Redundant power supply system

Abstract

This redundant power supply system is provided with: a first load that requires power that is less than a first voltage; a second load that requests power at a second voltage or more that is lower than the first voltage; and a redundant power supply that supplies backup power to the first load and the second load when the main power supply fails, notifies the first load of the failure of the main power supply and supplies backup power at an output voltage that satisfies the requirement of the second load when the failure of the main power supply is detected, and supplies backup power at an output voltage that satisfies the requirement of the second load when the input voltage from the redundant power supply is less than the first voltage. Alternatively, when the slave redundant power supply notifies that the master power supply fails, the first load does not output a misdiagnosis.

Description

Technical Field

[0001] The present disclosure relates to a redundant power supply system having a redundant power supply provided as a backup for a main power supply. Background Art

[0002] A system having a redundant power supply is disclosed in Japanese Unexamined Patent Application Publication No. 2021-090246. When an abnormality occurs in the main power supply that supplies power to a load (actuator) mounted on a vehicle, the redundant power supply can supply backup power. In the system described in Japanese Unexamined Patent Application Publication No. 2021-090246, redundant power supplies are independently provided for a shift-by-wire (SBW) and a brake, which are loads having different required backup voltages.

[0003] In the system described in Japanese Unexamined Patent Application Publication No. 2021-090246, it is necessary to separately provide redundant power supplies for the shift-by-wire (SBW) and the brake. Therefore, there are problems that the mounting space in the vehicle increases and the system cost increases.

[0004] On the other hand, a configuration in which backup power is supplied from a single redundant power supply to the shift-by-wire (SBW) and the brake can be considered, but the required input voltages of these loads are different from each other. Therefore, there is a problem of outputting an incorrect diagnostic result (false diagnosis) depending on the voltage value of the backup power output from the redundant power supply. Summary of the Invention

[0005] The present disclosure provides a redundant power supply system that can prevent output of false diagnosis when backup power is supplied from a single redundant power supply to a plurality of loads having different required input voltages.

[0006] To solve the above problems, one aspect of the technology of the present disclosure is a redundant power supply system including: a first load that requires power less than a first voltage; a second load that requires 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 the main power supply fails. When it is detected that the main power supply has failed, the redundant power supply 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. When the input voltage from the redundant power supply is less than the first voltage, or when the failure of the main power supply is notified from the redundant power supply, the first load does not output a false diagnosis.

[0007] According to the redundant power supply system of the present disclosure, false diagnosis can be prevented when backup power is supplied from a single redundant power supply to a plurality of loads (first load, second load) having different required input voltages.

[0008] The features, advantages, and technical and industrial significance of the exemplary embodiments of the present invention will be described with reference to the accompanying drawings, in which like reference numerals denote like elements. Description of the Drawings

[0009] Figure 1 FIG. 1 is a functional block diagram of a redundant power supply system and its peripheral parts according to an embodiment of the present disclosure;

[0010] Figure 2 FIG. 2 is a diagram for explaining the operation of the redundant power supply system when the main power supply fails;

[0011] Figure 3 FIG. 3 is a functional block diagram of a redundant power supply system and its peripheral parts according to Reference Example 1 of the present disclosure;

[0012] Figure 4 FIG. 4 is a functional block diagram of a redundant power supply system and its peripheral parts according to Reference Example 2 of the present disclosure. Detailed Description of the Embodiment

[0013] The redundant power supply system according to the present disclosure notifies a shift-by-wire device of the failure of the main power supply. Thus, by integrating the backup functions of the shift-by-wire device and the brake device, which have different input voltage requirements for the power supply based on the redundant power supply, the requirements of multiple devices can be achieved without changing the system structure or adding or changing component circuits.

[0014] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

[0015] Embodiment

[0016] Structure

[0017] Figure 1 FIG. 1 is a functional block diagram of a redundant power supply system 100 and its peripheral parts according to an embodiment of the present disclosure. Figure 1 The illustrated redundant power supply system 100 includes a redundant power supply 110, a shift-by-wire (SBW) 120, and a brake 130. The redundant power supply system 100 and the HV-ECU 200 are mounted on a vehicle or the like and operate by receiving power supply from a main power supply (+B power supply) 300.

