Power supply device

Abstract

To provide a power supply device that can supply power to the load even if a battery failure occurs. [Solution] A power supply device according to one embodiment comprises a first system power supply unit, a backup power supply unit, and a second system power supply unit. The first system power supply unit is connected to a battery and is driven to supply power when the system is operating. The backup power supply unit is connected to a battery and is driven to supply power at least when the system is stopped. The second system power supply unit is connected to a power storage unit that stores power from the first system power supply unit and the battery, and supplies power stored in the power storage unit. The power supply device supplies power to loads connected to the backup power supply unit and the second system power supply unit from either the backup power supply unit or the second system power supply unit.

Description

Technical Field

[0001] The disclosed embodiments relate to a power supply device.

Background Art

[0002] Conventionally, various power supply devices mounted on vehicles, for example, have been proposed (see, for example, Patent Document 1). In the power supply device according to the prior art, a main battery and a sub-battery are provided, and when the voltage of the main battery drops, the sub-battery functions as a backup power supply to supply power to a load.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the prior art, when a failure occurs in the main battery, there is a risk that power will not be supplied to the load. That is, in the prior art, the switching between the main battery and the sub-battery is performed by a changeover switch. Therefore, for example, when a failure such as an instantaneous break or a disconnection occurs in the main battery, the battery switching by the changeover switch may not be performed, and there is a risk that power will not be supplied to the load.

[0005] One aspect of the embodiment has been made in view of the above, and an object thereof is to provide a power supply device that can supply power to a load even when a failure occurs in a battery.

Means for Solving the Problems

[0006] To solve the above problems and achieve the objective, a power supply device according to one embodiment comprises a first system power supply unit, a backup power supply unit, and a second system power supply unit. The first system power supply unit is connected to a battery and is driven to supply power when the system is operating. The backup power supply unit is connected to the battery and is driven to supply power at least when the system is stopped. The second system power supply unit is connected to a power storage unit that stores power from the first system power supply unit and the battery, and supplies power stored in the power storage unit. The power supply device supplies power to loads connected to the backup power supply unit and the second system power supply unit from either the backup power supply unit or the second system power supply unit. [Effects of the Invention]

[0007] In one embodiment, the power supply unit comprises a backup power supply unit connected to a battery and a second system power supply unit connected to a first system power supply unit and supplying power stored in a power storage unit. The power supply unit is configured to supply power to loads connected to the backup power supply unit and the second system power supply unit from either the backup power supply unit or the second system power supply unit. This allows the power supply unit to supply power to the load from the backup power supply unit when the battery is functioning normally, for example. It also allows the power supply unit to supply power to the load from the second system power supply unit when the battery fails, thus ensuring that power can be supplied to the load even if the battery fails. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is an explanatory diagram showing an example configuration of an in-vehicle system including a power supply unit according to an embodiment. [Figure 2] Figure 2 is an explanatory diagram showing the operation of the power supply unit when the battery is functioning correctly. [Figure 3] Figure 3 is an explanatory diagram showing the operation of the power supply unit in the event of a battery failure. [Figure 4] Figure 4 is an explanatory diagram showing the operation of the power supply unit when the third system power supply unit fails. [Modes for carrying out the invention]

[0009] The embodiments of the power supply device disclosed herein will be described in detail below with reference to the attached drawings. However, the present invention is not limited to the embodiments described below.

[0010] Furthermore, the expressions "designated," "specific," and "certain" in the following explanation may be interpreted as "predetermined."

[0011] An in-vehicle system including a power supply unit according to an embodiment will be described with reference to Figure 1. Figure 1 is an explanatory diagram showing an example configuration of an in-vehicle system 1 including a power supply unit 10 according to an embodiment.

[0012] As shown in Figure 1, the in-vehicle system 1 comprises a power supply unit 10, an ignition switch 20 (hereinafter referred to as "IG20"), system loads 100a and 100b, and a backup load 200. The in-vehicle system 1 is installed in vehicles such as electric vehicles and hybrid vehicles, but is not limited to these. Note that the in-vehicle system 1 is just one example of a system. Such a system may also be installed in devices other than vehicles (e.g., electrical products).

[0013] IG20 is a switch that is turned ON by the driver when operating (starting) the in-vehicle system 1, such as when starting the vehicle to move. When IG20 is turned ON, it outputs an ON signal to the power supply unit 10. Also, IG20 is a switch that is turned OFF by the driver when stopping the in-vehicle system 1, such as when stopping the vehicle. When IG20 is turned OFF, it outputs an OFF signal to the power supply unit 10.

