Power supply control device and power supply control system

Abstract

To provide a power supply controller capable of more stably supplying power to a load mounted on a vehicle.SOLUTION: A power supply controller 100 comprises a first voltage conversion unit 110, a switch unit 130, a first diode 140, and a second diode 150. The first voltage conversion unit 110 lowers first power to second power and outputs it. The switch unit 130 comprises a first terminal connected to the first voltage conversion unit 110, a second terminal connected to the cathode side of the second diode 150, and a third terminal connected to a second battery. The cathode side of each of the first diode 140 and the second diode 150 is connected to a second load 420 driven using the second battery. In the switch unit 130, a path between the first terminal T1 and the third terminal T3 becomes effective when the second power is output from the first voltage conversion unit 110 and a path between the second terminal T2 and the third terminal T3 becomes effective when the second power is not output from the first voltage conversion unit 110.SELECTED DRAWING: Figure 2A

Description

Technical Field

[0001] The present invention relates to a power control device and a power control system.

Background Art

[0002] Conventionally, in order to supply power to loads mounted on a vehicle, a technique has been proposed for switching a plurality of power sources (batteries) to supply power. Patent Document 1 discloses a power supply system that switches a power source according to an operation mode. The power supply system disclosed in Patent Document 1 switches the power source used when shifting from a manual operation mode to an automatic operation mode.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the power supply system disclosed in Patent Document 1, the control unit provided in the power supply system switches the power source according to the operation mode. That is, control by the control unit is required for switching the power source. For example, even if the first battery is defective during the manual operation mode, the power source cannot be switched to the second battery, and stable power supply to the load cannot be maintained.

[0005] The present invention has been made in view of such problems of the prior art. An object of the present invention is to provide a power control device capable of more stably supplying power to loads mounted on a vehicle.

Means for Solving the Problems

[0006] A power control device according to an aspect of the present invention includes: a first voltage conversion unit that acquires first power output from a first battery that supplies power to a first load driven by first power, steps it down to a second power with a voltage lower than the voltage of the first power, and outputs the second power from an output terminal; a switch unit comprising a first terminal connected to the output terminal of the first voltage conversion unit, a second terminal connected to the cathode side of a second diode, a third terminal connected to a second battery, and a passive element with one end connected to the first terminal and the other end connected to ground; a first diode with its anode side connected to the output terminal of the first voltage conversion unit and its cathode side connected to a second load driven by second power; and a second diode with its anode side connected to the second terminal of the switch unit and its cathode side connected to the second load, wherein the path between the first terminal and the third terminal becomes active when the second power is output from the first voltage conversion unit, and the path between the second terminal and the third terminal becomes active when the second power is not output from the first voltage conversion unit.

[0007] A power control system according to an aspect of the present invention is a power control system for controlling power supplied to a first load and a second load provided in a vehicle, comprising: a first battery that supplies first power; a second battery that supplies second power; and a power control device, wherein the power control device includes: a first voltage conversion unit that acquires first power output from the first battery, steps down the voltage to second power which is lower than the voltage of first power, and outputs second power from an output terminal; a first terminal connected to the output terminal of the first voltage conversion unit; a second terminal connected to the cathode side of a second diode; and a third terminal connected to the second battery. The switch unit comprises a terminal and a passive element having one end connected to the first terminal and the other end connected to ground; a first diode having its anode connected to the output terminal of the first voltage conversion unit and its cathode connected to a second load driven by the second power; and a second diode having its anode connected to the second terminal of the switch unit and its cathode connected to the second load. The switch unit enables the paths of the first and third terminals when the second power is output from the first voltage conversion unit, and enables the paths of the second and third terminals when the second power is not output from the first voltage conversion unit. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a power control device that can supply power more stably to a load mounted on a vehicle. [Brief explanation of the drawing]

[0009] [Figure 1] This is a diagram showing the configuration of the power control system according to the first embodiment. [Figure 2A] This diagram shows the configuration of a power control device according to the first embodiment. [Figure 2B] This diagram shows the configuration of a power control device according to the first embodiment. [Figure 3A] This diagram shows the configuration of a power supply control device according to the second embodiment. [Figure 3B] This diagram shows the configuration of a power supply control device according to the second embodiment. [Modes for carrying out the invention]

[0010] The power control system 10 according to this embodiment will be described in detail below with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from the actual ratios. In addition, in the following drawings, identical or similar parts are denoted by the same or similar reference numerals.

