Vehicle-mounted power supply system

Abstract

This vehicle-mounted power supply system (1) comprises a power supply device (10) that supplies power, a power reception device (50) that receives the power supplied from the power supply device (10), and a cable (80) that connects the power supply device (10) and the power reception device (50). The power supply device (10) superimposes and transmits a data signal and the power via the cable (80) to the power reception device (50). Furthermore, the power supply device (10) has: a power supply input unit (21) to which the power is input from the outside; a power path (22) provided between the power supply input unit (21) and the cable (80); and a current detection unit (25) that detects the current flowing through the power path (22). The power supply device (10) identifies the current consumption or the power consumption of the power reception device (50) on the basis of the detection result of the current detection unit (25), and determines an abnormality of the power reception device (50) on the basis of the identified value.

Description

In-vehicle power supply system

[0001] The present disclosure relates to an in-vehicle power supply system.

[0002] Patent Document 1 discloses a technique in which a power supply device superimposes power on a twisted pair line used for data communication and supplies it to a power receiving device.

[0003] Japanese Patent Application Laid-Open No. 2013-148943

[0004] In a technique of superimposing power on a data signal transmitted from a power supply device to a power receiving device as in Patent Document 1, it is desirable that the power supply device can determine an abnormality of the power receiving device.

[0005] An object of the present disclosure is to provide a technique capable of determining an abnormality of a power receiving device by a power supply device.

[0006] The in-vehicle power supply system of the present disclosure includes a power supply device that supplies power, a power receiving device that receives the power supplied from the power supply device, and a cable that connects the power supply device and the power receiving device. The power supply device superimposes a data signal and power via the cable and transmits it to the power receiving device. Further, the power supply device has a power input unit to which power is input from the outside, a power path provided between the power input unit and the cable, and a current detection unit that detects a current flowing through the power path. Based on the detection result of the current detection unit, the power consumption current or power consumption of the power receiving device is specified, and an abnormality of the power receiving device is determined based on the specified value.

[0007] According to the technique according to the present disclosure, an abnormality of a power receiving device can be determined by a power supply device.

[0008] Figure 1 is a schematic configuration diagram showing the in-vehicle power supply system of the first embodiment. Figure 2 is a conceptual explanatory diagram showing the state in which data signals and current are transmitted superimposed in the first embodiment. Figure 3 is a flowchart of the processing performed by the first control unit of the first embodiment. Figure 4 is a schematic configuration diagram showing the in-vehicle power supply system of the second embodiment. Figure 5 is a schematic configuration diagram showing the in-vehicle power supply system of the third embodiment. Figure 6 is a conceptual explanatory diagram showing the state in which current flows in the third embodiment. Figure 7 is a schematic configuration diagram showing the in-vehicle power supply system of the fourth embodiment. Figure 8 is a conceptual explanatory diagram showing the state in which current flows in the fourth embodiment.

[0009] [Description of Embodiments of the Disclosure] First, embodiments of the Disclosure will be listed and described.

[0010] [1] An in-vehicle power supply system comprising: a power supply device that supplies power; a power receiving device that receives power supplied from the power supply device; and a cable connecting the power supply device and the power receiving device, wherein the power supply device transmits data signals and power superimposed on each other to the power receiving device via the cable; further comprising: a power input unit into which power is input from an external source; a power path provided between the power input unit and the cable; and a current detection unit that detects the current flowing through the power path, wherein the current consumption or power consumption of the power receiving device is determined based on the detection result of the current detection unit, and an abnormality of the power receiving device is determined based on the determined value.

[0011] The power supply device can supply data signals and power to the power receiving device by superimposing them via a cable. Moreover, the power supply device can determine the current consumption or power consumption of the power receiving device without receiving any information from the outside. Based on the determined current consumption or power consumption, the power supply device can then determine any abnormalities in the power receiving device.

[0012] [2] The in-vehicle power supply system according to [1], wherein the cable is a twisted pair cable including a pair of electric wires, and the power supply device superimposes a data signal and current onto the power receiving device via one of the electric wires, and the power receiving device then returns the current to the other electric wire and receives the current supplied from the power receiving device.

[0013] With this configuration, the path for the current traveling back and forth between the power supply device and the power receiving device can be realized using a single twisted-pair cable.

[0014] [3] The power supply device comprises a communication unit that transmits data signals and a transmission line provided between the communication unit and the cable, wherein the power line is branched from the transmission line, the in-vehicle power supply system according to [1] or [2].

