JP2020026215A - Redundant power source system - Google Patents

Abstract

To provide a redundant power source system which can maintain a backup function of a normal load in an engine re-starting and a main power source failure after an idle stop.SOLUTION: A redundant power source system can supply a redundant power source from a main power source and a sub power source to a first load, and can supply a power source from the main power source to a second load necessary for suppression of voltage fluctuation. The redundant power source system includes a first relay connecting DDC and the sub power source in an energization cutting manner, a second relay connecting the DDC and the second load in the energization cutting manner, a regulator connecting the sub power source and the first load, and a control part controlling an energization cut-off state of the first relay and the second relay, in which the control part cuts off the first relay and energizes the second relay and connects the second load to the main power source via the DDC and connects the first load to the sub power source via the regulator in the engine restarting processing, and energizes the first relay and cuts off the second relay, separates the second load from the main power source, and connects the first load to the sub power source via the DDC in the same processing in the case of a main power source failure.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a redundant power supply system.

  There are vehicles equipped with a so-called idle stop & start function that stops the engine when stopped to improve fuel efficiency. In a vehicle power supply system equipped with this function, the effect of voltage fluctuations caused by large current consumption when the engine is restarted after an idle stop is reduced to a load requiring a stable voltage (hereinafter referred to as a "protection load"). There is a measure to insert a DCDC converter that suppresses voltage fluctuations in front of the protective load in order to prevent the fluctuation. FIG. 5 shows a configuration example of a redundant power supply system 200 provided with a DCDC converter (DDC) for suppressing electric transformation and employing a redundant configuration for loads other than the protection load (hereinafter, referred to as “normal loads”).

  In the configuration of the redundant power supply system 200 illustrated in FIG. 5, two DCDC converters are used for the suppression of the electric power change and for the backup power supply. Therefore, Patent Documents 1 and 2 propose a configuration of a power supply system having a single DCDC converter. In the conventional power supply systems described in these patent documents, a backup power supply and a protection load are connected to a starter or the like via the same DCDC converter. As a result, in the conventional power supply system, when the engine is restarted after the engine is idle-stopped, the DC-DC converter is controlled to separate the protective load from the starter, thereby reducing the influence of voltage fluctuations caused by large current consumption in the starter. It does not reach the protection load.

JP 2017-154579 A JP 2012-090404 A

  In the power supply system described in the above-mentioned conventional patent document, a backup power supply is connected to a normal load via a DCDC converter. Therefore, if the protection load is disconnected from the starter by controlling the DCDC converter in the engine restart processing after the idle stop, the backup power supply is also disconnected from the normal load. If the main power supply fails, the load cannot usually be backed up.

  The present invention has been made in view of the above problems, and has a redundant power supply system capable of maintaining a backup function for a normal load when an engine is restarted after an idle stop and a main power supply fails in the processing. The purpose is to provide.

  In order to solve the above problem, one embodiment of the present invention can supply power redundantly from a main power supply and a backup power supply to a first load, and can supply power from the main power supply to a second load that needs to suppress voltage fluctuation. A redundant power supply system capable of supplying power, comprising: a DCDC converter provided between a backup power supply and a first load; and a first relay for connecting the DCDC converter and the backup power supply so as to be able to conduct and cut off. A second relay that connects the DCDC converter and the second load so as to be able to conduct and cut off, a third relay that connects the main power supply and the DCDC converter so that the current can be turned on and off, a main power supply and the second load. And a fourth relay for connecting the backup power supply and the first load, and a first and a second relay. And a control unit that controls the state of energization and cutoff of the first relay and the fourth relay in the engine restart processing after the idle stop. The third relay is energized, the second load is connected to the main power supply via the DCDC converter, the first load is connected to the backup power supply via the regulator, and the main load is used in the engine restart processing after the idle stop. In the event of a power failure, the first relay is energized and the second, third, and fourth relays are shut off to disconnect the second load from the main power source, Connect the load to a backup power supply via a DCDC converter.

  According to the above-described redundant power supply system of the present invention, a backup function for a normal load (first load) can be maintained during engine restart processing after an idle stop and when the main power supply fails in the processing.

FIG. 1 is a diagram illustrating a schematic configuration of a redundant power supply system according to an embodiment of the present invention. Diagram for explaining power supply path formed by relay control Diagram for explaining power supply path formed by relay control Diagram for explaining power supply path formed by relay control Diagram showing a schematic configuration of a conventional redundant power supply system

[Embodiment]
Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings.

