Apparatus for charge exchange among a plurality of series connected energy accumulators or energy converters

• US 5,814,970 A
• Filed: 01/29/1997
• Issued: 09/29/1998
• Est. Priority Date: 07/30/1994
• Status: Expired due to Term

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: Schmidt, Heribert
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US08/793,088
• Time in Patent Office: 608 Days
• Field of Search: 320/1, 320/6, 320/16, 320/17, 320/18, 320/65, 320/103, 320/116, 320/117, 320/118, 320/119, 320/120, 320/122, 320/166, 323/316
• US Class Current: 320/118
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H02J 7/0018 using separate charge circuits
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A method and apparatus for allowing charge exchange among a plurality of energy accumulators of the same type which are interconnected in series. At least one electric accumulator is cyclically and alternatively connected in parallel to the energy accumulators. Each electric accumulator consists of a capacitive element charged by the energy accumulators. The electric accumulators are also each cyclically connected in parallel to one of the energy accumulators, so that during each phase of the cycle al energy accumulators of the same type are individually connected in parallel to an electric accumulator thereby establishing a direct power flow from higher voltage accumulators to lower voltage accumulators. The method and apparatus may be used for equalizing the charge of energy accumulators, and energy converters.

Claims

1. An apparatus for effecting an exchange of electric charge between a plurality of like, series connected, energy accumulators which define an overall energy accumulator, said apparatus comprising:

a plurality of series connected energy accumulators;

a plurality of electric storage elements, each said storage element comprising an element which is capacitively charged from said energy accumulators;

a plurality of switches for respectively connecting one of said energy accumulators in parallel with one of said electric storage elements;

a clock for defining alternate time periods for alternately opening and closing said plurality of switches, whereby two adjacent said energy accumulators are alternately connected in parallel with one of said electric storage elements in said time periods.

2. The apparatus according to claim 1, wherein said plurality of electric storage elements are connected in series.

3. The apparatus according to claim 1 further comprising a sequence control circuit and an activating means for activating said sequence control circuit for one of a predetermined period of time and a period of time determined by a connected load.