JP2017154604A - Power supply device and method for controlling power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the power consumption of a power source when an ignition switch is off.SOLUTION: An auxiliary power supply device 20 includes a capacitor 22, a charge circuit 24 for charging the capacitor 22, a control circuit 21 connected so that power can be supplied from a battery 11 and the capacitor 22 to be able to control the charge circuit 24, and a feeding switch 27 arranged in a path between the battery 11 and the control circuit 21 to be able to switch an on state where the battery 11 feeds power to the control circuit 21 and an off state where the battery 11 does not feed the power to the control circuit 21. The control circuit 21 controls the feeding switch 27 to be in an off state when the ignition switch 13 is off.SELECTED DRAWING: Figure 1

Description

  In this specification, the technique regarding a power supply device is disclosed.

Conventionally, vehicles such as automobiles have been known to have an auxiliary power source in addition to a battery as a main power source. With this auxiliary power source, for example, an engine after idling stop is started, or when the main power source is abnormal It is possible to supply electric power to the load at. Since this type of auxiliary power supply uses, for example, a large-capacity electric double layer capacitor or the like, it has the property that if the state close to full charge is continued, the deterioration of the capacitor is accelerated.
The power storage device of Patent Document 1 is supplied with power from a main power source, a power storage unit including a capacitor, a charging circuit that charges the power storage unit, a discharge circuit that discharges the charge of the power storage unit, and the main power source and the power storage unit. And a control circuit for controlling the charging circuit and the discharging circuit. When the vehicle is driven, the control circuit controls the charging circuit to charge the power storage unit. On the other hand, when the ignition switch is turned off, the control circuit controls the discharge circuit to discharge the charge in the power storage unit and suppress the progress of deterioration of the capacitor.

JP 2010-145143 A

  By the way, in the configuration of Patent Document 1, since the control circuit is connected to both the main power supply and the power storage unit, the voltage of the main power supply can be obtained even in a situation where the ignition switch is turned off and the charge of the power storage unit is discharged. Is higher than the power storage unit, power is supplied from the main power source to the control circuit, which causes a problem that power consumption of the main power source increases.

  The technique described in the present specification has been completed based on the above-described circumstances, and aims to suppress power consumption of a power source when an ignition switch is turned off.

  The power supply device described in the present specification includes a capacitor, a charging circuit that charges the capacitor, a power source and a control circuit that is connected to be able to supply power from the capacitor and can control the charging circuit, the power source, and the power source. A power supply switch that is arranged on a path between the power supply and the power supply switch and can be switched between an on state in which power is supplied from the power source to the control circuit and an off state in which power is not supplied from the power source to the control circuit. The control circuit controls the power supply switch to be in the off state when the ignition switch is off.

  The control method of the power supply device described in this specification includes a capacitor, a charging circuit that charges the capacitor, a power supply and a control circuit that is connected to be able to supply power from the capacitor, and that can control the charging circuit, A power supply switch arranged on a path between a power supply and the control circuit, and capable of switching between an on state in which power is supplied from the power supply to the control circuit and an off state in which power is not supplied from the power supply to the control circuit; When the control circuit receives a signal indicating that the ignition switch is turned off, the control circuit controls the power supply switch to be in the off state.

  According to this configuration, since the control circuit connected so as to be able to supply power from the power source and the capacitor controls the power feeding switch to the off state when the ignition switch is off, the power is not supplied from the power source to the control circuit. To supply power to the control circuit. As a result, since the ignition switch is off, the charge of the capacitor that originally needs to be discharged can be used for driving the control circuit, so that the control circuit is driven without using the power of the power supply. It becomes possible. Therefore, it is possible to suppress power consumption of the power supply when the ignition switch is turned off.

The following embodiments are preferable as the embodiments of the technology described in this specification.
A discharge circuit for discharging the charge of the capacitor; and the control circuit controls the discharge circuit to discharge the charge of the capacitor when the ignition switch is OFF, and the power supply switch is in the OFF state. Control to be
In this way, when the ignition switch is off, not only the power is supplied from the capacitor to the control circuit, but also the discharge of the capacitor can be discharged by the discharge circuit, so that the speed of extracting the charge of the capacitor can be increased.

A power supply state detection unit capable of detecting the state of the power supply, and the control circuit turns off the power supply switch when the power supply state detected by the power supply state detection unit is not in a state where power can be supplied. And not.
In this way, since the power supply state is not in a state where power can be supplied, and when it is not necessary to turn off the power supply switch, the power supply switch is not turned off, thereby reducing the processing of the control circuit. Can do.

A voltage detection circuit configured to detect a voltage of the capacitor, wherein the control circuit controls the power supply switch to be in the on state when the voltage of the capacitor detected by the voltage detection circuit is equal to or lower than a predetermined value; To do.
According to this configuration, after the charge of the capacitor is reduced, the control circuit is driven by the power of the power source, so that the operation of the control circuit can be continued while suppressing the deterioration of the capacitor.

