Redundant power supply system

Abstract

To provide a redundant power supply system capable of preventing erroneous diagnosis caused by deviation between start-timing of a load system and start-timing of the redundant power supply system from being generated.SOLUTION: A redundant power supply system connected to a load system where power is fed from a main power supply comprises: a redundant power supply redundantly provided to the main power supply; a first semiconductor relay to which the redundant power supply and the load system are connected to be capable of feeding backup power to the load system from the redundant power supply; and a second semiconductor relay to which the main power supply and the redundant power supply are connected to be capable of charging the redundant power supply by the main power supply. The second semiconductor relay maintains a conductive state, while power supply to the load system from the main power supply is normal.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a redundant power supply system installed in a vehicle or the like. [Background technology]

[0002] Patent Document 1 discloses a power supply system that employs a so-called redundant configuration in which power is supplied from a main power supply (primary power supply) to a load via a main system bus, and power is supplied from a sub-power supply (redundant power supply) to the load via a sub-system bus. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-040475 Summary of the Invention [Problem to be solved by the invention]

[0004] In a power supply system equipped with a main power supply and a redundant power supply as a power supply source to a load, if the start-up timing of the load system including the load differs from the start-up timing of the redundant power supply system including the redundant power supply, there is a risk of an erroneous diagnosis occurring due to the difference in start-up timing.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a redundant power supply system that can prevent the occurrence of erroneous diagnosis caused by a mismatch between the startup timing of the load system and the startup timing of the redundant power supply system. [Means for solving the problem]

[0006] In order to solve the above problems, one aspect of the disclosed technology is a redundant power supply system connected to a load system supplied with power from a main power source, the redundant power supply being provided redundantly for the main power source, a first semiconductor relay connecting the redundant power supply and the load system so as to enable backup power supply from the redundant power supply to the load system, and a second semiconductor relay connecting the main power supply and the redundant power supply so as to enable the redundant power supply to be charged by the main power source, the second semiconductor relay maintaining a conductive state while power supply from the main power source to the load system is normal. Effect of the Invention

[0007] According to the redundant power supply system of the present disclosure, since the second semiconductor relay is in a conductive state while the power supply from the main power supply to the load system is normal, even if the load system starts up before the redundant power supply system, it is possible to prevent a current from flowing back from the load system to the redundant power supply system. This makes it possible to prevent the occurrence of erroneous diagnosis of an abnormality (such as a ground fault) in the load system due to the occurrence of this backflow current. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic configuration diagram illustrating a connection state between a redundant power supply system and a load system according to an embodiment of the present disclosure. [Diagram 2] 1 is a process flowchart illustrating control by a power supply system of a vehicle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In the redundant power supply system of the present disclosure, when there is no problem with the power supply from the main power supply to the load system, a semiconductor relay for disconnecting the main power supply from the redundant power supply in the event of an abnormality is always kept in a conductive state by a hardware configuration such as a latch circuit. As a result, when the power supply is normal, the potential on the redundant power supply side of the semiconductor relay for supplying power from the redundant power supply to the load system can be maintained always higher than the potential on the opposite side. Therefore, even if the load system starts up earlier than the redundant power supply system, current does not flow back from the load system to the redundant power supply system. Therefore, it is possible to prevent the occurrence of erroneous diagnosis such as a ground fault in the load system. Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0010] <Embodiment> [composition] Fig. 1 is a schematic diagram showing a connection state between a redundant power supply system 10 and a load system 30 according to an embodiment of the present disclosure. In Fig. 1, the redundant power supply system 10 and the load system 30 are each connected to a main power supply 50 so as to be capable of receiving power. In addition, the redundant power supply system 10 is connected to the load system 30 so as to be capable of supplying backup power.

[0011] The redundant power supply system 10 according to this embodiment can be installed in a vehicle or the like equipped with a load system 30 (such as brakes, steering, and shift-by-wire) that requires a redundant power supply configuration. The redundant power supply system 10 will be described below using an example in which the redundant power supply system 10 is installed in a power supply system of a vehicle.

