Power supply unit, distributed power supply system and electric vehicle loaded therewith

• US 6,680,600 B2
• Filed: 02/27/2002
• Issued: 01/20/2004
• Est. Priority Date: 11/22/2001
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Emori, Akihiko, Miyazaki, Hideki, Kinoshita, Takuya
• Primary Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US10/083,645
• Publication Number:
  US 20030094923A1
• Time in Patent Office: 692 Days
• Field of Search: 320/126, 320/104, 307/10.1
• US Class Current: 320/126
• CPC Class Codes: B60L 53/11 DC charging controlled by the charging station, e.g. mode 4
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: H01M 10/05 Accumulators with non-aqueous electrolyte H01M10/39 takes precedence
• CPC Class Codes: H01M 10/06 Lead-acid accumulators semi-lead accumulators H01M10/20
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/52 Removing gases inside the secondary cell, e.g. by absorption vent plugs or other mechanical arrangements for facilitating escape of gases H01M50/30
• CPC Class Codes: H01M 12/06 with one metallic and one gaseous electrode
• CPC Class Codes: H01M 16/00 Structural combinations of different types of electrochemical generators
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A power supply unit, a distributed power supply system and an electric vehicle loaded therewith, capable of charge/discharge operation are disclosed. A first cell group is connected in parallel to a second cell group in which the electrolytic solution can be electrolyzed or the generated gas can be recombined. A plurality of the parallel circuit pairs are connected in series, and the series circuit is connected with a charger/discharger to constitute the power supply unit. The charger/discharger charges the power supply unit up to a voltage at which the electrolytic solution of the second cell group is electrolyzed or the generated gas is recombined.

Claims

1. A power supply unit comprising:

at least one storage battery comprising a plurality of circuits connecting in series, each of the plurality of circuits including a first cell group and a second cell group connected in parallel;

wherein said second cell group utilizes an electrolyzable electrolytic solution, or generates recombinable gas; and

a charger/discharger for controlling charge/discharge of said storage battery adapted to charge said storage battery up to a voltage at which the electrolytic solution of said second cell group is electrolyzed, or to a voltage at which the generated gas is recombined.

2. A power supply unit according to claim 1, wherein said first cell group and said second cell group are connected in parallel through a current limiter.

3. A power supply unit according to claim 1, wherein the at least one storage battery comprises a plurality of said storage batteries connected in parallel.

4. A power supply unit according to claim 1, wherein the withstanding voltage of said first cell group is higher than the withstanding voltage of said second cell group.

5. A power supply unit according to claim 1, wherein each of the plurality of circuits includes a plurality of said second cell groups connected in series.

6. A power supply unit according to claim 1, wherein said first cell group and said second cell group share at least one component element.

7. A power supply unit according to claim 6, wherein said shared component element is the electrolytic solution.

8. A power supply unit according to claim 6, wherein at least selected one of said first cell group and said second cell group has an electrode formed of selected one of carbon fiber and carbon nanotube.

9. A power supply unit according to claim 1, wherein

the first cell group of each of the plurality of circuits is connected to the first cell group of other circuits in series;

the second cell group of each of the plurality of circuits is connected to the second cell group of other circuits in series; and

the first cell group and the second cell group of each of the plurality of circuits are connected with an intermediate terminal.

10. A power supply unit according to claim 5, wherein

the first cell group of each of the plurality of circuits is connected to the first cell group of other circuits in series;

the second cell group of each of the plurality of circuits is connected to the second cell group of other circuits in series; and

the first cell group and the second cell group of each of the plurality of circuits are connected with an intermediate terminal.