[0014] System loads 100a and 100b are loads (devices) that receive power when the in-vehicle system 1 is operating. Conversely, system loads 100a and 100b are loads that do not receive power when the in-vehicle system 1 is stopped. In other words, system loads 100a and 100b are loads that receive power and operate only when the in-vehicle system 1 is operating. System loads 100a and 100b include, but are not limited to, devices related to vehicle driving control and driving safety, such as power steering systems, shift-by-wire systems, accelerator systems, brake systems, and various microcontrollers. In the example in Figure 1, two system loads 100a and 100b are shown, but this is not limited to one or more.

[0015] The backup load 200 is a load (device) that receives power when the in-vehicle system 1 is operating and when the in-vehicle system 1 is stopped. In other words, the backup load 200 is a load that receives power and operates both when the in-vehicle system 1 is operating and when it is stopped. The backup load 200 includes, but is not limited to, devices that operate continuously, such as a drive recorder, a clock device, and various microcontrollers. The backup load 200 may also include the controller 80 of the power supply unit 10, which will be described later. The backup load 200 may also be a load that receives power only when the in-vehicle system 1 is stopped. In other words, the backup load 200 only needs to be a load that receives power at least when the in-vehicle system 1 is stopped. In the example in Figure 1, one backup load 200 is shown, but it is not limited to this, and there may be two or more.

[0016] The power supply unit 10 includes a battery 30, a first system power supply unit 40, a charge / discharge system power supply unit 41, a second system power supply unit 42, a third system power supply unit 43a, 43b, a backup power supply unit 50, an energy storage unit 60, diodes 70, 71, 72, and a controller 80.

[0017] The battery 30 outputs the electric power supplied to the system loads 100a, 100b, the backup load 200, the power storage unit 60, etc. As the battery 30, for example, a lithium ion battery, a lead battery, etc. can be used.

[0018] One end of the coil 31 is connected to the battery 30. The coil 31 is a coil for a filter that removes the noise of the battery voltage (+B).

[0019] The first system power supply unit 40 is connected to the battery 30. Specifically, the first system power supply unit 40 is connected to the other end of the coil 31. The first system power supply unit 40 drives and supplies electric power when the in-vehicle system 1 operates. Specifically, the first system power supply unit 40 is a power supply circuit including a DC-DC converter, etc. The first system power supply unit 40 steps down the voltage of the electric power output from the battery 30 (for example, 12V) to a predetermined voltage (for example, 5V) when the in-vehicle system 1 operates. The first system power supply unit 40 outputs the stepped-down electric power. In the above, an example where the first system power supply unit 40 steps down the voltage is shown, but it is not limited to this, and a configuration that steps up the voltage may also be possible.

[0020] The charge / discharge system power supply unit 41 is connected to the first system power supply unit 40 and the power storage unit 60. To explain in detail, the charge / discharge system power supply unit 41 and the first system power supply unit 40 are connected via a diode 70. The anode of the diode 70 is connected to the first system power supply unit 40, and the cathode is connected to the charge / discharge system power supply unit 41. Also, the power storage unit 60 is connected between the charge / discharge system power supply unit 41 and the ground. The power storage unit 60 is a capacitor that is charged and stores electric power by the electric power from the battery 30. The power storage unit 60 can output the stored electric power. Note that the power storage unit 60 is not limited to a capacitor, and may be a storage battery such as a lithium ion battery.

[0021] The system power supply unit 41 for charging and discharging drives to charge or discharge the power storage unit 60 during the operation of the in-vehicle system 1. Specifically, the system power supply unit 41 for charging and discharging is a power supply circuit including a DC-DC converter or the like. The system power supply unit 41 for charging and discharging steps down (or steps up) the voltage of the power supplied from the battery 30 via the first system power supply unit 40 to a voltage capable of charging the power storage unit 60 and supplies it to the power storage unit 60 to charge the power storage unit 60. Also, as will be described later, the system power supply unit 41 for charging and discharging discharges the power charged in the power storage unit 60 when a failure occurs in the battery 30. Specifically, the system power supply unit 41 for charging and discharging steps down (or steps up) the voltage of the power stored in the power storage unit 60 and supplies it to the system loads 100a and 100b via the third system power supply units 43a and 43b.

