system potential V1, the second power supply system potential V2, the state of the switch 41, and the state of the switch 42. In the figure, the vertical axes of the third power supply system potential V3, the first power supply system potential V1, and the second power supply system potential V2 represent voltages. The state of the switch 41 indicates the connection state of the switch 41. The state of the switch 42 indicates the connection state of the switch 42.

The control device 90 obtains the third power supply system potential V3, the first power supply system potential V1, and the second power supply system potential V2 measured by the potential measuring unit 91, not shown. The control device 90 determines that the electric power system is normal when the third power system electric potential V3 is in a range from the normal time maximum value V3MAX to the normal time minimum value V3MIN, and determines that the electric power system is abnormal when the third power system electric potential V3 is not in a range from the normal time maximum value V3MAX to the normal time minimum value V3 MIN. The control device 90 determines that the first power supply system potential V1 is normal when it is in a range from the normal time maximum value V1MAX to the normal time minimum value V1MIN, and determines that the first power supply system potential V1 is abnormal when it is not in a range from the normal time maximum value V1MAX to the normal time minimum value V1 MIN. The control device 90 determines that the second power supply system potential V2 is normal when the second power supply system potential V2 is in a range from the normal time maximum value V2MAX to the normal time minimum value V2MIN, and determines that the second power supply system potential V2 is abnormal when the second power supply system potential V2 is not in a range from the normal time maximum value V2MAX to the normal time minimum value V2 MIN.

In one example of the figure, an abnormality occurs in the third power supply system 30 at time t _p. That is, the state of the third power supply system 30 is normal before time t _p, and the state of the third power supply system 30 is abnormal after time t _p.

The control device 90 controls any of the switches 41 and 42 to be on when the third power supply system 30 is normal.

When an abnormality such as grounding occurs in the third power supply system 30, the third power supply system potential V3 decreases. At time t _p, the switch 41 is turned on, and thus the third power supply system 30 is connected to the first power supply system 10. Therefore, the first power supply system potential V1 decreases similarly to the decrease in the third power supply system potential V3. Further, at time t _p, the switch 42 is turned on, and therefore the third power supply system 30 is connected to the second power supply system 20. Therefore, the second power supply system potential V2 decreases as well as the decrease in the third power supply system potential V3.

The control device 90 detects that the third power supply system potential V3 is not in the interval from the normal time maximum value V3MAX to the normal time minimum value V3MIN (time t ₁). When detecting that the third power supply system potential V3 is not in the range from the maximum value V3MAX at normal time to the minimum value V3MIN at normal time, the control device 90 turns off the switches 41 and 42 (time t ₂). That is, when an abnormality occurs on the third power supply 31 side of the connection point P3, the control device 90 controls the switch 41 and the switch 42 to the disconnected state.

The switch 41 is controlled to be turned off, and thus the first power supply system 10 and the third power supply system 30 are brought into a disconnected state. Further, the switch 42 is controlled to be turned off, and therefore the second power supply system 20 and the third power supply system 30 are brought into a disconnected state. That is, the first power supply system 10 and the second power supply system 20 are no longer affected by the third power supply system 30.

The first power supply system 10 is no longer affected by the third power supply system 30, and thus power is supplied from the first power supply 11 to the first load 12. The first power supply system potential V1 starts to rise after the switch 41 is controlled to the disconnected state (after time t ₂). Since the third power supply system potential V3 is higher than the first power supply system potential V1, the first power supply system potential Vl after the switch 41 is controlled to the disconnected state (after time t ₂) is lower than before the occurrence of the abnormality in the third power supply system 30 (before time t _p).

In addition, as in the first power supply system 10, the second power supply system 20 is not affected by the third power supply system 30, and thus power is supplied from the second power supply 21 to the second load 22. The second power supply system potential V2 starts to rise after the switch 42 is controlled to the disconnected state (after time t ₂). Since the third power supply system potential V3 is higher than the second power supply system potential V2, the second power supply system potential V2 after the switch 42 is controlled to the disconnected state (after time t ₂) is lower than before the occurrence of the abnormality in the third power supply system 30 (before time t _p).

Therefore, in the present embodiment, even when an abnormality such as grounding occurs in the third power supply system 30, the first power supply system 10 and the second power supply system 20 can operate normally.

[ Action at occurrence of abnormality of first Power supply System potential V1 ]

In one example of the figure, an abnormality occurs in the first power supply system 10 at time t _p. That is, the state of the first power supply system 10 is the normal state before the time t _p, and the state of the first power supply system 10 is the abnormal state after the time t _p.

The control device 90 controls any of the switches 41 and 42 to be on when the first power supply system 10 is normal.

When an abnormality such as grounding occurs in the first power supply system 10, the first power supply system potential V1 decreases. At time t _p, the switch 41 and the switch 42 are turned on, and thus the first power supply system 10 is connected to the second power supply system 20. Therefore, the second power supply system potential V2 decreases similarly to the decrease of the first power supply system potential V1.

The control device 90 detects that the first power supply system potential V1 is not in the interval from the normal time maximum value V1MAX to the normal time minimum value V1MIN (time t ₁). When detecting that the first power supply system potential V1 is not in the range from the maximum value V1MAX at normal time to the minimum value V1MIN at normal time, the control device 90 turns off the switches 41 and 42 (time t ₂). That is, when an abnormality occurs on the first load 12 side with respect to the switch 41, the control device 90 controls the switch 41 to the disconnected state. The switch 41 and the switch 42 are controlled to be turned off, and thus the first power supply system 10 and the second power supply system 20 are disconnected. That is, the second power supply system 20 is no longer affected by the first power supply system 10.

The second power supply system 20 is no longer affected by the first power supply system 10, and thus power is supplied from the second power supply 21 to the second load 22. The second power supply system potential V2 starts to rise after the switch 41 and the switch 42 are controlled to the disconnected state (after time t ₂). Since the third power supply system potential V3 is higher than the second power supply system potential V2, the second power supply system potential V2 after the switch 41 and the switch 42 are controlled to the disconnected state (after time t ₂) is lower than before the occurrence of the abnormality in the first power supply system 10 (before time t _p).

