Redundant power supply system

Abstract

To provide a redundant power supply system capable of preventing an erroneous diagnosis from being output in the case of supplying, from a single redundant power supply, backup power to a plurality of loads having different input voltage requests, respectively.SOLUTION: A redundant power supply system comprises: a first load that requests power lower than a first voltage; a second load that requests power equal to or higher than a second voltage lower than the first voltage; and a redundant power supply that supplies backup power to the first load and the second load when a main power supply fails. When a failure of the main power supply is detected, the redundant power supply notifies the first load of the failure of the main power supply and supplies backup power at an output voltage satisfying the request of the second load. The first load does not output an erroneous diagnosis when an input voltage from the redundant power supply is lower than the first voltage or when the failure of the main power supply is notified from the redundant power supply.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a redundant power supply system having a redundant power supply provided to back up a main power supply. [Background technology]

[0002] Patent Document 1 discloses a system equipped with a redundant power supply that can supply backup power when an abnormality occurs in the main power supply that supplies power to a load (actuator) mounted on a vehicle. In the system described in Patent Document 1, a redundant power supply is provided separately for a shift-by-wire (SBW) and a brake, which are loads that require different backup voltages. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-090246 Summary of the Invention [Problem to be solved by the invention]

[0004] The system described in Patent Document 1 requires redundant power supplies for the shift-by-wire (SBW) system and the brakes, which poses the problems of increased installation space in the vehicle and increased system costs.

[0005] On the other hand, a configuration is conceivable in which backup power is supplied to the shift-by-wire (SBW) system and the brakes from a single redundant power supply. However, because these loads require different input voltages, there is a problem that an incorrect diagnostic result (false diagnosis) may be output depending on the voltage value of the backup power output by the redundant power supply.

[0006] 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 erroneous diagnostics from being output when a single redundant power supply supplies backup power to multiple loads with different input voltage requirements. [Means for solving the problem]

[0007] In order to solve the above problems, one aspect of the disclosed technology is a redundant power supply system including a first load requiring power less than a first voltage, a second load requiring power equal to or greater than a second voltage lower than the first voltage, and a redundant power supply that supplies backup power to the first load and the second load in the event of a failure of the main power supply, wherein when the redundant power supply detects a failure of the main power supply, it notifies the first load of the failure of the main power supply and supplies backup power at an output voltage that satisfies the requirements of the second load, and the first load does not output a fault diagnosis when the input voltage from the redundant power supply is less than the first voltage or when the first load is notified of the failure of the main power supply by the redundant power supply. [Effects of the Invention]

[0008] According to the redundant power supply system of the present disclosure, when backup power is supplied from a single redundant power supply to a plurality of loads (first load, second load) having different input voltage requirements, it is possible to prevent an erroneous diagnosis from being output. [Brief explanation of the drawings]

[0009] [Figure 1] A functional block diagram of a redundant power supply system and its peripheral components according to an embodiment of the present disclosure. [Figure 2] A diagram explaining the operation of the redundant power supply system when the main power supply fails. [Figure 3] A functional block diagram of a redundant power supply system and its peripheral components according to a first embodiment of the present disclosure. [Figure 4] A functional block diagram of a redundant power supply system and its peripheral components according to a second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] The redundant power supply system according to the present disclosure notifies the shift-by-wire device of a failure in the main power supply, thereby integrating backup functions using redundant power supplies for the shift-by-wire device and the brake device, which have different input voltage requirements for the power supplies, and meeting the requirements of multiple devices without changing the system configuration or adding / changing element circuits. Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0011] <Embodiment> [composition] Fig. 1 is a functional block diagram of a redundant power supply system 100 and its peripheral components according to an embodiment of the present disclosure. The redundant power supply system 100 illustrated in Fig. 1 includes a redundant power supply 110, a shift-by-wire (SBW) 120, and a brake 130. The redundant power supply system 100 and an HV-ECU 200 are mounted on a vehicle or the like, and operate by receiving power from a main power supply (+B power supply) 300.