[0018] The main power supply 300 is a power supply source such as a generator including an alternator that generates electricity and a DCDC converter that converts the generated electricity into a specified voltage, a secondary battery such as a lithium-ion battery or a lead-acid battery that can be charged and discharged.

[0019] The redundant power supply 110 is a structure that functions as an auxiliary power supply for backup power supply to the steer-by-wire (SBW) 120 and the brake 130 when an abnormality occurs in the power supply from the main power supply 300 to the steer-by-wire (SBW) 120 and the brake 130. The abnormality in the power supply may be caused by 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.

[0020] The sub-power supply 111 is, for example, a power supply source composed of a secondary battery such as a lithium-ion battery that can be charged and discharged, a power storage element such as a capacitor. The sub-power supply 111 is connected to the DC-DC converter (DDC) 112 in such a way that it can charge the power input from the main power supply 300. In addition, the sub-power supply 111 is connected to the DC-DC converter (DDC) 112 in such a way that it can discharge the power stored in itself (backup power) to the steer-by-wire (SBW) 120 and the brake 130.

[0021] 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. The DC-DC converter 112 can convert the power input from the main power supply 300 into power of a specified voltage and output it to the sub-power supply 111 based on an instruction from a control unit (not shown). In addition, the DC-DC converter 112 can convert the power stored in the sub-power supply 111 into power of a specified voltage and output it to the steer-by-wire (SBW) 120 and the brake 130 based on an instruction from a control unit (not shown).

[0022] Devices (or systems) such as the steer-by-wire (SBW) 120 and the brake 130 are in-vehicle loads for realizing specified functions related to the vehicle, and are devices that particularly require a redundant power supply structure. These multiple devices are respectively connected and configured to be able to receive power supply from the main power supply 300 without passing through the redundant power supply system 100. In addition, the multiple devices are respectively connected and configured to be able to receive backup power supply based on the sub-power supply 111 from the redundant power supply system 100. Furthermore, the multiple devices mounted on the vehicle are not limited to Figure 1 the devices shown.

[0023] The shift-by-wire (SBW) 120 is a device (first load) that performs shift-by-wire control for changing the gear position of a transmission (not shown) using an electric signal. When the main power supply 300 is normal, the shift-by-wire 120 operates with power directly supplied from the main power supply 300 via the redundant power supply 110 (+B direct connection). When the main power supply 300 fails, the shift-by-wire 120 operates with power supplied from the sub-power supply 111 via the DCDC converter (DDC) 112. In addition, when the main power supply 300 fails, the shift-by-wire 120 can receive a notification of the failure of the main power supply 300 (hereinafter referred to as the "+B failure notification") from the redundant power supply 110. The reception of this +B failure notification can be achieved through communication using the existing direct connection line that connects the redundant power supply 110 and the shift-by-wire 120. Also, the shift-by-wire 120 is communicably connected to the HV-ECU 200 that controls the hybrid system of the vehicle.

[0024] For the shift-by-wire (SBW) 120 of the present embodiment, if the voltage value input as power from the redundant power supply 110 is less than 10V, or if a +B failure notification is received from the redundant power supply 110, diagnostic information indicating anomaly detection and anomaly diagnosis is not output. That is, the shift-by-wire (SBW) 120 causes so-called diagnostic masking (diagnosis invalidation) to occur. As a state where the input voltage value is less than 10V, examples include a state where the main power supply 300 fails due to grounding or the like, a state where a large current temporarily flows due to power steering, braking, etc. (short-term load), a state where the engine starts and operates, a state where unexpected power is consumed from the sub-power supply 111 due to a failure of a high-voltage DCDC converter (not shown), etc.

