Power and life extension of battery-ultracapacitor hybrids

Author

Dougal, R.A. ; Liu, Shengyi ; White, Ralph E.

Author_Institution

Coll. of Eng., South Carolina Univ., Columbia, SC, USA

Volume

25

Issue

1

fYear

2002

fDate

3/1/2002 12:00:00 AM

Firstpage

120

Lastpage

131

Abstract

The performance of a battery-ultracapacitor hybrid power source under pulsed load conditions is analytically described using simplified models. We show that peak power can be greatly enhanced, internal losses can be considerably reduced, and that discharge life of the battery is extended. Greatest benefits are seen when the load pulse rate is higher than the system eigenfrequency and when the pulse duty is small. Actual benefits are substantial; adding a 23 F ultracapacitor bank (3 × 7 PC10 ultracapacitors) in parallel with a typical Li-ion battery of 7.2 V and 1.35 A hr capacity can boost the peak power capacity by 5 times and reduce the power loss by 74%, while minimally impacting system volume and weight, for pulsed loads of 5 A, 1 Hz repetition rate, and 10% duty

Keywords

capacitor storage; eigenvalues and eigenfunctions; losses; power capacitors; secondary cells; 1 Hz; 23 F; 5 A; 7.2 V; battery-ultracapacitor hybrids; discharge life; internal losses; load pulse rate; peak power capacity; power loss; power source; pulse duty; pulsed load conditions; repetition rate; system eigenfrequency; system volume; weight; Batteries; Capacitors; Energy loss; Frequency domain analysis; Fuel cells; Impedance; Pulse power systems; Steady-state; Supercapacitors; Voltage;

fLanguage

English

Journal_Title

Components and Packaging Technologies, IEEE Transactions on

Publisher

ieee

ISSN

1521-3331

Type

jour

DOI

10.1109/6144.991184

Filename

991184