[0011] (First Embodiment) Figure 1 shows the configuration of the power control system 10 according to the first embodiment. The power control system 10 is a system for supplying power to electronic control devices and electronic components mounted on a vehicle.

[0012] As shown in Figure 1, the power control system 10 comprises a power control device 100, a first battery 210, a second battery 220, a first load 410, and a second load 420. The power control system 10 may also include an alternator 500. In other words, the power control system 10 is a system that controls the power supplied to the first load 410 and the second load 420 provided in the vehicle.

[0013] Furthermore, the power control system 10 includes a first path 310, a second path 320, and a third path 330 as power supply lines.

[0014] As shown in Figure 1, the first battery 210, the power control device 100, the first load 410, and the alternator 500 are connected via the first path 310. The second battery 220 and the power control device 100 are connected via the second path 320. Furthermore, the power control device 100 and the second load 420 are connected via the third path 330.

[0015] The power control device 100 steps down the 48V power supplied from the first battery 210 or alternator 500 during normal operation to 12V and supplies it to the second load 420 and the second battery 220. Details of the power control device 100 will be described later. In this embodiment, the power with a voltage of 48V corresponds to the first power. Also in this embodiment, the power with a voltage of 12V corresponds to the second power.

[0016] The first battery 210 is the main battery in the power control system 10 and, under normal conditions, supplies power to the first load 410 and the second load 420. The first load 410 is a device that operates at a voltage of 48V. The alternator 500, described later, also operates at a voltage of 48V. The second load 420 is a device that operates at a voltage of 12V, and under normal operation, the 48V power supplied from the first battery 210 is stepped down to 12V by the power control device 100 and supplied to the second load 420.

[0017] The second battery 220 is a sub-battery in the power control system 10, and supplies 12V power to the second load 420 in a state such as when the first battery 210 is defective or when the alternator 500 stops. Also, normally, the 48V power supplied from the first battery 210 or the alternator 500 is stepped down to 12V in the power control device 100 and supplied to the second battery 220, thereby charging the second battery 220. Note that the first battery 210 becomes defective when the vehicle is parked without driving the engine for a long period (for example, two months or more). Also, in the present embodiment, the stop of the alternator 500 occurs, for example, in a state during the idling stop of the vehicle.

[0018] The first load 410 is an in-vehicle device that consumes 48V power. Also, as described above, the first load 410 is configured to operate with the power stored in the first battery 210 and / or the power output by the alternator 500. Note that in the present embodiment, the first load 410 corresponds to, for example, an air conditioner or the like.

[0019] The second load 420 is an in-vehicle device that consumes 12V power. Also, as described above, normally, the 48V power supplied from the first battery 210 is stepped down to 12V in the power control device 100 and supplied. Also, the second load 420 is supplied with 12V power from the second battery 220 in a state such as when the first battery 210 is defective or when the alternator 500 stops.

[0020] Note that in the present embodiment, the second load 420 corresponds to, for example, a power window motor or a door lock motor. Also, in the present embodiment, the second load 420 can be a device related to the safe driving of the vehicle. Specifically, the second load 420 may be an important load that requires power supply from the second battery 220 even when the power supply from the first battery 210 is lost.

[0021] The alternator 500 generates electricity using the rotation of the vehicle engine as a power source, and charges the first battery 210 and the second battery 220 with the generated electricity. That is, the alternator 500 is a generator that converts the running energy of the vehicle into electrical energy and charges the first battery 210 and the second battery 220.

[0022] (Configuration of the power control device 100) FIGS. 2A and 2B are block diagrams showing the configuration of the power control device 100 according to the first embodiment. As shown in FIGS. 2A and 2B, the power control device 100 includes a first voltage conversion unit 110, a switch unit 130, a first diode 140, and a second diode 150.