[0025] The brake 130 is a device (second load) that performs braking control capable of generating braking force for the vehicle. For this brake 130, when the main power supply 300 is normal, it operates with power supplied from the main power supply 300, and when the main power supply 300 fails, it operates with power supplied from the sub-power supply 111 via the DCDC converter (DDC) 112.

[0026] The HV-ECU 200 is an electronic control unit (ECU: Electronic Control Unit) that performs hybrid control of the vehicle. This HV-ECU 200 performs prescribed communication with the shift-by-wire (SBW) 120, and when the main power supply 300 fails, it stops and interrupts communication with the shift-by-wire 120.

[0027] Operation example

[0028] Next, with further reference to Figure 2 , the operation of the redundant power supply system 100 according to an embodiment of the present disclosure will be described.Figure 2 This is a diagram for explaining the operation of the redundant power supply system 100 in the case of the failure of the main power supply 300.

[0029] In this operation example, the following situation is assumed: as the voltage of the power supply received from the redundant power supply 110, the shift-by-wire (SBW) 120 requires a voltage of less than 10V (first voltage), and the brake 130 requires a voltage of 9V (second voltage) or more. In addition, the second voltage is set lower than the first voltage.

[0030] Step 1

[0031] If an abnormality such as the failure of the main power supply 300 occurs ( Figure 2 the × mark in it), the redundant power supply 110 detects the failure of the main power supply 300. This detection can be performed by monitoring the voltage of the wiring connecting the main power supply 300, etc. In addition, since the influence of the failure of the main power supply 300 does not affect the shift-by-wire (SBW) 120, a switch (relay, etc.) capable of performing an electric cut-off process can also be inserted in the +B direct connection path. In addition, along with the failure of the main power supply 300, the operation of the HV-ECU 200 stops and the communication with the shift-by-wire 120 is interrupted.

[0032] Step 2

[0033] In response to detecting the failure of the main power supply 300, the redundant power supply 110 sends a +B failure notification to the shift-by-wire (SBW) 120. This +B failure notification is sent using a dedicated direct connection wire connecting the redundant power supply 110 and the shift-by-wire 120. In addition, in order to meet the input voltage requirements of the brake 130, the redundant power supply 110 supplies backup power to the shift-by-wire 120 and the brake 130 respectively from the sub-power supply 111. The backup power is power that controls the output voltage of the DCDC converter (DDC) 112 to 10V or more. In this output voltage of 10V or more, the voltage drop amount caused by the wiring resistance from the DCDC converter 112 to the brake 130 is considered (added). In addition, as long as the input voltage requirements of the brake 130 (9V or more) are met, backup power that controls the output voltage to less than 10V (for example, in the range of 9.3V to 9.9V if the voltage drop amount is 0.2V) can also be supplied to the shift-by-wire 120 and the brake 130 respectively from the DCDC converter 112.

[0034] Step 3

[0035] When the shift-by-wire (SBW) 120 outputs diagnostic information based on a communication interruption determination from the HV-ECU 200, it determines whether to make the diagnostic mask valid. More specifically, when the voltage of the backup power input from the redundant power supply 110 is less than 10V, or when a +B failure notification is received from the redundant power supply 110, the shift-by-wire 120 determines that the diagnostic mask is made valid.

[0036] Through the above operation, even if the voltage of the backup power input from the redundant power supply 110 becomes 10V or more due to the failure of the main power supply 300, the shift-by-wire (SBW) 120 can make the diagnostic mask valid based on the reception of the +B failure notification. Thus, even when the input voltage of the shift-by-wire 120 is 10V or more (failing to meet the requirement of an input voltage less than 10V), it can meet the requirement of an input voltage of 9V or more in the brake 130 and can meet the requirement of avoiding false determination (output of false diagnosis) in the shift-by-wire 120.

[0037] Function and Effect

[0038] As described above, according to the redundant power supply system 100 according to an embodiment of the present disclosure, information on the occurrence of an abnormality (power failure) of the main power supply 300 that can be detected by the redundant power supply 110 is notified to the shift-by-wire (SBW) 120. By receiving this power failure notification, the shift-by-wire 120 can perform diagnostic masking even when it receives an input voltage higher than its required input voltage from the redundant power supply 110, thereby preventing the output of false diagnosis.

