Power supply device for vehicle

Patent metadata

Field	Value
Publication number	US-9797361-B2
Application number	US-201514939559-A
Country	US
Kind code	B2
Filing date	Nov 12, 2015
Priority date	Nov 28, 2014
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A power supply device for a vehicle which is used in a vehicle, includes: a first switch unit that is provided between a power generator which is driven by an internal combustion engine of the vehicle and a secondary battery which is connected to the power generator and supplies electric power to a starting device for starting the internal combustion engine; a second switch unit that is provided between the power generator and a capacitor which accumulates electric power supplied by the power generator; and a control unit that controls the connection state of the first switch unit and the connection state of the second switch unit.

First claim

What is claimed is:

1. A power supply device for a vehicle which is used in a vehicle, comprising:
a first switch unit that is provided between a power generator which is driven by an internal combustion engine of the vehicle and a secondary battery which is connected to the power generator and supplies electric power to a starting device for starting the internal combustion engine and between the starting device and the secondary battery;
a second switch unit that is provided between the power generator and a capacitor which accumulates electric power supplied by the power generator and between the starting device and the capacitor; and
a control unit that controls the connection state of the first switch unit and the connection state of the second switch unit, wherein:
during first starting of the internal combustion engine, the control unit connects the first switch unit and opens the second switch unit, resulting in a first connection state in which electric power is supplied from the secondary battery to the starting device, and
during restarting of the internal combustion engine from a temporal stop state thereof, the control unit opens the first switch unit and connects the second switch unit, resulting in a second connection state in which electric power is supplied from the capacitor to the starting device.

2. The power supply device for a vehicle according to claim 1 , further comprising:
a direct-current transducer that is provided between a first connection portion at which the secondary battery and the first switch unit are connected and a second connection portion at which the capacitor and the second switch unit are connected, and converts an input direct-current voltage into another direct-current voltage, and outputs the converted direct-current voltage,
wherein during the first starting of the internal combustion engine, the control unit connects the first switch unit and opens the second switch unit, resulting in a third connection state in which electric power which is generated by the power generator is supplied from the power generator to the capacitor through the direct-current transducer, and
during decelerating of the vehicle, the control unit connects the second switch unit, resulting in a fourth connection state in which regenerative electric power which is generated by the power generator is supplied from the power generator to the capacitor without passing through the direct-current transducer.

3. The power supply device for a vehicle according to claim 1 , further comprising:
an acquiring unit that acquires information on charged states of the secondary battery and the capacitor,
wherein, if the charged state of the secondary battery is equal to or lower than a first threshold value or the charged state of the capacitor is equal to lower than a second threshold value, regardless of a state of the vehicle, the control unit connects the first switch unit and opens the second switch unit, resulting in a fifth connection state.

4. A power supply device for a vehicle which is used in a vehicle, comprising:
a first switch unit that is provided between a power generator which is driven by an internal combustion engine of the vehicle and a secondary battery which is connected to the power generator and supplies electric power to a starting device for starting the internal combustion engine;
a second switch unit that is provided between the power generator and a capacitor which accumulates electric power supplied by the power generator; and
a control unit that controls the connection state of the first switch unit and the connection state of the second switch unit, wherein:
the first switch unit includes a first MOSFET,
the second switch unit includes a second MOSFET,
the first MOSFET has a parasitic diode connecting its drain and its source, and the anode and cathode of the parasitic diode are connected to the power generator and the secondary battery, respectively, and
the second MOSFET has a parasitic diode connecting its drain and its source, and the anode and cathode of the parasitic diode are connected to the power generator and the capacitor, respectively.

5. The power supply device for a vehicle according to claim 4 , wherein:
after the control unit switches the first MOSFET from an ON state to an OFF state, the control unit turns on the second MOSFET, and
after the control unit switches the second MOSFET from the ON state to an OFF state, the control unit turns on the first MOSFET.

Assignees

• Fujitsu Ten Ltd

Inventors

• Shibachi Yoshinori

Classifications

• F02N2011/0888

  DC/DC converters · CPC title

• F02N11/00

  Starting of engines by means of electric motors · CPC title

• F02N11/0814

  comprising means for controlling automatic idle-start-stop · CPC title

• Y02T10/48

  Cross-Sectional Technologies · mapped topic

• F02N2011/0885

  Capacitors, e.g. for additional power supply · CPC title