Power system

Abstract

To provide a power system capable of supplying power required for a load from a backup power source within a requested time in a case where a defect occurs in a main power source and a backup operation is required.SOLUTION: A power system for supplying power to a load system, which requires a redundant power source configuration, comprises: a main power source which supplies power to the load system via a first path; a backup power source for backing up the power supply due to the main power source; and a switching unit which is connected to the main power source and the backup power source and supplies power of either power source to the load system via a second path that is different from the first path. The switching unit supplies power of a power source, of which the output voltage is higher between the main power source and the backup power source, to the load system via the second path.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a power system that supplies power to a load system that requires a redundant power supply configuration mounted on a vehicle or the like.

Background Art

[0002] Patent Document 1 discloses a backup control device for vehicle use. In this backup control device, control is described such that the power of the backup power supply is not consumed when the main power supply is normal, and the power of the backup power supply is quickly supplied to the load when the main power supply is abnormal.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the backup control device described in Patent Document 1 above, during the period when the backup power supply is waiting in a state where backup operation can be performed at any time, the backup power supply is controlled in a charged state. For this reason, when a failure occurs in the main power supply and the backup operation is actually performed, it takes time to switch the backup power supply from the charge control state to the discharge control state, and there is a possibility that the required power cannot be supplied from the backup power supply to the load within the time when the required power is demanded.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to provide a power system that can supply the required power to a load from a backup power supply within the time when the required power is demanded when a failure occurs in the main power supply and the backup operation becomes necessary.

Means for Solving the Problems

[0006] To solve the above problems, one aspect of the disclosed technology is a power system for supplying power to a load system that requires a redundant power supply configuration, including a main power supply for supplying power to the load system via a first path, a backup power supply for backing up the power supply by the main power supply, and a switching unit connected to the main power supply and the backup power supply for supplying the power of either one of the power supplies to the load system via a second path different from the first path. The switching unit is a power system that supplies the power of the power supply with the higher output voltage among the main power supply and the backup power supply to the load system via the second path.

Advantages of the Invention

[0007] According to the power system of the present disclosure, when a failure occurs in the main power supply and the output voltage decreases (or disappears), the switching unit quickly supplies the power of the backup power supply with the higher output voltage to the load system. As a result, when the main power supply fails, the required power can be supplied from the backup power supply to the load within the required time.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0009] The power system of the present disclosure is provided with a switch that can separately handle a path for passing through the main power supply and a path for supplying power from the backup power supply. Further, a switching unit is provided that consumes the power of the backup power supply in a discharged state when the main power supply is normal and consumes it by backup power supply when the main power supply fails. Thereby, backup power supply using the backup power supply when the main power supply fails is suitably executed. Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0010] <Embodiment> [Configuration] FIG. 1 is a block diagram showing a schematic configuration of a power system 100 according to an embodiment of the present disclosure and a load system 200 that receives power supply from the power system 100. The power system 100 and the load system 200 are mounted on a vehicle or the like.

[0011] The load system 200 is a system that operates with the power supplied from the power system 100 and is a system that requires a backup operation using backup power in an emergency. The load system 200 includes a primary system device 210 and a secondary system device 220 having the same function / performance, and realizes redundancy by making the power supply paths for each device different. Examples of the load system 200 mounted on a vehicle include a shift-by-wire (SBW) system, a brake system, and a steering system. Examples of the primary system device 210 and the secondary system device 220 include an actuator (ACT) and an electronic control unit (ECU) necessary for system operation. Although the number of load systems 200 shown in FIG. 1 is one, the number of load systems 200 that receive power supply from the power system 100 is not limited to one.

[0012] The power system 100 is a system with a redundant power supply configuration for supplying power to the load system 200. This power system 100 includes a main power supply 110, a backup power supply 120, a switching unit 130, a first switch 141, and a second switch 142.

[0013] The main power supply 110 is a power supply that supplies the power necessary for the operation of the load system 200. In the power system 100, as a path capable of supplying power to the load system 200, there are a "first path 151" connected to the primary system device 210 of the load system 200 via the first switch 141, and a "second path 152" connected to the secondary system device 220 of the load system 200 via the switching unit 130 (third switch 131). Also, the main power supply 110 is a power supply capable of supplying power for charging the backup power supply 120 as needed. This main power supply 110 can be a power supply that always supplies +B voltage power regardless of the ignition state in a vehicle.

[0014] The first switch 141 is a configuration for switching the electrical conduction / break state between the main power supply 110 and the primary system device 210, with one end connected to the main power supply 110 and the other end connected to the primary system device 210 of the load system 200. This first switch 141 is electrically conductive during normal operation, and when the main power supply 110 fails due to a ground fault or the like, it disconnects to disconnect the main power supply 110 from the load system 200 so that the influence of the failure does not reach the load system 200.

