Vehicle power supply system

Abstract

To provide a vehicle power supply system capable of further simplifying a configuration.SOLUTION: The vehicle-power-supply system 1 includes the control unit 50 that controls conduction and disconnection of the switches SW1 to SW4, and in a normal state in which it is determined that there is no abnormality in the first power supply unit 10 and the first and second load units Lo1 and Lo2, the control unit 50 brings only the third switch SW3 into a disconnected state and supplies power from the first power supply unit 10 and the battery unit 30 to the first and second load units Lo1 and Lo2. In a first abnormal condition in which it is determined that there is an abnormality in the first power supply unit 10 or the first load unit Lo1, only the first switch SW1 is set to the cut-off state and power is supplied from the second power supply unit 20 and the battery unit 30 to the second load unit Lo2, and in a second abnormal condition in which it is determined that there is an abnormality in the second load unit Lo2, the first and fourth switches SW1 and SW4 are set to the conductive state and the second and third switches SW2 and SW3 are set to the cut-off state, power is supplied from the first power supply unit 10 and the battery unit 30 to the first load unit Lo1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to vehicle power supply systems. [Background technology]

[0002] Conventionally, a vehicle power supply system has been proposed that includes a main power supply device that supplies power to a first load section and a second load section mounted on a vehicle, and a backup power supply device that does not supply power to the first load section when an abnormality occurs in the main power supply device, but supplies power only to the second load section (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7013500 Summary of the Invention [Problem to be solved by the invention]

[0004] In the vehicle power supply system described in Patent Document 1, the main power supply unit includes a main power supply unit, such as a DC / DC converter that receives power from a high-voltage battery or generator mounted on the vehicle and performs power conversion, as well as a power storage means that is charged by the high-voltage battery or generator. Similarly, the backup power supply unit also includes a backup power supply unit, such as a DC / DC converter, as well as a power storage means. By including a power storage means, each power supply unit can respond to situations where power is insufficient from the power supply unit alone, for example, during load fluctuations. On the other hand, the vehicle power supply system described in Patent Document 1 requires a power storage means for each of the main system and the backup system, which poses a problem in terms of simplifying the configuration.

[0005] Therefore, an object of the present disclosure is to provide a vehicle power supply system that can be further simplified in configuration. [Means for solving the problem]

[0006] In order to solve the above problem, a vehicle power supply system according to one embodiment of the present disclosure is a vehicle power supply system that supplies power to a first load section and a second load section mounted on a vehicle, and includes: a first line connecting a vehicle power supply section capable of supplying power to the first load section; a second line connecting the first line to the second load section; a first switch that is provided on the second line and performs conduction and interruption; a second switch that is provided in series on the second line closer to the second load section than the first switch and performs conduction and interruption; a third line that connects a connection point between the first switch and the second switch to a storage means that stores electricity in advance; and control means that controls the conduction and interruption of the first switch and the second switch. In a normal state where it is determined that there is no abnormality in the vehicle power supply unit, the first load unit, and the second load unit, the control means sets the first switch and the second switch to a conductive state to supply power from the vehicle power supply unit and the power storage means to the first load unit and the second load unit; in a first abnormal state where it is determined that there is an abnormality in the vehicle power supply unit or the first load unit, the control means sets the first switch to a cut-off state and the second switch to a conductive state to supply power from the power storage means to the second load unit; and in a second abnormal state where it is determined that there is an abnormality in the second load unit, the control means sets the first switch to a conductive state and the second switch to a cut-off state to supply power from the vehicle power supply unit and the power storage means to the first load unit. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a vehicle power supply system that can further simplify the configuration. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a configuration diagram showing a vehicle power supply system according to a first embodiment. [Figure 2] 4 is a table showing the operating states of switches in the vehicle power supply system according to the first embodiment. [Figure 3] 1 is a conceptual diagram showing the state of power supply in each operating state, illustrating a normal state. [Figure 4] 1 is a conceptual diagram showing the state of power supply in each operating state, illustrating a first abnormal state. [Figure 5] 10 is a conceptual diagram showing the state of power supply in each operating state, illustrating a second abnormal state. [Figure 6] 10A and 10B are conceptual diagrams showing the state of power supply in each operating state, illustrating a state in which there is an abnormality in the battery unit. [Figure 7] FIG. 6 is a configuration diagram showing a vehicle power supply system according to a second embodiment. [Figure 8] 10 is a table showing the operating states of switches in a vehicle power supply system according to a second embodiment. [Figure 9] 10A and 10B are conceptual diagrams showing how power is supplied in each operating state in the second embodiment, illustrating a normal state. [Figure 10] 10 is a conceptual diagram showing how power is supplied in each operating state in the second embodiment, illustrating a first abnormal state. [Figure 11] 10A to 10C are conceptual diagrams showing how power is supplied in each operating state in the second embodiment, illustrating a second abnormal state. [Figure 12] 10A to 10C are conceptual diagrams showing how power is supplied in each operating state in the second embodiment, illustrating a state in which there is an abnormality in the battery unit. [Figure 13] FIG. 4 is a configuration diagram showing a vehicle power supply system according to a modified example of the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present disclosure will be described below in accordance with preferred embodiments. Note that the present disclosure is not limited to the embodiments described below and can be modified as appropriate without departing from the spirit of the present disclosure. In addition, in the embodiments described below, some configurations are omitted from illustration and description, but it goes without saying that publicly known or well-known technologies are applied as appropriate to the details of the omitted technologies within the scope of the content described below.