[0015] With this configuration, the current detection unit of the power supply device can detect the current obtained by removing the data signal from the combined waveform of the data signal and current. Therefore, the power supply device can determine the current consumption or power consumption of the power receiving device with higher accuracy compared to when detecting the combined current.

[0016] [4] The power supply device and the power receiving device are each ECUs. The in-vehicle power supply system according to any one of [1] to [3].

[0017] In this configuration, one ECU can supply data signals and power to the other ECU via a cable, superimposed on each other. Moreover, one ECU can determine the current consumption or power consumption of the other ECU without receiving any external information. Based on the determined current consumption or power consumption, one ECU can then determine if there is an abnormality in the other ECU.

[0018] [5] The power supply device comprises a switch unit provided in the power line, a parallel power line provided in parallel with the power line between the power input unit and the cable, a parallel current detection unit for detecting the current flowing through the parallel power line, a parallel switch unit provided in the parallel power line, and a control unit for controlling the switch unit and the parallel switch unit, wherein the control unit identifies the current consumption or power consumption of the power receiving device based on the detection results of the current detection unit and the parallel current detection unit, and determines an abnormality in the power receiving device based on the identified value. The in-vehicle power supply system according to any one of [1] to [4].

[0019] The control unit can adjust the amount of power that can be supplied to the power receiving device by turning on either the switch unit or the parallel switch unit, or both. Furthermore, the control unit can determine the current consumption or power consumption of the power receiving device based on the current flowing through the power line and the parallel power line, and can determine an abnormality in the power receiving device based on the determined value.

[0020] [6] The power supply device has a second power input separate from the power input unit, and the power path is provided between the power input unit and the cable, and between the second power input unit and the cable, the in-vehicle power supply system according to any one of [1] to [5].

[0021] With this configuration, power supplied from outside the power supply device can be supplied to the power path from both the power input unit and the second power input unit.

[0022] [7] The power receiving device is an in-vehicle power supply system according to any one of [1] to [6], having a power receiving side input section.

[0023] With this configuration, in addition to power supply via cables, power can also be supplied directly to the power receiving device via the power receiving input.

[0024] [Details of Embodiments of the Disclosure] 1. First Embodiment 1-1. Configuration of the In-Vehicle Power Supply System 1 The in-vehicle power supply system 1 shown in Figure 1 comprises a power supply device 10, a power receiving device 50, a cable 80, a power supply unit 90, and a load 91. The power supply device 10 is connected to the power supply unit 90. The power supply device 10 is connected to the power receiving device 50 via the cable 80. The power receiving device 50 is connected to the load 91. The power supply device 10 transmits data signals to the power receiving device 50 via the cable 80. The power supply device 10 also supplies power supplied from the power supply unit 90 to the cable 80, and supplies power to the power receiving device 50 via the cable 80. The power supply device 10 transmits data signals and power superimposed on each other. The power receiving device 50 supplies power supplied from the power supply device 10 to the load 91.

[0025] The power supply device 10 is a device that supplies power to the power receiving device 50. The power supply device 10 is, for example, an ECU (Electronic Control Unit). The power supply device 10 includes a first communication unit 11, a first transmission line 12, capacitors 13 and 14, a power input unit 21, a first power line 22, inductors 23 and 24, a current detection unit 25, a switch unit 26, a DC-DC converter 27, a first control unit 28, and a first display unit 29.

[0026] The first communication unit 11 is an example of a communication unit. The first communication unit 11 transmits and receives data signals. The first communication unit 11 is, for example, a transceiver. The first communication unit 11 transmits data signals to the power receiving device 50 via the first transmission line 12 and cable 80. The first communication unit 11 receives signals transmitted from the power receiving device 50 via the first transmission line 12 and cable 80.

[0027] The first transmission line 12 is an example of a transmission line. The first transmission line 12 is provided between the first communication unit 11 and the cable 80 and is connected to the first communication unit 11 and the cable 80. The first transmission line 12 includes a first positive-side transmission line 12A and a first negative-side transmission line 12B.

[0028] Cable 80 connects the power supply device 10 and the power receiving device 50. Cable 80 is a twisted pair cable containing a pair of wires 81 and 82. Wire 81 is connected to the first positive side transmission line 12A. Wire 82 is connected to the first negative side transmission line 12B.

[0029] Capacitor 13 is provided in the first positive side transmission line 12A. Capacitor 14 is provided in the first negative side transmission line 12B. Capacitors 13 and 14 insulate the first communication unit 11 from the cable 80.