Therefore, in the present embodiment, even when an abnormality such as grounding occurs in the first power supply system 10, the second power supply system 20 can be operated normally.

[ Action at occurrence of abnormality of the second Power supply System potential V2 ]

In one example of the figure, an abnormality occurs in the second power supply system 20 at time t _p. That is, the state of the second power supply system 20 is normal before time t _p, and the state of the second power supply system 20 is abnormal after time t _p.

The control device 90 controls any of the switches 41 and 42 to be on when the second power supply system 20 is normal.

When an abnormality such as grounding occurs in the second power supply system 20, the second power supply system potential V2 decreases. At time t _p, the switch 41 and the switch 42 are turned on, and thus the first power supply system 10 is connected to the second power supply system 20. Therefore, the first power supply system potential V1 decreases similarly to the decrease in the second power supply system potential V2.

The control device 90 detects that the second power supply system potential V2 is not in the interval from the normal time maximum value V2MAX to the normal time minimum value V2MIN (time t ₁). When detecting that the second power supply system potential V2 is not within the range from the maximum value V2MAX at normal time to the minimum value V2MIN at normal time, the control device 90 turns off the switches 41 and 42 (time t ₂). That is, when an abnormality occurs on the second load 22 side with respect to the switch 42, the control device 90 controls the switch 42 to the disconnected state. The switch 41 and the switch 42 are controlled to be turned off, and thus the first power supply system 10 and the second power supply system 20 are disconnected. That is, the first power supply system 10 is no longer affected by the second power supply system 20.

The first power supply system 10 is no longer affected by the second power supply system 20, and thus power is supplied from the first power supply 11 to the first load 12. After the switch 41 and the switch 42 are controlled to the disconnected state (after time t ₂), the first power supply system potential Vl starts to rise. Since the third power supply system potential V3 is higher than the first power supply system potential V1, the first power supply system potential V1 after the switch 41 and the switch 42 are controlled to the disconnected state (after time t ₂) is lower than before the occurrence of the abnormality in the second power supply system 20 (before time t _p).

Therefore, in the present embodiment, even when an abnormality such as grounding occurs in the second power supply system 20, the first power supply system 10 can be operated normally.

As described above, by switching the state of the switch 49, the control device 90 can normally use another power supply system in which no abnormality such as grounding has occurred even when any one of the third power supply system 30, the first power supply system 10, and the second power supply system 20 has an abnormality such as grounding.

The connection unit 40 may be provided with a switch 43 in addition to the switch 41. In this case, the switch 41 is a switch having a contact of a normally open (n.o.) type. The normally open contact is a contact that maintains a disconnected state when no operation signal is applied to the switch 49. Specifically, in the case of an electromagnetic switch (e.g., an electromagnetic contactor, an electromagnetic on-off device) in which the operation force is an electromagnetic force, the off state is maintained when the electromagnetic force by the operation current is not generated. That is, the switch 41 is in a disconnected state when not controlled. The switch 41 may also be a semiconductor switch.

The switch 43 is a switch having a normally closed (n.c.) type contact. The normally closed contact is a contact that maintains a conductive state when an operation signal is not applied to the switch 49. Specifically, in the case of an electromagnetic switch (e.g., an electromagnetic contactor, an electromagnetic on-off device) in which the operation force is an electromagnetic force, the on state is maintained when the electromagnetic force based on the operation current occurs. That is, the switch 43 is in a connected state when not controlled. The switch 43 may also be a semiconductor switch.

The switches 41 and 43 are arranged in parallel between the first power supply system 10 and the third power supply system 30, and switch the connection state between the first power supply system 10 and the third power supply system 30. That is, in the vehicle power supply device 100, the switch 41 having the normally open contact is connected in parallel with the switch 43 having the normally closed contact. Therefore, even in a state where power is not supplied to the control device 90, power can be supplied from the first power supply system 10 to the third load 32.

Note that the switch 43 is also described as a third switch.

[ Operation of the Power supply device 100 for vehicle at the time of ignition Power supply switching ]

In the present embodiment, the vehicle power supply device 100 obtains information on whether the ignition power supply is in an on state or an off state, which is determined based on the state of an ignition switch not shown. The control device 90 controls the switch 49 based on information of whether the ignition power source is in the on state or in the off state.

Fig. 6 is a diagram showing an example of the timing of the switching operation of the switch 49 at the time of switching the ignition power supply in the embodiment of the present invention.

In the figure, the horizontal axis represents time to indicate the time change of the state of the third power supply, the state of the switch 41, the state of the switch 42, and the state of the switch 43. Note that, at each time point, it is shown from which power source the power supplied to the third power supply system 30 is supplied as the third power supply system power.

When the ignition power is turned on (before time t ₁ or after time t ₄), the state of the third power supply 31 is an on state. The state of the switch 41 and the switch 42 is an on state, and the state of the switch 43 is an off state. That is, when the ignition power is turned on, the first power supply system 10 and the third power supply system 30 are connected by the switch 41, and the second power supply system 20 and the third power supply system 30 are connected by the switch 43.

In this state, the power supply to the third power supply system 30 is performed by the third power supply 31 itself. Or the power is supplied from the first power source 11 via the switch 41. Or the power is supplied from the second power source 21 via the switch 43.

When information indicating that the ignition power source is controlled to be in the off state is acquired (time t ₁), the control device 90 controls the state of the switch 43 to be on. When the ignition power source is turned off, the third power source 31 is also turned off.

The control device 90 controls the state of the switch 41 to be off at time t ₂ after a predetermined time has elapsed from time t ₁. In addition, the state of the switch 42 is controlled to be off. During the period from time t ₁ to time t ₂, both the switch 41 and the switch 43 are controlled to be on. Accordingly, in the period from time t ₁ to time t ₂, power is supplied from the first power supply 11 to the third power supply system 30 via the switch 41. Or power is supplied from the second power source 21 to the third power source system 30 via the switch 43.

After the switch 41 and the switch 43 are turned off (time t ₂), when the ignition power is turned off (a period from time t ₂ to time t ₃), power is supplied from the first power supply 11 to the third power supply system 30 via the switch 43.