[0010] Fig. 1 is a configuration diagram showing a vehicle power supply system according to a first embodiment. The vehicle power supply system 1 shown in Fig. 1 is mounted on, for example, an autonomously driven vehicle, and supplies power to a first load unit Lo1 and a second load unit Lo2 mounted on the vehicle. In addition to the first load unit Lo1 and the second load unit Lo2, the vehicle power supply system 1 includes a first power supply unit (vehicle power supply unit) 10, a second power supply unit 20, a battery unit (power storage means) 30, and first to fourth voltage detection units 41 to 44. The vehicle power supply system 1 also includes first to fourth switches SW1 to SW4, first to fourth lines L1 to L4, and a control unit (control means) 50.

[0011] The first load unit Lo1 is provided with functions necessary for vehicle travel during, for example, autonomous driving, as well as auxiliary equipment such as an air conditioner and car navigation system. The second load unit Lo2 is provided for performing reduced functions such as at least evacuating the vehicle to a safe place during, for example, autonomous driving. Note that the first load unit Lo1 and the second load unit Lo2 are not particularly limited to those described above.

[0012] The first power supply unit 10 is configured with a DC / DC converter that receives power from a high-voltage battery mounted on the vehicle and performs power conversion. Similarly to the first power supply unit 10, the second power supply unit 20 is also configured with a DC / DC converter that receives power from the high-voltage battery and performs power conversion. The battery unit 30 is configured with an electric double-layer capacitor, a lithium-ion battery, or a lead-acid battery, and is charged in advance with power from a power supply unit or the like. The battery unit 30 operates as a supplementary power supply to prevent power shortages when there is a load fluctuation in the first load unit Lo1 or the second load unit Lo2, i.e., when the power required by the first load unit Lo1 or the second load unit Lo2 temporarily increases. As shown in FIG. 6 (described later), the first power supply unit 10 is designed to be able to respond to load fluctuations expected in the second load unit Lo2 even without the battery unit 30 when supplying power only to the second load unit Lo2.

[0013] The first line L1 is a conductive path connecting the first power supply unit 10 and the first load unit Lo1. The second line L2 is a conductive path connecting the branch point P1 on the first line L1 and the second load unit Lo2.

[0014] The first switch SW1 is provided on the second line L2 and is configured to turn on and off the power supply. The second switch SW2 is provided in series on the second line L2 closer to the second load section Lo2 than the first switch SW1 and is configured to turn on and off the power supply. The first switch SW1 and the second switch SW2 are connected via a connection point P2.

[0015] The first and second switches SW1 and SW2 each include two switch sections SW1a, SW1b, SW2a, and SW2b, which are configured using n-type metal-oxide-semiconductor field-effect transistors (MOSFETs).