[0030] A terminal 90A can be connected to the power input unit 21. The power input unit 21 is connected to the power supply unit 90 via terminal 90A. Power is input to the power input unit 21 from the power supply unit 90. The power input unit 21 is configured, for example, by a connector.

[0031] The first power line 22 is an example of a power line. The first power line 22 is provided between the power input unit 21 and the first transmission line 12 and is connected to the power input unit 21 and the first transmission line 12. The first power line 22 branches off from the first transmission line 12 on the cable 80 side of the capacitors 13 and 14. The first power line 22 includes a first positive-side power line 22A and a first negative-side power line 22B. The first positive-side power line 22A is connected to the first positive-side transmission line 12A. The first negative-side power line 22B is connected to the first negative-side transmission line 12B.

[0032] Inductor 23 is provided in the first positive-side power line 22A. Inductor 24 is provided in the first negative-side power line 22B.

[0033] The current detection unit 25 detects the current flowing through the first power line 22. The current detection unit 25 detects the current flowing through the first power line 22 on the power input unit 21 side of the inductors 23 and 24. In Figure 1, the current detection unit 25 detects the current flowing through the first positive-side power line 22A, but it may also detect the current flowing through the first negative-side power line 22B. The current detection unit 25 includes a resistor 25A and a detection unit 25B. The resistor 25A is provided in the first power line 22 (specifically, the first positive-side power line 22A). The detection unit 25B detects the voltage across the resistor 25A. The detection unit 25B may include, for example, a control circuit such as a microcomputer, or it may include a differential amplifier circuit. Note that the current detection unit 25 is not limited to a configuration using a resistor 25A, but may also include, for example, a magnetic sensor.

[0034] The switch unit 26 is provided in the first power line 22. In Figure 1, the switch unit 26 is provided in the first positive power line 22A, but it may also be provided in the first negative power line 22B. When the switch unit 26 is ON, power is supplied from the first power line 22 to the power receiving device 50 via the cable 80. When the switch unit 26 is OFF, the power supplied from the power supply device 10 to the power receiving device 50 is cut off.

[0035] The DC-DC converter 27 is installed in the first power line 22. The DC-DC converter 27 is installed between the power input unit 21 and the inductors 23 and 24. The DC-DC converter 27 is controlled by the first control unit 28 to adjust the voltage applied from the first power line 22 to the cable 80. In other words, the DC-DC converter 27 adjusts the output voltage of the power supply device 10.

[0036] The first control unit 28 is an example of a control unit. The first control unit 28 controls the switch unit 26, the DC-DC converter 27, and the first display unit 29. The first control unit 28 is configured by, for example, a microcomputer. The microcomputer is configured to include a CPU, memory, etc. The first control unit 28 and the detection unit 25B described above may be configured by the same microcomputer.

[0037] The first display unit 29, under the control of the first control unit 28, displays information indicating the surplus power supply. The first display unit 29 may be, for example, an LED, a 7-segment LED, or a display. If the first display unit 29 is an LED, it may display information indicating the surplus power supply by changing its state, such as being off, blinking, or lit.

[0038] The power receiving device 50 is a device that receives power supplied from the power supply device 10. The power receiving device 50 is, for example, an ECU. The power receiving device 50 includes a second communication unit 51, a second transmission line 52, capacitors 53 and 54, a load connection unit 61, a second power line 62, inductors 63 and 64, a second control unit 68, and a second display unit 69.

[0039] The second communication unit 51 transmits and receives data signals. The second communication unit 51 is, for example, a transceiver. The second communication unit 51 transmits and receives data signals to and from the first communication unit 11 of the power supply device 10 via the second transmission line 52 and the cable 80.

[0040] The second transmission line 52 is provided between the second communication unit 51 and the cable 80 and is connected to the second communication unit 51 and the cable 80. The second transmission line 52 includes a second positive-side transmission line 52A and a second negative-side transmission line 52B. The second positive-side transmission line 52A is connected to the electric wire 81. The second negative-side transmission line 52B is connected to the electric wire 82.

[0041] The capacitor 53 is provided on the second positive-side transmission line 52A. The capacitor 54 is provided on the second negative-side transmission line 52B. The capacitors 53 and 54 insulate between the second communication unit 51 and the cable 80.

