Power supply system

• US 8,084,988 B2
• Filed: 05/19/2009
• Issued: 12/27/2011
• Est. Priority Date: 05/21/2008
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Fujino, Takeshi, Noguchi, Minoru, Komazawa, Eisuke, Hirakawa, Mitsuaki
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US12/453,696
• Publication Number:
  US 20090289589A1
• Time in Patent Office: 952 Days
• Field of Search: 320/101, 320/104, 320/107, 320/134, 320/136, 320/137, 320/138, 320/150
• US Class Current: 320/104
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: H02J 2300/30 The power source being a fuel cell
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A power supply system includes a fuel cell, a capacitor connected in parallel to the fuel cell, a voltage boost means for boosting output voltages from the fuel cell and the capacitor to supply the electric motor with electric power resulting from the boosted voltages, a voltage control means for further boosting an output voltage from the voltage boost means, a secondary battery connected to the voltage control means, an external power source connecting means connected to the one end of the voltage boost means and in parallel with the fuel cell and for receiving supply of electric power from an external power source, and an electronic control unit which charges the secondary battery from the external power source by controlling step-up ratios of the voltage boost means and the voltage control means such that a voltage applied to the secondary battery during the charging becomes a desired voltage.

Claims

1. A power supply system mounted on a vehicle, the system comprising:

an electric power supply means;

a first voltage boosting means having one end connected to the electric power supply means and another end connected to an electric motor for driving the vehicle, the first voltage boosting means boosting an output voltage from the electric power supply means for supplying the electric motor with electric power resulting from the boosted voltage;

a second voltage boosting means having one end connected to the other end of the first voltage boosting means and in parallel with the electric motor, the second voltage boosting means further boosting an output voltage from the first voltage boosting means;

an electric power accumulating means connected to another end of the second voltage boosting means; and

an external power source connecting means connected to the one end of the first voltage boosting means and in parallel with the electric power supply means, the external power source connecting means receiving supply of electric power from an external power source.

2. The power supply system according to claim 1, further comprising:

a first suppressing means for suppressing supply of electric power from the external power source to the electric power supply means; and

a charging control means for charging the electric power accumulating means from the external power source by controlling step-up ratios of the first voltage boosting means and the second voltage boosting means such that a voltage applied to the electric power accumulating means during the charging becomes a desired voltage.

3. The power supply system according to claim 2, further comprising a temperature detecting means for detecting a temperature of the electric power accumulating means, wherein

the charging control means derives a maximum current that can flow into the electric power accumulating means in accordance with the temperature detected by the temperature detecting means, to charge the electric power accumulating means with the maximum current.

4. The power supply system according to claim 1, wherein

the external power source connecting means includes a power supply voltage detecting means for detecting an output voltage from the external power source, and

the charging control means controls the step-up ratios of the first voltage boosting means and the second voltage boosting means in accordance with the output voltage detected by the power supply voltage detecting means.

5. The power supply system according to claim 1, wherein the electric power supply means includes a fuel cell.

6. The power supply system according to claim 5, further comprising:

a capacitor connected to the one end of the first voltage boosting means and in parallel with the fuel cell; and

a second suppressing means for suppressing supply of electric power from the external power source to the capacitor.

7. The power supply system according to claim 1, wherein the electric power supply means includes an engine and a generator, the generator being connected to an output shaft of the engine and serving as an electric power generator.

8. The power supply system according to claim 1, wherein

the electric power supply means includes a high energy density secondary battery, and

the electric power accumulating means includes a high output density secondary battery.