[0016] One switch section SW1a of the first switch SW1 has a drain terminal D serving as a first terminal connected to branch point P1, and a source terminal S serving as a second terminal connected to connection point P2 and the source terminal S of the other switch section SW1b. A gate terminal G serving as a third terminal is configured to receive a gate signal from the control unit 50. One switch section SW1a has a parasitic diode D1a that allows current to flow from the source terminal S to the drain terminal D and blocks current from the drain terminal D to the source terminal S.

[0017] The other switch section SW1b of the first switch SW1 has a drain terminal D serving as a first terminal connected to the connection point P2, and a source terminal S serving as a second terminal connected to the source terminal S of one switch section SW1a. A gate terminal G serving as a third terminal is configured to receive a gate signal from the control unit 50. The other switch section SW1b also has a parasitic diode D1b that allows current to flow from the source terminal S to the drain terminal D and blocks current from the drain terminal D to the source terminal S.

[0018] One switch section SW2a of the second switch SW2 has a drain terminal D serving as a first terminal connected to the connection point P2, and a source terminal S serving as a second terminal connected to the source terminal S of the other switch section SW2b. A gate terminal G serving as a third terminal is configured to receive a gate signal from the control section 50. One switch section SW2a has a parasitic diode D2a that allows current to flow from the source terminal S to the drain terminal D and blocks current to flow from the drain terminal D to the source terminal S.

[0019] The other switch section SW2b of the second switch SW2 has a drain terminal D serving as a first terminal connected to the second load section Lo2 side, and a source terminal S serving as a second terminal connected to the source terminal S of one switch section SW2a. A gate terminal G serving as a third terminal is configured to receive a gate signal from the control section 50. The other switch section SW2b also has a parasitic diode D2b that allows current to flow from the source terminal S to the drain terminal D and blocks current to flow from the drain terminal D to the source terminal S.

[0020] The third line L3 is a conductive path that connects a connection point P2 between the first switch SW1 and the second switch SW2 and the battery unit 30. The fourth line L4 is a conductive path that connects a connection point (second connection point) P3 between the second switch SW2 and the second load unit Lo2 and the second power supply unit 20.

[0021] The third switch SW3 is provided on the fourth line L4 and performs conduction and cutoff. Similar to the first switch SW1 and the second switch SW2, the third switch SW3 is composed of two switch sections SW3a and SW3b. The two switch sections SW3a and SW3b are composed of n-type MOSFETs.

[0022] One switch section SW3a of the third switch SW3 has a drain terminal D serving as a first terminal connected to the second power supply section 20, and a source terminal S serving as a second terminal connected to the source terminal S of the other switch section SW3b. A gate terminal G serving as a third terminal is configured to receive a gate signal from the control section 50. One switch section SW3a has a parasitic diode D3a that allows current to flow from the source terminal S to the drain terminal D and blocks current to flow from the drain terminal D to the source terminal S.

[0023] The other switch section SW3b of the third switch SW3 has a drain terminal D serving as a first terminal connected to the connection point P3, and a source terminal S serving as a second terminal connected to the source terminal S of one switch section SW3a. A gate terminal G serving as a third terminal is configured to receive a gate signal from the control unit 50. The other switch section SW3b also has a parasitic diode D3b that allows current to flow from the source terminal S to the drain terminal D and blocks current from the drain terminal D to the source terminal S.

[0024] The fourth switch SW4 is provided on the first line L1 between the branch point P1 and the first load unit Lo1, and is configured to make the line conductive and cut off. The fourth switch SW4 has a drain terminal D, which serves as a first terminal, connected to the branch point P1, and a source terminal S, which serves as a second terminal, connected to the first load unit Lo1. A gate signal from the control unit 50 is input to a gate terminal G, which serves as a third terminal. The fourth switch SW4 also has a parasitic diode D4 that allows current to flow from the source terminal S to the drain terminal D and blocks current from the drain terminal D to the source terminal S.

[0025] The first voltage detection unit 41 detects the voltage on the first line L1, and in particular the voltage on the first load unit Lo1 side of the fourth switch SW4. The second voltage detection unit 42 detects the voltage on the second line L2, and detects the voltage at the connection point P2. The third voltage detection unit 43 detects the voltage on the second line L2, and detects the voltage on the second load unit Lo2 side of the connection point P3. The fourth voltage detection unit 44 detects the voltage on the fourth line L4, and detects the voltage on the second power supply unit 20 side of the third switch SW3.