[0042] A load-side terminal 91A can be connected to the load connection part 61. The load connection part 61 is connected to the load 91 via the load-side terminal 91A. The power receiving device 50 supplies the power supplied from the power supply device 10 to the load 91. The load connection part 61 is constituted by, for example, a connector.

[0043] The second power path 62 is provided between the load connection part 61 and the second transmission line 52 and is connected to the load connection part 61 and the second transmission line 52. The second power path 62 branches from the second transmission line 52 on the cable 80 side of the capacitors 53 and 54. The second power path 62 includes a second positive-side power path 62A and a second negative-side power path 62B. The second positive-side power path 62A is connected to the second positive-side transmission line 52A. The second negative-side power path 62B is connected to the second negative-side transmission line 52B.

[0044] The inductor 63 is provided on the second positive-side power path 62A. The inductor 64 is provided on the second negative-side power path 62B.

[0045] The second control unit 68 controls the second display unit 69. The second control unit 68 is constituted by, for example, a microcomputer.

[0046] The second display unit 69 displays information indicating the presence or absence of power shortage in the power receiving device 50 under the control of the second control unit 68. The second display unit 69 may be, for example, an LED, a 7-segment LED, or a display. When the first display unit 29 is an LED, information indicating the presence or absence of power shortage may be displayed according to states such as turning off, blinking, and lighting.

[0047] 1-2. Operation of the in-vehicle power supply system 1 The first communication unit 11 of the power supply device 10 transmits and receives data signals to and from the second communication unit 51 of the power receiving device 50 via the cable 80 as shown in FIG. 2. Also, the power supply device 10 supplies power to the power receiving device 50 via the first power path 22 and the cable 80. Moreover, the power supply device 10 superimposes a data signal and power and transmits them to the power receiving device 50 via the cable 80. Also, the power supply device 10 superimposes a data signal and a current and sends them through the wire 81 to the power receiving device 50, and receives the current supplied from the power receiving device 50 via the wire 82 after being turned back on the power receiving device 50 side. Specifically, a power supply technology called PoDL (Power over Data Line) is used.

[0048] The first control unit 28 specifies the current consumption or power consumption of the power receiving device 50 based on the detection result of the current detection unit 25, and determines an abnormality of the power receiving device 50 based on the specified value.

[0049] When the start condition is satisfied, the first control unit 28 performs the process shown in FIG. 3. The start condition may be, for example, that the first control unit 28 has been activated, or that the start switch of the vehicle has been switched to the on state, or another condition. The start switch is, for example, an ignition switch or a power switch.

[0050] When the first control unit 28 starts the process shown in FIG. 3, first, in step S11, it switches the switch unit 26 to the on state. Then, in step S12, the first control unit 28 determines whether a current is flowing through the first power path 22. The first control unit 28 determines whether a current is flowing through the first power path 22 based on the detection result of the current detection unit 25.

[0051] The current supplied from the power supply unit 90 to the first positive-side power line 22A flows to the power receiving device 50 via the first positive-side transmission line 12A and the wire 81, and then returns to the first negative-side power line 22B via the wire 82 and the first negative-side transmission line 12B. In other words, when the power receiving device 50 is not connected to the power supply device 10, no current flows in the first power line 22, and when the power receiving device 50 is connected to the power supply device 10, current flows in the first power line 22. For this reason, when the first control unit 28 determines that no current is flowing in the first power line 22, it determines in step S13 that the power receiving device 50 is not connected.

[0052] After determining that the power receiving device 50 is not connected, the first control unit 28 returns to step S12. In other words, the first control unit 28 repeats the process in step S12 until it determines that current is flowing through the first power line 22. If the first control unit 28 determines that current is flowing through the first power line 22, it determines in step S14 that the power receiving device 50 is connected to the power supply device 10.

[0053] After determining that the power receiving device 50 is connected to the power supply device 10, the first control unit 28 identifies the current consumption or power consumption of the power receiving device 50 in step S15. The first control unit 28 identifies the current consumption or power consumption of the power receiving device 50 based on the detection result of the current detection unit 25. The first control unit 28 stores the resistance value of the resistor 25A in advance. The first control unit 28 identifies the current consumption or power consumption of the power receiving device 50 based on the resistance value of the resistor 25A and the voltage across the resistor 25A detected by the current detection unit 25.

[0054] In step S16, the first control unit 28 determines whether the value identified in step S15 exceeds a preset threshold. When identifying power consumption, the first control unit 28 may set the threshold to a value greater than the maximum power consumption of the power receiving device 50. The maximum power consumption is, for example, a value defined by the power class of the PoDL.