[0015] The second switch 142 is configured to switch the electrical conduction / blocking state between the backup power supply 120 and the primary system device 210, with one end connected to the primary system device 210 of the load system 200 and the other end connected to the backup power supply 120 (DCDC converter 122). This second switch 142 is electrically blocked during normal operation. When bypassing the main power supply 110 or when the main power supply 110 fails to supply power to the primary system device 210 of the load system 200, it conducts to connect the first path 151 and the backup power supply 120.

[0016] For these first switch 141 and second switch 142, for example, a relay unit in which two field effect transistors (FETs) are connected in series with the rectification direction of the body diodes reversed can be used. The switching control of the first switch 141 and the second switch 142 is performed based on an instruction from a control device (not shown) such as a microcontroller.

[0017] The backup power supply 120 is a power supply for backup-supplying power to the load system 200 in place of the main power supply 110 when an abnormality occurs in the power supply from the main power supply 110 to the load system 200 due to a power failure or the like. This backup power supply 120 includes a power storage unit 121 and a DCDC converter 122.

[0018] The power storage unit 121 is composed of a power storage element such as a capacitor, for example, and functions as a redundant power supply for the main power supply 110. This power storage unit 121 is connected to the DCDC converter 122 so as to be chargeable and dischargeable. Note that the power storage unit 121 may be composed of a secondary battery (such as a lithium-ion battery) configured to be chargeable and dischargeable.

[0019] The DCDC converter 122 is a power converter for converting the input power into power of a predetermined voltage and outputting it. This DCDC converter 122 can charge the power storage unit 121 with the power supplied from the main power source 110 via the first switch 141 and the second switch 142 (charging control state). Also, the DCDC converter 122 can supply the power stored in the power storage unit 121 (backup power) to the primary device 210 of the load system 200 via the second switch 142, or supply it to the secondary device 220 of the load system 200 via the switching unit 130 (diode 132) (discharging control state). For example, a buck-boost type bidirectional DCDC converter is used for this DCDC converter 122. Note that the control of the DCDC converter 122 is performed based on an instruction from a control device (not shown) such as a microcomputer.

[0020] The switching unit 130 is configured to connect the main power source 110 and the backup power source 120 as input sources and connect the load system 200 as an output destination. This switching unit 130 supplies the power of either one of the main power source 110 and the backup power source 120 to the secondary device 220 of the load system 200 with priority over the power of the other power source. The power supply is performed via a second path 152 different from the first path 151. This switching unit 130 includes a third switch 131 and a diode 132.

[0021] The third switch 131 is configured to switch the electrical conduction / blocking state between the main power supply 110 and the secondary system device 220, with one end connected to the main power supply 110 and the other end connected to the secondary system device 220 of the load system 200. For this third switch 131, for example, a relay unit in which two field effect transistors (FETs) are connected in series with the rectification direction of the body diodes reversed can be used. This third switch 131 is electrically conductive during normal operation, and when the main power supply 110 fails due to a ground fault or the like, it shuts off to disconnect the main power supply 110 from the switching unit 130 so that the influence of the failure does not reach the backup power supply 120 or the load system 200. Note that the switching control of the third switch 131 is performed based on an instruction from a control device (not shown) such as a microcomputer.

[0022] The diode 132 has its anode connected to the backup power supply 120 and its cathode connected to the secondary system device 220 of the load system 200, and is an element that rectifies from the backup power supply 120 toward the secondary system device 220.

[0023] With the circuit configuration described above, when the output voltage (+B) of the main power supply 110 is higher than the output voltage (Vb) of the DCDC converter 122 in the backup power supply 120, the switching unit 130 operates so that the power of the main power supply 110 is supplied to the secondary system device 220 of the load system 200. On the other hand, when the output voltage (+B) of the main power supply 110 is lower than the output voltage (Vb) of the DCDC converter 122 in the backup power supply 120, the switching unit 130 operates so that the power of the power storage unit 121 in the backup power supply 120 is supplied to the secondary system device 220 of the load system 200. That is, in the switching unit 130, control is performed to switch the power supply source for the secondary system device 220 according to the level of the output voltage of the power supply.

[0024] [Control] Next, with further reference to FIGS. 2, 3, and 4, the control state in the power system 100 according to an embodiment of the present disclosure will be described.

[0025] (1) Backup standby state FIG. 2 shows the circuit state in the "backup standby state" where, when there is no abnormality such as a power failure in the main power supply 110 and the power system 100 is in a normal state, a function that requires backup control such as remote parking operates and the power system 100 waits in a backup-enabled state.

[0026] As shown in FIG. 2, when the power system 100 is in the backup standby state, the first switch 141 and the third switch 131 are respectively controlled to be in a conductive state, and the second switch 142 is controlled to be in an open state. Also, when the power system 100 is in the backup standby state, the DCDC converter 122 of the backup power supply 120 is controlled to be in a state where it can discharge from the power storage unit 121 while setting its output voltage (Vb) to a value lower than the output voltage (+B) of the main power supply 110 (discharge control state).