[0026] The control unit 50 controls the conduction and cut-off of the first to fourth switches SW1 to SW4. The control unit 50 receives information on detected voltages from the first to fourth voltage detection units 41 to 44, determines the ground fault state (one of the abnormal states) of each unit, and controls the conduction and cut-off of the first to fourth switches SW1 to SW4.

[0027] For example, suppose the third switch SW3 is off and the other switches SW1, SW2, and SW4 are on. In this case, if there is no ground fault in the first power supply unit 10 or the first load unit Lo1, the first and second voltage detection units 41 and 42 should detect appropriate voltage values ​​expected in normal operation. In this case, the voltage detected by the first voltage detection unit 41 will be higher than the voltage detected by the second voltage detection unit 42. However, if there is a ground fault in the first power supply unit 10 or the first load unit Lo1 (including the first line L1), the voltage detected by the first voltage detection unit 41 will be lower than the voltage detected by the second voltage detection unit 42. In this case, the control unit 50 determines that a ground fault abnormality has occurred in the first power supply unit 10 or the first load unit Lo1.

[0028] Similarly, suppose the third switch SW3 is off and the other switches SW1, SW2, and SW4 are on. In this case, if there is no ground fault in the second load unit Lo2, the second and third voltage detection units 42 and 43 should detect appropriate voltage values ​​expected under normal conditions. In this case, the difference between the voltages detected by the second voltage detection unit 42 and the third voltage detection unit 43 will be equal to or less than a predetermined threshold. However, if a ground fault occurs in the second load unit Lo2 (including the portion of the second line L2 closer to the second load unit Lo2 than the connection point P3), the difference between the voltages detected by the two units will be excessive and exceed the predetermined threshold. In this case, the control unit 50 determines that a ground fault abnormality has occurred in the second load unit Lo2.

[0029] Furthermore, for example, if no ground fault has occurred in the second power supply unit 20, the third and fourth voltage detection units 43, 44 should detect appropriate voltage values ​​expected under normal conditions. In this case, the voltage detected by the fourth voltage detection unit 44 will be higher than the voltage detected by the third voltage detection unit 43. However, if a ground fault has occurred in the second power supply unit 20, the voltage detected by the fourth voltage detection unit 44 will be lower than the voltage detected by the third voltage detection unit 43. In this case, the control unit 50 determines that a ground fault abnormality has occurred in the second power supply unit 20.

[0030] In this way, the control unit 50 can determine whether a ground fault has occurred in each unit, and controls the conduction and cut-off of each of the switches SW1 to SW4 in accordance with the state of the ground fault, as will be described later.

[0031] The above is merely one example of a ground fault detection method, and various known and publicly known methods can be applied to detect ground faults. Furthermore, the control unit 50 is not limited to detecting abnormalities in which the voltage drops, such as a ground fault, but may also detect abnormalities in the high-voltage side, in which the voltage rises to an abnormal value, based on information from the voltage detection units 41-44. Furthermore, the vehicle power supply system 1 may include a current sensor instead of or in addition to the voltage detection units 41-44, and the control unit 50 may be configured to detect overcurrent abnormalities (including momentary overcurrent due to a layer short circuit). Furthermore, an abnormality such as a ground fault may be determined based on the functions of the power supply units 10 and 20 and the functions of the loads constituting the load units Lo1 and Lo2, and the control unit 50 may determine the abnormality by inputting this information.

[0032] Furthermore, the battery unit 30 according to the first embodiment is equipped with a function for detecting an abnormal state by itself and includes a battery cutoff unit (cutoff unit) 31. The battery cutoff unit 31 cuts off the connection between the battery unit 30 and the connection point P2 when an abnormal voltage is detected based on a voltage sensor or the like included in the battery unit 30 itself. Here, in the first embodiment, the battery cutoff unit 31 is assumed to be switchable between a conductive state and a cutoff state, similar to the first to fourth switches SW1 to SW4. However, this is not limiting, and the battery cutoff unit 31 may be a fuse that melts to cut off the connection when an abnormal voltage occurs on the high-voltage side. In addition, the battery unit 30 may not include the battery cutoff unit 31, and the vehicle power supply system 1 may include the battery cutoff unit 31 on the third line L3.