[0055] If the first control unit 28 determines that the identified value does not exceed the threshold, it returns to the process in step S15. In other words, the first control unit 28 repeatedly identifies the current consumption or power consumption of the power receiving device 50 and determines whether the identified value exceeds the threshold until it determines that the identified value has exceeded the threshold.

[0056] If the first control unit 28 determines that the specified value exceeds the threshold, it determines in step S17 that the power receiving device 50 is abnormal. Then, in step S18, the first control unit 28 switches the switch unit 26 to the off state, interrupting the current supplied from the power supply device 10 to the power receiving device 50. After that, the first control unit 28 terminates the process shown in Figure 3.

[0057] Furthermore, the first control unit 28 displays information indicating the surplus power supply capacity on the first display unit 29. The power supply device 10 has a maximum power supply set. Note that the maximum power supply is not the upper limit of its capacity, but is set to a value lower than the upper limit. The first control unit 28 stores the maximum power supply in advance. When the power receiving device 50 is connected to the power supply device 10, the first control unit 28 calculates the power consumption of the power receiving device 50 while temporarily allowing a power supply exceeding the maximum power supply. Specifically, when the power receiving device 50 is connected to the power supply device 10, the first control unit 28 controls the DC-DC converter 27 so that a preset initial voltage (for example, 12V) is output. As a result, the initial voltage is applied to the cable 80, the second transmission line 52, and the second power line 62. With the initial voltage applied to the cable 80, the first control unit 28 calculates the power consumption of the power receiving device 50. The first control unit 28 then calculates the surplus power supply by calculating the power consumption of the power receiving device 50 relative to the maximum power supply.

[0058] Although not shown in Figure 3, the first control unit 28 calculates the surplus power supply, then switches the switch unit 26 to the off state, and then switches the switch unit 26 back to the on state. If the calculated power consumption of the power receiving device 50 is less than or equal to the maximum supply power, the first control unit 28 adjusts the output voltage of the power supply device 10 so that the power supplied by the power supply device 10 becomes equal to the calculated power consumption of the power receiving device 50. If the calculated power consumption of the power receiving device 50 is greater than the maximum supply power, the first control unit 28 lowers the output voltage of the power supply device 10 so that the power supplied by the power supply device 10 becomes equal to the maximum supply power.

[0059] The second control unit 68 displays information indicating whether or not there is a power shortage on the second display unit 69. The second control unit 68 compares the applied voltage when the switch unit 26 is in the ON state before and after it switches to the OFF state, and determines that there is a power shortage if the voltage has decreased. Specifically, the second control unit 68 stores the amount of power it needs in advance, and calculates the power actually supplied by multiplying the amount of power by the rate of decrease in the applied voltage when the switch unit 26 is in the ON state before and after it switches to the OFF state. Then, the second control unit 68 determines whether or not there is a power shortage by comparing the amount of power needed with the power actually supplied.

[0060] 1-3. Effects of the In-Vehicle Power Supply System 1 The power supply device 10 can supply data signals and power to the power receiving device 50 by superimposing them via the cable 80. Moreover, the power supply device 10 can determine the current consumption or power consumption of the power receiving device 50 without receiving any information from the outside. In other words, the power supply device 10 can determine the current consumption or power consumption of the power receiving device 50 without communicating with the power receiving device 50 using SCCP (Serial Communication Classification Protocol). Based on the determined current consumption or power consumption, the power supply device 10 can determine if there is an abnormality in the power receiving device 50.

[0061] According to the in-vehicle power supply system 1, the current path between the power supply device 10 and the power receiving device 50 can be realized by a single twisted-pair cable.

[0062] According to the in-vehicle power supply system 1, the current detection unit 25 of the power supply device 10 can detect the current obtained by removing the data signal from the combined waveform of the data signal and the current. Therefore, the power supply device 10 can determine the current consumption or power consumption of the power receiving device 50 with higher accuracy compared to when detecting the combined current.

[0063] 2. Second Embodiment In the second embodiment, a configuration in which a parallel power path is provided in parallel with the first power path will be described. The same reference numerals are used for components that are the same as in the first embodiment, and detailed explanations will be omitted.

[0064] The in-vehicle power supply system 201 of the second embodiment shown in Figure 4 includes a power supply device 210 instead of the power supply device 10 described in the first embodiment. The in-vehicle power supply system 201 is otherwise the same as the in-vehicle power supply system 1 described in the first embodiment.