  According to the technique described in this specification, it is possible to suppress power consumption of the power supply when the ignition switch is turned off.

The figure which shows the electrical constitution of the power supply system provided with the auxiliary power supply device of Embodiment 1. Flow chart showing processing of control circuit The figure which shows the electric constitution of the power supply system as a comparative example

<Embodiment 1>
The first embodiment will be described with reference to FIGS.
A power supply system 10 including the auxiliary power supply device 20 (an example of a “power supply device”) according to the present embodiment includes:
For example, it is mounted on a vehicle such as an electric vehicle or a hybrid vehicle.

(Power supply system 10)
As shown in FIG. 1, the power supply system 10 includes a battery 11 (an example of “power supply”) as a main power supply, and a battery state detection unit 12 (an example of “power supply state detection unit”) that detects the state of the battery 11. The ignition switch 13 and the auxiliary power supply device 20 are provided.

  The battery 11 is a secondary battery, and for example, a lead storage battery, a nickel hydrogen secondary battery, a lithium ion secondary battery, or the like can be used. The battery state detection unit 12 detects deterioration or the like of the battery 11 (whether or not the battery 11 is in a state in which power can be supplied). For example, the battery state detection unit 12 assists the detection signal Se according to the voltage of the electrode of the battery 11. Output to the power supply device 20.

  The ignition switch 13 is a switch for operating an ignition device or the like that ignites the engine. It is arranged in a power supply path from the battery 11 to the ignition device or the like (note that a circuit or the like for driving the ignition device is omitted in FIG. 1). For example, OFF, ACC (accessory), ON, and START can be selected as the key cylinder of the vehicle. When the key cylinder is turned ON, the ignition switch 13 is turned ON, and at START, the cell motor is turned and the engine is started. On the other hand, when the key cylinder is turned OFF or ACC, the ignition switch 13 is turned off and the engine is stopped. An output signal Sg indicating the on / off state of the ignition switch 13 is output to the control circuit 21 of the auxiliary power supply device 20.

(Auxiliary power supply 20)
The auxiliary power supply device 20 supplies electric power to a load LD composed of, for example, an ECU (Electronic Control Unit) or a motor, and includes a control circuit 21, a capacitor 22, and a voltage detection circuit 23 that detects the voltage of the capacitor 22. A charging circuit 24 that charges the capacitor 22, a discharging circuit 25 that discharges the electric charge of the capacitor 22, and a plurality of terminals 26A and 26B. The control circuit 21 receives the output signal Sg from the ignition switch 13 and the detection signal Se from the battery state detection unit 12.

  The capacitor 22 is, for example, a capacitor having a relatively large capacity such as an electric double layer capacitor or a lithium ion capacitor. For example, a plurality of electric double layer capacitors are connected in series so that a charge can be obtained up to a predetermined voltage. It is possible to store electricity. The capacitor 22 is electrically connected to the voltage detection circuit 23, the charging circuit 24, and the discharging circuit 25.

  The charging circuit 24 is connected to the battery 11 via the power supply terminal 26 </ b> A. When receiving the control signal Sb from the control circuit 21, the charging circuit 24 charges the capacitor 22 with the power supplied from the battery 11. The voltage detection circuit 23 detects the voltage of the capacitor 22 and outputs a detection signal Sd corresponding to the detected voltage to the control circuit 21.

  The discharge circuit 25 discharges the electric charge of the capacitor 22 according to the control signal Sc from the control circuit 21. The capacitor 22 is normally used in a state close to full charge when the vehicle is running. However, if the capacitor 22 is used in such a state close to full charge, the deterioration of the capacitor 22 is accelerated, so that an ignition switch for parking or the like is used. When 13 is off, the discharge circuit 25 discharges the electric charge of the capacitor 22 to a predetermined voltage (in this embodiment, a voltage that is ½ of full charge). As will be described in detail later, in the present embodiment, in addition to discharging the capacitor 22 by the discharge circuit 25, the electric charge from the capacitor 22 is extracted until a predetermined voltage is obtained by feeding power from the capacitor 22 to the control circuit 21. .

  A first diode D1 and a power feed switch 27 are connected in series to the first power feed line PL1, which is a conductive path from the power feed terminal 26A to the control circuit 21. Further, the cathode side of the first diode D1 in the first power supply line PL1 and the capacitor 22 are connected by a second power supply line PL2 as a conductive path. A second diode D2 is connected in series to the second power feed line PL2. The first diode D <b> 1 and the second diode D <b> 2 are power supply direction regulating means that regulates the direction of power supplied to the control circuit 21 in a direction toward the control circuit 21.