When information indicating that the ignition power source is controlled to be on is acquired (time t ₃), the control device 90 controls the states of the switch 41 and the switch 42 to be on. The control device 90 controls the state of the switch 43 to be off at time t ₄ after a predetermined time has elapsed from time t ₃. During the period from time t ₃ to time t ₄, both the switch 41 and the switch 43 are turned on. Accordingly, in the period from time t ₃ to time t ₄, power is supplied from the first power source 11 to the third power source system 30 via the switch 41. Or the power supply from the second power source 21 to the third power source system 30 is performed via the switch 43.

After the switch 43 is turned off (time t ₄), when the ignition power is turned on (time t ₄ and later), the third power supply 31 itself supplies power to the third power supply system 30. Or the power is supplied from the first power source 11 via the switch 41. Or the power is supplied from the second power source 21 via the switch 43.

Therefore, even when the ignition power is switched between the on state and the off state, electric power is supplied to the third power supply system 30 through either one of the switch 41 and the switch 43 or through both of the switch 41 and the switch 43. That is, even when switching between the on state and the off state of the ignition power supply, the supply of electric power to the third power supply system 30 is not cut off.

In the present embodiment, the control device 90 controls the switch 41 and the switch 43 to control the switch when the ignition power is switched. However, at the time of switching the ignition power supply, either one of the switch 41 and the switch 43 or both of the switch 41 and the switch 43 may be turned on.

For example, the above-described functions may be realized by a configuration of hardware such as a delay circuit using a capacitor and a resistor.

[ Operation of the vehicle power supply device 100 during ECU rewriting when the ignition power is turned off ]

The vehicle power supply device 100 according to the present embodiment includes ECU (Engine Control Unit), which is not shown, and an ECU rewriting unit (not shown) that rewrites the ECU. In the present embodiment, the ECU and the ECU rewriting unit belong to the third load 32. That is, the ECU and the ECU rewriting unit belong to the third power supply system 30.

The control device 90 acquires ECU rewriting start information and ECU rewriting end information from the ECU rewriting unit. The control device 90 controls the switch 49 based on information acquired from the ECU rewriting unit.

In the figure, the horizontal axis shows time changes in the state of the switch 41, the state of the switch 42, and the state of the switch 43. In addition, it is shown from which power source the power supplied to the third load is supplied at each point in time.

The operation of the switch 49 at time t ₁, time t ₂, time t ₃, and time t ₄ is the same as that described with reference to fig. 6.

The control device 90 acquires ECU rewriting start information from the ECU rewriting unit (time t _ES). When the ECU rewriting start information is acquired from the ECU rewriting unit, the control device 90 turns on the state of the switch 42.

The control device 90 acquires ECU rewriting end information from the ECU rewriting unit (time t _EE). When the ECU rewriting end information is acquired from the ECU rewriting unit, the control device 90 turns off the state of the switch 42.

That is, the first power supply 11 or the third power supply 31 supplies electric power to the third load 32 (Gr 1 in fig. 7) before the ECU rewriting start information is acquired (before time t _ES) and after the ECU rewriting start information is acquired (after time t _EE). In addition, at the time of the ECU rewriting (from time tES to time t _EE), electric power is supplied from the first power supply 11 or the second power supply 21 to the third load 32 (in fig. 7, "Gr1 and Gr 2") in addition to the third power supply 31.

In the present embodiment, the states of the switch 41 and the switch 43 in the period from the time t _ES to the time t _EE may be arbitrary states. The states of the switch 41 and the switch 43 in the period from the time t _ES to the time t _EE include a case where both the switch 41 and the switch 43 are in an off state, a case where either the switch 41 or the switch 43 is in an on state, or a case where both the switch 41 and the switch 43 are in an on state.

That is, when the output from the third power supply 31 is stopped, the control device 90 supplies power to the third load 32 from the first power supply 11 or the second power supply 21, or from both the first power supply 11 and the second power supply 21.

[ Anti-connection confirmation action of storage Battery ]

In the present embodiment, the first power supply 11 includes a secondary battery. In this example, the secondary battery provided in the first power supply 11 is a removable secondary battery. The second power supply 21 includes a secondary battery. In this example, the secondary battery provided in the second power supply 21 is a removable secondary battery.

The vehicle power supply device 100 detects that the battery provided in the first power supply 11 or the battery provided in the second power supply 21 is reversely connected. The reverse connection means that the polarity of the battery itself is connected to the polarity of a battery connection unit (not shown) provided in the vehicle power supply device 100.

Fig. 8 is a diagram showing an example of the reverse connection confirmation operation of the battery in the embodiment of the present invention. (step S10) the control device 90 controls the switch 41, the switch 42, and the switch 43 to be turned off.

(Step S12) the control device 90 obtains the first power supply system potential V1 and the second power supply system potential V2 measured by the potential measuring unit 91, not shown.

The control device 90 compares the first power supply system potential V1 acquired from the potential measuring unit 91 with a predetermined value set in advance (step S14). The control device 90 compares the second power supply system potential V2 obtained from the potential measuring unit 91 with a predetermined value set in advance. When the first power supply system potential V1 and the second power supply system potential V2 are equal to or greater than the predetermined values (yes in step S14), the process proceeds to step S16. If at least one of the first power supply system potential V1 and the second power supply system potential V2 is not equal to or greater than a predetermined value (step S14; no), the process proceeds to step S18.

(Step S16) the control device 90 determines that the battery is normally connected, and ends the process.

(Step S18) the control device 90 determines that the battery is reversely connected, and ends the process.

The control device 90 obtains information indicating the voltage of the connection point P1 when the switch 41 is controlled to be in the non-connected state and the voltage of the connection point P2 when the switch 42 is controlled to be in the non-connected state, and controls the switch 41 to be in the connected state if the voltage of the connection point P1 is within a predetermined range and controls the switch 42 to be in the connected state if the voltage of the connection point P2 is within a predetermined range.

That is, when it is determined that the battery is reversely connected, the control device 90 does not turn on the switch 41 and the switch 42. Therefore, the potential of the reverse-connected battery can be prevented from being applied to the third power supply system 30.