[0065] The power supply device 210 includes, in addition to the configuration of the power supply device 10 described in the first embodiment, a parallel power path 32, inductors 33 and 34, a parallel current detection unit 35, and a parallel switch unit 36.

[0066] The parallel power path 32 is provided in parallel with the first power path 22 between the power input unit 21 and the first transmission path 12. One end of the parallel power path 32 is connected to the first transmission path 12 on the cable 80 side of the capacitors 13 and 14. The other end of the parallel power path 32 is connected to the first power path 22 on the power input unit 21 side of the inductors 23 and 24, the current sensing unit 25, and the switch unit 26, and on the first transmission path 12 side of the DC-DC converter 27. The parallel power path 32 includes a positive-side parallel power path 32A and a negative-side parallel power path 32B. The positive-side parallel power path 32A is connected to the first positive-side transmission path 12A and the first positive-side power path 22A. The negative-side parallel power path 32B is connected to the first negative-side transmission path 12B and the first negative-side power path 22B.

[0067] Inductor 33 is provided in the positive-side parallel power path 32A. Inductor 34 is provided in the negative-side parallel power path 32B.

[0068] The parallel current detection unit 35 detects the current flowing through the parallel power path 32. The parallel current detection unit 35 detects the current flowing through the parallel power path 32 on the power input unit 21 side of the inductors 33 and 34. In Figure 4, the parallel current detection unit 35 detects the current flowing through the positive side parallel power path 32A, but it may also detect the current flowing through the negative side parallel power path 32B. The parallel current detection unit 35 includes a resistor 35A and a detection unit 35B. The resistor 35A is provided in the parallel power path 32 (specifically, the positive side parallel power path 32A). The detection unit 35B detects the voltage across the resistor 35A. The detection unit 35B may be configured by a control circuit such as a microcomputer, or by a differential amplifier circuit. Note that the parallel current detection unit 35 is not limited to a configuration using a resistor 35A, but may also be a magnetic sensor, for example.

[0069] The parallel switch unit 36 ​​is provided in the parallel power path 32. In Figure 4, the parallel switch unit 36 ​​is provided in the positive-side parallel power path 32A, but it may also be provided in the negative-side parallel power path 32B. When the switch unit 26 and the parallel switch unit 36 ​​are ON, power is supplied from the first power path 22 and the parallel power path 32 to the cable 80, and power is supplied to the power receiving device 50 via the cable 80. When the switch unit 26 is ON and the parallel switch unit 36 ​​is OFF, power is supplied to the power receiving device 50 via the first power path 22 and the cable 80. When the switch unit 26 is OFF and the parallel switch unit 36 ​​is ON, power is supplied to the power receiving device 50 via the parallel power path 32 and the cable 80. When the switch unit 26 and the parallel switch unit 36 ​​are OFF, the power supplied from the power supply device 210 to the power receiving device 50 is cut off.

[0070] The first control unit 28 identifies the current consumption or power consumption of the power receiving device 50 based on the detection results of the current detection unit 25 and the parallel current detection unit 35, and determines an abnormality in the power receiving device 50 based on the identified value.

[0071] The first control unit 28 stores the resistance values ​​of the resistors 25A and 35A in advance. Based on the resistance value of resistor 25A and the voltage across resistor 25A detected by the current detection unit 25, the first control unit 28 identifies the current flowing through the first power line 22 or the power supplied to the power receiving device 50 via the first power line 22. The first control unit 28 also identifies the current flowing through the parallel power line 32 or the power supplied to the power receiving device 50 via the parallel power line 32 based on the resistance value of resistor 35A and the voltage across resistor 35A detected by the parallel current detection unit 35. The first control unit 28 identifies the current consumption of the power receiving device 50 by adding the current value flowing through the first power line 22 and the current value flowing through the parallel power line 32. Alternatively, the first control unit 28 determines the power consumption of the power receiving device 50 by summing the power value supplied to the power receiving device 50 via the first power line 22 and the power value supplied to the power receiving device 50 via the parallel power line 32.

[0072] Furthermore, when only one of the switch unit 26 and the parallel switch unit 36 ​​is ON, the first control unit 28 may determine the current consumption or power consumption of the power receiving device 50 based on the current flowing through only one of the first power line 22 and the parallel power line 32.