  The power supply switch 27 is in an ON state in which power is supplied from the battery 11 to the control circuit 21 by the control signal Sa from the control circuit 21, and power is supplied from the battery 11 to the control circuit 21 by opening the contact. The off state is not switched. In the present embodiment, when the ignition switch 13 is off (when the key cylinder is OFF or ACC), the power supply switch 27 is turned off by the control signal Sa from the control circuit 21.

  Here, in the power supply system 1 having the auxiliary power supply device 2 as the comparative example shown in FIG. 3, since there is no power supply switch 27, power supply from the battery 11 to the control circuit 21 cannot be cut off, and the ignition switch 13 is off. However, if the voltage of the battery 11 is higher than the voltage of the capacitor 22, power is supplied from the battery 11 to the control circuit 21. On the other hand, according to the present embodiment, as shown in FIG. 1, since the power supply switch 27 is provided in the first power supply line PL1, the power supply switch 27 is controlled to be in the off state when the ignition switch 13 is off. Thus, power is not supplied from the battery 11 to the control circuit 21, and power is supplied from the capacitor 22 to the control circuit 21. When the power supply switch 27 is on, power can be supplied from the battery 11 (and the capacitor 22) to the control circuit 21.

Next, the operation of the auxiliary power supply device 20 will be described. FIG. 2 is a flowchart showing the processing of the control circuit 21.
Since the ignition switch 13 is on when the vehicle is traveling (“YES” in S1), the control circuit 21 controls the power supply switch 27 to be in the on state in accordance with the output signal Sg from the ignition switch 13 (S2). Thus, power is supplied from the battery 11 to the control circuit 21 via the first power supply line PL1. Further, the control circuit 21 outputs a control signal Sb to the charging circuit 24 and drives the charging circuit 24 (S3). Thereby, the capacitor 22 is charged with the power of the battery 11.

Thereafter, it is determined whether or not the ignition switch 13 is turned off (S4).
When the key cylinder is turned off and the ignition switch 13 is turned off due to parking of the vehicle or the like (“YES” in S4), the battery 11 can be supplied with power in accordance with the detection signal Se from the battery state detection unit 12. It is determined whether it exists (S5). If the battery 11 is not in a state in which power can be supplied, the process is terminated while the power supply switch 27 remains on (“NO” in S5). On the other hand, if the battery 11 is in a state in which power can be supplied (“YES” in S5), the control circuit 21 outputs a control signal Sa to turn off the power feed switch 27 (S6), and the first power feed line PL1 Turn off the power. Further, the control circuit 21 stops the charging circuit 24 and drives the discharging circuit 25 (S7). As a result, energization of the first power supply line PL1 is interrupted, and thus power is supplied from the capacitor 22 to the control circuit 21 via the second power supply line PL2.

Thereafter, it is determined whether or not the ignition switch 13 is turned off (S8). When the ignition switch 13 is turned on ("YES" in S8), the power feeding switch 27 is turned on, and the charging circuit 24 is The capacitor 22 is charged with the electric power of the battery 11 (S2, S3). On the other hand, if the ignition switch 13 is not turned on ("NO" in S8), it is determined whether or not the voltage of the capacitor 22 has dropped to a predetermined value (1/2 of the full charge voltage) (S9). If the capacitor voltage has decreased to a predetermined value (“YES” in S9), the control circuit 21 turns on the power supply switch 27 (S10) and stops the charging circuit 24 and the discharging circuit 25 (S11). . Thereby, electric power is supplied from the battery 11 to the control circuit 21 via the first power supply line PL1.
Thereafter, when the ignition switch 13 is turned on, the above process can be performed again.

According to this embodiment, the following operations and effects are achieved.
The auxiliary power supply device 20 (power supply device) is connected to the capacitor 22, the charging circuit 24 that charges the capacitor 22, and the battery 11 (power supply) and the capacitor 22 so that power can be supplied, and the control circuit 21 that can control the charging circuit 24. And an on state where power is supplied from the battery 11 to the control circuit 21 and an off state where power is not supplied from the battery 11 to the control circuit 21 can be switched. The control circuit 21 controls the power supply switch 27 to be in an off state when the ignition switch 13 is off.

  According to the present embodiment, the control circuit 21 connected so as to be able to supply power from the battery 11 and the capacitor 22 controls the power supply switch 27 to be in an off state when the ignition switch 13 is off, thereby controlling the control circuit from the battery 11. No power is supplied to the power supply 21, and power is supplied from the capacitor 22 to the control circuit 21. Thereby, since the ignition switch 13 is off, the electric charge of the capacitor 22 that should be discharged is used to drive the control circuit 21. Therefore, the control circuit 21 does not use the power of the battery 11. Can be driven. Therefore, it is possible to suppress power consumption of the battery 11 when the ignition switch 13 is turned off.