[0023] The anode side of the first diode 140 is connected to the branch portion D1, and the cathode side is connected to the branch portion D3. Further, the branch portion D1 is connected to the output terminal 110b of the first voltage conversion unit 110. Furthermore, the branch portion D3 is connected to the second load 420. That is, the anode side of the first diode 140 is connected to the output terminal 110b of the first voltage conversion unit 110, and the cathode side is connected to the second load 420 driven by the second power.

[0024] Also, the first diode 140 allows the flow of power from the anode side (branch portion D1 side) to the cathode side (branch portion D3 side), while restricting the flow of power from the cathode side (branch portion D3 side) to the anode side (branch portion D1 side).

[0025] The anode side of the second diode 150 is connected to the second terminal T of the switch unit 130, and the cathode side is connected to the branch portion D3. As described above, since the branch portion D3 is connected to the second load 420, the cathode side of the second diode 150 is connected to the second load 420.

[0026] Furthermore, the second diode 150 allows power to flow from the anode side (second terminal T2 side) to the cathode side (branch D3 side), while restricting power flow from the cathode side (branch D3 side) to the anode side (second terminal T2 side).

[0027] The first voltage conversion unit 110 steps down a 48V voltage to a 12V voltage. The first voltage conversion unit 110 is configured, for example, by a DC-DC converter. The input terminal 110a of the first voltage conversion unit 110 is connected to the first path 310, and the 48V power supplied from the first battery 210 is obtained via the input terminal 110a.

[0028] The output terminal 110b of the first voltage conversion unit 110 is connected to the first diode 140 via wiring through branching unit D1. Furthermore, the output terminal 110b of the first voltage conversion unit 110 is connected to the switch unit 130 via wiring through branching units D1 and D2. Therefore, the power stepped down to 12V by the first voltage conversion unit 110 is supplied to the first diode 140 and the switch unit 130.

[0029] Specifically, the first voltage conversion unit 110 acquires the first power output from the first battery 210, which supplies a first power of 48V to the first load 410. The first voltage conversion unit 110 then steps down the acquired power to a second power of 12V, which is lower than the 48V voltage. The first voltage conversion unit 110 then outputs the 12V power from the output terminal 110b.

[0030] The switch unit 130 is composed of a general 5-pole relay. In this embodiment, the switch unit 130 includes a first terminal T1 connected to the output terminal 110b of the first voltage conversion unit 110, a second terminal T2 connected to the cathode side of the second diode 150, and a third terminal T3 connected to the second battery 220.

[0031] Furthermore, the switch unit 130 includes a passive element L1, one end of which is connected to the first terminal T1 and the other end of which is connected to ground. In this embodiment, the ground may be a ground corresponding to the vehicle's body ground. In this embodiment, the passive element L1 is composed of an inductor (coil). The switch unit 130 is a switch that automatically switches contacts using the magnetic force generated when current flows through the passive element L1.

[0032] When 12V power is supplied to the branching section D2, the switch section 130 causes current to flow through the passive element L1, and the magnetic force generated in the passive element L1 connects the first terminal T1 and the third terminal T3, thereby enabling the path between the first terminal T1 and the third terminal T3. As a result, the 12V power supplied to the branching section D2 is supplied to the second battery 220 via the first terminal T1, the third terminal T3, and the second path 320. The 12V power supplied to the second battery 220 charges the second battery 220.

[0033] Figure 2A shows the state of the switch unit 130 and the power supply flow under normal conditions. As described above, under normal conditions, the 12V power converted by the first voltage conversion unit 110 is supplied to the second battery 220 via the switch unit 130 and the second path 320. Also under normal conditions, the 12V power converted by the first voltage conversion unit 110 is supplied to the second load 420 via the first diode 140 and the third path 330.

[0034] Figure 2B shows the state of the switch unit 130 and the power supply flow in conditions such as when the first battery 210 is defective or when the alternator 500 is stopped. In this embodiment, the state shown in Figure 2B is when the first battery 210 is defective or the alternator 500 is stopped, and therefore 48V power is not supplied to the first voltage conversion unit 110.