[0022] The third system power supply units 43a and 43b are connected to the first system power supply unit 40 and drive to supply power from the battery 30 during the operation of the in-vehicle system 1. Specifically, the third system power supply units 43a and 43b are connected to the connection point 90 of the power line connecting the first system power supply unit 40 and the system power supply unit 41 for charging and discharging. The connection point 90 is provided on the cathode side of the diode 70. The system load 100a is connected to the third system power supply unit 43a. The system load 100b is connected to the third system power supply unit 43b. The third system power supply units 43a and 43b are each a power supply circuit including a DC-DC converter or the like. The third system power supply units 43a and 43b step down the voltage of the power supplied from the battery 30 via the first system power supply unit 40 (for example, 5V) to a voltage corresponding to the system loads 100a and 100b (for example, 1.8V, 1.5V, etc.). The third system power supply units 43a and 43b each supply the stepped-down power to the system loads 100a and 100b. Note that in the above, an example where the third system power supply units 43a and 43b step down the voltage is shown, but it is not limited to this, and a configuration that steps up the voltage may also be used.

[0023] The backup power supply unit 50 is connected to the battery 30. More precisely, the backup power supply unit 50 is connected to the connection point 91 of the power line connecting the battery 30 and the first system power supply unit 40. The connection point 91 is located on the other end side of the coil 31. The backup load 200 is connected to the backup power supply unit 50. More specifically, the backup power supply unit 50 and the backup load 200 are connected via a diode 71. The anode of the diode 71 is connected to the backup power supply unit 50, and the cathode is connected to the backup load 200.

[0024] The backup power supply unit 50 is driven to supply power when the in-vehicle system 1 is operating and when the in-vehicle system 1 is stopped. In other words, the backup power supply unit 50 is driven to supply power both when the in-vehicle system 1 is operating and when it is stopped. However, the backup power supply unit 50 may be configured to be driven only when the in-vehicle system 1 is stopped. In other words, the backup power supply unit 50 is configured to be driven to supply power at least when the in-vehicle system 1 is stopped.

[0025] The backup power supply unit 50 is a power supply circuit including a DC-DC converter. The backup power supply unit 50 steps down the voltage of the power output from the battery 30 (e.g., 12V) to a predetermined voltage (e.g., 3.3V) when the in-vehicle system 1 is operating and when it is stopped. The backup power supply unit 50 supplies the stepped-down power to the backup load 200. Although the above example shows the backup power supply unit 50 stepping down the voltage, it is not limited to this and may also be configured to step up the voltage.

[0026] The second system power supply unit 42 is connected to the first system power supply unit 40 and the energy storage unit 60. More specifically, the second system power supply unit 42 is connected to the first system power supply unit 40 via the charge / discharge system power supply unit 41. Specifically, the second system power supply unit 42 is connected to the connection point 92 of the power line connecting the charge / discharge system power supply unit 41 and the energy storage unit 60.

[0027] A backup load 200 is connected to the second system power supply unit 42. More specifically, the second system power supply unit 42 and the backup load 200 are connected via a diode 72. The anode of the diode 72 is connected to the second system power supply unit 42, and the cathode is connected to the backup load 200. Specifically, the anode of the diode 72 is connected to the connection point 93 of the power line connecting the backup power supply unit 50 and the backup load 200. The connection point 93 is located on the cathode side of the diode 71.

[0028] As will be described later, the second system power supply unit 42 supplies power stored in the energy storage unit 60 when the battery 30 fails. Specifically, the second system power supply unit 42 is a power supply circuit including a DC-DC converter. When the battery 30 fails, the second system power supply unit 42 steps down the voltage of the power stored in the energy storage unit 60 to a predetermined voltage (for example, 3.3V). The second system power supply unit 42 supplies the stepped-down power to the backup load 200. Although the above example shows the second system power supply unit 42 stepping down the voltage, it is not limited to this and may also be configured to step up the voltage.

[0029] The power supply unit 10 according to this embodiment is configured to supply power to the backup load 200 from either the backup power supply unit 50 or the second system power supply unit 42, which will be described later.

[0030] The controller 80 may be composed of a microcomputer (MCU) having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc. Such a MCU may be composed of hardware such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array), either partially or entirely.