[ Suppression action of Current between storage batteries at ignition Power on ]

In the present embodiment, the vehicle power supply device 100 may include a voltage control device 92 that controls the output voltage outputted from the third power supply 31.

The voltage control device 92 controls the output potential of the third power supply 31 based on the first power supply system potential V1 and the second power supply system potential V2. The operation of the voltage control device 92 when the ignition power is turned on will be described.

In one example of the figure, at time t _p, the ignition power is turned on. Before time t _p, the state of the switch 41 and the switch 42 is the off state. The output of the third power supply 31 is in an off state. That is, the output potential of the third power supply 31 is equivalent to 0V (ground potential). Therefore, before time t _p, the output potential of the third power supply 31 is equal to 0V (ground potential), the first power supply system potential V1 is equal to the output potential of the first power supply 11, and the second power supply system potential V2 is equal to the output potential of the second power supply 21.

The control device 90 obtains a first power supply system potential V1 when the switch 41 is controlled to the disconnected state and a second power supply system potential V2 when the switch 42 is controlled to the disconnected state.

At time t _p, when the ignition power is turned on, the third power supply system potential V3 rises.

At time t ₁, the control device 90 obtains the first power supply system potential V1 and the second power supply system potential V2, and supplies them to the voltage control device 92. The voltage control means 92 compares the third power supply system potential V3 with the first power supply system potential V1. In addition, the voltage control device 92 compares the third power supply system potential V3 with the second power supply system potential V2.

When the third power supply system potential V3 is lower than at least one of the first power supply system potential V1 and the second power supply system potential V2, the voltage control device 92 controls the output voltage of the third power supply 31 to a voltage higher than the first power supply system potential V1 and the second power supply system potential V2.

The voltage control device 92 confirms that the third power supply system potential V3 is higher than the first power supply system potential V1 and the second power supply system potential V2, and notifies the control device 90 of this.

When receiving notification that the third power supply system potential V3 is higher than the first power supply system potential V1 and the second power supply system potential V2, the control device 90 controls the switch 41 and the switch 42 to be on (time t ₁).

The first power supply system potential V1 and the second power supply system potential V2 are lower than the third power supply system potential V3, and therefore no current flows from the first power supply 11 and the second power supply 21. Therefore, the vehicle power supply device 100 can suppress the inter-battery current when the ignition power is turned on.

As an example, the voltage control device 92 may control the switch 41 to the connected state in a state in which the output voltage of the third power supply 31 is controlled to a voltage obtained based on the voltage of the connection point P1 when the switch 41 is in the disconnected state, and may control the switch 42 to the connected state in a state in which the output voltage of the third power supply 31 is controlled to a voltage obtained based on the voltage of the connection point P2 when the switch 42 is in the disconnected state.

When the voltage difference between the first power supply system potential V1 and the second power supply system potential V2 is equal to or greater than a predetermined voltage difference, the voltage control device 92 sets the output voltage of the third power supply 31 to an output voltage corresponding to the voltage value of each of the first power supply system potential V1 and the second power supply system potential V2, whereby the rush current flowing to each of the first power supply system 10 and the second power supply system 20 can be suppressed.

[ Detection of on-adhesion and off-adhesion of switch 49 ]

The power supply device 100 for a vehicle in the present embodiment has a function of detecting the off-adhesion and on-adhesion of the switch 49.

The on-stick is 1 of the failure modes of the switch 49, and is a failure mode in which the contacts of the switch 49 are fixed in the connected state (on state). For example, in the case where the switch 49 is a mechanical switch having contacts, when an arc occurs accompanying the opening and closing of the contacts and when a current exceeding a rated value flows through the contacts, the contacts may be welded. In this case, the switch 49 is fixed to the on state, and the on stuck fault occurs, regardless of the control device 90.

The break adhesion is 1 of the failure modes of the switch 49, and is a failure mode in which the contacts of the switch 49 are fixed in a non-connected state (open state). Contact loss, disconnection, and the like due to life may be caused, and the contacts may be fixed in a disconnected state. In this case, the switch 49 is fixed in the off state, and the off-stuck fault occurs, independently of the control device 90.

The vehicle power supply device 100 has a function of determining whether the switch 49 is in a failure due to on-sticking or off-sticking.

[ Adhesion detection of switch 41, switch 42, and switch 43 ]

Fig. 10 is a diagram showing an example of a series of operations for detecting adhesion failure of the switch 41, the switch 42, and the switch 43 in the embodiment of the present invention.

(Step S300) the control device 90 controls the switch 41 and the switch 42 to be turned off. The control device 90 controls the switch 43 to be turned on.

(Step S302) the control device 90 obtains the first power supply system potential V1 and the third power supply system potential V3 measured by the potential measuring unit 91, not shown.

The control device 90 compares the first power supply system potential V1 obtained from the potential measuring unit 91 with the third power supply system potential V3 (step S310). When the difference between the first power supply system potential V1 and the third power supply system potential V3 is equal to or greater than a predetermined value (yes in step S310), the process proceeds to step S312. If the difference between the first power supply system potential V1 and the third power supply system potential V3 is not equal to or greater than the predetermined value (step S310; no), the process proceeds to step S320.

The control device 90 determines (step S312) that the switch 43 is in the off-state, and ends the process. That is, when the output from the third power supply 31 is stopped, and the switch 41 and the switch 42 are controlled to be in the disconnected state and the switch 43 is controlled to be in the connected state, the control device 90 determines that the switch 43 is in the stuck-fault in the disconnected state when the potential difference between the first power supply system potential V1 and the third power supply system potential V3 is larger than the predetermined value.

(Step S320) the control device 90 controls the switch 41, the switch 42, and the switch 43 to be turned off. The control means 90 activate the third power supply 31.

(Step S322) the control device 90 obtains the first power supply system potential V1 and the third power supply system potential V3 measured by the potential measuring unit 91, not shown.

