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Discharger using cascaded switched capacitor converters and selectable intermediate taps for electric double‐layer capacitors
Author(s) -
Uno Masatoshi,
Tanaka Koji
Publication year - 2013
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/eej.22281
Subject(s) - converters , capacitor , voltage , electrical engineering , switched capacitor , power (physics) , range (aeronautics) , engineering , energy conversion efficiency , electronic engineering , materials science , computer science , physics , quantum mechanics , aerospace engineering
Abstract Electric double‐layer capacitors (EDLCs) offer several advantages over traditional batteries, such as a long cycle life, high power capability, and good low‐temperature performance. However, their major drawbacks, such as low specific energy and large voltage variation due to charge/discharge cycling, necessitate the use of high‐efficiency power conversion electronics that can be used to efficiently discharge EDLCs and thus completely utilize the precious stored energy. In this study, we propose a novel discharger for EDLCs; this discharger uses cascaded switched capacitor converters (SCCs) and selectable intermediate taps. Although the voltage conversion ratio of SCCs is fixed, the load voltage can be maintained within a desired range by the selectable intermediate taps. The circuit configuration, operating principles, and procedure for designing SCCs and selectable intermediate taps are presented. Experimental tests were performed using an EDLC module and a 200‐W prototype of the discharger. The obtained results showed that the 60‐V EDLC could be discharged to 30 V with an average efficiency of 96% when the load voltage was maintained within the range of 30 to 40 V. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 183(3): 37–45, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22281