[0033] Furthermore, the control unit 50 acquires information from the battery unit 30 and determines whether there is an abnormality in the battery unit 30. The control unit 50 may also determine whether there is an abnormality in the battery unit 30 based on information on the detected voltage from the second voltage detection unit .

[0034] Next, the operation of the vehicle power supply system 1 according to the first embodiment will be described. Fig. 2 is a diagram showing the operating states of switches SW1 to SW4 in the vehicle power supply system 1 according to the first embodiment, and Figs. 3 to 6 are conceptual diagrams showing how power is supplied in each operating state. In Figs. 3 to 6, thick lines indicate that power is being supplied, and dashed lines indicate that power is not being supplied.

[0035] First, it is assumed that the control unit 50 determines that the first power supply unit 10, the first load unit Lo1, the second power supply unit 20, the second load unit Lo2, and the battery unit 30 are in a normal state, i.e., no abnormalities are present. In this case, the control unit 50 sets the first, second, and fourth switches SW1, SW2, and SW4 to a conducting state (ON) and sets the third switch SW3 to a non-conducting state (OFF), as shown in Fig. 2. As a result, as shown in Fig. 3, the vehicle power supply system 1 supplies power to the first and second load units Lo1 and Lo2 from the first power supply unit 10 and the battery unit 30. In this case, the second power supply unit 20 does not operate.

[0036] Furthermore, it is assumed that the control unit 50 determines that there is an abnormality in the first power supply unit 10 or the first load unit Lo1 (first abnormal state). In this case, the control unit 50 sets the first switch to an OFF state and the second to fourth switches SW2 to SW4 to a COND state, as shown in Fig. 2. As a result, as shown in Fig. 4, the vehicle power supply system 1 supplies power from the second power supply unit 20 and the battery unit 30 to the second load unit Lo2, enabling the autonomously driven vehicle to make an evacuation run.

[0037] Although the control unit 50 may turn off the fourth switch SW4 in the first abnormal state, it is preferable to keep the fourth switch SW4 in a conductive state at least when the first load unit Lo1 is abnormal. Each load constituting the first load unit Lo1 is usually provided with a fuse or a cutoff switch to respond to abnormalities. For this reason, the vehicle power supply system 1 turns on the fourth switch SW4 in the first abnormal state and cuts off only the load in the first load unit Lo1 that is in the abnormal state, thereby enabling the operation of the other loads in the first load unit Lo1.

[0038] Furthermore, it is assumed that the control unit 50 determines that the second power supply unit 20 is in an abnormal state (third abnormal state). In this case, the control unit 50 sets the first, second, and fourth switches SW1, SW2, and SW4 in a conductive state and the third switch SW3 in a cut-off state, as shown in FIG. 2. That is, the control unit 50 sets the conductive and cut-off states of the switches SW1 to SW4 to the same as the normal state. As a result, as shown in FIG. 3, the vehicle power supply system 1 supplies power to the first and second load units Lo1 and Lo2 from the first power supply unit 10 and the battery unit 30.

[0039] Furthermore, it is assumed that the control unit 50 determines that the second load unit Lo2 is in an abnormal state (second abnormal state). In this case, the control unit 50 sets the first and fourth switches SW1 and SW4 to a conductive state and the second and third switches SW2 and SW3 to a non-conductive state, as shown in Fig. 2. As a result, the vehicle power supply system 1 supplies power to the first load unit Lo1 from the first power supply unit 10 and the battery unit 30, as shown in Fig. 5.

[0040] Furthermore, it is assumed that the control unit 50 determines that the battery unit 30 is in an abnormal state (open battery state) such as overvoltage, overcharge, or overdischarge. In this case, the control unit 50 turns the first and second switches SW1 and SW2 on and turns the third and fourth switches SW3 and SW4 off, as shown in Fig. 2. In addition, the battery cutoff unit 31 cuts off the connection between the battery unit 30 and the connection point P2. As a result, the vehicle power supply system 1 supplies power from the first power supply unit 10 to the second load unit Lo2, as shown in Fig. 6.

