Electricity accumulator

• US 6,404,165 B1
• Filed: 09/28/1998
• Issued: 06/11/2002
• Est. Priority Date: 09/29/1997
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Jidosha Kogyo Kabushiki Kaisha
• Original Assignee: Mitsubishi Jidosha Kogyo
• Inventors: Shinpo, Toshiya, Suzuki, Hiroyasu
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US09/161,455
• Time in Patent Office: 1,352 Days
• Field of Search: 320/116, 320/118, 320/124, 307/10.7
• US Class Current: 320/116
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• CPC Class Codes: H02J 7/0018 using separate charge circuits
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

An electricity accumulator which is capable of equalizing the voltages of a plurality of electricity accumulating devices such as batteries in an inexpensive and simple construction and quickly even in a state which is not a fully charged state. Dissipation of electrical energy is prevented. The electricity device includes a plurality connected in series. There is a capacitor connectable in parallel with at least two of the electricity accumulating devices. A connection switching device switches selectively a first connection mode in which the capacitor is connected to a first electricity accumulating device so that the capacitor is charged or discharged through the first electricity accumulating device and a second connection mode in which the capacitor is connected to a second electricity accumulating device.

Claims

1. An electricity accumulator comprising:

a plurality of electricity accumulating means connected in series;

selection means to partition said plurality of electricity accumulating means into a plurality of electricity accumulating blocks and select two electricity accumulating blocks from among said plurality of electricity accumulating blocks, each electricity accumulating block being constituted by one electricity accumulating means or a plurality of electricity accumulating means;

a capacitor provided so that it is connectable in parallel with an arbitrary block of said plurality of electricity accumulating blocks; and

connection switching means to switch selectively a first connection mode in which said capacitor is connected to a first electricity accumulating block of said two electricity accumulating blocks selected by said selection means so that part of the electric power of said first electricity accumulating block is transferred to said capacitor and a second connection mode in which said capacitor is connected to a second electricity accumulating block differing from said first electricity accumulating block so that said second electricity accumulating block is charged;

wherein the selection of said two electricity accumulating blocks by said selection means and the switch of said first and second connection modes by said connection switching means are repeatedly performed.

2. The electricity accumulator as set forth in claim 1, wherein said capacitor is connectable in parallel with all electricity accumulating means of said electricity accumulating block which becomes an object of selection, selected by said selection means.

3. The electricity accumulator as set forth in claim 2, wherein said selection means has voltage monitoring means to monitor respective voltages of said plurality of electricity accumulating means and, based on said voltages detected by said voltage monitoring means, said selection means sets said plurality of electricity accumulating blocks and also selects two electricity accumulating blocks from among the set plurality of electricity accumulating blocks.

4. The electricity accumulator as set forth in claim 3, wherein:

said selection means computes a mean voltage value of the voltages of said plurality of electricity accumulating means detected by said voltage monitoring means;

when the voltages of all electricity accumulating means within said first and second electricity accumulating blocks with respect to said mean voltage are caused to be within a third predetermined voltage difference by the switch of said first and second connection modes performed by said connection switching means, said selection means ends said switch of said first and second connection modes performed by said connection switching means and selects a subsequent electricity accumulating block; and

the selection of said subsequent electricity accumulating block by said selection means and the switch of said first and second connection modes by said connection switching means are reiteratedly executed.

5. The electricity accumulator as set forth in claim 1, wherein said selection means has voltage monitoring means to monitor respective voltages of said plurality of electricity accumulating means and, based on said voltages detected by said voltage monitoring means, said selection means sets said plurality of electricity accumulating blocks and also selects two electricity accumulating blocks from among the set plurality of electricity accumulating blocks.

6. The electricity accumulator as set forth in claim 5, wherein said selection means sets as a single electricity accumulating block a plurality of electricity accumulating means in which said voltages detected by said voltage monitoring means are within a predetermined range.

7. The electricity accumulator as set forth in claim 6, wherein said selection means computes a mean voltage value of the voltages of said plurality of electricity accumulating means detected by said voltage monitoring means, and sets, as said first electricity accumulating block, electricity accumulating means in which a voltage difference with said mean voltage is equal to or greater than a first predetermined voltage.

8. The electricity accumulator as set forth in claim 7, wherein said selection means sets, as said second electricity accumulating block, electricity accumulating means in which a voltage difference with said mean voltage is equal to or less than a second predetermined voltage.

9. The electricity accumulator as set forth in claim 1, wherein said selection means has voltage monitoring means to monitor respective voltages of said plurality of electricity accumulating means and sets, as a single electricity accumulating block, single electricity accumulating means in which said voltage detected by said voltage monitoring means is in a predetermined state.

10. The electricity accumulator as set forth in claim 9, wherein electricity accumulating means in which said voltage detected by said voltage monitoring means is in a highest voltage state is set as said first electricity accumulating block from among said plurality of electricity accumulating means by said selection means.

11. The electricity accumulator as set forth in claim 10, wherein electricity accumulating means in which said voltage detected by said voltage monitoring means is in a lowest voltage state is set as said first electricity accumulating block from among said plurality of electricity accumulating means by said selection means.

12. The electricity accumulator as set forth in claim 1, wherein said connection switching means performs the switch of said first and second connection modes reiteratedly once or a predetermined number of times.

13. The electricity accumulator as set forth in claim 12, wherein said selection means selects a subsequent electricity accumulating block when the switch of said first and second connection modes by said connection switching means has been performed said predetermined number of times and wherein the selection of said subsequent electricity accumulating block by said selection means and the switch of said first and second connection modes by said connection switching means are reiteratedly executed.