[0012] The main power supply 300 is a power supply source such as a generator including an alternator that generates electricity and a DC-DC converter that converts the generated power to a predetermined voltage, or a secondary battery that is configured to be rechargeable, such as a lithium-ion battery or a lead-acid battery.

[0013] The redundant power supply 110 is configured to function as an auxiliary power supply for backing up and supplying power to the shift-by-wire (SBW) 120 and the brakes 130 when an abnormality occurs in the power supply from the main power supply 300 to the shift-by-wire (SBW) 120 and the brakes 130 due to a power failure of the main power supply 300 or the like. The redundant power supply 110 includes a sub-power supply 111 and a DC-DC converter (DDC) 112.

[0014] The sub-power supply 111 is a power supply source that is configured, for example, with a secondary battery (battery) such as a lithium ion battery that is configured to be chargeable and dischargeable, or with a power storage element such as a capacitor. The sub-power supply 111 is connected to a DC-DC converter (DDC) 112 so that it can be charged with power input from the main power supply 300 and can discharge its own stored power (backup power) to the shift-by-wire (SBW) 120 and the brake 130.

[0015] The DC-DC converter (DDC) 112 is a power converter (step-up / step-down type) for charging and discharging the power of the sub-power supply 111. Based on instructions from a control unit (not shown), this DC-DC converter 112 can convert the power input from the main power supply 300 into power of a predetermined voltage and output it to the sub-power supply 111, or convert the power stored in the sub-power supply 111 into power of a predetermined voltage and output it to the shift-by-wire (SBW) 120 and the brake 130.

[0016] Devices (or systems) such as shift-by-wire (SBW) 120 and brake 130 are on-board loads for realizing predetermined vehicle functions, and may be devices that particularly require a redundant power supply configuration. These multiple devices are each connected and configured so that they can receive power from main power supply 300 without going through redundant power supply system 100, and can also receive backup power from redundant power supply system 100 based on sub-power supply 111. Note that the multiple devices mounted on the vehicle are not limited to those shown in FIG. 1.

[0017] The shift-by-wire (SBW) 120 is a device (first load) that performs shift-by-wire control, capable of changing gear positions of a transmission (not shown) using an electric signal. When the main power supply 300 is normal, the shift-by-wire 120 operates on power supplied directly from the main power supply 300 via the redundant power supply 110 (+B pass-through), and when the main power supply 300 fails, the shift-by-wire 120 operates on power supplied from the sub-power supply 111 via a DC-DC converter (DDC) 112. Furthermore, when the main power supply 300 fails, the shift-by-wire 120 can receive a notification from the redundant power supply 110 notifying the failure of the main power supply 300 (hereinafter referred to as a "+B failure notification"). Receipt of this +B failure notification can be achieved by communication using an existing direct wire connecting the redundant power supply 110 and the shift-by-wire 120. Furthermore, the shift-by-wire 120 is connected so as to be able to communicate with an HV-ECU 200 that controls the hybrid system of the vehicle.

[0018] The shift-by-wire (SBW) system 120 of this embodiment establishes a so-called diagnostic mask (diagnostic disablement) that prevents the output of diagnostic information indicating abnormality detection or abnormality diagnosis when the value of the voltage input as a power supply from the redundant power supply 110 is less than 10 V or when a +B failure notification is received from the redundant power supply 110. Examples of states in which the input voltage value is less than 10 V include a state in which the main power supply 300 has failed due to a ground fault or the like, a state in which a large current is temporarily flowing due to power steering, braking, or the like (short-term load), a state in which the engine is being cranked to start, a state in which unexpected power is being consumed from the sub-power supply 111 due to a failure of the high-voltage DC-DC converter (not shown), or the like.

[0019] The brake 130 is a device (second load) that performs brake control and is capable of generating a braking force on the vehicle. The brake 130 operates on power supplied from the main power supply 300 when the main power supply 300 is normal, and operates on power supplied from the sub-power supply 111 via a DC-DC converter (DDC) 112 when the main power supply 300 fails.