[0041] In this way, the vehicle power supply system 1 according to the first embodiment supplies power from the first power supply unit 10 and the battery unit 30 to the first and second load units Lo1 and Lo2 in a normal state. Furthermore, the vehicle power supply system 1 supplies power from the battery unit 30 to the second load unit Lo2 in a first abnormal state, and supplies power from the first power supply unit 10 and the battery unit 30 to the first load unit Lo1 in a second abnormal state. Therefore, the vehicle power supply system 1 supplies power from the battery unit 30 to the load side in any of the normal state, the first abnormal state, and the second abnormal state. Therefore, the battery unit 30 is shared between the power supply system in a normal state and the power supply system in an abnormal state, eliminating the need to provide a dedicated battery for dealing with abnormal states, and making it possible to provide a vehicle power supply system 1 that can further simplify its configuration.

[0042] The vehicle power supply system 1 according to the first embodiment further includes a battery cutoff unit 31 that cuts off the connection between the battery unit 30 and the connection point P2 when an abnormal voltage occurs in the battery unit 30. This allows the battery unit 30 to be cut off from the load units Lo1 and Lo2 when an abnormality occurs in the battery unit 30, thereby preventing the abnormal voltage of the battery unit 30 from affecting the entire system.

[0043] Furthermore, the vehicle power supply system 1 according to the first embodiment includes the second power supply unit 20, and in the first abnormal state, the third switch SW3 is turned on to supply power from the second power supply unit 20 and the battery unit 30 to the second load unit Lo2. Therefore, in the first abnormal state, the vehicle power supply system 1 does not supply power to the second load unit Lo2 only from the battery unit 30, but also supplies power to the second load unit Lo2 from the second power supply unit 20. This eliminates the need for a battery unit 30 with a relatively large capacity, as is the case when power is supplied to the second load unit Lo2 only from the battery unit 30, and contributes to reducing the capacity of the battery unit 30.

[0044] Furthermore, since the battery unit 30 is an electric double layer capacitor, a lithium ion battery, or a lead storage battery, any of these can respond to load fluctuations in the first load unit Lo1 and the second load unit Lo2, and can contribute to driving the load appropriately.

[0045] Next, a vehicle power supply system according to a second embodiment will be described. The vehicle power supply system according to the second embodiment is similar to that of the first embodiment, but has a partially different configuration. The differences from the first embodiment will be described below.

[0046] FIG. 7 is a configuration diagram showing a vehicle power supply system according to a second embodiment. As shown in FIG. 7, the vehicle power supply system 2 according to the second embodiment has a structure in which the second power supply unit 20, the fourth line L4, and the third switch SW3 are removed from the system according to the first embodiment. Furthermore, the battery unit 30 according to the second embodiment has a larger capacity than that according to the first embodiment. Therefore, the battery unit 30 according to the second embodiment may be an electric double-layer capacitor or a lead-acid battery, but is preferably a lithium-ion battery. Furthermore, the first power supply unit 10 is not limited to a DC / DC converter, and may be configured with another power converter, such as an AC / DC converter that receives and converts power from a generator.

[0047] Fig. 8 is a diagram showing the operating states of switches SW1, SW2, and SW4 in vehicle power supply system 2 according to the second embodiment, and Figs. 9 to 12 are conceptual diagrams showing how power is supplied in each operating state in the second embodiment. In Figs. 9 to 12, bold lines indicate that power is being supplied, and dashed lines indicate that power is not being supplied.

[0048] First, it is assumed that the control unit 50 determines that the first power supply unit 10, the first load unit Lo1, the second load unit Lo2, and the battery unit 30 are in a normal state, i.e., no abnormalities exist. In this case, the control unit 50 turns on all the switches SW1, SW2, and SW4, as shown in Fig. 8. As a result, the vehicle power supply system 2 supplies power from the first power supply unit 10 and the battery unit 30 to the first and second load units Lo1 and Lo2, as shown in Fig. 9.