[0035] Furthermore, in the state shown in Figure 2B, since 48V power is not supplied to the first voltage conversion unit 110, the second power with a voltage of 12V is not output from the first voltage conversion unit 110. As a result, no current flows through the passive element L1 of the switch unit 130, and the switch unit 130 is in a state where the second terminal T2 and the third terminal T3 are connected. In other words, the paths of the second terminal T2 and the third terminal T3 become effective.

[0036] Therefore, in the state shown in Figure 2B, no power is supplied to the second battery 220. Also, in the state shown in Figure 2B, the 12V power charged in the second battery 220 is supplied to the second load 420 via the second path 320, the third terminal T3 and second terminal T2 of the switch unit 130, the second diode 150, and the third path 330.

[0037] Accordingly, in the power control system 10 according to the first embodiment, when the first battery 210 is defective, the switch unit 130 automatically switches, and power from the second battery 220 is supplied to the second load 420. In other words, the power control system 10 in the first embodiment can switch the battery that is the power source without providing a control device such as a CPU when the first battery 210 is defective, and can stably supply power to the second load 420.

[0038] Furthermore, in the power control system 10 according to the first embodiment, the switch unit 130 is composed of a 5-pole relay, and the third terminal T3 is connected to either the first terminal T1 or the second terminal T2 depending on the current flowing through the passive element L1. As a result, the power control system 10 can automatically switch to a path in which the second power is supplied from the second battery 220 to the second load 420 when the first voltage conversion unit 110 fails to convert the first power to the second power, such as when the first battery 210 is defective. In addition, by configuring the switch unit 130 of the power control device 100 with a 5-pole relay, it is possible to switch power sources with a simple configuration.

[0039] Furthermore, the second battery 220 of the power control system 10 acquires the second power from the switch unit 130 and charges the second power when the second power is output from the first voltage conversion unit 110. Also, when the second power is not output from the first voltage conversion unit 110, the second battery 220 supplies the second power to the second load 420 via the switch unit 130. As a result, even in the event of a defect in the first battery 210, the power control system 10 can automatically switch the path of the switch unit 130 and supply power to the second load 420 mounted on the vehicle more stably.

[0040] (Second embodiment) As described above, one specific embodiment has been explained, but the embodiment described above is illustrative and does not limit the embodiments. For example, in the embodiment described above, a configuration in which the power source (battery) for power supplied to the second load 420 is switched by the switch unit 130 was illustrated. Here, we will further describe a power control device 100 according to a second embodiment in which the power control device 100 includes a second voltage conversion unit 120 and adjusts the power from the second battery 220, and will describe a configuration that differs from the first embodiment.

[0041] The power control device 100 according to the second embodiment differs from the power control device 100 according to the first embodiment in that it includes a second voltage conversion unit 120. As shown in Figures 3A and 3B, the input terminal 120a of the second voltage conversion unit 120 is connected to the second terminal T2 of the switch unit 130, and the output terminal 120b is connected to the cathode side of the second diode 150.

[0042] For example, if the power supplied from the second battery 220 drops slightly below 12V and is supplied to the second load 420, it will affect the marketability of the vehicle, such as causing the lamps installed in the vehicle to dim. The second voltage conversion unit 120 according to the second embodiment has a function to adjust the supplied voltage and return it to 12V, thereby supplying 12V power to the second load 420 more appropriately.

[0043] Figure 3A shows the state of the switch unit 130 and the power supply flow in the second embodiment under normal conditions. Figure 3B shows the state of the switch unit 130 and the power supply flow in the second embodiment under conditions such as when the first battery 210 is defective or when the alternator 500 is stopped.

[0044] In the second embodiment, the second voltage conversion unit 120 is provided between the second terminal T2 of the switch unit 130 and the anode side of the second diode 150. Also, as shown in Figures 3A and 3B, the second voltage conversion unit 120 is supplied with second power from the second battery 220 in the event of a failure of the first battery 210 or when the alternator 500 stops, and the voltage is adjusted to 12V. The 12V power properly adjusted in the second voltage conversion unit 120 is then supplied to the second load 420 via the second diode 150 and the third path 330.