The control device 90 compares the first power supply system potential V1 obtained from the potential measuring unit 91 with the third power supply system potential V3 (step S330). When the difference between the first power supply system potential V1 and the third power supply system potential V3 is equal to or less than a predetermined value (yes in step S330), the process proceeds to step S332. If the difference between the first power supply system potential V1 and the third power supply system potential V3 is not equal to or less than the predetermined value (step S330; no), the process proceeds to step S202.

(Step S332) the control device 90 determines that the switch 41 or the switch 43 is on and stuck, and ends the process. That is, when the potential difference between the first power supply system potential V1 and the third power supply system potential V3 is smaller than the predetermined value in a state in which the switch 41, the switch 42, and the switch 43 are controlled to be in the disconnected state and the output voltage of the third power supply 31 is controlled to be higher than the output voltage of the first power supply 11, the control device 90 determines that the switch 43 is in the stuck-at fault in the connected state.

(Step S202) the control device 90 acquires the first power supply system potential V1, the second power supply system potential V2, and the third power supply system potential V3 measured by the potential measuring unit 91, not shown.

The control device 90 compares the second power supply system potential V2 obtained from the potential measuring unit 91 with the third power supply system potential V3 (step S220). When the difference between the second power supply system potential V2 and the third power supply system potential V3 is equal to or less than a predetermined value (yes in step S220), the process proceeds to step S222. If the difference between the second power supply system potential V2 and the third power supply system potential V3 is not equal to or less than the predetermined value (step S220; no), the process proceeds to step S230.

The control device 90 determines (step S222) that the switch 42 is in the on-state and the process is terminated. That is, when the potential difference between the connection point P2 and the connection point P3 in the case where the switch 42 is controlled to be in the connected state is smaller than the predetermined potential difference, the control device 90 determines that the switch 42 is in the stuck-at fault in the connected state.

(Step S230) the control device 90 controls the switch 41 and the switch 42 to be on and controls the switch 43 to be off. The control means 90 activate the third power supply 31. The voltage control device 92 controls the output voltage of the third power supply 31 to a voltage higher than the first power supply system potential V1 and the second power supply system potential V2.

(Step S232) the control device 90 obtains the first power supply system potential V1, the second power supply system potential V2, and the third power supply system potential V3 measured by the potential measuring unit 91, not shown.

The control device 90 compares the first power supply system potential V1 obtained from the potential measuring unit 91 with the third power supply system potential V3 (step S240). When the difference between the first power supply system potential V1 and the third power supply system potential V3 is equal to or greater than the predetermined value (yes in step S240), the process proceeds to step S242. If the difference between the first power supply system potential V1 and the third power supply system potential V3 is not equal to or greater than the predetermined value (step S240; no), the process proceeds to step S250.

The control device 90 determines (step S242) that the switch 41 is in the off-state, and ends the process. That is, when the potential difference between the first power supply system potential V1 and the third power supply system potential V3 in the case where the switch 41 is controlled to the connected state is larger than the predetermined value, the control device 90 determines that the switch 41 is in the stuck-at fault in the disconnected state.

The control device 90 compares the second power supply system potential V2 obtained from the potential measuring unit 91 with the third power supply system potential V3 (step S250). When the difference between the second power supply system potential V2 and the third power supply system potential V3 is equal to or greater than the predetermined value (yes in step S250), the process proceeds to step S252. If the difference between the second power supply system potential V2 and the third power supply system potential V3 is not equal to or greater than the predetermined value (step S250; no), the process proceeds to step S260.

The control device 90 determines (step S252) that the switch 42 is in the off-adhesion state, and ends the process. That is, when the potential difference between the second power supply system potential V2 and the third power supply system potential V3 in the case where the switch 42 is controlled to the connected state is larger than the predetermined value, the control device 90 determines that the switch 42 is in the stuck-at fault in the disconnected state.

The control device 90 determines (step S260) that the switches 41 and 42 are normal, and ends the process.

[ Reconnection operation after abnormality occurrence ]

As described above, the control device 90 turns off the switch 49 when any one of the first power supply system potential V1, the second power supply system potential V2, and the third power supply system potential V3 is lower than a predetermined value. The control device 90 cuts off the connection state of the first power supply system 10, the second power supply system 20, and the third power supply system 30 by cutting off the switch 49.

In the present embodiment, the control device 90 can connect the normal power supply system again by turning on the connection state of the switch 49 for the power supply system having a potential higher than the predetermined value after the switch 49 is turned off.

In the figure, the horizontal axis shows time variations of the first power supply system potential V1, the second power supply system potential V2, the state of the switch 41, and the state of the switch 42, with time being the horizontal axis. In the figure, the vertical axes of the first power supply system potential V1 and the second power supply system potential V2 represent voltages. The state of the switch 41 indicates the connection state of the switch 41. The state of the switch 42 indicates the connection state of the switch 42.

The control device 90 obtains the first power supply system potential V1 and the second power supply system potential V2 measured by the potential measuring unit 91, not shown. The control device 90 determines that the first power supply system potential V1 is normal when it is in a range from the normal time maximum value V1MAX to the normal time minimum value V1MIN, and determines that the first power supply system potential V1 is abnormal when it is not in a range from the normal time maximum value V1MAX to the normal time minimum value V1 MIN. The control device 90 determines that the second power supply system potential V2 is normal when the second power supply system potential V2 is in a range from the normal time maximum value V2MAX to the normal time minimum value V2MIN, and determines that the second power supply system potential V2 is abnormal when the second power supply system potential V2 is not in a range from the normal time maximum value V2MAX to the normal time minimum value V2 MIN.

The control device 90 controls on of either the switch 41 or the switch 42 when the second power supply system 20 is normal.

When an abnormality such as grounding occurs in the second power supply system 20, the second power supply system potential V2 decreases. At time t _p, the switch 41 and the switch 42 are turned on, and thus the second power supply system 20 is connected to the first power supply system 10. Therefore, the first power supply system potential V1 decreases similarly to the decrease in the second power supply system potential V2.

The control device 90 detects that the second power supply system potential V2 is not in the interval from the normal time maximum value V2MAX to the normal time minimum value V2MIN (time t ₁). When detecting that the second power supply system potential V2 is not in the interval from the normal time maximum value V2MAX to the normal time minimum value V2MIN, the control device 90 turns off the switch 41 and the switch 42 (time t ₂). The switch 41 and the switch 42 are controlled to be turned off, and thus the first power supply system 10 and the second power supply system 20 are disconnected. That is, the first power supply system 10 is no longer affected by the second power supply system 20.