[0049] Furthermore, it is assumed that the control unit 50 determines that there is an abnormality in the first power supply unit 10 or the first load unit Lo1 (first abnormal state). In this case, as shown in FIG. 8, the control unit 50 sets the first switch to an OFF state and the second and fourth switches SW2 and SW4 to a COND state. Note that the control unit 50 may also set the fourth switch SW4 to an OFF state. As a result, as shown in FIG. 10, the vehicle power supply system 2 supplies power from the battery unit 30 to the second load unit Lo2, enabling the autonomously driven vehicle to make an evacuation run.

[0050] Furthermore, it is assumed that the control unit 50 determines that the second load unit Lo2 is in an abnormal state (second abnormal state). In this case, the control unit 50 sets the first and fourth switches SW1 and SW4 to a conductive state and the second switch SW2 to a cut-off state, as shown in Fig. 8. As a result, the vehicle power supply system 2 supplies power to the first load unit Lo1 from the first power supply unit 10 and the battery unit 30, as shown in Fig. 11.

[0051] Furthermore, it is assumed that the control unit 50 determines that there is an abnormality in the battery unit 30 (battery open). In this case, the control unit 50 sets the first and second switches SW1 and SW2 to a conductive state and the fourth switch SW4 to a cut-off state, as shown in Fig. 8. As a result, the vehicle power supply system 2 supplies power from the first power supply unit 10 to the second load unit Lo2, as shown in Fig. 12.

[0052] In this way, the vehicle power supply system 2 according to the second embodiment, like the first embodiment, is in a state in which power is supplied from the battery unit 30 to the load side in any of the normal state, the first abnormal state, and the second abnormal state. Therefore, the battery unit 30 is shared between the power supply system in the normal state and the power supply system in the abnormal state. This makes it possible to provide a vehicle power supply system 2 that can be further simplified in configuration. In particular, because the vehicle power supply system 2 according to the second embodiment does not include the second power supply unit 20, the number of power supply units can be reduced, further simplifying the configuration.

[0053] Furthermore, similar to the first embodiment, the vehicle power supply system 2 according to the second embodiment can disconnect the battery unit 30 from the load units Lo1 and Lo2 when an abnormality occurs in the battery unit 30. This can prevent the abnormal voltage of the battery unit 30 from affecting the entire system.

[0054] In the second embodiment, the battery unit 30 is an electric double layer capacitor, a lithium ion battery, or a lead storage battery, and any of these can respond to load fluctuations and contribute to driving the load appropriately. In the second embodiment, the battery unit 30 is preferably a lithium ion battery.

[0055] The present disclosure has been described above based on the embodiments, but the present disclosure is not limited to the above embodiments, and modifications may be made within the scope of the spirit of the present disclosure, and if possible, techniques from the embodiments or publicly known or well-known techniques may be combined.

[0056] For example, in the above embodiments, the vehicle power supply systems 1 and 2 have been described assuming an autonomous vehicle. However, the present invention is not limited to this. The vehicle power supply systems 1 and 2 may also be applied to an autonomous vehicle during manual driving or to a vehicle that does not have an autonomous driving function. Furthermore, the first load unit Lo1 and the second load unit Lo2 may be changed between autonomous driving and manual driving. For example, when it is raining, windshield wipers are not important during autonomous driving but become more important during manual driving. For this reason, there may be a load, such as windshield wipers, that is the second load unit Lo2 during autonomous driving and the first load unit Lo1 during manual driving.

[0057] Furthermore, in the above-described embodiments, the vehicle power supply systems 1 and 2 supply power to the first load unit Lo1 in the second abnormal state in which the second load unit Lo2 has an abnormality. In this case, the control unit 50 may supply power only to a portion of the first load unit Lo1 to perform evacuation running.

[0058] In the above embodiment, each of the switches SW1 to SW4 is configured to include an n-type MOSFET. However, as long as the switches SW1 to SW4 can perform conduction blocking, they are not limited to the above configuration and may be configured to include other switching means such as a p-type MOSFET, a relay switch, or a transistor.