  The redundant power supply system according to the present embodiment is provided with a path for supplying power to the normal load from the backup power supply and a path for supplying power to the protection load from the main power supply via the DCDC converter, and uses a plurality of relays to respond to the state of the vehicle. Switch the connection status appropriately.

<Structure>
FIG. 1 is a diagram showing a schematic configuration of a redundant power supply system 100 according to one embodiment of the present invention. The redundant power supply system 100 illustrated in FIG. 1 includes an alternator (ALT) 11, a starter (ST) 12, a first power supply 13, a first load 14, a bidirectional DCDC converter (DDC) 15, , A second load 17, a regulator (Reg) 18, a controller 20, a first relay RL1, a second relay RL2, a third relay RL3, and a fourth relay. RL4. The redundant power supply system 100 can be used, for example, in a vehicle equipped with an idle stop & start function.

  The alternator 11 is a power generation device that converts torque generated by being driven by the engine into electric energy to generate power. The alternator 11 sends out the generated electric power to the first power supply 13, the first load 14, and the like.

  The starter 12 is a starting device that starts the engine by cranking. The starter 12 operates with electric power supplied from a first power supply 13.

  The first power supply 13 is a power storage device configured to be chargeable and dischargeable. The first power supply 13 can be, for example, a lead storage battery. The first power source 13 is connected to the alternator 11, the starter 12, and the first load 14, and stores the power generated by the alternator 11, or stores the power stored by the alternator 11 in the starter 12 or the first load 14. Or a so-called main power supply.

  The first load 14 is an in-vehicle device that operates with electric power supplied from the first power supply 13 and realizes a predetermined function. More specifically, the first load 14 is an in-vehicle device that needs to continue operation even when the first power supply 13 that is the main power supply fails. The first load 14 has a double power supply so that the second load 16 can supply power independently of the first power supply 13. In the configuration illustrated in FIG. 1, the first load 14 is connected to the first power supply 13 via a rectifier D1 so as to be able to supply power, and the second load 16 is connected to the bidirectional DCDC converter 15 and the second power supply 16. It is connected so as to be able to supply power via the rectifier element D2 and is connected via the regulator 18. The rectifiers D1 and D2 can be, for example, diodes. A third relay RL3 is inserted between the anode of the rectifier D1 and the anode of the rectifier D2.

  Examples of functions realized by the first load 14 include a door unlock function, a shift-by-wire function, and an electric parking brake function, which allow the vehicle to travel to a safe place even when an abnormality occurs in the vehicle. That can operate the functions (run, turn, stop) necessary to stop the vehicle.

  The bidirectional DC-DC converter 15 can convert a voltage input to the primary side into a predetermined voltage and output it to the secondary side, and convert a voltage input to the secondary side into a predetermined voltage. This is a bidirectional voltage converter that can output to the primary side. The bidirectional DCDC converter 15 has a primary side connected to a first power supply 13 via a third relay RL3, and a secondary side connected to a second power supply 16 via a first relay RL1. I have.

  The second power supply 16 is a power storage device configured to be chargeable and dischargeable. The second power supply 16 can be, for example, an electric double layer capacitor (EDLC). When an electric double layer capacitor is used as a power storage material, it is recommended that the electric charge be reduced to zero or minimized during parking to prevent deterioration, and that the vehicle be charged and used when the vehicle is started (after ignition is turned on, etc.). desirable. Therefore, in order to use up the capacity of the electric double layer capacitor without waste, the bidirectional DCDC converter 15 is used. The second power supply 16 is connected to the alternator 11 via the first relay RL1, the bidirectional DCDC converter 15, and the third relay RL3, and converts the power generated by the alternator 11 with the bidirectional DCDC converter 15. The power stored therein is converted by the bidirectional DCDC converter 15 and supplied to the first load 14. The second power supply 16 supplies the power stored therein to the first load 14 via the regulator 18. Therefore, the second power supply 16 functions as a backup power supply for the first power supply 13.

  The second load 17 is an in-vehicle device that operates with electric power supplied from the first power supply 13 and realizes a predetermined function. More specifically, the second load 17 is an in-vehicle device that requires a stable voltage by suppressing a voltage change occurring in the first power supply 13. The second load 17 is connected to the first power supply 13 via the fourth relay RL4, and is connected to the first power supply 13 via the third relay RL3, the bidirectional DCDC converter 15, and the second relay RL2. 1 power supply 13.