[0045] As described above, the second embodiment of the power control system 10 includes a second voltage conversion unit 120 in the power control device 100. This makes it possible to supply a more appropriate 12V power to the second load 420.

[0046] (Other embodiments) While embodiments have been described in detail with reference to the drawings, these embodiments are not limited to those described above. Furthermore, the components described above include those easily conceivable by those skilled in the art, and those that are substantially the same. Moreover, the configurations described above can be combined as appropriate. In addition, various omissions, substitutions, or modifications of the configurations can be made without departing from the spirit of the embodiments.

[0047] The features of the power control device 100 and the power control system 10 are described below.

[0048] The power control device 100 according to the first embodiment includes a first voltage conversion unit 110. The first voltage conversion unit 110 acquires first power output from a first battery 210 that supplies power to a first load 410 driven by first power, steps it down to a second power with a voltage lower than the voltage of the first power, and outputs the second power from an output terminal 110b. The power control device 100 also includes a switch unit 130. The switch unit 130 includes a first terminal T1 connected to the output terminal 110b of the first voltage conversion unit 110, a second terminal T2 connected to the cathode side of the second diode 150, and a third terminal T3 connected to the second battery 220. The switch unit 130 also includes a passive element L1, one end of which is connected to the first terminal T1 and the other end of which is connected to ground. Furthermore, the power control device 100 includes a first diode 140 whose anode is connected to the output terminal 110b of the first voltage conversion unit 110 and whose cathode is connected to a second load 420 driven by the second power. The power control device 100 also includes a second diode 150 whose anode is connected to the second terminal T2 of the switch unit 130 and whose cathode is connected to the second load 420. Furthermore, the switch unit 130 enables the path between the first terminal T1 and the third terminal T3 when the second power is output from the first voltage conversion unit 110, and enables the path between the second terminal T2 and the third terminal T3 when the second power is not output from the first voltage conversion unit 110.

[0049] With the above configuration, the power control device 100 can switch batteries without providing a control device such as a CPU in the event of a defect in the first battery 210, and can stably supply power to the second load 420.

[0050] The switch unit 130 of the power control device 100 according to the second embodiment may be a 5-pole relay. In addition, the switch unit 130 may have a third terminal T3 connected to either the first terminal T1 or the second terminal T2 depending on the current flowing through the passive element L1.

[0051] With the above configuration, the power control device 100 can automatically switch to a path in which the second power is supplied from the second battery 220 to the second load 420 when the first voltage conversion unit 110 fails to convert the first power to the second power, such as when the first battery 210 is defective. Furthermore, by configuring the switch unit 130 of the power control device 100 with a 5-pole relay, the power source can be switched with a simple configuration.

[0052] The power control device 100 according to the third embodiment may further include a second voltage conversion unit 120, the input terminal 120a of which is connected to the second terminal T2 of the switch unit 130, and the output terminal 120b of which is connected to the cathode side of the second diode 150. The second voltage conversion unit 120 may also regulate the voltage of the second power supplied from the second battery 220.

[0053] With the above configuration, the power control device 100 can supply a more appropriate 12V power to the second load 420.

[0054] The fourth embodiment of the power control system 10 is a power control system 10 that controls the power supplied to a first load 410 and a second load 420 provided in a vehicle. The power control system 10 includes a first battery 210 that supplies first power, a second battery 220 that supplies second power, and a power control device 100. The power control device 100 has a first voltage conversion unit 110 that acquires first power output from the first battery 210, steps it down to a second power with a voltage lower than the voltage of the first power, and outputs the second power from an output terminal 110b. The power control device 100 also has a switch unit 130. The switch unit 130 includes a first terminal T1 connected to the output terminal 110b of the first voltage conversion unit 110, a second terminal T2 connected to the cathode side of the second diode 150, and a third terminal T3 connected to the second battery 220. Furthermore, the switch unit 130 includes a passive element L1, one end of which is connected to the first terminal T1 and the other end of which is connected to ground. The power control device 100 has a first diode 140, the anode side of which is connected to the output terminal 110b of the first voltage conversion unit 110 and the cathode side of which is connected to the second load 420 driven by the second power. The power control device 100 also has a second diode 150, the anode side of which is connected to the second terminal T2 of the switch unit 130 and the cathode side of which is connected to the second load 420. Furthermore, the switch unit 130 has a path between the first terminal T1 and the third terminal T3 that is enabled when the second power is output from the first voltage conversion unit 110, and a path between the second terminal T2 and the third terminal T3 that is enabled when the second power is not output from the first voltage conversion unit 110.