[0012] The main power supply 50 is a main power supply that supplies the load system 30 with the power required for its operation. The main power supply 50 is also a power supply that supplies the redundant power supply system 10 with power for charging a redundant power supply, which will be described later. In a vehicle, the main power supply 50 can be a power supply that always supplies power of +B voltage regardless of the ignition state.

[0013] The redundant power supply system 10 is a system for supplying backup power to the load system 30 in place of the main power supply 50 when an abnormality occurs in the power supply from the main power supply 50 to the load system 30 due to a power supply failure or the like. This redundant power supply system 10 is started up when the vehicle ignition is turned on (IGR-ON).

[0014] The redundant power supply system 10 includes a redundant power supply 11, a DC-DC converter 12, a capacitor 13, a first semiconductor relay 14, a control unit 15, a second semiconductor relay 21, and a latch circuit 22.

[0015] The redundant power supply 11 is, for example, a storage element such as a capacitor, or a secondary battery (such as a lithium ion battery) configured to be capable of being charged and discharged. The redundant power supply 11 is connected to a DC-DC converter 12 so as to be capable of being charged and discharged.

[0016] The DCDC converter 12 is a power converter for converting input power into power of a predetermined voltage and outputting it. This DCDC converter 12 can charge the redundant power supply 11 with power supplied from the main power supply 50 via the second semiconductor relay 21 based on an instruction (such as a voltage command value) from the control unit 15. In addition, the DCDC converter 12 can supply the power (backup power) stored in the redundant power supply 11 to the load system 30 via the first semiconductor relay 14 based on an instruction from the control unit 15.

[0017] The capacitor 13 is an electrolytic capacitor provided on the output side of the DC-DC converter 12 to handle transient current consumption when the power supply fails.

[0018] The first semiconductor relay 14 is a switch element using, for example, a field effect transistor (FET). The first semiconductor relay 14 is inserted between the DCDC converter 12 and the load system 30 with a body diode (parasitic diode) oriented to rectify from the load system 30 to the DCDC converter 12. The first semiconductor relay 14 switches between an electrically conductive and cut-off state based on an instruction from the control unit 15.

[0019] The control unit 15 is configured to control the charging and discharging of the redundant power supply 11 by instructing the DCDC converter 12 to operate (such as a voltage command value). The control unit 15 also controls the conductive and cut-off states of the first semiconductor relay 14. The control unit 15 is configured, for example, by a microcomputer including a processor, a memory, an input / output interface, and the like, and realizes a predetermined function by the processor reading and executing a program stored in the memory.

[0020] The second semiconductor relay 21 is a switch element using, for example, a field effect transistor. The second semiconductor relay 21 is inserted between the main power supply 50 and the DCDC converter 12 with the body diode rectifying the current from the DCDC converter 12 to the main power supply 50. The second semiconductor relay 21 switches between an electrically conductive and cut-off state based on the hardware control by the latch circuit 22.

[0021] The latch circuit 22 is an electric circuit that can hold the second semiconductor relay 21 in either a conductive or cut-off state, regardless of whether the redundant power supply system 10 is activated or not. An example of the mechanism of the latch circuit 22 is a mechanism in which the output of a comparator, which receives as inputs the voltage of the main power supply 50 and a predetermined reference voltage (a voltage that the main power supply 50 can fully exceed under normal conditions), is connected to the gate terminal of the second semiconductor relay 21 (FET), and if the voltage of the main power supply 50 is higher than the predetermined reference voltage, the comparator outputs a high level to fix the second semiconductor relay 21 in the on state, and if the voltage of the main power supply 50 is lower than the predetermined reference voltage, the comparator outputs a low level to fix the second semiconductor relay 21 in the off state. Note that other well-known mechanisms can be used as the latch circuit 22 in addition to this mechanism.

[0022] The load system 30 is a vehicle equipment that operates with power from the main power supply 50, and is a system that requires a backup operation using the redundant power supply 11 in the event of an emergency. Examples of the load system 30 include a brake, a steering system, and a shift-by-wire system. The load system 30 includes a load 31 and semiconductor relays 32 and 33.