[0027] By these controls, in this backup standby state, power is supplied from the main power supply 110 to the primary system device 210 of the load system 200 via the first path 151, and power is supplied from the main power supply 110 to the secondary system device 220 of the load system 200 via the second path 152 (thick line paths in FIG. 2).

[0028] (2) Backup operation state FIG. 3 shows the circuit state in the "backup operation state" where backup control has been activated when an abnormality such as a power failure occurs in the main power supply 110 during the operation of a function that requires backup control such as remote parking (the state in FIG. 2) and the power system 100 becomes abnormal.

[0029] As shown in FIG. 3, when the power system 100 is in the backup operation state, the first switch 141 and the third switch 131 are respectively controlled to be in the off state, and the second switch 142 is controlled to be in the on state. Also, when the third switch 131 is turned off, the output voltage (Vb) of the backup power supply 120 (DCDC converter 122) becomes higher than the other end of the third switch 131.

[0030] By these controls, in this backup operation state, power is supplied from the backup power supply 120 to the primary system device 210 of the load system 200 via the first path 151, and power is supplied from the backup power supply 120 to the secondary system device 220 of the load system 200 via the second path 152 (thick line path in FIG. 3). Since the backup power supply 120 starts the backup process of the main power supply 110 in the discharge control state, it can immediately supply power to the load system 200 via the first path 151 and the second path 152 without taking time to switch from the charge control state to the discharge control state.

[0031] (3) Backup Capacity Assurance State FIG. 4 shows the circuit state in the case of the "backup capacity assurance state" where the power storage unit 121 of the backup power supply 120 is charged with the power of the main power supply 110 when the capacity of the backup power supply 120 is insufficient for the backup capacity.

[0032] As shown in FIG. 4, when the power system 100 is in the backup capacity assurance state, the first switch 141, the second switch 142, and the third switch 131 are all controlled to be in the on state.

[0033] With these controls, in this backup capacity ensuring state, power is supplied from the main power supply 110 to the primary device 210 of the load system 200 via the first path 151, and power is supplied from the main power supply 110 to the secondary device 220 of the load system 200 via the second path 152 (thick line path in FIG. 4). Further, in the backup capacity ensuring state, power is supplied from the main power supply 110 to the backup power supply 120 and the power storage unit 121 is charged (main power supply pass-through).

[0034] <Function and Effect> As described above, the power system 100 according to an embodiment of the present disclosure provides the first path 151 and the second path 152 as paths for supplying power from the main power supply 110 to the load system 200, and a switching unit 130 that outputs the power of the power supply with the higher output voltage among the main power supply 110 and the backup power supply 120 is inserted into the second path 152. Also, a second switch 142 capable of switching the two paths between a conductive state and a cut-off state is provided between the first path 151 and the second path 152 to enable a main power supply pass-through to the backup power supply 120. And in this configuration, the power system 100 according to the present embodiment waits for supplying backup power to the load system 200 while controlling the backup power supply 120 to be in a state where it can be discharged from the power storage unit 121 (discharge control state).

[0035] Thereby, when the main power supply 110 is normal, it is possible to suppress power consumption from the backup power supply 120 (reduction of backup power consumption when the main power supply is normal). Also, even when a fault occurs in the main power supply 110 and the output voltage drops or disappears, and the power supply source of the switching unit 130 to the load system 200 switches from the main power supply 110 to the backup power supply 120, it is possible to quickly supply power from the backup power supply 120 in the discharge control state to the load system 200 (ensuring responsiveness of backup power supply when the main power supply fails).

[0036] As described above, one embodiment of the disclosed technology has been explained. However, the present disclosure can be understood as a power system, a control method executed by a power system including 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 power system, and so on.

Industrial Applicability

[0037] The power system of the present disclosure can be used in vehicles equipped with a load system that requires a redundant power supply configuration, and so on.

Explanation of Signs

[0038] 100 Power system 110 Main power supply 120 Backup power supply 121 Power storage unit 122 DCDC converter 130 Switching unit 131 Third switch 132 Diode 141 First switch 142 Second switch 151 First path 152 Second path 200 Load system 210 Primary system device 220 Secondary system device

Claims

1. A power system for supplying power to a load system that requires a redundant power configuration, comprising: a main power source for supplying power to the load system via a first path; a backup power source for backing up the power supply by the main power source; a switching unit connected to the main power source and the backup power source, and supplying the power of either one of the power sources to the load system via a second path different from the first path; wherein the switching unit supplies the power of the power source with the higher output voltage among the main power source and the backup power source to the load system via the second path.

2. further comprising a switch for controlling the electrical conduction / interruption state between the first path and the backup power source; wherein the switch controls the first path and the backup power source to be in a conductive state when charging the backup power source with the power of the main power source and when the main power source fails. The power system according to claim 1.

3. The backup power source includes a power storage unit for storing power and a DC-DC converter for controlling the charge / discharge state of the power storage unit; wherein the DC-DC converter controls the power storage unit to be in a discharge state and outputs power to the switching unit when backup-capable power is stored in the power storage unit. The power system according to claim 1 or 2.

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