[0073] The first control unit 28 controls the switch unit 26 and the parallel switch unit 36. The first control unit 28 may, for example, control only one of the switch unit 26 and the parallel switch unit 36 ​​to the ON state when the current consumption or power consumption of the power receiving device 50 is less than or equal to the switching reference value, and control both the switch unit 26 and the parallel switch unit 36 ​​to the ON state when the current consumption or power consumption of the power receiving device 50 exceeds the switching reference value. The switching reference value is less than a threshold value.

[0074] As described above, the first control unit 28 can adjust the amount of power that can be supplied to the power receiving device 50 by turning on only one of the switch unit 26 and the parallel switch unit 36, or by turning on both. Furthermore, the first control unit 28 can determine the current consumption or power consumption of the power receiving device 50 based on the current flowing through the first power line 22 and the parallel power line 32, and can determine an abnormality in the power receiving device 50 based on the determined value.

[0075] 3. Third Embodiment In the third embodiment, a configuration in which the power supply device has a second power input unit will be described. The same reference numerals are used for components that are the same as in the first embodiment, and detailed explanations will be omitted.

[0076] The in-vehicle power supply system 301 of the third embodiment shown in Figure 5 includes a power supply device 310 instead of the power supply device 10 described in the first embodiment. The in-vehicle power supply system 301 is also provided with terminal 90B. The in-vehicle power supply system 301 is otherwise identical to the in-vehicle power supply system 1 described in the first embodiment.

[0077] The power supply device 310 includes, in addition to the configuration of the power supply device 10 described in the first embodiment, a second power input unit 31 and a branch line 38.

[0078] A terminal 90B can be connected to the second power input section 31. The second power input section 31 is connected to the power supply section 90 via terminal 90B. Power from the power supply section 90 is input to the second power input section 31. The second power input section 31 is configured, for example, by a connector.

[0079] The branch line 38 branches off from the first power line 22 and is connected to the second power input section 31 on the power input section 21 side of the inductors 23, 24, current sensing unit 25, switch unit 26, and DC-DC converter 27. The branch line 38 includes a positive-side branch line 38A and a negative-side branch line 38B. The positive-side branch line 38A branches off from the first positive-side power line 22A. The negative-side branch line 38B branches off from the first negative-side power line 22B.

[0080] As shown in Figure 6, by connecting terminal 90B to the second power input unit 31, when the switch unit 26 is ON, power supplied from the power supply unit 90 can be supplied to the first power line 22 from both the power input unit 21 and the second power input unit 31. In other words, when the power receiving device 50 is experiencing a power shortage, the user can increase the power supplied to the power receiving device 50 by connecting terminal 90B to the second power input unit 31.

[0081] 4. Fourth Embodiment In the fourth embodiment, a configuration in which the power receiving device has a power receiving side power input unit will be described. The same reference numerals are used for components that are the same as in the first embodiment, and detailed explanations will be omitted.

[0082] The in-vehicle power supply system 401 of the fourth embodiment shown in Figure 7 is equipped with a power receiving device 450 instead of the power receiving device 50 described in the first embodiment. In addition, the in-vehicle power supply system 401 is provided with terminal 90C. The in-vehicle power supply system 401 is otherwise the same as the in-vehicle power supply system 1 described in the first embodiment.

[0083] The power receiving device 450 includes, in addition to the configuration of the power receiving device 50 described in the first embodiment, a power receiving side input section 58 and a branch line 59.

[0084] A terminal 90C can be connected to the power receiving input section 58. The power receiving input section 58 is connected to the power supply unit 90 via terminal 90C. Power from the power supply unit 90 is input to the power receiving input section 58. The power receiving input section 58 is configured, for example, by a connector.

[0085] The branch line 59 branches off from the second power line 62 on the load connection section 61 side of the inductors 63 and 64 and is connected to the power receiving side input section 58. The branch line 59 includes a positive side branch line 59A and a negative side branch line 59B. The positive side branch line 59A branches off from the second positive side power line 62A. The negative side branch line 59B branches off from the second negative side power line 62B.

[0086] As shown in Figure 8, by connecting terminal 90C to the power receiving input section 58, power can be supplied directly to the power receiving device 450 via the power receiving input section 58, in addition to power supply via the cable 80. In other words, if the power receiving device 450 is experiencing a power shortage, the user can increase the power supplied to the power receiving device 450 by connecting terminal 90C to the power receiving input section 58.

[0087] <Other Embodiments> This disclosure is not limited to the embodiments described above and in the drawings. For example, any combination of the features of the embodiments described above or below is possible as long as it does not contradict the original. Furthermore, any feature of the embodiments described above or below may be omitted unless explicitly stated as essential. In addition, the embodiments described above may be modified as follows.