[0023] The load 31 is an actuator (ACT) and an electronic control unit (ECU) required to realize the operation of the system. The semiconductor relays 32 and 33 are switch elements provided to perform a fault diagnosis (whether the load 31 operates normally, whether the semiconductor relays 32 and 33 can perform a switching operation normally, etc.) when the load system 30 is started up, and the on / off state is controlled in the fault diagnosis. As an example, the fault diagnosis of the load system 30 is performed when a door (such as the driver's door) of the vehicle is opened, which is before the ignition of the vehicle is turned on (IGR-ON).

[0024] [control] Next, control executed in a vehicle equipped with the redundant power supply system 10 according to this embodiment will be described with further reference to Fig. 2. Fig. 2 is a process flowchart illustrating control by the power supply system of the vehicle.

[0025] The control illustrated in FIG. 2 is initiated when the main power source 50 is initially connected to the redundant power source system 10 (normal state), and is repeatedly performed until an abnormality occurs in the power supply of the main power source 50 (abnormal state) and backup power supply to the load system 30 is performed by the redundant power source 11.

[0026] (Step S201) In the redundant power supply system 10, the second semiconductor relay 21 (second FET) is controlled to an on state (ON) by the latch circuit 22. This on state of the second semiconductor relay 21 is maintained in hardware regardless of the start / stop state of the redundant power supply system 10. This control causes the +B voltage of the main power supply 50 to be constantly applied to the DC-DC converter 12 side of the first semiconductor relay 14 (first FET) (+B pass-through). When the second semiconductor relay 21 is controlled to an on state, the process proceeds to step S202.

[0027] (Step S202) It is determined whether the vehicle ignition state is on (IGR-ON) or off (IGR-OFF). If the ignition is on (step S202, ON), the process proceeds to step S203. On the other hand, if the ignition is off (step S202, OFF), the process proceeds to step S205.

[0028] (Step S203) The redundant power supply system 10 is started up when the vehicle ignition is turned on (IGR-ON), and controls the first semiconductor relay 14 (first FET) to the off state (OFF) via an instruction from the control unit 15. If the redundant power supply system 10 has already been started up and is operating, it maintains that operating state. When the first semiconductor relay 14 is controlled to the off state, the process proceeds to step S204.

[0029] (Step S204) The redundant power supply system 10 operates the DC-DC converter 12 and performs charging control, which is control for charging the redundant power supply 11 to a predetermined storage amount (power required for backup) using the power of the main power supply 50 supplied via the second semiconductor relay 21. When the charging control of the redundant power supply 11 is performed, the process proceeds to step S206.

[0030] (Step S205) When the redundant power supply system 10 is operating, it ends the charging control of the redundant power supply 11 and stops the system. When the redundant power supply system 10 is not operating, the system does not start up. When the charging control of the redundant power supply 11 is ended, the process proceeds to step S206.

[0031] (Step S206) The redundant power supply system 10 determines whether or not an abnormality has occurred in the power supply from the main power supply 50 to the load system 30. The occurrence of this abnormality can be determined by, for example, monitoring the output voltage and output current of the main power supply 50. If it is determined that an abnormality has occurred in the power supply (step S206, Yes), the process proceeds to step S207. On the other hand, if it is determined that no abnormality has occurred in the power supply (step S206, No), the process proceeds to step S202.

[0032] (Step S207) The redundant power supply system 10 controls the first semiconductor relay 14 (first FET) to an on state (ON) via an instruction from the control unit 15. Also, in the redundant power supply system 10, the second semiconductor relay 21 (second FET) is controlled to an off state (OFF) by the latch circuit 22. The off state of the second semiconductor relay 21 is maintained in a hardware manner regardless of the start / stop state of the redundant power supply system 10. Once the states of the first semiconductor relay 14 and the second semiconductor relay 21 have been controlled, the process proceeds to step S208.