  The regulator 18 is inserted between the second power supply 16 and the first load 14, and can input the second power supply 16 and output a constant voltage to the first load 14. As the regulator 18, for example, a low dropout (LDO) linear regulator that operates even when the voltage difference between input and output is small can be used. Alternatively, a DCDC converter that performs a switching operation may be used as the regulator 18.

  The first relay RL1 is inserted between the bidirectional DCDC converter 15 and the second power supply 16, and connects the bidirectional DCDC converter 15 and the second power supply 16 so as to be able to conduct and cut off. The second relay RL2 is inserted between the bidirectional DCDC converter 15 and the second load 17, and connects the bidirectional DCDC converter 15 and the second load 17 so as to be able to conduct and cut off. The third relay RL3 is inserted between the first power supply 13 and the bidirectional DCDC converter 15, and connects the first power supply 13 and the bidirectional DCDC converter 15 so as to be able to conduct and cut off. The fourth relay RL4 is inserted between the first power supply 13 and the second load 17, and connects the first power supply 13 and the second load 17 so as to be able to conduct and cut off. As the first to fourth relays RL1 to RL4, for example, semiconductor relays can be used.

  The control unit 20 acquires predetermined vehicle information from an in-vehicle device (not shown). The vehicle information includes at least the running state of the vehicle, whether or not the engine has been restarted after the idle stop (release of the brake pedal), the state of the first power supply 13, and the state of the second power supply 16. Then, based on the obtained vehicle information, the control unit 20 turns on (ON) and cuts off (OFF) the first relay RL1, the second relay RL2, the third relay RL3, and the fourth relay RL4. Control the state. The relay control method by the control unit 20 will be described later.

<Control>
The relay control executed by the redundant power supply system 100 according to the present embodiment will be described with reference to FIGS. 2 to 4 are diagrams illustrating a power supply path formed by relay control in a specific state of the vehicle.

  FIG. 2 shows a power supply path formed by the relay control of the control unit 20 when the vehicle is normally driving (running). In this state, the first relay RL1 and the fourth relay RL4 are controlled to be turned on (ON) and the second relay RL2 is turned off (OFF). The third relay RL3 is controlled to be turned off (OFF) in principle, but is appropriately controlled to be turned on (ON) according to the state of charge of the second power supply 16 (when charging or discharging is necessary). .

  By this relay control, a power supply path is formed from the first power supply 13 → the rectifier D1 → the first load 14, and power is supplied to the first load 14 from the first power supply 13 via the rectifier D1. (Normal power supply). In addition, a power supply path is formed from the second power supply 16 → the bidirectional DCDC converter 15 → the rectifier D2 → the first load 14. The first load 14 is connected to the first load 14 via the bidirectional DCDC converter 15 and the rectifier D2. Power can be supplied from the second power supply 16 (backup power supply). Note that if the voltage difference between the second power supply 16 and the first load 14 is a voltage difference at which the regulator 18 can operate, the second power supply 16 can also supply the first load 14 via the regulator 18. Backup power supply becomes possible. On the other hand, a power path from the first power supply 13 to the second load 17 is formed by the relay control, and the second load 17 is directly supplied with power from the first power supply 13.

  As described above, in the case where the voltage fluctuation occurring in the first power supply 13 does not affect the second load 17, the normal power supply by the first power supply 13 to the first load 14 and the second power supply The second load 17 can be directly supplied with power from the first power supply 13 while maintaining the redundant power supply configuration with the backup power supply by the power supply 16.

  FIG. 3 shows a power supply path formed by the relay control of the control unit 20 when the engine is restarted after the vehicle stops and idling is stopped. In this state, the first relay RL1 and the fourth relay RL4 are controlled to be turned off (OFF), and the second relay RL2 and the third relay RL3 are controlled to be turned on (ON).

  By this relay control, a power supply path is formed from the first power supply 13 → the rectifier D1 → the first load 14, and power is supplied to the first load 14 from the first power supply 13 via the rectifier D1. (Normal power supply). In addition, a power supply path is formed from the second power supply 16 → the regulator 18 → the first load 14, and the first load 14 can be supplied with power from the second power supply 16 via the regulator 18 ( Backup power supply). On the other hand, by the relay control, a power supply path of the first power supply 13 → the bidirectional DCDC converter 15 → the second load 17 is formed, and the second load 17 is connected to the first load via the bidirectional DCDC converter 15. Power is supplied from the power supply 13.

