Capacitor unit with electric double layer capacitors, control method and control apparatus for the same, and accumulator system for motor vehicles

• US 20030020334A1
• Filed: 07/08/2002
• Published: 01/30/2003
• Est. Priority Date: 07/19/2001
• Status: Active Grant

• Current Assignee: Nisshinbo Industries, Inc. (Kawasaki Heavy Industries Limited)
• Original Assignee: Nisshinbo Industries, Inc. (Kawasaki Heavy Industries Limited)
• Inventors: Nozu, Ryutaro
• Granted Patent: US 6,809,433 B2
• Time in Patent Office: Days
• US Class Current: 307/109
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• 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

Abstract

A capacitor unit with plural double layer capacitors eliminating irregularity in a state of charge of the respective double layer capacitor in the capacitor unit. A capacitor unit, a capacitor unit control method, a capacitor unit control apparatus and a vehicle charging system, wherein a chargeable and dischargeable capacitor unit 1 with plural electronic double layer capacitors 11 connected in series is characterized in that electric double layer capacitors 11 in a higher state of charge is subject to discharge so that a state of charging of the respective electric double layer capacitor 11 may become approximately equal to each other.

Claims

1. A chargeable and dischargeable capacitor unit with plural electronic double layer capacitors connected in series is characterized in that an electric double layer capacitor in a higher state of charge is subject to discharge so that a state of charging of the respective electric double layer capacitor may become approximately equal to other electric double layer capacitors.

2. The capacitor unit with plural electric double layer capacitors connected in series according to claim 1, wherein a state of charge of an electric double layer capacitor is calculated by the voltage of the electric double layer capacitor.

3. The capacitor unit with plural electric double layer capacitors connected in series according to claim 1, wherein plural series circuits, each comprising an adjusting resistance and an electric switch, are connected parallel to the respective electric double layer capacitor;

and when an electric switch is turned on, an electric current running through the adjusting resistance is to be within an allowable range for the electric double layer capacitor.

4. The capacitor unit with plural electric double layer capacitors connected in series according to claim 1, wherein an adjusting resistance being connected parallel to the respective electric double layer capacitor and adjusting a state of charge of the respective electric double layer capacitor is to be larger than a value dividing a rated voltage or a withstand voltage of the electric double layer capacitor by an upper limit current of wiring materials and parts.

5. The capacitor unit with plural electric double layer capacitors connected in series according to Claim 1, wherein if a difference between a state of charging of an electric double layer capacitor in a highest state of charge and an average state of charge of the rest of electric double layer capacitors becomes an upper limit value or more, the electric double layer capacitor in the highest state of charge is subject to discharge and if the difference becomes a lower limit value or less, discharging of the electric double layer capacitor in the highest state of charge is suspended.

6. The capacitor unit with plural electric double layer capacitors connected in series according to claim 1, wherein if a difference between a state of charging of an electric double layer capacitor in a highest state of charge and a state of charging of an electric double layer capacitor in a lowest state of charge becomes an upper limit value or more, the electric double layer capacitor in the highest state of charge is subject to discharge and if the difference becomes a lower limit value or less, discharging of the electric double layer capacitor in the highest state of charge is suspended.

7. A control method of a chargeable and dischargeable capacitor unit with plural electronic double layer capacitors connected in series is characterized in that electric double layer capacitors in a higher state of charge is subject to discharge so that a state of charging of the respective electric double layer capacitor may become approximately equal to other electric double layer capacitors.

8. A capacitor unit control apparatus, comprising a chargeable and dischargeable capacitor unit with plural electric double layer capacitors connected in series;

a voltmeter measuring the voltage of the respective electric double layer capacitor;

a series circuit having an adjusting resistance and an electric switch connected parallel to the respective electric double layer capacitor; and

an electric switch control device turning the electric switch on to discharge the electric double layer capacitor, wherein an electric switch for an electric double layer capacitor in a higher state of charge is turned on to discharge the same so that a state of charging of the respective electric double layer capacitor may become approximately equal to other electric double layer capacitors.

9. A chargeable and dischargeable capacitor system with plural electronic double layer capacitors connected in series, wherein an electric double layer capacitor in a higher state of charge is subject to discharge so that a state of charging of the respective electric double layer capacitor may become approximately equal to other electric double layer capacitors.