[0033] (Step S208) The redundant power supply system 10 performs backup power supply, supplying power from the redundant power supply 11 to the load system 30. This backup power supply is performed, for example, until a predetermined evacuation action by the load system 30 is completed. When the backup power supply by the redundant power supply system 10 is performed, this control ends.

[0034] It is preferable that upon completion of this control, information (such as a warning display) be provided to a user of the vehicle to notify that an abnormality has occurred in the power supply system.

[0035] <Actions and Effects> As described above, the redundant power supply system 10 according to an embodiment of the present disclosure includes the redundant power supply 11 provided redundantly for the main power supply 50 that supplies power to the load system 30, the first semiconductor relay 14 that connects the redundant power supply 11 (and the DCDC converter 12) to the load system 30 so as to enable backup power supply from the redundant power supply 11 to the load system 30, and the second semiconductor relay 21 that connects the main power supply 50 to the redundant power supply 11 (and the DCDC converter 12) so as to enable charging of the redundant power supply 11 by the main power supply 50. The second semiconductor relay 21 maintains a conductive state (+B pass-through) by hardware control of the latch circuit 22 while the power supply from the main power supply 50 to the load system 30 is normal.

[0036] This control allows the potential of the first semiconductor relay 14 on the redundant power supply 11 side to be maintained higher than the potential of the load system 30 side when the power supply from the main power supply 50 to the load system 30 is normal. Therefore, even if the start-up timing of the load system 30 is earlier than the start-up timing of the redundant power supply system 10, current does not flow back from the load system 30 to the redundant power supply system 10 via the body diode of the first semiconductor relay 14 (current sneaking). This makes it possible to prevent the occurrence of erroneous diagnosis, such as determining that charging of the capacitor 13 due to sneaking current is a ground fault in the load system 30.

[0037] Furthermore, according to the redundant power supply system 10 of this embodiment, the conductive state of the second semiconductor relay 21 is maintained by hardware control of the latch circuit 22. This eliminates the need for control such as having the startup of the load system 30 notified by direct wiring or the like and matching the startup timing of the redundant power supply system 10 with the startup timing of the load system 30. This makes it possible to suppress increases in system costs and changes to the control logic.

[0038] The above describes one embodiment of the disclosed technology. However, the present disclosure can be understood as a redundant power supply system, a control method executed by a redundant power supply system having a processor and a memory, a control program for executing the control method, a computer-readable non-transitory storage medium storing the control program, and a vehicle equipped with the redundant power supply system. [Industrial Applicability]

[0039] The redundant power supply system of the present disclosure can be used in vehicles and the like equipped with loads that require a redundant power supply configuration. [Explanation of symbols]

[0040] 10 Redundant Power System 11 Redundant power supply 12 DC-DC Converter 13 Capacitor 14 First Solid State Relay 15 Control section 21 Second semiconductor relay 22 Latch circuit 30 Resistance System 31 Load 32, 33 Semiconductor relay 50 Mains power

Claims

1. 1. A redundant power supply system connected to a load system powered by a primary power supply, comprising: A redundant power supply provided redundantly to the main power supply; a first semiconductor relay that connects the redundant power supply and the load system so as to enable backup power supply from the redundant power supply to the load system; a second semiconductor relay that connects the main power supply and the redundant power supply so that the redundant power supply can be charged by the main power supply; the second semiconductor relay maintains a conductive state while power supply from the main power source to the load system is normal; Redundant power supply system.

2. The second semiconductor relay is a field effect transistor interposed between the redundant power supply and the load system; a latch circuit that holds the field effect transistor in an on state if the voltage of the main power supply is equal to or higher than a predetermined reference voltage.

2. The redundant power supply system of claim 1.

3. the latch circuit holds the field effect transistor in an off state when the voltage of the main power supply is less than the predetermined reference voltage; The first semiconductor relay is controlled to a conductive state based on the occurrence of an abnormality in the power supply from the main power source.

3. The redundant power supply system of claim 2.

Images