The first power supply system 10 is no longer affected by the second power supply system 20, and thus power is supplied from the first power supply 11 to the first load 12. After the switch 41 is controlled to the disconnected state (after time t ₂), the first power supply system potential V1 starts to rise. Since the third power supply system potential V3 is higher than the first power supply system potential V1, the first power supply system potential V1 after the switch 41 is controlled to the disconnected state (after time t ₂) is lower than before the occurrence of the abnormality in the third power supply system 30 (before time t _p).

After the switch 49 is turned off (after time t ₂), the control device 90 monitors the first power supply system potential V1 and the second power supply system potential V2 for a predetermined period. When the potential difference between the first power supply system potential V1 and the third power supply system potential V3 is equal to or less than the predetermined value, the first power supply system 10 can be said to be normal. In this case, the control device 90 controls the switch 41 to the connected state (time t ₂). Since the third power supply system potential V3 is higher than the first power supply system potential V1, the first power supply system potential V1 rises after the switch 41 is controlled to the connected state (after time t ₃). Therefore, in the present embodiment, even when an abnormality such as grounding occurs in the second power supply system 20 and an abnormality does not occur in the first power supply system 10, the second power supply system 20 can be disconnected from the third power supply system 30, and the third power supply system 30 and the first power supply system 10 can be brought into a connected state.

In the above example, the case where the abnormality occurs in the second power supply system 20 has been described, but the present embodiment is not limited to this. The same applies to the case where an abnormality occurs in the first power supply system 10. That is, the control device 90 controls the switch 41 and the switch 42 to be in the disconnected state when an abnormality occurs on the first load 12 side or the second load 22 side with respect to the switch 41, controls the switch 41 to be in the connected state when the potential difference between the connection point P1 and the connection point P3 when the switch 41 is controlled to be in the disconnected state is smaller than a predetermined potential difference, and controls the switch 42 to be in the connected state when the potential difference between the connection point P2 and the connection point P3 when the switch 42 is controlled to be in the disconnected state is smaller than a predetermined potential difference.

In the above example, the processing is performed after time t ₂.

After time t ₂, control device 90 controls switch 41 and switch 42 to the off state (step S40). When the switches 41 and 42 are in the off state (yes in step S40), the process proceeds to step S42. When the switch 41 and the switch 42 are not in the off state (step S40; no), the process ends.

The control device 90 obtains the first power supply system potential V1, the second power supply system potential V2, and the third power supply system potential V3 measured by the potential measuring unit 91 (step S42).

The control device 90 compares the first power supply system potential V1 obtained from the potential measuring unit 91 with the third power supply system potential V3 (step S44). When the difference between the first power supply system potential V1 and the third power supply system potential V3 is equal to or less than a predetermined value (yes in step S44), the process proceeds to step S45. If the difference between the first power supply system potential V1 and the third power supply system potential V3 is not equal to or less than the predetermined value (step S44; no), the process proceeds to step S46.

(Step S45) the control device 90 controls the switch 41 to the connected state, and ends the process.

The control device 90 compares the second power supply system potential V2 obtained from the potential measuring unit 91 with the third power supply system potential V3 (step S46). When the difference between the second power supply system potential V2 and the third power supply system potential V3 is equal to or less than a predetermined value (yes in step S46), the process proceeds to step S47. If the difference between the second power supply system potential V2 and the third power supply system potential V3 is not equal to or less than the predetermined value (step S46; no), the process proceeds to step S48.

(Step S47) the control device 90 controls the switch 42 to the connected state and ends the process.

(Step S48) the control device 90 ends the process while maintaining the non-connected state of both the hold switch 41 and the switch 43.

In the present embodiment, the control device 90 reconnects the power supply system in the normal state. Therefore, only the power supply system having the abnormality can be shut off.

Summary of effects of the embodiments

As described above, the vehicle power supply device 100 includes the switch 41 between the first power supply 11 and the first load 12 and the third power supply 31. A switch 42 is provided between the second power supply 21 and the second load 22 and the third power supply 31. The control device 90 controls the connection state of the switch 41 and the switch 42. The first load 12 and the second load 22 take on important functions related to running or stopping of the vehicle.

When an abnormality such as a ground fault occurs in either the first power supply system 10 or the second power supply system 20, the control device 90 controls the switch 41 and the switch 42 to the disconnected state. Therefore, when at least one of the first power supply system 10 to which the first load 12 belongs and the second power supply system 20 to which the second load 22 belongs is normal, electric power can be supplied to the normal load.

Therefore, although the supply of electric power to the important load has been cut off in the past, the structure of the present embodiment can prevent the supply of electric power to the important load from being cut off.

In addition, according to the above embodiment, the control device 90 controls the switch 41 and the switch 42 to the disconnected state when the third power supply system 30 is abnormal. When the switch 41 and the switch 42 are controlled to be in the disconnected state, the first power supply system 10 and the third power supply system 30 are disconnected, and the second power supply system 20 and the third power supply system 30 are disconnected.

In the power supply device 100 for a vehicle, a first load 12 including an important load belongs to the first power supply system 10, and a second load 22 including an important load belongs to the second power supply system 20. Therefore, when an abnormality occurs in the third power supply system 30, the vehicle power supply device 100 can separate the important load, and thereby continue the supply of electric power to the important load.

In addition, according to the above-described embodiment, when an abnormality occurs in the power supply system, the vehicle power supply device 100 controls the switch 41 and the switch 42 to the disconnected state. The vehicle power supply device 100 is controlled to be in a non-connected state by the switch 41 and the switch 42, and can switch the connected states of the first power supply system 10, the second power supply system 20, and the third power supply system 30 to be in a non-connected state.

Therefore, the vehicle power supply device 100 includes the switch 41, so that the load of the system in which an abnormality has occurred and the load of the system in which no abnormality has occurred can be separated from each other.