[0031] When the controller 80 receives an ON signal from IG20, it puts the in-vehicle system 1 into an operating state. Specifically, when the controller 80 receives an ON signal from IG20, it outputs ON signals to the first system power supply unit 40, the charge / discharge system power supply unit 41, the second system power supply unit 42, the third system power supply units 43a and 43b, and the backup power supply unit 50. As a result, the first system power supply unit 40, the charge / discharge system power supply unit 41, the second system power supply unit 42, the third system power supply units 43a and 43b, and the backup power supply unit 50 are driven. Therefore, power is supplied to the system loads 100a and 100b and the backup load 200, and the in-vehicle system 1 becomes operational.

[0032] On the other hand, when the controller 80 receives an OFF signal from IG20, it puts the in-vehicle system 1 into a stopped state. Specifically, when the controller 80 receives an OFF signal from IG20, it outputs OFF signals to the first system power supply unit 40, the charge / discharge system power supply unit 41, the second system power supply unit 42, and the third system power supply units 43a and 43b. The controller 80 also outputs an ON signal to the backup power supply unit 50. As a result, the first system power supply unit 40, the charge / discharge system power supply unit 41, the second system power supply unit 42, and the third system power supply units 43a and 43b stop, and the backup power supply unit 50 starts up. Therefore, power is not supplied to the system loads 100a and 100b, power is supplied to the backup load 200, and the in-vehicle system 1 is put into a stopped state.

[0033] Next, the operation of the power supply unit 10 when the battery 30 is functioning normally will be explained with reference to Figure 2. Figure 2 is an explanatory diagram showing the operation of the power supply unit 10 when the battery 30 is functioning normally.

[0034] As shown in Figure 2, when the battery 30 is functioning normally, in other words, when the battery 30 is not experiencing any malfunctions such as momentary interruptions or disconnections, the power output from the battery 30 is supplied to the system loads 100a and 100b via the first system power supply unit 40 and the third system power supply units 43a and 43b. The power output from the battery 30 is also supplied to the backup load 200 via the backup power supply unit 50. Thus, in this embodiment, the power supply device 10 supplies power to the backup load 200 from the backup power supply unit 50 when the battery 30 is functioning normally. In addition, the power output from the battery 30 is supplied to the energy storage unit 60 via the first system power supply unit 40 and the charge / discharge system power supply unit 41, and the energy storage unit 60 is charged (stored).

[0035] As described above, in the power supply device 10 according to this embodiment, the power supply system for supplying power to the system loads 100a and 100b and the power supply system for supplying power to the backup load 200 are configured to be independent of each other. The power supply system for supplying power to the system loads 100a and 100b includes the first system power supply unit 40 and the third system power supply units 43a and 43b. The power supply system for supplying power to the backup load 200 includes the backup power supply unit 50.

[0036] Next, the operation of the power supply unit 10 in the event of a malfunction such as a momentary interruption or wire break in the battery 30 will be explained with reference to Figure 3. Figure 3 is an explanatory diagram showing the operation of the power supply unit 10 when the battery 30 malfunctions.

[0037] As shown in Figure 3, if a failure such as a momentary interruption or wire break occurs in the battery 30 (see mark A1), the battery 30 will not be able to output power. Therefore, in this embodiment, the power stored in the power storage unit 60 is supplied to the system loads 100a, 100b and the backup load 200. Specifically, the power stored in the power storage unit 60 is supplied to the system loads 100a and 100b via the charge / discharge system power supply unit 41 and the third system power supply units 43a and 43b. In addition, the power stored in the power storage unit 60 is supplied to the backup load 200 via the second system power supply unit 42. Thus, in this embodiment, the power supply device 10 supplies power to the backup load 200 from the second system power supply unit 42 when the battery 30 fails.

[0038] As can be seen from Figures 2 and 3, the power supply unit 10 according to this embodiment is configured to supply power to the backup load 200 from either the backup power supply unit 50 or the second system power supply unit 42.

[0039] Furthermore, if a failure occurs in the battery 30, the controller 80 may notify the driver of the failure and also prompt the driver to move the vehicle to a safe location while power from the energy storage unit 60 is being supplied to the system loads 100a, 100b, etc. In addition, if the vehicle is equipped with an automatic driving control device, the controller 80 may perform a fail-safe control (automatic driving) to move the vehicle to a safe location.