[0059] Furthermore, the first to third switches SW1 to SW3 are configured as bidirectional cutoff switches with their source terminals S connected together, but this is not limited thereto and may be configured as a single n-type MOSFET. FIG. 13 is a configuration diagram showing a vehicle power supply system according to a modified example of the first embodiment. As shown in FIG. 13, in the vehicle power supply system 1a according to the modified example, the first switch SW1 does not have a first switch unit SW1a and is configured only with a second switch unit SW1b. Similarly, in the vehicle power supply system 1a according to the modified example, the second switch SW2 does not have a second switch unit SW2b and is configured only with a first switch unit SW2a. Furthermore, the third switch SW3 does not have a second switch unit SW3b and is configured only with a first switch unit SW3a. This configuration does not pose any problems in blocking the path as shown in FIGS. 3 to 6 above. Furthermore, although FIG. 13 shows the switch configuration according to the first embodiment, it may also be applied to the first and second switches SW1 and SW2 according to the second embodiment.

[0060] Here, as shown in FIGS. 1 and 7, when the first and second switches SW1 and SW2 include first switch sections SW1a and SW2a and second switch sections SW1b and SW2b, respectively, it is possible to cope with high-voltage abnormalities in the first power supply unit 10 and the second power supply unit 20 (limited to the configuration of FIG. 1). That is, suppose that the first power supply unit 10 is in a state where it outputs a voltage higher than its design value due to a malfunction. In this case, both the first switch section SW1a and the second switch section SW1b of the first switch SW1 are turned off. Meanwhile, the first switch section SW2a and the second switch section SW2b of the second switch SW2 are both turned on. This prevents high voltage from being applied from the first power supply unit 10 to the second load unit Lo2. Meanwhile, suppose that the second power supply unit 20 is in a state where it outputs a voltage higher than its design value due to a malfunction. In this case, both the first switch section SW2a and the second switch section SW2b of the second switch SW2 are turned off. The first switch section SW1a and the second switch section SW1b of the first switch SW1 are both on, which prevents a high voltage from being applied from the second power supply section 20 to the first load section Lo1. [Explanation of symbols]

[0061] 1, 1a, 2: Vehicle power supply system 10: First power supply unit (vehicle power supply unit) 20:Second power supply section 30: Battery section (electricity storage means) 31: Battery cutoff unit (cutoff unit) 50: Control unit (control means) L1: First line L2: Second line L3: Third line L4: Fourth line Lo1: 1st load section Lo2: 2nd load section P2: Connection point P3: Connection point (second connection point) SW1: First switch SW2: Second switch SW3: Third switch SW4: 4th switch

Claims

1. A vehicle power supply system that supplies power to a first load section and a second load section mounted on a vehicle, a first line connecting a vehicle power supply unit capable of supplying electric power to the first load unit; a second line connecting the first line and the second load section; a first switch provided on the second line for conducting and blocking; a second switch that is provided in series on the second line closer to the second load section than the first switch and that performs conduction and interruption; a third line connecting a connection point between the first switch and the second switch to a storage means that stores electricity in advance; a control unit that controls the first switch and the second switch to be turned on and off, The control means In a normal state in which it is determined that there is no abnormality in the vehicle power supply unit, the first load unit, and the second load unit, the first switch and the second switch are brought into a conductive state to supply power to the first load unit and the second load unit from the vehicle power supply unit and the power storage means, In a first abnormal state in which it is determined that an abnormality has occurred in the vehicle power supply unit or the first load unit, the first switch is brought into an interrupted state and the second switch is brought into a conductive state, thereby supplying power from the storage means to the second load unit, In a second abnormal state in which it is determined that an abnormality exists in the second load section, the first switch is brought into a conductive state and the second switch is brought into a cut-off state, and power is supplied to the first load section from the vehicle power supply section and the power storage means. A vehicle power supply system comprising:

2. The control means further includes a cutoff unit that cuts off the connection between the storage means and the connection point when an abnormal voltage occurs in the storage means.

2. The vehicle power supply system according to claim 1.

3. a fourth line connecting a second connection point between the second switch and the second load unit in the second line and a second power supply unit capable of supplying power; a third switch provided on the fourth line for turning on and off the power supply; The control means The third switch is turned off in the normal state and the second abnormal state. In the first abnormal state, the third switch is brought into a conductive state to supply power from the second power supply unit and the power storage means to the second load unit.

2. The vehicle power supply system according to claim 1.

4. The power storage means is an electric double layer capacitor, a lithium ion battery, or a lead storage battery.

2. The vehicle power supply system according to claim 1.

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