In addition, according to the above-described embodiment, the control device 90 resumes the supply of electric power to the power supply system in which the electric potential is restored to the normal state after the abnormality is detected to control the switch 49 to the disconnected state.

Therefore, even when an abnormality occurs in one of the important loads, the vehicle power supply device 100 can supply electric power to the other important load that is not abnormal.

In addition, according to the above-described embodiment, the vehicle power supply device 100 includes the third load 32 that performs a function related to the normal operation of the vehicle. The third power supply 31 supplies electric power to the third load 32. When the output from the third power supply 31 is stopped, the vehicle power supply device 100 supplies electric power from the second power supply 21 to the third load 32.

Here, the vehicle power supply device 100 may perform ECU rewriting in a state where the third power supply 31 is turned off. The vehicle power supply device 100 can supply electric power for ECU rewriting from the second power supply 21 even when the ignition power supply is in an off state.

In addition, according to the above embodiment, the third load 32 is connected to the third power supply 31 without the switch 41 and the switch 42. The current flowing from the third power supply 31 to the third load 32 does not pass through the switch 41 and the switch 42.

Therefore, in the present embodiment, the current flowing to the switch 41 and the switch 42 can be suppressed to the minimum. That is, the rated currents of the switch 41 and the switch 42 can be suppressed to be small.

In addition, according to the above embodiment, the first power supply 11 and the second power supply 21 include power supplies that can be charged and discharged.

The first power supply 11 receives the power supply from the third power supply 31, and charges the supplied power. The second power supply 21 receives the power supply from the third power supply 31 and charges the supplied power. The first power supply 11 and the second power supply 21 can be reused by charging even after the power stored in the first power supply is consumed.

Therefore, the vehicle provided with the vehicle power supply device 100 can also replace the first power supply 11 and the second power supply 21 less frequently.

In addition, according to the above-described embodiment, when the ignition power is turned on, the vehicle power supply device 100 confirms reverse connection of the battery before the switch 49 is controlled to the connected state.

In contrast to this, the power supply device 100 for a vehicle according to the present embodiment is provided with a device for reverse connection confirmation, so that reverse connection confirmation can be performed even if the device for reverse connection confirmation is not provided.

In addition, according to the above embodiment, the control device 90 can determine whether or not the switch 41 is on adhesion by controlling the switch 41 and comparing the voltages across the switch 41. Further, by controlling the switch 42 and comparing the voltages across the switch 42, it is possible to determine whether the switch 42 is on adhesion.

Therefore, the control device 90 can detect an abnormal state caused by the on-state adhesion of the switch 41 or the switch 42 before a failure occurs due to the adhesion abnormality of the switch.

In addition, according to the above embodiment, the output voltage outputted from the third power supply 31 is higher than the output voltage outputted from the first power supply 11 and the output voltage outputted from the second power supply 21. That is, the electric power for use by the third load 32 is supplied from the third power supply 31.

Therefore, since the third load 32 is not supplied with electric power from the first power source 11 and the second power source 21, the current capacity of the switch 41 and the switch 42, or the current capacity of the fuse or the wire harness can be reduced.

In addition, according to the above-described embodiment, in a state in which the output voltage of the third power supply 31 is controlled by the voltage control device 92, the control device 90 controls the switch 49, and compares the voltages across the switch 41, whereby it can be determined whether or not the switch 41 is in the off-state. The control device 90 can determine whether or not the switch 42 is in the off-state by controlling the switch 49 and comparing the voltages across the switch 42.

Therefore, the control device 90 can detect an abnormal state caused by the off-adhesion of the switch 41 or the switch 42 before a failure occurs due to the adhesion abnormality of the switch.

In addition, according to the above embodiment, the vehicle power supply device 100 is provided with the voltage control device 92. The voltage control device 92 adjusts the output voltage outputted from the third power supply 31. Before the control device 90 controls the switch 41 to the connected state, the voltage control device 92 controls the output voltage of the third power supply 31 to be the same as the output voltage of the first power supply 11. Therefore, the rush current flowing between the power supply systems when the switch 41 is switched to the connected state can be suppressed.

Before the control device 90 controls the switch 42 to the connected state, the voltage control device 92 controls the output voltage of the third power supply 31 to be the same as the output voltage of the second power supply 21. Therefore, the rush current flowing between the power supply systems when the switch 42 is switched to the connected state can be suppressed.

In addition, according to the above embodiment, the switch 41 has a normally open contact, and the switch 43 has a normally closed contact.

The switch 41 and the switch 43 are disposed between the first power supply system 10 and the second power supply system 20, and the switch 41 and the switch 43 are connected in parallel to each other. The control device 90 controls the switch 41 and the switch 43 based on whether the ignition power is on or off.

Therefore, the vehicle power supply device 100 can supply electric power to the second power supply 21 even when the ignition power supply is in an off state.

In addition, according to the above embodiment, the control device 90 controls the switch 49 and compares the voltages across the switch 43, thereby making it possible to determine whether the switch 43 is in the off-adhesion state.

Therefore, the control device 90 can detect an abnormal state caused by the off-adhesion of the switch 43 before a failure occurs due to the adhesion abnormality of the switch.

In addition, according to the above-described embodiment, in a state where the output voltage of the third power supply 31 is controlled by the voltage control device 92, the control device 90 controls the switch 49 and compares the voltages across the switch 43, whereby it can be determined whether or not the switch 43 is on-blocking.

Therefore, the control device 90 can detect an abnormal state caused by the on-state adhesion of the switch 43 before a failure occurs due to the adhesion abnormality of the switch.

In addition, according to the above embodiment, the first load 12 and the second load 22 each include at least one of an auxiliary load for braking of the vehicle, an auxiliary load for steering, and an auxiliary load for driving assistance or automatic driving of the vehicle.

The power supply device 100 for a vehicle can be provided with a redundant system for important loads such as an auxiliary load for braking of the vehicle, an auxiliary load for steering, and an auxiliary load for driving assistance or automatic driving of the vehicle.

In addition, according to the above-described embodiment, the second power supply 21 includes a lithium ion secondary battery. Since the lithium ion secondary battery can achieve high efficiency and long life of charge and discharge, the second power supply 21 can achieve high efficiency and long life of charge and discharge.