The discharge circuit 25 discharges the electric charge of the capacitor 22, and the control circuit 21 controls the discharge circuit 25 to discharge the electric charge of the capacitor 22 when the ignition switch 13 is off. Control to turn off.
In this way, when the ignition switch 13 is off, not only the power is supplied from the capacitor 22 to the control circuit 21, but also the discharge of the capacitor 22 can be discharged by the discharge circuit 25. Therefore, the speed at which the charge of the capacitor 22 is extracted is increased. You can expedite.

Moreover, the battery state detection part 12 (power supply state detection part) which can detect the state of the battery 11 is provided, and the control circuit 21 is not in the state which can supply electric power in the state of the battery 11 which the battery state detection part 12 detected. Sometimes, the power supply switch 27 is not turned off.
In this way, when the power supply switch 27 does not need to be turned off because the state of the battery 11 is not in a state where power can be supplied, the power supply switch 27 is not turned off. Can be reduced.

In addition, a voltage detection circuit 23 for detecting the voltage of the capacitor 22 is provided, and the control circuit 21 causes the power supply switch 27 to be turned on when the voltage of the capacitor 22 detected by the voltage detection circuit 23 becomes a predetermined value or less. To control.
In this way, since the control circuit 21 is driven by the power of the battery 11 after the charge of the capacitor 22 is reduced, the operation of the control circuit 21 can be continued while suppressing the deterioration of the capacitor 22.

<Embodiment 2>
Embodiment 2 will be described.
In the second embodiment, for a vehicle having an idling stop function, when the ignition switch 13 is not turned off at the time of idling stop, the power feeding switch 27 is kept on. Other configurations are the same as those of the first embodiment, and thus the description thereof is omitted.

In the circuit of the vehicle, for example, an idling stop switch capable of detecting the stop of the traveling of the vehicle and stopping the idling state is provided separately from the ignition switch 13. When the control circuit 21 detects that the vehicle has stopped running (unless the key cylinder is turned off or ACC), the control circuit 21 turns off the idling stop switch while stopping the ignition switch 13 and stops driving the engine.
According to the second embodiment, at the time of idling stop, the power supply switch 27 continues to be in the on state, so that the capacity of the capacitor 22 is maintained, and the power of the capacitor 22 (close to full charge) can be used at the time of restart. .

<Other embodiments>
The technology described in the present specification is not limited to the embodiments described with reference to the above description and the drawings. For example, the following embodiments are also included in the technical scope of the technology described in the present specification.
(1) In the above embodiment, the charge of the capacitor 22 after the ignition switch 13 is turned off is not only supplied to the control circuit 21, but also discharged by the discharge circuit 25. However, the present invention is not limited to this. . For example, the discharge circuit 25 may not be provided in the auxiliary power supply device, and all the charges of the capacitor 22 may be supplied to the control circuit 21 and other loads so that the discharge circuit 25 does not discharge.

10: Power supply system 11: Battery 12: Battery state detection unit (power supply state detection unit)
13: Ignition switch 20: Auxiliary power supply device 21: Control circuit 22: Capacitor 23: Voltage detection circuit 24: Charging circuit 25: Discharging circuit 27: Feed switch D1: First diode D2: Second diode

Claims (5)

A capacitor;
A charging circuit for charging the capacitor;
A control circuit that is connected so as to be able to supply power from a power source and the capacitor, and that can control the charging circuit;
A power supply switch arranged on a path between the power supply and the control circuit and capable of switching between an on state in which power is supplied from the power supply to the control circuit and an off state in which power is not supplied from the power supply to the control circuit And comprising
The control circuit is a power supply device that controls the power supply switch to be in the off state when the ignition switch is off. A discharge circuit for discharging the charge of the capacitor;
2. The control circuit according to claim 1, wherein when the ignition switch is off, the control circuit controls the discharge circuit to discharge the electric charge of the capacitor and controls the power supply switch to be in the off state. Power supply. A power supply state detection unit capable of detecting the state of the power supply;
3. The power supply device according to claim 1, wherein the control circuit does not set the power supply switch to the off state when the power supply state detected by the power supply state detection unit is not in a state where power can be supplied. A voltage detection circuit for detecting the voltage of the capacitor;
4. The control circuit according to claim 1, wherein when the voltage of the capacitor detected by the voltage detection circuit becomes equal to or lower than a predetermined value, the control circuit controls the power supply switch to be in the ON state. 5. The power supply device described in 1. A capacitor;
A charging circuit for charging the capacitor;
A control circuit that is connected so as to be able to supply power from a power source and the capacitor, and that can control the charging circuit;
A power supply switch arranged on a path between the power supply and the control circuit and capable of switching between an on state in which power is supplied from the power supply to the control circuit and an off state in which power is not supplied from the power supply to the control circuit A method of controlling a power supply device comprising:
When the control circuit receives a signal indicating that the ignition switch is turned off, the control circuit controls the power supply switch to be in the off state.

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