[0040] Next, the operation of the power supply unit 10 in the event of a failure such as a ground fault in the third system power supply units 43a and 43b will be explained with reference to Figure 4. Figure 4 is an explanatory diagram showing the operation of the power supply unit 10 in the event of a failure in the third system power supply unit 43a.

[0041] As shown in Figure 4, for example, when the in-vehicle system 1 is stopped, a fault such as a ground fault may occur in the third system power supply unit 43a (see Mark A2). If the power supply unit 10 is configured not to include the first system power supply unit 40 when a fault occurs in the third system power supply unit 43a, current from the battery 30 will continue to flow to the third system power supply unit 43a, as indicated by the dashed arrow, and this will increase the dark current. This increase in dark current (current consumption) may lead to battery failure.

[0042] In the power supply unit 10 according to this embodiment, the first system power supply unit 40 is provided between the battery 30 and the third system power supply units 43a and 43b. When the in-vehicle system 1 is stopped, the first system power supply unit 40 is also stopped, so no current flows from the battery 30 to the third system power supply unit 43a, and the dark current does not increase. Therefore, the occurrence of battery drain can be suppressed.

[0043] Furthermore, in the power supply unit 10 according to this embodiment, the power supply system for supplying power to the system loads 100a and 100b and the power supply system for supplying power to the backup load 200 are configured to be independent of each other. Therefore, in this embodiment, even if a failure occurs in the power supply system for supplying power to the system loads 100a and 100b (in this case, the third system power supply unit 43a), the power from the battery 30 can be supplied to the backup load 200 using the power supply system for supplying power to the backup load 200.

[0044] As described above, the power supply unit 10 according to the embodiment comprises a first system power supply unit 40, a backup power supply unit 50, and a second system power supply unit 42. The first system power supply unit 40 is connected to the battery 30 and is driven to supply power when the in-vehicle system 1 is operating. The backup power supply unit 50 is connected to the battery 30 and is driven to supply power at least when the in-vehicle system 1 is stopped. The second system power supply unit 42 is connected to a power storage unit 60 that stores power from the first system power supply unit 40 and the battery 30, and supplies power stored in the power storage unit 60. The power supply unit 10 supplies power to the backup load 200 connected to the backup power supply unit 50 and the second system power supply unit 42 from either the backup power supply unit 50 or the second system power supply unit 42.

[0045] Thus, the power supply unit 10 includes a backup power supply unit 50 connected to the battery 30 and a second system power supply unit 42 connected to the first system power supply unit 40 and supplying power stored in the energy storage unit 60. Furthermore, the power supply unit 10 is configured to supply power to loads connected to the backup power supply unit 50 and the second system power supply unit 42 from either the backup power supply unit 50 or the second system power supply unit 42. As a result, the power supply unit 10 can, for example, supply power to the load from the backup power supply unit when the battery 30 is functioning normally. Also, in the case of the power supply unit 10, if the battery fails, it is possible to supply power to the backup load 200 from the second system power supply unit 42, and therefore power can be supplied to the backup load 200 even if the battery 30 fails.

[0046] Further effects and modifications can be readily derived by those skilled in the art. Therefore, broader aspects of the present invention are not limited to the specific details and representative embodiments expressed and described above. Accordingly, various modifications are possible without departing from the spirit or scope of the overall concept of the invention as defined by the appended claims and their equivalents. [Explanation of symbols]

[0047] 1. In-vehicle systems 10 Power supply 30 batteries 40. First System Power Supply Unit 42 Second System Power Supply Unit 43a, 43b Third System Power Supply Unit 50 Backup power supply unit 60 Energy Storage Unit 100a, 100b System Load 200 backup load

Claims

1. A first system power supply unit, which is connected to the battery and operates to supply power when the system is running, A backup power supply unit connected to the aforementioned battery, which operates to supply power at least when the system is shut down, The first system power supply unit and the second system power supply unit connected to the power storage unit that stores power from the battery, and which supplies power stored in the power storage unit. Equipped with, Power is supplied from either the backup power supply unit or the second system power supply unit to the loads connected to the backup power supply unit and the second system power supply unit. power supply.

2. If the aforementioned battery fails, the second system power supply unit will supply power to the load. The power supply device according to claim 1.

3. When the battery is functioning correctly, the backup power supply unit supplies power to the load. The power supply device according to claim 1.

4. A third system power supply unit is connected to the first system power supply unit and is driven when the system is operating to supply power from the battery. The power supply device according to claim 1, comprising:

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