The specific embodiments of the present invention have been described above using the embodiments, but the present invention is not limited to such embodiments, and various modifications and substitutions can be made without departing from the scope of the present invention.

Claims

1. A power supply device for a vehicle is provided with:

a first power supply;

a first load that is connected to the first power supply through a first connection point and that assumes an important function related to running or stopping of the vehicle;

A second power supply connected in parallel with the first power supply;

a second load that is connected to the second power supply through a second connection point and that assumes an important function related to running or stopping of the vehicle; and

A third power supply connected to the first power supply through a third connection point and capable of outputting a voltage higher than that of the first power supply,

Wherein the power supply device for a vehicle comprises:

a first switch disposed between the first connection point and the third connection point;

a second switch disposed between the second connection point and the third connection point; and

Control means for controlling the first switch and the second switch,

The control device controls the first switch and the second switch to be in a disconnected state when an abnormality occurs on the third power supply side from the third connection point.

2.A power supply device for a vehicle is provided with:

a first power supply;

A second power supply connected in parallel with the first power supply;

Wherein the power supply device for a vehicle comprises:

Control means for controlling the first switch and the second switch,

The control device controls the first switch and the second switch to be in a disconnected state when an abnormality occurs on the first load side or the second load side of the first switch or the second switch.

3. The power supply device for a vehicle according to claim 1 or 2, wherein,

The control device controls the first switch and the second switch to be in a disconnected state when an abnormality occurs on the first load side or on the second load side than the first switch, controls the first switch to be in a connected state when a potential difference between the first connection point and the third connection point when the first switch is controlled to be in a disconnected state is smaller than a predetermined potential difference, and controls the first switch to be in a connected state when a potential difference between the second connection point and the third connection point when the second switch is controlled to be in a disconnected state is smaller than a predetermined potential difference.

4. The power supply device for a vehicle according to claim 1 or 2, wherein,

The power supply device for a vehicle further includes a third load connected to the third connection point and serving as a normal load that is a function other than an important function related to running or stopping of the vehicle,

The control device supplies power to the third load from the first power source, the second power source, or both the first power source and the second power source when the output from the third power source is stopped.

5. The power supply device for a vehicle according to claim 1 or 2, wherein,

The first power supply and the second power supply comprise power supplies capable of being charged and discharged.

6. The power supply device for a vehicle according to claim 1 or 2, wherein,

The control device acquires information indicating a voltage of the first connection point when the first switch is controlled to be in a non-connected state and a voltage of the second connection point when the second switch is controlled to be in a non-connected state, and controls the first switch to be in a connected state if the voltage of the first connection point is within a predetermined range, and controls the second switch to be in a connected state if the voltage of the second connection point is within a predetermined range.

7. The power supply device for a vehicle according to claim 1 or 2, wherein,

The control device determines that the first switch is in a stuck-at fault in the connected state when a potential difference between the first connection point and the third connection point in the case where the first switch is controlled to be in the disconnected state is smaller than a predetermined potential difference, and determines that the second switch is in a stuck-at fault in the connected state when a potential difference between the second connection point and the third connection point in the case where the second switch is controlled to be in the disconnected state is smaller than a predetermined potential difference.

8. The power supply device for a vehicle according to claim 1 or 2, wherein,

The power supply device for a vehicle further includes a voltage control device that controls an output voltage outputted from the third power supply,

The control device obtains information indicating a voltage at the first connection point when the first switch is controlled to be in a disconnected state and a voltage at the second connection point when the second switch is controlled to be in a disconnected state,

The voltage control device controls the output voltage of the third power supply to a voltage higher than the voltages of the first connection point and the second connection point.

9. The power supply device for a vehicle according to claim 8, wherein,

The control device determines that the first switch is in a stuck-at fault in a non-connected state when a potential difference between the first connection point and the third connection point in a case where the first switch is controlled to be in a connected state is larger than a predetermined value, and determines that the second switch is in a stuck-at fault in a non-connected state when a potential difference between the second connection point and the third connection point in a case where the second switch is controlled to be in a connected state is larger than a predetermined value.

10. The power supply device for a vehicle according to claim 8, wherein,

The control device obtains information indicating a voltage at the first connection point when the first switch is in a disconnected state and a voltage at the second connection point when the second switch is in a disconnected state,

The voltage control device controls the first switch to be in a connected state in a state in which an output voltage of the third power supply is controlled to be a voltage obtained based on a voltage of the first connection point when the first switch is in a disconnected state, and controls the second switch to be in a connected state in a state in which an output voltage of the third power supply is controlled to be a voltage obtained based on a voltage of the second connection point when the second switch is in a disconnected state.

11. The power supply device for a vehicle according to claim 1 or 2, wherein,

The vehicle power supply device further includes a third switch arranged in parallel with the first switch between the first connection point and the third connection point,

The first switch becomes disconnected without being controlled,

The third switch is in a connected state when not controlled.

12. The power supply device for a vehicle according to claim 11, wherein,

The control device determines that the third switch is in a stuck-at fault in a disconnected state when an output from the third power supply is stopped, and when the first switch and the second switch are controlled to be in a disconnected state and the third switch is controlled to be in a connected state, a potential difference between the first connection point and the third connection point is greater than a predetermined value.

13. The power supply device for a vehicle according to claim 12, wherein,

The control device determines that the third switch is in a stuck-at fault in a connected state when a potential difference between the first connection point and the third connection point in a state where the first switch, the second switch, and the third switch are controlled to be in a disconnected state and an output voltage of the third power supply is controlled to be a voltage higher than an output voltage of the first power supply is smaller than a predetermined value.

14. The power supply device for a vehicle according to claim 11, wherein,

15. The power supply device for a vehicle according to claim 1 or 2, wherein,

The first load and the second load each include at least one of an auxiliary load for braking of the vehicle, an auxiliary load for steering, and an auxiliary load for driving assistance or automatic driving of the vehicle.

16. The power supply device for a vehicle according to claim 1 or 2, wherein,

The second power source includes a lithium ion secondary battery.