[0055] With the above configuration, the power control system 10 can switch batteries without providing a control device such as a CPU in the event of a defect in the first battery 210, and can stably supply power to the second load 420.

[0056] In the fifth embodiment of the power control system 10, the second battery 220 may acquire the second power from the switch unit 130 and charge the second power when the second power is output from the first voltage conversion unit 110 of the power control device 100. Alternatively, the second battery 220 may supply the second power to the second load 420 via the switch unit 130 when the second power is not output from the first voltage conversion unit 110 of the power control device 100.

[0057] With the above configuration, the power control system 10 can automatically switch the path of the switch unit 130 even in the event of a defect in the first battery 210, enabling a more stable supply of power to the second load 420 mounted on the vehicle. [Explanation of Symbols]

[0058] 10 Power Control System 100 Power supply control device 110 First Voltage Conversion Unit 120 Second Voltage Conversion Section 130 Switch section 140 First Diode 150 Second Diode 210 First Battery 220 Second Battery 310 Route 1 320 Second Route 330 Third Route 410 1st load 420 2nd load 500 Alternator

Claims

1. A first voltage conversion unit acquires the first power output from a first battery that supplies power to a first load driven by the first power, steps it down to a second power with a voltage lower than the voltage of the first power, and outputs the second power from an output terminal. A switch unit comprising: a first terminal connected to the output terminal of the first voltage conversion unit; a second terminal connected to the cathode side of the second diode; a third terminal connected to the second battery; and a passive element having one end connected to the first terminal and the other end connected to ground. A first diode whose anode is connected to the output terminal of the first voltage conversion unit and whose cathode is connected to a second load driven by the second power, The second diode comprises an anode side connected to the second terminal of the switch section and a cathode side connected to the second load, The switch unit is a power control device in which the paths of the first terminal and the third terminal become active when the second power is output from the first voltage conversion unit, and the paths of the second terminal and the third terminal become active when the second power is not output from the first voltage conversion unit.

2. The power control device according to claim 1, wherein the switch section is a 5-pole relay, and the third terminal is connected to either the first terminal or the second terminal depending on the current flowing through the passive element.

3. The system further comprises a second voltage conversion unit, the input terminal of which is connected to the second terminal of the switch unit, and the output terminal of which is connected to the cathode side of the second diode. The power control device according to claim 2, wherein the second voltage conversion unit regulates the voltage of the second power supplied from the second battery.

4. A power supply control system that controls the power supplied to a first load and a second load installed in a vehicle, It comprises a first battery that supplies first power, a second battery that supplies second power, and a power control device. The power supply control device is A first voltage conversion unit that acquires the first power output from the first battery, steps down the voltage to a second power with a voltage lower than the voltage of the first power, and outputs the second power from the output terminal, A switch unit comprising: a first terminal connected to the output terminal of the first voltage conversion unit; a second terminal connected to the cathode side of the second diode; a third terminal connected to the second battery; and a passive element having one end connected to the first terminal and the other end connected to ground. A first diode whose anode is connected to the output terminal of the first voltage conversion unit and whose cathode is connected to the second load driven by the second power, The second diode has an anode side connected to the second terminal of the switch section and a cathode side connected to the second load, The switch unit is a power control system in which the paths of the first terminal and the third terminal become active when the second power is output from the first voltage conversion unit, and the paths of the second terminal and the third terminal become active when the second power is not output from the first voltage conversion unit.

5. The second battery, when the second power is output from the first voltage conversion unit of the power control device, acquires the second power from the switch unit and charges the second power. The power control system according to claim 4, wherein the second battery supplies the second power to the second load via the switch unit when the first voltage conversion unit of the power control device does not output the second power.

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