  As described above, in the case where the voltage fluctuation generated in the first power supply 13 due to the operation of the starter 12 affects the second load 17, the first load 14 normally operates on the first load 14. While maintaining the redundant power supply configuration of the power supply and the backup power supply by the second power supply 16, the power whose voltage fluctuation is suppressed through the bidirectional DCDC converter 15 is supplied from the first power supply 13 to the second load 17. Can be supplied.

  FIG. 4 is a diagram illustrating a case where the first power supply 13 fails while the engine is being restarted after the vehicle is stopped and idling is stopped. FIG. In this state, the first relay RL1 is controlled to be energized (ON), and the second relay RL2, the third relay RL3, and the fourth relay RL4 are controlled to be cut off (OFF).

  By this relay control, the power supply to the second load 17 is cut off, but for the first load 14 that cannot normally supply power, the second power supply 16 → the bidirectional DCDC converter 15 → the rectifier A power supply path of D2 → first load 14 is formed, and backup power supply is performed.

  If there is a delay from the occurrence of the failure of the first power supply 13 to the switching of the first relay RL1 from the cutoff (OFF) to the energization (ON), the power supply to the first load 14 is momentarily cut off. (Instantaneous interruption), the first load 14 may be reset. Therefore, in this embodiment, as a countermeasure against this, in the present embodiment, the regulator 18 is inserted between the second power supply 16 and the first load 14 to secure a power supply path, and the power supply to the first load 14 caused by the delay is provided. The effects of momentary interruption are suppressed.

[Action / Effect]
As described above, according to the redundant power supply system 100 according to the embodiment of the present invention, the power is redundantly supplied from the first power supply 13 and from the second power supply 16 to the first load 14 via the DCDC converter. In a system configuration for supplying and supplying power from the first power supply 13 to the second load 17, a regulator 18 is inserted between the second power supply 16 and the first load 14, and the bidirectional DCDC converter 15 A path for supplying power to the second load 17 is provided. In the engine restart process after the idle stop, the control unit 20 supplies power to the second load 17 via the bidirectional DCDC converter 15 and backup power to the first load 14 via the regulator 18. So that each relay is controlled. Further, when the main power supply fails in the engine restart processing after the idle stop, the control unit 20 stops supplying power to the second load 17 and backs up the power to the first load 14 via the bidirectional DCDC converter 15. Each relay is controlled so that power is supplied.

  According to this control, in the engine restart process after the idle stop, the second load 17 suppresses the voltage fluctuation while maintaining the redundant power supply configuration by the normal power supply and the backup power supply to the first load 14. Can be supplied. Further, when the main power supply fails in the engine restart processing after the idle stop, the backup power supply to the first load 14 can be continued.

  INDUSTRIAL APPLICABILITY The redundant power supply system of the present invention can be used for vehicles equipped with an idle stop & start function.

11 Alternator (ALT)
12 Starter (ST)
13 First power supply 14 First load 15 Bidirectional DCDC converter (DDC)
16 Second power supply 17 Second load 18 Regulator (Reg)
20 Control unit 100, 200 Redundant power supply system RL1, RL2, RL3, RL4 Relay

Claims (1)

A redundant power supply system capable of redundantly supplying power from a main power supply and a backup power supply to a first load, and supplying power from the main power supply to a second load requiring voltage fluctuation suppression,
A DCDC converter provided between the backup power supply and the first load;
A first relay for connecting the DCDC converter and the backup power supply so that the DCDC converter can be energized and cut off;
A second relay that connects the DCDC converter and the second load so as to be able to conduct and cut off;
A third relay that connects the main power supply and the DCDC converter so as to be able to conduct and cut off;
A fourth relay that connects the main power supply and the second load so as to be able to conduct and cut off;
A regulator for connecting the backup power supply and the first load;
A control unit that controls the energization and cutoff states of each of the relays,
The control unit includes:
In the engine restart processing after the idle stop, the first relay and the fourth relay are shut off, and the second relay and the third relay are energized to apply the second load to the DCDC. Connecting to the main power supply via a converter, connecting the first load to the backup power supply via the regulator,
If the main power supply fails during the engine restart processing after the idle stop, the first relay is energized and the second, third, and fourth relays are shut off. Disconnecting the second load from the main power supply and connecting the first load to the backup power supply via the DCDC converter;
Redundant power system.

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