[0039] In addition, according to the redundant power supply system 100 according to the present embodiment, the power failure notification from the redundant power supply 110 to the shift-by-wire (SBW) 120 can use the original direct connection line. Therefore, without changing the system structure, adding / changing component circuits, etc., it is possible to easily supply backup power from the single redundant power supply 110 to the shift-by-wire 120 and the brake 130.

[0040] Reference Example 1

[0041] Figure 3 It is a functional block diagram of the redundant power supply system 500 according to Reference Example 1 of the present disclosure and its peripheral parts. Compared with the above redundant power supply system 100, the structure of the redundant power supply 510 is different in this Reference Example 1.

[0042] The redundant power supply 510 of the redundant power supply system 500 has a buck circuit 511 between the DCDC converter (DDC) 112 and the shift-by-wire (SBW) 120. The buck circuit 511 is configured to reduce the voltage on the input side to a specified voltage and output it. In this redundant power supply 510, when a failure of the main power supply 300 is detected, the output voltage of the DCDC converter 112 is controlled to be 10V or more, and in the buck circuit 511, the input voltage of the shift-by-wire 120 is buck-controlled to be less than 10V. Thus, both the input voltage requirements of the shift-by-wire 120 and the input voltage requirements of the brake 130 can be satisfied.

[0043] In this way, when the structure of the redundant power supply system 500 of Reference Example 1 is adopted, system structure changes and component circuits need to be added, but there is no +B failure notification from the redundant power supply 510 to the shift-by-wire (SBW) 120. Also, the requirements of the shift-by-wire 120 and the brake 130 can be satisfied respectively, and backup power can be supplied to the shift-by-wire 120 and the brake 130 from a single redundant power supply 510.

[0044] Reference Example 2

[0045] Figure 4 It is a functional block diagram of the redundant power supply system 600 and its peripheral part related to Reference Example 2 of the present disclosure. The redundant power supply system 600 of this Reference Example 2 has a different structure of the redundant power supply 610 compared with the above-mentioned redundant power supply system 100.

[0046] The redundant power supply 610 of the redundant power supply system 600 has a boost circuit 611 between the DCDC converter (DDC) 112 and the brake 130. The boost circuit 611 is configured to raise the voltage on the input side to a specified voltage and output it. In this redundant power supply 610, when a failure of the main power supply 300 is detected, the output voltage of the DCDC converter 112 is controlled to be less than 10V, and in the boost circuit 611, the input voltage of the brake 130 is boost-controlled to be 10V or more. Thus, both the input voltage requirements of the shift-by-wire (SBW) 120 and the input voltage requirements of the brake 130 can be satisfied.

[0047] In this way, when the structure of the redundant power supply system 600 of Reference Example 2 is adopted, system structure changes and component circuits need to be added, but there is no +B failure notification from the redundant power supply 610 to the shift-by-wire (SBW) 120. Also, the requirements of the shift-by-wire 120 and the brake 130 can be satisfied respectively, and backup power can be supplied to the shift-by-wire 120 and the brake 130 from a single redundant power supply 610.

[0048] The redundant power supply system of the present disclosure can be used in situations such as attempting to supply backup power to multiple loads with different input voltage requirements from a single redundant power supply.

Claims

1. A redundant power supply system, wherein, the redundant power supply system includes: a first load that requires power less than a first voltage; a second load that requires 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 the main power supply fails, in the case where the 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 the backup power at an output voltage that satisfies the requirements of the second load, in the case where the input voltage from the redundant power supply is less than the first voltage, or in the case where the failure of the main power supply is notified from the redundant power supply, the first load does not output a false diagnosis.

2. The redundant power supply system according to claim 1, wherein, the output voltage is equal to or higher than the second voltage plus a voltage drop caused by wiring from the redundant power supply to the second load.

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

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