[0020] The HV-ECU 200 is an electronic control unit (ECU) that performs hybrid control of the vehicle, etc. The HV-ECU 200 performs predetermined communication with the shift-by-wire (SBW) 120, and stops when the main power supply 300 fails, causing communication with the shift-by-wire 120 to be interrupted.

[0021] [Example of operation] Next, the operation of the redundant power supply system 100 according to an embodiment of the present disclosure will be described with further reference to Figure 2. Figure 2 is a diagram illustrating the operation of the redundant power supply system 100 when the main power supply 300 fails.

[0022] In this operation example, it is assumed that the shift-by-wire (SBW) 120 requires a voltage of less than 10 V (first voltage) and the brake 130 requires a voltage of 9 V (second voltage) or more as the voltage of the power supply supplied from the redundant power supply 110. The second voltage is set lower than the first voltage.

[0023] (Step 1) When an abnormality such as a failure occurs in the main power supply 300 (marked with an x in FIG. 2 ), the redundant power supply 110 detects the failure of the main power supply 300. This detection can be achieved by, for example, monitoring the voltage of the wiring to which the main power supply 300 is connected. Note that, to prevent the failure of the main power supply 300 from affecting the shift-by-wire (SBW) 120, a switch (such as a relay) capable of performing an electrical cutoff process may be inserted in the +B pass-through path. Furthermore, when the main power supply 300 fails, the operation of the HV-ECU 200 stops, and communication with the shift-by-wire 120 is interrupted.

[0024] (Step 2) In response to detecting a failure of the main power supply 300, the redundant power supply 110 transmits a +B failure notification to the shift-by-wire (SBW) 120. This +B failure notification is transmitted using a dedicated direct line connecting the redundant power supply 110 and the shift-by-wire 120. Furthermore, in order to satisfy the input voltage requirement of the brake 130, the redundant power supply 110 supplies backup power from the sub-power supply 111 to the shift-by-wire 120 and the brake 130, with the output voltage of the DCDC converter (DDC) 112 controlled to 10 V or higher. This output voltage of 10 V or higher takes into account (adds) the voltage drop due to wiring resistance from the DCDC converter 112 to the brake 130. If the input voltage requirement (9 V or more) of the brake 130 can be satisfied, backup power with the output voltage controlled to a voltage less than 10 V (for example, in the range of 9.3 V to 9.9 V if the voltage drop is 0.2 V) may be supplied from the DC-DC converter 112 to the shift-by-wire 120 and the brake 130, respectively.

[0025] (Step 3) Shift-by-wire (SBW) 120 determines whether to establish a diagnostic mask when outputting diagnostic information based on a communication disruption determination from HV-ECU 200. More specifically, shift-by-wire 120 determines to establish a diagnostic mask when the voltage of the backup power input from redundant power supply 110 is less than 10 V or when shift-by-wire 120 receives a +B failure notification from redundant power supply 110.

[0026] By the above-described operation, even if the voltage of the backup power input from redundant power supply 110 becomes 10 V or higher due to a failure of main power supply 300, shift-by-wire (SBW) 120 can establish a diagnostic mask by receiving the +B failure notification. As a result, even if the input voltage of shift-by-wire 120 is 10 V or higher (the input voltage requirement of less than 10 V cannot be satisfied), the input voltage requirement of 9 V or higher in brake 130 can be satisfied, and the requirement to avoid erroneous determination (output of erroneous diagnostic) in shift-by-wire 120 can be satisfied.

[0027] <Actions and Effects> As described above, according to redundant power supply system 100 according to an embodiment of the present disclosure, information about an abnormality (power supply failure) in main power supply 300 that can be detected by redundant power supply 110 is notified to shift-by-wire (SBW) 120. By receiving this power supply failure notification, shift-by-wire 120 can implement diagnostic masking even if it receives an input voltage from redundant power supply 110 that is higher than the input voltage that it requires, thereby preventing erroneous diagnostic output.