[0088] In the embodiments described above, examples using PoDL as the power supply technology were explained, but any technology other than PoDL may be used as long as it transmits data signals and power superimposed. For example, PoE (Power over Ethernet) or PoC (Power over Coaxial) may be used.

[0089] In the second embodiment described above, only one parallel power path was provided in parallel with the power path, but a configuration in which multiple parallel power paths are provided is also possible.

[0090] In the embodiments described above, the load was provided outside the power receiving device, but the load may also be provided inside the power receiving device.

[0091] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, but is indicated by the claims, and all modifications within the meaning and scope of the claims are intended to be included.

[0092] 1...In-vehicle power supply system 10...Power supply device 11...First communication unit (communication unit) 12...First transmission line (transmission line) 12A...First positive side transmission line 12B...First negative side transmission line 13...Capacitor 14...Capacitor 21...Power input unit 22...First power line (power line) 22A...First positive side power line 22B...First negative side power line 23...Inductor 24...Inductor 25...Current detection unit 25A...Resistor unit 25B...Detection unit 26...Switch unit 27...DC-DC converter 28...First control unit (control unit) 29...First display unit 31...Second power input unit 32...Parallel power line 32A...Positive side parallel power line 32B...Negative side parallel power line 33...Inductor 34...Inductor 35...Parallel current detection unit 35A...Resistor unit 35B...Detection unit 36...Parallel switch unit 38...Branch line 38A...Positive side branch line 38B...Negative side branch line 50...Power receiving device 51...Second communication unit 52...Second transmission line 52A...Second positive side transmission line 52B...Second negative side transmission line 53...Capacitor 54...Capacitor 58...Power receiving side input unit 59...Branch line 59A...Positive side branch line 59B...Negative side branch line 61...Load connection unit 62...Second power line 62A...Second positive side power line 62B...Second negative side power line 63...Inductor 64...Inductor 68...Second control unit 69...Second display unit 80...Cable 81...Wire 82...Wire 90...Power supply unit 90A...Terminal 90B...Terminal 90C...Terminal 91...Load 91A...Load-side terminal 201...Vehicle-mounted power supply system 210...Power supply device 301...Vehicle-mounted power supply system 310...Power supply device 401...Vehicle-mounted power supply system 450...Power receiving device

Claims

1. An in-vehicle power supply system comprising: a power supply device that supplies power; a power receiving device that receives power supplied from the power supply device; and a cable connecting the power supply device and the power receiving device, wherein the power supply device transmits data signals and power superimposed on each other to the power receiving device via the cable; further comprising: a power input unit into which power is input from an external source; a power path provided between the power input unit and the cable; and a current detection unit that detects the current flowing through the power path, wherein the system identifies the current consumption or power consumption of the power receiving device based on the detection result of the current detection unit, and determines an abnormality in the power receiving device based on the identified value.

2. The in-vehicle power supply system according to claim 1, wherein the cable is a twisted pair cable including a pair of electric wires, the power supply device superimposes a data signal and current onto the power receiving device via one of the electric wires, and the power receiving device receives the current supplied from the power receiving device via the other electric wire after the signal is returned to the power receiving device.

3. The in-vehicle power supply system according to claim 1 or 2, wherein the power supply device comprises a communication unit for transmitting data signals and a transmission line provided between the communication unit and the cable, and the power line is branched from the transmission line.

4. The in-vehicle power supply system according to claim 1 or claim 2, wherein the power supply device and the power receiving device are each ECUs.

5. The in-vehicle power supply system according to claim 1 or 2, wherein the power supply device comprises a switch unit provided in the power line, a parallel power line provided in parallel with the power line between the power input unit and the cable, a parallel current detection unit for detecting the current flowing through the parallel power line, a parallel switch unit provided in the parallel power line, and a control unit for controlling the switch unit and the parallel switch unit, wherein the control unit identifies the current consumption or power consumption of the power receiving device based on the detection results of the current detection unit and the parallel current detection unit, and determines an abnormality in the power receiving device based on the identified value.

6. The in-vehicle power supply system according to claim 1 or 2, wherein the power supply device has a second power input separate from the power input unit, and the power path is provided between the power input unit and the cable, and between the second power input unit and the cable.

7. The in-vehicle power supply system according to claim 1 or claim 2, wherein the power receiving device has a power receiving side input section.

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