[0028] Furthermore, according to the redundant power supply system 100 of this embodiment, an existing direct wiring can be used to notify the shift-by-wire (SBW) 120 of a power failure from the redundant power supply 110, so there is no need to change the system configuration or add / change element circuits, and it is possible to easily supply backup power from a single redundant power supply 110 to the shift-by-wire 120 and the brake 130.

[0029] <Reference example 1> 3 is a functional block diagram of a redundant power supply system 500 and its peripheral components according to a first embodiment of the present disclosure. The redundant power supply system 500 of the first embodiment differs from the redundant power supply system 100 described above in the configuration of the redundant power supply 510.

[0030] The redundant power supply 510 of the redundant power supply system 500 includes a step-down circuit 511 between the DC-DC converter (DDC) 112 and the shift-by-wire (SBW) 120. The step-down circuit 511 is configured to be able to reduce the input voltage to a predetermined voltage and output it. When a failure of the main power supply 300 is detected in this redundant power supply 510, the output voltage of the DC-DC converter 112 is controlled to 10 V or more, and the step-down circuit 511 controls the input voltage of the shift-by-wire 120 to be reduced to less than 10 V. This makes it possible to satisfy both the input voltage requirements of the shift-by-wire 120 and the brake 130.

[0031] In this way, when the configuration of redundant power supply system 500 of Reference Example 1 is adopted, it becomes possible to supply backup power from the single redundant power supply 510 to shift-by-wire 120 and brake 130 while satisfying the requirements of shift-by-wire 120 and brake 130, respectively, without issuing a +B failure notification from redundant power supply 510 to shift-by-wire (SBW) 120.

[0032] <Reference example 2> 4 is a functional block diagram of a redundant power supply system 600 and its peripheral components according to a second embodiment of the present disclosure. The redundant power supply system 600 of the second embodiment differs from the redundant power supply system 100 described above in the configuration of the redundant power supply 610.

[0033] The redundant power supply 610 of the redundant power supply system 600 includes a boost circuit 611 between the DC-DC converter (DDC) 112 and the brake 130. The boost circuit 611 is configured to boost the input voltage to a predetermined voltage and output it. When a failure of the main power supply 300 is detected in this redundant power supply 610, the output voltage of the DC-DC converter 112 is controlled to be less than 10 V, and the boost circuit 611 controls the input voltage of the brake 130 to be boosted to 10 V or more. This makes it possible to satisfy both the input voltage requirements of the shift-by-wire (SBW) 120 and the brake 130.

[0034] In this way, when the configuration of redundant power supply system 600 of Reference Example 2 is adopted, it becomes possible to supply backup power from the single redundant power supply 610 to shift-by-wire 120 and brake 130 while satisfying the requirements of shift-by-wire (SBW) 120 and brake 130, respectively, although it becomes necessary to change the system configuration and add element circuits. [Industrial Applicability]

[0035] The redundant power supply system of the present disclosure can be used in situations where it is desired to supply backup power from a single redundant power supply to multiple loads with different input voltage requirements. [Explanation of symbols]

[0036] 100, 500, 600 Redundant Power Systems 110, 510, 610 redundant power supply 111 Sub-power supply 112 DC-DC Converter (DDC) 120 Shift-by-wire (SBW) 130 Brake 200 HV-ECU 300 Main Power Supply 511 Step-down circuit 611 Booster Circuit

Claims

1. a first load requiring power less than a first voltage; a second load requiring power equal to or greater than a second voltage lower than the first voltage; a redundant power supply that supplies backup power to the first load and the second load when a main power supply fails, when the redundant power supply detects a failure of the main power supply, it notifies the first load of the failure of the main power supply and supplies the backup power at an output voltage that satisfies a requirement of the second load; the first load does not output a fault diagnosis signal when an input voltage from the redundant power supply is lower than the first voltage or when a failure of the main power supply is notified from the redundant power supply; Redundant power supply system.

2. the output voltage is equal to or greater than the second voltage plus a voltage drop due to wiring from the redundant power supply to the second load; 10. The redundant power supply system of claim 1.

3. the first load is a shift-by-wire device, the second load is a brake device; 3. The redundant power supply system according to claim 1 or 2.

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